ANALYSIS OF THE OPERATING ANALYSIS OF THE OPERATING CONDITION OF Qalqilia ELECTRICAL CONDITION OF Qalqilia ELECTRICAL
NETWORKNETWORK
An- Najah National University Faculty of EngineeringElectrical Engineering
Prepared by :Prepared by :
Fadi Bassam Sabri MahmoudFadi Bassam Sabri MahmoudBelal Abed Alkareem Abu Sha’rBelal Abed Alkareem Abu Sha’r
Supervised by : Supervised by :
Dr. MAHER KHAMMASHDr. MAHER KHAMMASH
Introduction to Qalqilia Introduction to Qalqilia NetworkNetwork
Qalqilia electrical distribution network is fed from one connection point by the Israel Electrical Company (IEC) , at 22 KV.
The development of electrical energy purchased from I.E.C.
and growth rate are:
Year
Annual Purcha
sed M.W.H
Growth Rate%
200234727.40
200334727.40
200437273.87.3
200539264.85.34
200644708.013.86
200750830.9613.7
The energy consumed is distributed into different types
Type of loadConsumptio
n
Residential 77.83 %
Commercial 15.61 %
Industrial 2.84 %
Agricultural 2.14 %
Organization 1.58 %
Year∆p %
199515 %
199614 %
199710 %
19989 %
The change of losses in the Qalqilia electrical
distribution network as
shown in the table But in 2008 it decreases to reach about 3 % for max
case.
Elements Of The NetworkElements Of The Network
1. Electrical Supply: One connection point at 22 kV from IEC .The peak power consumption is 11.804 MW 2. Medium voltage lines (Transmission line):There are two type of conductor : a)) The Over Head Lines :The Over Head Lines used in the network are
22KV, ACSR (Aluminum conductor steel reinforced )
With two cross sectional areas ( 50mm2 called Rabbit , 95mm2 called Dog ) .
b)) Under ground cables : Under ground cables used in the network are 22KV , XLPE , 240mm2Cu , 150mm2Cu , 120 mm2AL , 95mm2AL.The resistance / km and reactance / km and max current for all T.L ( Over head lines and under ground cables ) as shown :
Type of T.L
ResistanceOhms/Km
ReactanceOhms/Km
MaxCurrentcapacity
(A)
O.H.LRabbit50 mm2
0.5430.333174
O.H.LDog95 mm2
0.3010.332250
UGC Al 95 mm2
0.410.121250
UGC Cu120 mm2
0.1960.117360
UGC Cu150 mm2
0.1590.114410
3. Distribution Transformers : Number of distribution transformers in Qalqilia network are 49 .All transformer 22KV / 0.4KV Δ-Υ connected , distribution transformers with ratings 630 , 400 ,250 KVA .
Transformer Ratings KVA
No. of Transformers
63018
40029
2502
Problems in Qalqilia networkProblems in Qalqilia network
1. the main T.L coming from the connection point is Rabbit ( 50 mm2 ) did not have the capability to hold the over current resulting in cutting off the supply on the maximum load condition , because total current pass from this line equal 344 A but max capacity current of this line is 174 A.
2 . High drop voltage : this effect on the losses in the network and on the power factor .
Solution: use capacitor banks ( fixed or variable )
3. Bad distribution of the loads on the existing Transformers which cause a poor load factor , because there are some transformers work at max load factor more than 100 % and some transformers work with load factor less than 60 % .
Note that the transformer work with max efficiency when load factor between ( 65-75 ) %.
Solution: change the configuration of some branches
and transformers .
4. One connection point and this lead to make the performance of the network weak .
( no reliability in network )Solution: it is very important to get another
connection point to supply the city .
ETAP Power Station ProgramETAP Power Station Program::
With ETAP’s advanced Load Flow module, you can create and validate your system model with ease and obtain accurate and reliable results. Built-in features like automatic device evaluation, summary alarms / warnings, result analyzer, and intelligent graphics make it the most efficient Load Flow program available today.
ETAP calculates bus voltages, branch power factors, currents, and power flows throughout the electrical system. ETAP allows for swing, voltage regulated, and unregulated power sources with multiple power grids and generator connections. It is capable of performing analysis on both radial and loop systems. ETAP allows you to select from several different methods in order to achieve the best calculation efficiency and accuracy.
IIn our project we do the following stepsn our project we do the following steps::
Step1: collection of data which consist of :Actual loads on transformer and power factorImpedances of transmission lines ( R, X) .
Step2: Plotting the one line diagram in ETAP
Step 3: Analysis and study the maximum and minimum case.
