power simulation1
TRANSCRIPT
LOAD FLOW SIMULATION OF 7-BUS-IEEE NETWORK
ampITS APPLICATION IN 400kV GRID NETWORK OF MSETCL SYSTEM
Department Of Electrical EngineeringNagpur
2010
AIM Of The project helliphellip
In
To determine the POWER FLOW SIMULATION USING IEEE-7 BUS NETWORK amp ITS APPLICATION IN 400 KV GRID NETWORK OF MSETCL(Maharashtra State Electricity Transmission Co Ltd) SYSTEM USING POWER WORLD SIMULATOR
For POWER FLOW SIMLATION N-R METHOD ADOPTED
AC POWER FLOW SIMULATION TO EVALUATE TOTAL LOAD IN TERMS OF ACTIVE POWER FLOW IN MW REACTIVE POWER FLOW MVARTOTAL GENERATION IN MW MVAR VOLTAGE ANGLE OF ALL BUSES REACTIVE REQUIREMENT OF 7-BUS SYSTEM
AFTER OUTAGES ON TYPICAL TIE LINES AGAIN Case is SIMULATED amp WORKS OUT LOADING ON THE AVAILABLE LINES IN TERMS OF MW MVAR amp VOLTAGE STABILITY ACCORDINGLY
ABOVE APPLICATION IMPLEMENTED IN MSETCL NETWORK ampAGAIN RUN THE POWER WORLD SIMULATOR amp SIMULATES THE POWER FLOW
Methodology adopted
Simulation tool used power world simulator 90 version
7 bus 138 kv network consider for power flow simulation
Newtons-Raphson Method adopted for power simulation due to fast amp accuracy in simulation
Contents
1) Objectives of load flow analysis2) How to analyze power flow in power network
3) Why N-R Method
4) Flow-Chart of N-R Method
5) 7 Bus IEEE Network ampits buswise information6) Load flow simulation of 7-Bus
7) Load flow output a) Buswise Voltages amp angle
b) Line flow in terms of Load MW amp Mvar c)Generator Loads in terms of active power MW amp Reactive Power
Mvar d) Active amp reactive loss
ldquoLOAD FLOW STUDY is the Steady state solution of POWER SYSTEMrdquo
Objectives of Load Flow analysis o Flow of Real and reactive powers in the branches of the networko Bus bar voltages
o Power system augmentation studies to plan expansion of the Network to meet future requirementso Effect of temporary loss of generation and transmission circuit on system loadingo Effect of injecting in phase and quadrature boost voltages on system loading o optimum system running condition and load distributionoGenerator Scheduling and Reactive Scheduling to minimise losses o starting point of other studies such as fault analysis and stability analysis
What is already known What has to be calculated
1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax
How to analyze power flow in power Network
To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method
Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts
upto 900
bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus
locationbull Long and short lines terminating --- can solve a system with a long to
on the same bus short ratio at any bus of 10000001
bull Long radial type of system ----- solves a wider range of such problems
bull Acceleration Factor ------ None required
Flow chart of N-R Method
Form bus admittance matrix YBUS
Assume bus voltagesEp0 where p=12hellipnampp=s
Set iteration countK=0
Calculate Real amp Reactive bus powers
Calculated difference between Scheduled ampcalculated powers
Determine Maximum change in power max del pk and Max Qk
T est for convergence Calculate line flows and power flows
Equal
Or less
Calculate Bus currents
Calculate elements for jacobian
Calculate new bus voltages
Greater
Advance Iteration
count
k+1k
Replace epk by epk+1and fpk
by fpk+1 where
p=12hellipnampp=s
Steps for calculation For the calculation of powerflow it is must to find out the
impedance between two buses Impedances given in fig is in ohm per kmso we have to
multiply that by the distance between two busesso the required impedance is obtained
In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
per unit calculation the data required for the powerflow analysis should be in
unit formfor that all data such as voltagesline impedance etc
The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit
Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
IEEEndash7 Bus System Load Flow Analysis
Using Powerworld
slack
1
2
3 4
5
6 7
100 pu
102 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVAA
MVA
A
MVA A
MVA
A
MVA
A
MVA
A
MVA
49 MW
49 MW
46 MW 46 MW 57 MW 57 MW
48 MW
48 MW
74 MW 73 MW
38 MW
38 MW
7 MW
50 MW
50 MW 25 MW 25 MW
0 MW
0 MW
A
MVA
25 MW 25 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
100A
MVA
Table 10 Areawise Generation amp Loads in MegaWatts
Area Generation in MW
Load in MW
Top -Area1 35204 4000
Left Area2 2500 2000
Right Area3 20023 2000
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
AIM Of The project helliphellip
In
To determine the POWER FLOW SIMULATION USING IEEE-7 BUS NETWORK amp ITS APPLICATION IN 400 KV GRID NETWORK OF MSETCL(Maharashtra State Electricity Transmission Co Ltd) SYSTEM USING POWER WORLD SIMULATOR
For POWER FLOW SIMLATION N-R METHOD ADOPTED
AC POWER FLOW SIMULATION TO EVALUATE TOTAL LOAD IN TERMS OF ACTIVE POWER FLOW IN MW REACTIVE POWER FLOW MVARTOTAL GENERATION IN MW MVAR VOLTAGE ANGLE OF ALL BUSES REACTIVE REQUIREMENT OF 7-BUS SYSTEM
AFTER OUTAGES ON TYPICAL TIE LINES AGAIN Case is SIMULATED amp WORKS OUT LOADING ON THE AVAILABLE LINES IN TERMS OF MW MVAR amp VOLTAGE STABILITY ACCORDINGLY
ABOVE APPLICATION IMPLEMENTED IN MSETCL NETWORK ampAGAIN RUN THE POWER WORLD SIMULATOR amp SIMULATES THE POWER FLOW
Methodology adopted
Simulation tool used power world simulator 90 version
7 bus 138 kv network consider for power flow simulation
Newtons-Raphson Method adopted for power simulation due to fast amp accuracy in simulation
Contents
1) Objectives of load flow analysis2) How to analyze power flow in power network
3) Why N-R Method
4) Flow-Chart of N-R Method
5) 7 Bus IEEE Network ampits buswise information6) Load flow simulation of 7-Bus
7) Load flow output a) Buswise Voltages amp angle
b) Line flow in terms of Load MW amp Mvar c)Generator Loads in terms of active power MW amp Reactive Power
Mvar d) Active amp reactive loss
ldquoLOAD FLOW STUDY is the Steady state solution of POWER SYSTEMrdquo
Objectives of Load Flow analysis o Flow of Real and reactive powers in the branches of the networko Bus bar voltages
o Power system augmentation studies to plan expansion of the Network to meet future requirementso Effect of temporary loss of generation and transmission circuit on system loadingo Effect of injecting in phase and quadrature boost voltages on system loading o optimum system running condition and load distributionoGenerator Scheduling and Reactive Scheduling to minimise losses o starting point of other studies such as fault analysis and stability analysis