Step 4 : improvement of power factor .
Step 5 : improvement of voltages level by the following scenarios:
1. Rise the swing bus about 105% .2. Using capacitor banks (fixed and regulated) .3. Putting two connection points ( without ring and
with ring ) .4. Changing the main transmission line of the
network .5. Load factor corrections .
Step 6 : economical study. Step 7 : Low Tension analysis.
One Line DiagramOne Line DiagramQalqilia Network
Analysis … Analysis … Results for the max. caseResults for the max. case
Bus
#
Voltage
act
P
MW
Q
MVar
PF
%20.3910.260.1191.850.3850.410.1991.060.3830.260.1291.170.3840.190.0891.480.3860.180.0891.490.3840.200.0991.8
100.3840.230.1190.7110.3850.190.0891.7120.3850.260.1290.9130.3870.360.1790.9140.3840.270.1390.1150.3820.650.2792.4160.3820.180.0890.8170.3800.530.2790.1180.3840.130.0690.7200.3850.160.0791.4210.3850.140.0594.1220.3780.230.1387.9230.3790.290.1292.4240.3860.200.0892.6260.3860.290.1291.7280.3850.130.0593.3
Low Tension Voltages
Bus
#
Voltage
act
P
MW
Q
MVar
PF
%290.3860.130.0494.7300.3840.250.1093.0310.3810.450.1992.2320.3810.340.1493.3340.3820.290.1292.4350.3810.200.0992.1360.3730.330.1593.1370.3720.350.1691.4380.3820.220.1091.3390.3790.340.1393.7400.3790.140.0593.7420.3780.200.1088.9430.3790.190.0990.9450.3810.150.0692.8460.3790.190.0992.8480.3770.240.1092.6490.3790.170.0890.0500.3800.170.0792.2510.3800.220.1189.5520.3810.310.1293.1540.3800.240.0993.4550.3820.360.1592.7560.3790.220.1190.1
Low Tension Voltages
TransformerS RATED
KVA
S ACTUAL
KVA
LF%
140029874.5
2400414103.6
363037559.6
463034454.5
540019849.4
640026165.4
740038095
8400402100.5
925017971.5
1063035856.9
1163035856.6
1240023558.6
1340014536.2
1463022435.6
1540014837.0
Transformer
S RATED
KVA
S ACTUAL
KVA
LF%
1663028745.5
1740019849.4
1863026341.7
1963029546.9
2063037359.3
2140021052.4
2240027167.6
2340038282.0
2440020551.4
2540019849.4
2640024861.9
2740024861.9
2840016942.3
2940021152.7
3040022456.0
Load Factor
Transformer
S RATED
KVA
S ACTUAL
KVA
LF%
3140022455.9
3240013433.5
3340014636.5
3463024238.4
3525014859.2
3640026466.0
3740019548.6
3840022857.0
3963024939.6
4063020833.0
4163036958.6
4240025262.9
4363032050.8
4440021152.7
4540019348.2
4663046774.1
4763027243.2
4863030047.7
4963032651.7
SUMMARY OF TOTAL GENERATION, SUMMARY OF TOTAL GENERATION, LOADING & DEMANDLOADING & DEMAND
MW Mvar MVA % PF ========= ========= ========= ==============
Swing Bus(es): 11.804 5.684 13.101 90.1 Lagging
Total Demand: 11.804 5.684 13.101 90.1 Lagging --------- --------- --------- --------------
Total Static Load: 11.444 4.988
Apparent Losses: 0.360 0.696
% Losses : 3 %
Total Current : 344 A
From the result we can notice thatFrom the result we can notice that
a) P = 11.804 MW and ∆p = 0.360 MWThen ∆p % = 0.36 \ 11.804 = 3 % b) Problem in load factor as shown in the above .d) The power factor at the swing bus is less than
0.92. This causes penalties on the municipality. So we should raise it to 0.92 to avoid penalties .
c) There are problems in network as shown in the Qalqilia network problems , such as the drop voltages in the network which effect on the P.F and on losses .