What is already known What has to be calculated
1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax
How to analyze power flow in power Network
To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method
Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts
upto 900
bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus
locationbull Long and short lines terminating --- can solve a system with a long to
on the same bus short ratio at any bus of 10000001
bull Long radial type of system ----- solves a wider range of such problems
bull Acceleration Factor ------ None required
Flow chart of N-R Method
Form bus admittance matrix YBUS
Assume bus voltagesEp0 where p=12hellipnampp=s
Set iteration countK=0
Calculate Real amp Reactive bus powers
Calculated difference between Scheduled ampcalculated powers
Determine Maximum change in power max del pk and Max Qk
T est for convergence Calculate line flows and power flows
Equal
Or less
Calculate Bus currents
Calculate elements for jacobian
Calculate new bus voltages
Greater
Advance Iteration
count
k+1k
Replace epk by epk+1and fpk
by fpk+1 where
p=12hellipnampp=s
Steps for calculation For the calculation of powerflow it is must to find out the
impedance between two buses Impedances given in fig is in ohm per kmso we have to
multiply that by the distance between two busesso the required impedance is obtained
In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
per unit calculation the data required for the powerflow analysis should be in
unit formfor that all data such as voltagesline impedance etc
The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit
Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
IEEEndash7 Bus System Load Flow Analysis
Using Powerworld
slack
1
2
3 4
5
6 7
100 pu
102 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVAA
MVA
A
MVA A
MVA
A
MVA
A
MVA
A
MVA
49 MW
49 MW
46 MW 46 MW 57 MW 57 MW
48 MW
48 MW
74 MW 73 MW
38 MW
38 MW
7 MW
50 MW
50 MW 25 MW 25 MW
0 MW
0 MW
A
MVA
25 MW 25 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
100A
MVA
Table 10 Areawise Generation amp Loads in MegaWatts
Area Generation in MW
Load in MW
Top -Area1 35204 4000
Left Area2 2500 2000
Right Area3 20023 2000
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Methodology adopted
Simulation tool used power world simulator 90 version
7 bus 138 kv network consider for power flow simulation
Newtons-Raphson Method adopted for power simulation due to fast amp accuracy in simulation
Contents
1) Objectives of load flow analysis2) How to analyze power flow in power network
3) Why N-R Method
4) Flow-Chart of N-R Method
5) 7 Bus IEEE Network ampits buswise information6) Load flow simulation of 7-Bus
7) Load flow output a) Buswise Voltages amp angle
b) Line flow in terms of Load MW amp Mvar c)Generator Loads in terms of active power MW amp Reactive Power
Mvar d) Active amp reactive loss
ldquoLOAD FLOW STUDY is the Steady state solution of POWER SYSTEMrdquo
Objectives of Load Flow analysis o Flow of Real and reactive powers in the branches of the networko Bus bar voltages
o Power system augmentation studies to plan expansion of the Network to meet future requirementso Effect of temporary loss of generation and transmission circuit on system loadingo Effect of injecting in phase and quadrature boost voltages on system loading o optimum system running condition and load distributionoGenerator Scheduling and Reactive Scheduling to minimise losses o starting point of other studies such as fault analysis and stability analysis
What is already known What has to be calculated
1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax
How to analyze power flow in power Network
To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method
Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts
upto 900
bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus
locationbull Long and short lines terminating --- can solve a system with a long to
on the same bus short ratio at any bus of 10000001
bull Long radial type of system ----- solves a wider range of such problems
bull Acceleration Factor ------ None required
Flow chart of N-R Method
Form bus admittance matrix YBUS
Assume bus voltagesEp0 where p=12hellipnampp=s
Set iteration countK=0
Calculate Real amp Reactive bus powers
Calculated difference between Scheduled ampcalculated powers
Determine Maximum change in power max del pk and Max Qk
T est for convergence Calculate line flows and power flows
Equal
Or less
Calculate Bus currents
Calculate elements for jacobian
Calculate new bus voltages
Greater
Advance Iteration
count
k+1k
Replace epk by epk+1and fpk
by fpk+1 where
p=12hellipnampp=s
Steps for calculation For the calculation of powerflow it is must to find out the
impedance between two buses Impedances given in fig is in ohm per kmso we have to
multiply that by the distance between two busesso the required impedance is obtained
In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
per unit calculation the data required for the powerflow analysis should be in
unit formfor that all data such as voltagesline impedance etc
The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit
Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
IEEEndash7 Bus System Load Flow Analysis
Using Powerworld
slack
1
2
3 4
5
6 7
100 pu
102 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVAA
MVA
A
MVA A
MVA
A
MVA
A
MVA
A
MVA
49 MW
49 MW
46 MW 46 MW 57 MW 57 MW
48 MW
48 MW
74 MW 73 MW
38 MW
38 MW
7 MW
50 MW
50 MW 25 MW 25 MW
0 MW
0 MW
A
MVA
25 MW 25 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
100A
MVA
Table 10 Areawise Generation amp Loads in MegaWatts
Area Generation in MW
Load in MW
Top -Area1 35204 4000
Left Area2 2500 2000
Right Area3 20023 2000
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Contents
1) Objectives of load flow analysis2) How to analyze power flow in power network
3) Why N-R Method
4) Flow-Chart of N-R Method
5) 7 Bus IEEE Network ampits buswise information6) Load flow simulation of 7-Bus
7) Load flow output a) Buswise Voltages amp angle
b) Line flow in terms of Load MW amp Mvar c)Generator Loads in terms of active power MW amp Reactive Power
Mvar d) Active amp reactive loss
ldquoLOAD FLOW STUDY is the Steady state solution of POWER SYSTEMrdquo
Objectives of Load Flow analysis o Flow of Real and reactive powers in the branches of the networko Bus bar voltages
o Power system augmentation studies to plan expansion of the Network to meet future requirementso Effect of temporary loss of generation and transmission circuit on system loadingo Effect of injecting in phase and quadrature boost voltages on system loading o optimum system running condition and load distributionoGenerator Scheduling and Reactive Scheduling to minimise losses o starting point of other studies such as fault analysis and stability analysis
What is already known What has to be calculated
1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax
How to analyze power flow in power Network
To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method
Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts
upto 900
bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus
locationbull Long and short lines terminating --- can solve a system with a long to
on the same bus short ratio at any bus of 10000001
bull Long radial type of system ----- solves a wider range of such problems
bull Acceleration Factor ------ None required
Flow chart of N-R Method
Form bus admittance matrix YBUS
Assume bus voltagesEp0 where p=12hellipnampp=s
Set iteration countK=0
Calculate Real amp Reactive bus powers
Calculated difference between Scheduled ampcalculated powers
Determine Maximum change in power max del pk and Max Qk
T est for convergence Calculate line flows and power flows
Equal
Or less
Calculate Bus currents
Calculate elements for jacobian
Calculate new bus voltages
Greater
Advance Iteration
count
k+1k
Replace epk by epk+1and fpk
by fpk+1 where
p=12hellipnampp=s
Steps for calculation For the calculation of powerflow it is must to find out the
impedance between two buses Impedances given in fig is in ohm per kmso we have to
multiply that by the distance between two busesso the required impedance is obtained
In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
per unit calculation the data required for the powerflow analysis should be in
unit formfor that all data such as voltagesline impedance etc
The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit
Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
IEEEndash7 Bus System Load Flow Analysis
Using Powerworld
slack
1
2
3 4
5
6 7
100 pu
102 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVAA
MVA
A
MVA A
MVA
A
MVA
A
MVA
A
MVA
49 MW
49 MW
46 MW 46 MW 57 MW 57 MW
48 MW
48 MW
74 MW 73 MW
38 MW
38 MW
7 MW
50 MW
50 MW 25 MW 25 MW
0 MW
0 MW
A
MVA
25 MW 25 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
100A
MVA
Table 10 Areawise Generation amp Loads in MegaWatts
Area Generation in MW
Load in MW
Top -Area1 35204 4000
Left Area2 2500 2000
Right Area3 20023 2000
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
ldquoLOAD FLOW STUDY is the Steady state solution of POWER SYSTEMrdquo
Objectives of Load Flow analysis o Flow of Real and reactive powers in the branches of the networko Bus bar voltages
o Power system augmentation studies to plan expansion of the Network to meet future requirementso Effect of temporary loss of generation and transmission circuit on system loadingo Effect of injecting in phase and quadrature boost voltages on system loading o optimum system running condition and load distributionoGenerator Scheduling and Reactive Scheduling to minimise losses o starting point of other studies such as fault analysis and stability analysis
What is already known What has to be calculated
1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax
How to analyze power flow in power Network
To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method
Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts
upto 900
bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus
locationbull Long and short lines terminating --- can solve a system with a long to
on the same bus short ratio at any bus of 10000001
bull Long radial type of system ----- solves a wider range of such problems
bull Acceleration Factor ------ None required
Flow chart of N-R Method
Form bus admittance matrix YBUS
Assume bus voltagesEp0 where p=12hellipnampp=s
Set iteration countK=0
Calculate Real amp Reactive bus powers
Calculated difference between Scheduled ampcalculated powers
Determine Maximum change in power max del pk and Max Qk
T est for convergence Calculate line flows and power flows
Equal
Or less
Calculate Bus currents
Calculate elements for jacobian
Calculate new bus voltages
Greater
Advance Iteration
count
k+1k
Replace epk by epk+1and fpk
by fpk+1 where
p=12hellipnampp=s
Steps for calculation For the calculation of powerflow it is must to find out the
impedance between two buses Impedances given in fig is in ohm per kmso we have to
multiply that by the distance between two busesso the required impedance is obtained
In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
per unit calculation the data required for the powerflow analysis should be in
unit formfor that all data such as voltagesline impedance etc
The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit
Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
IEEEndash7 Bus System Load Flow Analysis
Using Powerworld
slack
1
2
3 4
5
6 7
100 pu
102 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVAA
MVA
A
MVA A
MVA
A
MVA
A
MVA
A
MVA
49 MW
49 MW
46 MW 46 MW 57 MW 57 MW
48 MW
48 MW
74 MW 73 MW
38 MW
38 MW
7 MW
50 MW
50 MW 25 MW 25 MW
0 MW
0 MW
A
MVA
25 MW 25 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
100A
MVA
Table 10 Areawise Generation amp Loads in MegaWatts
Area Generation in MW
Load in MW
Top -Area1 35204 4000
Left Area2 2500 2000
Right Area3 20023 2000
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Objectives of Load Flow analysis o Flow of Real and reactive powers in the branches of the networko Bus bar voltages
o Power system augmentation studies to plan expansion of the Network to meet future requirementso Effect of temporary loss of generation and transmission circuit on system loadingo Effect of injecting in phase and quadrature boost voltages on system loading o optimum system running condition and load distributionoGenerator Scheduling and Reactive Scheduling to minimise losses o starting point of other studies such as fault analysis and stability analysis
What is already known What has to be calculated
1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax
How to analyze power flow in power Network
To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method
Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts
upto 900
bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus
locationbull Long and short lines terminating --- can solve a system with a long to
on the same bus short ratio at any bus of 10000001
bull Long radial type of system ----- solves a wider range of such problems
bull Acceleration Factor ------ None required
Flow chart of N-R Method
Form bus admittance matrix YBUS
Assume bus voltagesEp0 where p=12hellipnampp=s
Set iteration countK=0
Calculate Real amp Reactive bus powers
Calculated difference between Scheduled ampcalculated powers
Determine Maximum change in power max del pk and Max Qk
T est for convergence Calculate line flows and power flows
Equal
Or less
Calculate Bus currents
Calculate elements for jacobian
Calculate new bus voltages
Greater
Advance Iteration
count
k+1k
Replace epk by epk+1and fpk
by fpk+1 where
p=12hellipnampp=s
Steps for calculation For the calculation of powerflow it is must to find out the
impedance between two buses Impedances given in fig is in ohm per kmso we have to
multiply that by the distance between two busesso the required impedance is obtained
In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
per unit calculation the data required for the powerflow analysis should be in
unit formfor that all data such as voltagesline impedance etc
The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit
Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
IEEEndash7 Bus System Load Flow Analysis
Using Powerworld
slack
1
2
3 4
5
6 7
100 pu
102 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVAA
MVA
A
MVA A
MVA
A
MVA
A
MVA
A
MVA
49 MW
49 MW
46 MW 46 MW 57 MW 57 MW
48 MW
48 MW
74 MW 73 MW
38 MW
38 MW
7 MW
50 MW
50 MW 25 MW 25 MW
0 MW
0 MW
A
MVA
25 MW 25 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
100A
MVA
Table 10 Areawise Generation amp Loads in MegaWatts
Area Generation in MW
Load in MW
Top -Area1 35204 4000
Left Area2 2500 2000
Right Area3 20023 2000
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
What is already known What has to be calculated
1 Network1048707 Electric values for components and the equivalent circuits are known2 Loads1048707 known active and reactive power (PQ)1048707 calculated absolute value and angle of voltage (Uδ)3 Generators1048707 known active power and terminal voltage (PU)1048707 calculated reactive power and voltage angle (Q δ)1048707 Balance between generation and consumption1048707 Losses are not known rArr information required4 Reference point (eg connection to the transmission grid of North Sweden)1048707 known absolute value and angle of voltage (U δ)1048707 calculated active and reactive power (P Q) (may change freely)5 Boundary conditions1048707 Reactive power limits of the generator Qmin and Qmax
How to analyze power flow in power Network
To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method
Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts
upto 900
bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus
locationbull Long and short lines terminating --- can solve a system with a long to
on the same bus short ratio at any bus of 10000001
bull Long radial type of system ----- solves a wider range of such problems
bull Acceleration Factor ------ None required
Flow chart of N-R Method
Form bus admittance matrix YBUS
Assume bus voltagesEp0 where p=12hellipnampp=s
Set iteration countK=0
Calculate Real amp Reactive bus powers
Calculated difference between Scheduled ampcalculated powers
Determine Maximum change in power max del pk and Max Qk
T est for convergence Calculate line flows and power flows
Equal
Or less
Calculate Bus currents
Calculate elements for jacobian
Calculate new bus voltages
Greater
Advance Iteration
count
k+1k
Replace epk by epk+1and fpk
by fpk+1 where
p=12hellipnampp=s
Steps for calculation For the calculation of powerflow it is must to find out the
impedance between two buses Impedances given in fig is in ohm per kmso we have to
multiply that by the distance between two busesso the required impedance is obtained
In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
per unit calculation the data required for the powerflow analysis should be in
unit formfor that all data such as voltagesline impedance etc
The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit
Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
IEEEndash7 Bus System Load Flow Analysis
Using Powerworld
slack
1
2
3 4
5
6 7
100 pu
102 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVAA
MVA
A
MVA A
MVA
A
MVA
A
MVA
A
MVA
49 MW
49 MW
46 MW 46 MW 57 MW 57 MW
48 MW
48 MW
74 MW 73 MW
38 MW
38 MW
7 MW
50 MW
50 MW 25 MW 25 MW
0 MW
0 MW
A
MVA
25 MW 25 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
100A
MVA
Table 10 Areawise Generation amp Loads in MegaWatts
Area Generation in MW
Load in MW
Top -Area1 35204 4000
Left Area2 2500 2000
Right Area3 20023 2000
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
How to analyze power flow in power Network
To analyze the power flow in power network there are three methods Newton Raphson MethodGauss seidel method Fast decoupled method
Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts
upto 900
bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus
locationbull Long and short lines terminating --- can solve a system with a long to
on the same bus short ratio at any bus of 10000001
bull Long radial type of system ----- solves a wider range of such problems
bull Acceleration Factor ------ None required
Flow chart of N-R Method
Form bus admittance matrix YBUS
Assume bus voltagesEp0 where p=12hellipnampp=s
Set iteration countK=0
Calculate Real amp Reactive bus powers
Calculated difference between Scheduled ampcalculated powers
Determine Maximum change in power max del pk and Max Qk
T est for convergence Calculate line flows and power flows
Equal
Or less
Calculate Bus currents
Calculate elements for jacobian
Calculate new bus voltages
Greater
Advance Iteration
count
k+1k
Replace epk by epk+1and fpk
by fpk+1 where
p=12hellipnampp=s
Steps for calculation For the calculation of powerflow it is must to find out the
impedance between two buses Impedances given in fig is in ohm per kmso we have to
multiply that by the distance between two busesso the required impedance is obtained
In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
per unit calculation the data required for the powerflow analysis should be in
unit formfor that all data such as voltagesline impedance etc
The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit
Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