Raising the swing voltage from 22 kV to Raising the swing voltage from 22 kV to 23.1 kV23.1 kV
We raise voltages o f the swing bus about 105% of its rated voltage
SUMMARY OF TOTAL GENERATION, LOADING & DEMAND
MW Mvar MVA % PF ====== ====== ====== =====
SwingBus(es): 13.127 6.321 14.519 90.1 Lagging
Total Demand: 13.127 6.321 14.519 90.1 Lagging-------------- --------- --------- ---------
Total Static Load: 12.727 5.547Apparent Losses: 0.400 0.773
We note :In this case all voltages above 392 volt
Bus#
Voltage
nom
Voltageact
bus20.400 0.412 Bus50.400 0.406 Bus60.400 0.403 Bus70.400 0.408 Bus80.400 0.405 Bus90.400 0.405 Bus100.400 0.407 Bus110.400 0.405 Bus120.400 0.406 Bus130.400 0.395 Bus140.400 0.405 Bus150.400 0.403 Bus160.400 0.403 Bus170.400 0.401 Bus180.400 0.405 Bus200.400 0.399 Bus210.400 0.405 Bus220.400 0.398 Bus230.400 0.399 Bus240.400 0.407 Bus260.400 0.404 Bus280.400 0.406
Bus#
Voltagenom
Voltage
actBus290.400 0.407 Bus300.400 0.405 Bus310.400 0.402 Bus320.400 0.402 Bus340.400 0.403 Bus350.400 0.402 Bus360.400 0.394 Bus370.400 0.392 Bus380.400 0.403 Bus390.400 0.400 Bus400.400 0.400 Bus420.400 0.399 Bus430.400 0.400 Bus450.400 0.402 Bus460.400 0.400 Bus480.400 0.398 Bus490.400 0.400 Bus500.400 0.400 Bus510.400 0.401 Bus520.400 0.402 Bus540.400 0.400 Bus550.400 0.403 Bus560.400 0.399
We noteWe note
POWER FACTOR IMPROVEMENTPOWER FACTOR IMPROVEMENT
Benefits of Improving Power Factor :
1. Lower Apparent Power.2. Reduced KWH Losses.3. Improved Voltage leading to enhanced
life of the transformer, cables, switchgear, motors etc., and lower energy cost.
The first step is to raise the power factor to be 92% to avoid penalties .so we’ll add capacitors to meet this value of power factor .
Power factor improvementPF old = 90 %PF desired = 92%We can obtain QC needed by the equation Q c = Q old – Q new =P [tan cos-1(PF old) - tan cos-1(0.92)]We’ll get Qc = 670 kVAr Adding capacitors in delta connection parallel
to the Transformer in secondary side (0.4 kV) .
POWER FACTOR IMPROVEMENT SUMMARY MW Mvar MVA % PF
======= ====== ========= ====== wing Bus(es): 11.866 5. 000 12.876 92.2 Lagging
-------------- --------- Total Static Load: 11.520 4.327Apparent Losses: 0.3469 0.673
I Swing: 337 A
We notice when we increase power factor the losses in the network decrease
Losses before P.f improvement = 0.360 Mw . Losses after P.f improvement = 0.346 Mw .
Comparison between the original case and the case of power factor improvement
THE IMPROVEMENT OF VOLTAGE THE IMPROVEMENT OF VOLTAGE
LEVEL LEVEL Maximum load voltage level improvementAdding capacitors (fixed and regulated) in delta connection parallel to
the Transformer in secondary side (0.4 kv)
SUMMARY OF TOTAL GENERATION, LOADING & DEMAND MW Mvar MVA % PF
Swing Bus(es): 12.015 3.174 12.427 96.7 Lagging
Total Demand: 11.804 5.684 13.101 90.1 Lagging
-------------- --------- --------- --------- Total Static Load: 11.691 2.547
Apparent Losses: 0.324 0.627
Total current 326 A.
Comparison between three caseComparison between three case1. the origin case .1. the origin case .2. power factor improvement case . 2. power factor improvement case . 3. voltage level improvement case3. voltage level improvement case. .