IEEEndash7 Bus System Load Flow Analysis
Using Powerworld
slack
1
2
3 4
5
6 7
100 pu
102 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVAA
MVA
A
MVA A
MVA
A
MVA
A
MVA
A
MVA
49 MW
49 MW
46 MW 46 MW 57 MW 57 MW
48 MW
48 MW
74 MW 73 MW
38 MW
38 MW
7 MW
50 MW
50 MW 25 MW 25 MW
0 MW
0 MW
A
MVA
25 MW 25 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
100A
MVA
Table 10 Areawise Generation amp Loads in MegaWatts
Area Generation in MW
Load in MW
Top -Area1 35204 4000
Left Area2 2500 2000
Right Area3 20023 2000
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Why Newton Raphson Method Types of Problem N-R Methodbull Heavily Loaded System ----- Solves systems with phase shifts
upto 900
bull System containing negative reactance- Solves with ease such as three winding transformer or series line capacitorbull System with slack bus at desired location-More tolerant of slack bus
locationbull Long and short lines terminating --- can solve a system with a long to
on the same bus short ratio at any bus of 10000001
bull Long radial type of system ----- solves a wider range of such problems
bull Acceleration Factor ------ None required
Flow chart of N-R Method
Form bus admittance matrix YBUS
Assume bus voltagesEp0 where p=12hellipnampp=s
Set iteration countK=0
Calculate Real amp Reactive bus powers
Calculated difference between Scheduled ampcalculated powers
Determine Maximum change in power max del pk and Max Qk
T est for convergence Calculate line flows and power flows
Equal
Or less
Calculate Bus currents
Calculate elements for jacobian
Calculate new bus voltages
Greater
Advance Iteration
count
k+1k
Replace epk by epk+1and fpk
by fpk+1 where
p=12hellipnampp=s
Steps for calculation For the calculation of powerflow it is must to find out the
impedance between two buses Impedances given in fig is in ohm per kmso we have to
multiply that by the distance between two busesso the required impedance is obtained
In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
per unit calculation the data required for the powerflow analysis should be in
unit formfor that all data such as voltagesline impedance etc
The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit
Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
IEEEndash7 Bus System Load Flow Analysis
Using Powerworld
slack
1
2
3 4
5
6 7
100 pu
102 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVAA
MVA
A
MVA A
MVA
A
MVA
A
MVA
A
MVA
49 MW
49 MW
46 MW 46 MW 57 MW 57 MW
48 MW
48 MW
74 MW 73 MW
38 MW
38 MW
7 MW
50 MW
50 MW 25 MW 25 MW
0 MW
0 MW
A
MVA
25 MW 25 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
100A
MVA
Table 10 Areawise Generation amp Loads in MegaWatts
Area Generation in MW
Load in MW
Top -Area1 35204 4000
Left Area2 2500 2000
Right Area3 20023 2000
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Flow chart of N-R Method
Form bus admittance matrix YBUS
Assume bus voltagesEp0 where p=12hellipnampp=s
Set iteration countK=0
Calculate Real amp Reactive bus powers
Calculated difference between Scheduled ampcalculated powers
Determine Maximum change in power max del pk and Max Qk
T est for convergence Calculate line flows and power flows
Equal
Or less
Calculate Bus currents
Calculate elements for jacobian
Calculate new bus voltages
Greater
Advance Iteration
count
k+1k
Replace epk by epk+1and fpk
by fpk+1 where
p=12hellipnampp=s
Steps for calculation For the calculation of powerflow it is must to find out the
impedance between two buses Impedances given in fig is in ohm per kmso we have to
multiply that by the distance between two busesso the required impedance is obtained
In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
per unit calculation the data required for the powerflow analysis should be in
unit formfor that all data such as voltagesline impedance etc
The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit
Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
IEEEndash7 Bus System Load Flow Analysis
Using Powerworld
slack
1
2
3 4
5
6 7
100 pu
102 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVAA
MVA
A
MVA A
MVA
A
MVA
A
MVA
A
MVA
49 MW
49 MW
46 MW 46 MW 57 MW 57 MW
48 MW
48 MW
74 MW 73 MW
38 MW
38 MW
7 MW
50 MW
50 MW 25 MW 25 MW
0 MW
0 MW
A
MVA
25 MW 25 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
100A
MVA
Table 10 Areawise Generation amp Loads in MegaWatts
Area Generation in MW
Load in MW
Top -Area1 35204 4000
Left Area2 2500 2000
Right Area3 20023 2000
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Steps for calculation For the calculation of powerflow it is must to find out the
impedance between two buses Impedances given in fig is in ohm per kmso we have to
multiply that by the distance between two busesso the required impedance is obtained
In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
per unit calculation the data required for the powerflow analysis should be in
unit formfor that all data such as voltagesline impedance etc
The per unit value of any quantity is defined as =The actual value in any unitthe base or reference value in the same unit
Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
IEEEndash7 Bus System Load Flow Analysis
Using Powerworld
slack
1
2
3 4
5
6 7
100 pu
102 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVAA
MVA
A
MVA A
MVA
A
MVA
A
MVA
A
MVA
49 MW
49 MW
46 MW 46 MW 57 MW 57 MW
48 MW
48 MW
74 MW 73 MW
38 MW
38 MW
7 MW
50 MW
50 MW 25 MW 25 MW
0 MW
0 MW
A
MVA
25 MW 25 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
100A
MVA
Table 10 Areawise Generation amp Loads in MegaWatts
Area Generation in MW
Load in MW
Top -Area1 35204 4000
Left Area2 2500 2000
Right Area3 20023 2000
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
IEEEndash7 Bus System Load Flow Analysis
Using Powerworld
slack
1
2
3 4
5
6 7
100 pu
102 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVAA
MVA
A
MVA A
MVA
A
MVA
A
MVA
A
MVA
49 MW
49 MW
46 MW 46 MW 57 MW 57 MW
48 MW
48 MW
74 MW 73 MW
38 MW
38 MW
7 MW
50 MW
50 MW 25 MW 25 MW
0 MW
0 MW
A
MVA
25 MW 25 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
100A
MVA
Table 10 Areawise Generation amp Loads in MegaWatts
Area Generation in MW
Load in MW
Top -Area1 35204 4000
Left Area2 2500 2000
Right Area3 20023 2000
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Table 10 Areawise Generation amp Loads in MegaWatts
Area Generation in MW
Load in MW
Top -Area1 35204 4000
Left Area2 2500 2000
Right Area3 20023 2000
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
From Number
To Number Circuit Status
ResistanceR
pu
ReactanceX
pu
Line ChargingB
puLine LimitLim A MVA
1 2 1 Closed 0005 005 05 65
1 3 1 Closed 002 024 005 65
2 3 1 Closed 0015 018 004 80
3 4 1 Closed 00025 003 002 222
2 4 1 Closed 0015 018 004 100
2 5 1 Closed 001 012 003 100
7 5 1 Closed 0005 006 004 200
4 5 1 Closed 002 024 005 60
2 6 1 Closed 0005 006 005 200
6 7 2 Closed 002 024 005 200
6 7 1 Closed 002 024 005 200
Line Characteristics of 7-bus system
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Table 30Bus Types
Number Name Area Name Type
1 1 Top PV
2 2 Top PV
3 3 Top PQ
4 4 Top PV
5 5 Top PQ
6 6 Left PV
7 7 Right Slack
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Bus types
In 7-bus system there are 5 buses in which four Numbers of Voltage regulated buses two Numbers of load buses amp one Numbers of Slack Bus is consider for power flow simulation Slack Bus This bus known as swing bus is taken as reference where the magnitude and phase angle of the voltage are specified This bus makes us difference between the scheduled load and generated power that are caused by losses in the network Load Bus at these buses the active and reactive powers are specified The Magnitude and phase angle of the bus voltages are unknown These buses are called P-Q Buses Regulated Buses or voltage BusesThese buses are the generator buses They are also known as voltage controlled buses At these buses the real power and voltage magnitude are specified The phase angles of the voltages and the reactive power to be determined The Limits on the value of the reactive power are also specified These buses are called P-V Buses
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
POWER FLOW OUTPUT
Power Flow simulation of 7-bus IEEE System is as followsBus Flows
BUS 1 1 1380 MW Mvar MVA 10500 443 1 Top
GENERATOR 1 9554 743R 958
TO 2 2 1 4940 -1098 506 78
TO 3 3 1 4614 1841 497 76
BUS 2 2 1380 MW Mvar MVA 10400 317 1 Top
GENERATOR 1 15000 2806R 1526
LOAD 1 4000 2000 447
TO 1 1 1 -4928 -4239 650 100
TO 3 3 1 89 1996 519 65
TO 4 4 1 3807 1892 425 43
TO 5 5 1 7354 1425 749 75
TO 6 6 1 -023 -268 27 1
BUS 3 3 1380 MW Mvar MVA 09980 -141 1 Top
LOAD 1 15000 4000 1552
TO 1 1 1 -4567 -1805 491 76
TO 2 2 1 -4750 -1948 513 64
TO 4 4 1 -5683 -247 569 26
BUS 4 4 1380 MW Mvar MVA 10000 -043 1 Top
GENERATOR 1 10651 096R 1065
LOAD 1 8000 3000 854
TO 2 2 1 -3781 -1993 427 43
TO 3 3 1 5691 144 569 26
TO 5 5 1 741 -1055 129 21
BUS 5 5 1380 MW Mvar MVA 10180 -152 1 Top
LOAD 1 13000 4000 1360
TO 2 2 1 -7302 -1115 739 74
TO 4 4 1 -739 575 94 16
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
TO 7 7 1 -4960 -3460 605 30
BUS 6 6 1380 MW Mvar MVA 10400 318 2 Left
GENERATOR 1 25000 -1089R 2502
LOAD 1 20000 000 2000
TO 2 2 1 023 -272 27 1
TO 7 7 1 2488 -408 252 13
TO 7 7 2 2488 -408 252 13
BUS 7 7 1380 MW Mvar MVA 10400 000 3 Right
GENERATOR 1 20023 3251R 2028
LOAD 1 20000 000 2000
TO 5 5 1 4977 3240 594 30
TO 6 6 1 -2477 005 248 12
TO 6 6 2 -2477 005 24
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Bus No
Nom kV PU Volt Volt (kV) Angle (Deg) Load MW Load Mvar Gen MW Gen Mvar
1138 105 1449 443 9554 743
2 138 104 14352 317 40 20 150 2806
3138 099799 137723 -141 150 40
4 138 1 138 -043 80 30 10651 096
5138 101803 140488 -152 130 40
6 138 104 14352 318 200 0 250 -1089
7 138 104 14352 0 200 0 20023 3251
Voltage Magnitude and Phase angle
COMMENTS
Above shows Bus-wise Per unit voltages Nominal and actual voltages of the system Magnitude of the voltage and phase angle works out by powerworld
After simulation Low voltage problem observed at Bus 3 there is no any generator as well reactive compensation available in the system thatrsquos why voltage at this bus found low as compared to other
buses
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Power Transfer amp MW Mvar Losses
From Number
To Number Circuit Status
MW From
Mvar From
MVA From
Lim MVA
MW Loss
Mvar Loss
1 2 1 Closed 494 -11 506 65 012 -5337
1 3 1 Closed 461 184 497 65 047 036
2 3 1 Closed 479 20 519 80 039 048
2 4 1 Closed 381 189 425 100 026 -101
2 5 1 Closed 735 143 749 100 052 31
2 6 1 Closed -02 -27 27 200 0 -541
3 4 1 Closed -568 -25 569 222 008 -102
4 5 1 Closed 74 -106 129 60 002 -48
7 5 1 Closed 498 324 594 200 017 -22
6 7 1 Closed 249 -41 252 200 011 -403
6 7 2 Closed 249 -41 252 200 011 -403
From above Table it shows 7-Bus load flow study It gives the loading on the lines in terms of MW and Mvar also line loss in terms of MW and Mvar Some of the observations of Load flow study is as follows
Line flow between line2-5 is 735 Mw whereas line2-6 found in floating condition This line connected between Top amp Left area Bus 6 is generator bus Load and generation balanced at this bus
Line 6-7 double circuit connected to Left amp Right area carrying 50 Mw Load amp transfer the same load to Bus 5 through Line 7-5 Actual load at bus 5 is 130 Mw In which 730 MW power transferred from Line 2-5 50 MW
from line 7-5 amp remaining 7 Mw from Line 4-5 Such type of
Power flow study is possible only after simulation of power flows
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Conclusion
Output of the Load flow studies shows that Buswise Voltage Active Generation in MW Active Load MW Reactive Loads in Mvar MVA Loading Also Shows
the Generator connected to particular Buses As per Kirchoffs law total Load at the Bus clearly applicable from above Load flow study Buswise connected lines
with Line loads in MW amp Mvar is the output from Above simulation Bus 7 is SLACK Bus consider in above simulation From which we can find out the
losses in the Network Also find out the overloading of lines easily so as to provide reactive compensation at particular location of the system
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
CASE SIMULATION of LINE OUTAGE ON TIE-LINE CIRCUITS
slack
1
2
3 4
5
6 7
100 pu
098 pu
104 pu104 pu
104 pu
100 pu105 pu
A
MVA
A
MVA
A
MVA A
MVA
A
MVA
A
MVA
47 MW
47 MW
49 MW 49 MW 49 MW 49 MW
53 MW
52 MW
110 MW 109 MW
44 MW
44 MW
21 MW
0 MW
0 MW 0 MW 0 MW
50 MW
50 MW
A
MVA
0 MW 0 MW
96 MW
150 MW
250 MW 200 MW
150 MW
40 Mvar
80 MW 30 Mvar
130 MW
40 Mvar
40 MW
20 Mvar
107 MW
200 MW
0 Mvar200 MW
0 Mvar
AGC ON
AGC ON
AGC ON
AGC ON
AGC ON
97A
MVA
81A
MVA
119A
MVA
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Simulation output OUTAGE ON Tie Line 5 to Line7
Bus No
Nom kV
PU Volt
Before Outage
Volt (kV)
After Outage
Volt (kV)
Before OutageAngle in
(Deg)
After OutageAngle in
(Deg)Load MW
Load Mvar
Before outage
Gen Mvar
After Outage
Gen Mvar