Bus#
VoltageOrigin case
VoltageImprove
p.f
VoltageImprove
of voltage level
P.forigin
p.fimprove
p.f
p.fImprove
of voltage level
bus20.3910.3910.39591.891.899.80Bus50.3850.3850.38991.091.097.43Bus60.3830.3830.38991.191.199.45Bus70.3840.3870.39091.491.497.15Bus80.3860.3840.38791.491.497.17Bus90.3840.3840.38791.891.897.04
Bus100.3840.3860.39090.790.799.77Bus110.3850.3840.38791.791.797.23Bus120.3850.3850.38890.990.997.07Bus130.3750.3750.38190.990.997.76Bus140.3840.3840.38790.190.196.46Bus150.3820.3820.38592.492.496.47Bus160.3820.3830.38790.890.898.90
Bus#Voltage
Origin case
VoltageImprove
p.f
VoltageImprove
of voltage
level
P.forigin
p.fimprove
p.f
p.fImprove
of voltage
level
Bus170.3800.3800.38690.190.199.01Bus180.3840.3840.38790.790.798.42Bus200.3850.3790.38391.491.497.70Bus210.3850.3850.38594.194.194.10Bus220.3780.3840.38587.998.898.81Bus230.3790.3850.38692.499.499.42Bus240.3860.3860.38792.692.692.60Bus260.3860.3830.38591.791.795.58Bus280.3850.3860.38693.393.393.30Bus290.3860.3860.38794.794.794.70Bus300.3840.3850.38593.093.093.00Bus310.3810.3820.38492.292.295.83Bus320.3810.3810.38493.392.395.53Bus340.3820.3820.38792.492.499.46Bus350.3810.3810.38692.192.198.85
Bus#Voltage
Origin case
VoltageImprove
p.f
VoltageImprove
of voltage
level
P.forigin
p.fimprove
p.f
p.fImprove
of voltage
level
Bus360.3730.3740.38093.191.398.32
Bus370.3720.3780.37991.498.1098.10
Bus380.3820.3820.38591.391.398.15
Bus390.3790.3840.38493.799.499.40
Bus400.3790.3800.38693.793.799.40
Bus420.3780.3820.38388.997.197.15
Bus430.3790.3820.38390.996.796.65
Bus450.3810.3820.38492.892.896.92
Bus460.3790.3820.38392.896.696.61
Bus480.3770.3810.38192.698.496.82
Bus490.3790.3820.38390.096.496.43
Bus500.3800.3800.38392.292.297.80
Bus510.3800.3830.38489.597.096.99
Bus520.3810.3820.38693.193.199.49
Bus540.3800.3800.38493.493.498.81
Bus550.3820.3820.38492.792.795.66
Bus560.3790.3830.38390.197.397.29
Origin casepower factor improvement
case
voltage level improvement
caseTotal current 344 A337 A326 ATotal
losses0.36 Mw0.346 Mw0.324 Mw
From the pervious table we notice that the buses voltage in the voltage level improvement case the best of the three cases but we need to rise it more by another method. In three cases there is a change in the current and losses as shown in the next table :
MINIMUM LOAD
SUMMARY OF TOTAL GENERATION, LOADING & DEMAND
MW Mvar MVA % PF ========= ========= ========= ============== Swing Bus(es): 4.911 2.232 5.395 91.0 Lagging Total Demand: 4.911 2.232 5.395 91.0 Lagging --------- --------- --------- --------------
Total Static Load: 4.850 2.114 Apparent Losses: 0.061 0.118
Total current 141 A .
VOLTAGE LEVEL IMPROVEMENT of MINIMUM LOAD
SUMMARY OF TOTAL GENERATION, LOADING & DEMAND
M W Mvar MVA % PF ========= ========= ========= ============== Swing Bus(es): 4.931 1.676 5.208 94.7 Lagging Total Demand: 4.931 1.676 5.208 94.7 Lagging --------- --------- --------- -------------- Total Static Load: 4.874 1.565 Apparent Losses: 0.057 0.110
Total current 136 A .
Comparison between the case minimum load and Comparison between the case minimum load and voltage Level improvement of minimum loadvoltage Level improvement of minimum load
Bus#
Voltagebefore
Voltageafter
P.fbefore
p.fafter
bus20.3960.39891.7799.8Bus50.3940.39691.0099.4Bus60.3930.39591.1091.4Bus70.3950.39491.4091.4Bus80.3940.39591.4097.0Bus90.3930.39691.8099.8
Bus100.3940.39490.7091.7Bus110.3940.39491.7090.9Bus120.3940.39290.9097.8Bus130.3900.39490.9090.1Bus140.3930.39490.1096.5Bus150.3930.39392.3990.8Bus160.3930.39390.8093.5Bus170.3920.39490.0890.7Bus180.3930.39390.7097.7Bus200.3910.39491.4094.1Bus210.3940.39494.1098.8Bus220.3910.39387.9096.0Bus230.3910.39492.4092.6Bus240.3940.39492.6095.6
Bus
#Voltagebefore
Voltage
after
P.f