Gen MW
1 138 105 1449 1449 443 -043 743 778 9582
2 138 104 14352 14352 317 -161 40 20 2806 6391 15029
3 138 099 137723 137703 -141 -667 150 40
4 138 100 138 138 -043 -582 80 30 096 1693 10679
5 138 098 140488 135598 -152 -876 130 40
6 138 104 14352 14352 318 -001 200 0 -1089 -1157 250
7 138 104 14352 14352 0 0 200 0 3251 -542 20012
From above Table It concludes that
line outage event of tie Line No5 to line 7 amp simulated the data accordingly in powerworld Results tabulated in Table ie differences of bus voltages angle in degrees amp variation in generation mvar flows
Voltage before tripping at Bus 5 is 140488 Kv After outage voltage at Bus 5 suddrenly dropped upto 135598 Kv voltage angle also changed from -152 to -876 deg This is due to because Bus 5 is Load bus amp variation in reactive loads At Bus 7 there is no variation in Voltage because Generation unit is connected to the bus
Change in Voltage angle also observed at Bus3 due to Load bus
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Simulation OutputMwMvar Loss After Outage On line5-7
(Removing Transmission Line)
From Number
To Number Circuit
Before MW on
Line
AfterMW on
Line
BeforeMvar on
Line
After Mvar on
Line MVA
From
BeforeMW
Loss
AfterMW
LossMvar Loss
AfterTripping
Mvar Loss Status
1 2 1 494 466 -11 -108 479 012 011 -5337 -5349 Closed
1 3 1 461 492 184 185 526 047 052 036 101 Closed
2 3 1 479 527 20 20 563 039 045 048 128 Closed
2 4 1 381 442 189 188 48 026 033 -101 -018 Closed
2 5 1 735 1099 143 456 119 052 132 31 1281 Closed
2 6 1 -02 -50 -27 22 50 0 012 -541 -401 Closed
3 4 1 -568 -491 -25 -37 493 008 006 -102 -127 Closed
4 5 1 74 215 -106 35 218 002 01 -48 -372 Closed
7 5 1 498 0 324 0 0 017 0 -22 0 Open
6 7 1 249 -01 -41 -27 27 011 0 -403 -541 Closed
6 7 2 249 -01 -41 -27 27 011 0 -403 -541 Closed
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Simulation OutputMwMvar Loss After Outage On line5-7 (Removing Transmission Line)
From Table following are the observations of load flow study after tie line
Circuit 5-7 open for outage purpose Status of line 5-7 shows OPEN After opening of the circuit 5-7 Load of 50 Mw diverted
on line 2-5 amp loads increased on this line Due to overloading line 2-5 reactive loading I2R Loss
also increased from 31 to 128 Mvar Due to opening of ckt 5-7 loading on double circuit 6-7
suddenly reduces amp power exported on line 6 to line2 50 Mw Previously this line under floating it means that there is no power flow on that line
On Line 4-5 Loading in terms of MW Mvar also increased l
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
MSETCL 400 KV POWER NETWORK OVERVIEW
Maharashtra 400 KV power network consists of 25 buses including VKM (Vidhrbha-Khandesh-Marahwada amp KTRT (Western Maharashtra) includes all generating stations such as KoradiChandrapur amp Koyna This project analyses the power flow in various buses Inspite of taking all 25 buses only 8-buses are considered (Bhusawal2 Akola Korady Chandrapur Parly Bhilai Bhadravati (powergrid IIIIII ampIV) amp Solapur per Real time 400 Kv Overview on dt 05-09-2009 This information collected at the time of field visit at Area Load dispatch Centre Ambazari Nagpur
In order to perform a power flow analysis by N-R method Using Powerworld environment the following variables must be defined power system base MVA Power mismatch accuracy acceleration factor amp maximum number of iterations
In that Chandrapur is taken as Slack Bus denotes One Bus Koradi is a PV Bus denotes code 2 amp shown in table 100 all other Load Buses code is 0The loads are entered positive in Megwatts and
MegVars For this bus initial voltage estimate must be specified This is usually 1 and 0 for voltage magnitude and Phase angle respectively If voltage magnitude and phase angle for this type are specified they will be taken initial starting voltage for that bus instead of float starts of 1 and 0
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Real Time Active Power Flow on 8- Bus System MSETCL
Dt05-09-2009
Bus400 Kv Line
MSETCL400 Kv Line
Length Km
Line LoadingMW
ICT Loading MW Mvar
1 1-2 Bhusawal-Akola 200 341 Bhusawal 179 84
2 2-3 Akola-Koradi 151 391 Akola 464 31
3 1-3 Bhusawal-Koradi 347 448 Koradi 58 34
4 3-4 Koradi-Chandrapur 149 334 Chandrapur304 10
5 4-5 Chandrapur-Parli IIIIII 371 1306 Parli 246 134
6 7-4 Bhadravati-Chandrapur IIIIIIIV
18 840 Solapur 182 60
7 6-3 Bhilai--Koradi 150 454
8 5-8 Parli-Solapur 273 467
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Steps For CalculationsStep 1 For the calculation of powerflow it is must to find out the impedance between two buses In 400 Kv Network there are two or three parallel lines are presenting between some buses such as between chandrapur and parly Koradi and Bhusawal etc For calculation of impedance the parallel combination of these lines are taken as total length between these buses
Step2 Impedances given in fig is in ohm per kmso we have to multiply that by the distance between two buses so the required impedance is obtained
Step3 In the same way suspetance Ieb2 is also given in mhokm and multiplied by distance in km between two buses
Step4 per unit calculationThe data required for the powerflow analysis should be in unit form For that all data such as voltagesline impedance etc should be in per unit formsStep5 Formulae required for the unit calculation are given below
i) The per unit value of any quantity is defined as =The actual value in any unit the base or reference value in the same unit ii) Per unit impedance(z pu)=Z(ohm)x (MVA)B(KV)2B
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
8-Bus MSETCL SYSTEM NETWORK IN POWERWORLD
1 BHSWL2
2 AKOLA
3 KORADI 4 CHANDRAPUR
5 PARLI
6 BHILAI 7 BHADRAVATI
100 pu
098 pu
101 pu102 pu
099 pu
100 pu098 pu
83A
MW
A
MVAA
MVA
A
MVA
A
MVA
267A
MW
126A
MW
A
MVA
144A
MW
8 MW
8 MW
187 MW 189 MW 91 MW 91 MW
38 MW
39 MW
270
143 MW
332 MW332 MW
454 MW
58 MW 34 Mvar
304 MW
-10 Mvar
246 MW136 Mvar
46 MW 3 Mvar
-242 MW
122 MW
195 MW 92 Mvar
179 MW
84 Mvar
83A
MW
267A
MW
267A
MW
267A
MW
8 SOLAPUR
A
MVA
182 MW
6 Mvar
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Bus Mismatches
Number NameArea Name Type
Mismatch MW
1 Bhusawal Top PQ 0
2 AKOLA Top PQ 0
3 KORADI Top PV 0
4 CHANDRAPUR Top Slack 0
5 PARLI Top PQ 0
6 BHILAI Left PQ (Gens at Var Limit) 0
7 BHADRAVATI Right PQ (Gens at Var Limit) 0
8 SOLAPUR Top PQ 0
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
LINE Characteristics of 8-bus MSETCL System
From Number From Name To Number To Name Circuit StatusResista
nceReactan
ce
Line Charging
1 BHUSAWAL 2 AKOLA 1 Closed 0005 0035 05
1 BHUSWAL 3 KORADI 1 Closed 0005 00351 005
2 AKOLA 3 KORADI 1 Closed 0015 018 004
3 KORADI 4 CHANDRAPUR 1 Closed 0002 00152 002
4 CHANDRAPUR 5 PARLI 1 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 2 Closed 00058 00137 005
4 CHANDRAPUR 5 PARLI 3 Closed 00058 00137 004
7 BHADRAVATI 4 CHANDRAPUR 1 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 2 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 3 Closed 00002 00277 004
7 BHADRAVATI 4 CHANDRAPUR 4 Closed 00002 00277 004
5 PARLI 8 SOLAPUR 1 Closed 0002 00277 0
6 BHILAI 7 BHADRAVATI 1 Closed 0002 00152 005
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
From Name To Name CircuitMW
From Mvar From MVA From
Lim MVA
of MVA Limit (Max) MW Loss
Mvar Loss
1Bhusawal 2 AKOLA 1 8 -499 506 120 421 004 -4788
1Bhusawal 3 KORADI 1 -187 -341 190 150 129 188 834
2 AKOLA 3 KORADI 1 -385 -52 388 100 389 023 -118
3 KORADI 4 CHANDRAPUR 1 -906 116 913 222 412 017 -073
4 CHANDRAPUR 5 PARLI 1 1443 49 1523 100 1523 136 -171
4 CHANDRAPUR 5 PARLI 2 1443 49 1523 200 762 136 -171
4 CHANDRAPUR 5 PARLI 3 1443 495 1525 200 763 136 -073
7 BHADRAVATI 4 CHANDRAPUR 1 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 2 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 3 2675 386 2702 100 2702 014 1588
7 BHADRAVATI 4 CHANDRAPUR 4 2675 386 2702 100 2702 014 1588
5 PARLI 8 SOLAPUR 1 1827 156 1834 0 0 069 96
6 BHILAI 7 BHADRAVATI 1 332 66 3385 400 846 219 1147
Power Flow Simulation 8-Bus 400 Kv MSETCL
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Comments Power flow on Line in terms of MW amp
Mvar amp simulated the results It gives the output in terms of MW Mvar losses
Max Reactive Loss shown on 400 Kv Akola-Bhusawal Line due to Load Bus of Bhusawal This Line absorbs reactive power
It indicates Reactive compensation is required at Bhusawal end
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Bus Records Voltage Magnitude amp Angle
Bus Records
Number NameArea Name
Nom kV PU Volt
Volt (kV)
Angle (Deg)
Load MW
Load Mvar
Gen MW
Gen Mvar
1 1 Bhusawal Top 400 09769 39076 -643 179 84
2 2 AKOLA Top 400 098584 394338 -667 464 31
3 3 KORADI Top 400 1 400 -267 58 34 195 9193
4 4 CHANDRAPUR Top 400 1 400 -187 304 -10 -24174 3415
5 5 PARLI Top 400 098472 393889 -284 246 136
6 6 BHILAI Left 400 102453 40981 506 122 34 454 100
7 7 BHADRAVATI Right 400 1009 403601 234 100 0 840 100
8 8 SOLAPUR Top 400 097796 391183 -584 182 6
COMMENTS
It Shows Buswise nominal Voltage in terms of 400 Kv Load connected to the buses in terms of Active load amp Reactive loads Subsequently Generators also connected to the
Buses 34 6 amp 7
After simulation of 8-Bus data in Powerworld output shown in terms of pu voltages amp load angle accordingly In above case Voltage at Bhusawal Bus Parly amp Solapur Bus
found low as compared to other buses This is due to Load buses no generator is connected to the particular buses
Voltage at Koradi amp Chandrapur found in good limits due to Generator buses as well a number of lines connected to this buses Angle in deg indicates the stability angle
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
Conclusion For the calculation of powerflow it is must to find out the impedance
between two buses The solution to the power flow problem begins with identifying the known
and unknown variables in the system The known and unknown variables are dependent on the type of bus
The most popular is known as the Newton-Raphson Method This method begins with initial guesses of all unknown variables (voltage magnitude and angles at Load Buses and voltage angles at Generator Buses)
When Load flow is analysed for 7-buses amp 8-busesVoltage Magnitude is less in PQ buses than PV but Voltage angle is large in PQ buses and less in PV Number of iterations are required when 1 Slack amp all PQ Seven number of iterations are required
No Power MismatchThis conclude that in the Power System there should be one slack bus20 PV buses and 80 PQ buses present in the System
The great importance of power flow or load-flow studies is in the planning the future expansion of power systems as well as in determining the best operation of existing systems The principal information obtained from the power flow study is the magnitude and phase angle of the voltage at each bus and the real and reactive power flowing in each line
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
FUTURE SCOPE amp ITS APPLICATIONS
Load Flow Analysis is the most frequently performed system studies by electric utilities which also performed steady state operating condition of a power system This information is essential for long terms planning and Operational planning
The load flow analysis can be performed by using various tool boxes such as DSPANN and also by using FACTS devicesLoad Flow analysis become more simple and accurate when we simulate it by using ETAP and SKM software By using above method Load Flow Analysis is simpleeasyaccurate and require less iterations
Load Flow analysis in power system plays a vital rolebecause Load flow study is the starting point of various studies such as transient analysisstability analysis etc Load Flow programs are very useful to study Abnormal disturbance conditions This involves transient faultspermanent faults etc due to sharp rise in system demand Voltage collapse usually studied as a steady state problem using conventional or extended power flow programs
Load Flow analysis is also useful for the load forecasting Load forecasting is by knowing present day or past loading conditions on the basis of that we can predict future demand conditions On the basis of that Load despatcher daily performed Generation schedule for optimum utilisation of Resources Part of the Network of MSETCL System considered for Practical load flow studies in our project
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur
REFERENCES PAPERS StottB lsquo Review of load Flow Calculation Methodrsquo IEEEJuly
1974916 Harold Wood in reviewing Tinnney and Harts paper in ldquopower
flow by Newtons Methodrdquo IEEE Trans Power App Syst Vol86Nov 1967
BOOKS George L kusic Computer aided power system analysissecond
edition prentice HALL India Glean WStaggComputer method in power system analysis Powerworld SimulatorPowerworld Corporation Nagrath IJ and DP kothari modern power system Analysis CLWadhwaElectrical power system
INFORMATION FROM ALDCNagpur