before
p.f
afterBus260.3930.39491.7093.3Bus280.3940.39593.3094.7Bus290.3940.39494.7093.0Bus300.3940.39393.0095.8Bus310.3920.39392.1895.5Bus320.3920.39392.3092.4Bus340.3930.39492.4098.9Bus350.3920.39292.1098.3Bus360.3890.39191.3098.1Bus370.3890.39391.4091.3Bus380.3930.39291.3093.7Bus390.3920.39293.7093.7Bus400.3920.39393.7097.1Bus420.3910.39288.9090.9Bus430.3920.39390.9092.8Bus450.3920.39292.8090.9Bus460.3910.39290.9095.4Bus480.3910.39292.6090.0Bus490.3910.39290.0092.2Bus500.3920.39392.2097.0Bus510.3920.39389.5093.1Bus520.3920.39393.1098.8
We use capacitor with two types:
•Fixed capacitor = 1.385 Mvar .•Variable capacitor (controlled ) = 1.36 Mvar
Economical studyEconomical study
1 .Economical study o f p.f improvementZ∆p= (∆p1-∆P 2)*T*140 $/MWhWe take tmax = 5550 h , then we calculate TT=8760(0.124+0.0001tmax)^2T=4000 hour
Z∆p = ( 0.36 – 0.346 ) * 4000 * 140 = 7840$ Saving in P.f penalties = (0.92 – 0.90) *65465 *140 * 0.02
=3666 $ We know that the cost of the capacitor is as follow-:
Fixed Cap=5000 $/MvarRegulated Cap=15000 $/Mvar
Zc = 0.22 * 5000 * 0.67 = 737 $ Total saving = saving in Δp +saving in power factor – Zc
= 7840 + 3666 – 737 = 10769 $
2. Economical study of voltage level improvement
Z∆p = (∆p1-∆P 2 )*T*140 $/MWhZ∆p= ( 0.36 – 0.324 ) * 4000 * 140 = 20160 $ Saving in P.f penalties = 3666$
S.P.B.P = investment = 0.67*5000 = 0.31 year Annual saving 10769
= 0.31 year *12 = 3.7 months
Fixed Cap=5000 $/MvarRegulated Cap=15000 $/MvarZc = 0.22 * 5000 * 1.385 + 0.22 * 15000 * 1.36
= 1524 + 3300 = 6012 $ Total saving = saving in Δp +saving in power factor – Zc
= 20160 + 3666 – 6012 = 17814. $
S.P.B.P = investment = 5000 * 1.385 + 15000 * 1.36 = 1.5 year Annual saving 17814
= 1.5 year * 12 = 18 months.
Two connection points and other Two connection points and other improvementimprovement
1. Two connection points without ring configuration.2. Two connection points and change main T.L without ring configuration.3. Influence of Load factor correction.4. Two connection points, change main T.L, P.f improvement and load factor correction without rings configuration.5. Two connection points, change main T.L, P.f improvement and load factor correction with rings configuration .
SUMMARY OF TOTAL GENERATION, LOADING & DEMAND MW Mvar MVA % PF ======= ======= ========= ========== Swing Bus(es): 6.942 3.919 7.972 87.1 Lagging Generators: 5.000 2.000 5.385 92.8 Lagging Total Demand: 11.942 5.919 13.329 89.6 Lagging --------- --------- --------- -------------- Total Static Load: 11.693 5.096 Apparent Losses: 0.249 0.823
I swing 209 AI gen 93 A
Two connection points without ring configurationTwo connection points without ring configuration..
Bus
#
Voltage
nom
Voltage
act
bus20.4000.392
Bus50.4000.386
Bus60.4000.385
Bus70.4000.390
Bus80.4000.387
Bus90.4000.387
Bus100.4000.389
Bus110.4000.387
Bus120.4000.388
Bus130.4000.378
Bus140.4000.387
Bus150.4000.385
Bus160.4000.385
Bus170.4000.383
Bus180.4000.387
Bus200.4000.381
Bus210.4000.388
Bus
#
Voltag
e
nom
Voltage
act
Bus220.4000.381
Bus230.4000.382
Bus240.4000.390
Bus260.4000.387
Bus280.4000.389
Bus290.4000.390
Bus300.4000.388
Bus310.4000.385
Bus320.4000.386
Bus340.4000.387
Bus350.4000.386
Bus360.4000.378
Bus370.4000.377
Bus
#
Voltag
e
nom
Voltage
act
Bus380.4000.387
Bus390.4000.385
Bus400.4000.385
Bus420.4000.383
Bus430.4000.385
Bus450.4000.387
Bus460.4000.384
Bus480.4000.382
Bus490.4000.384
Bus500.4000.385
Bus510.4000.386
Bus520.4000.387
Bus540.4000.386
Bus550.4000.389
Bus560.4000.388
Two connection points and change main Two connection points and change main T.L without ring configurationT.L without ring configuration..
In this case we notice the difference in the losses from the previous case as shown :
The losses before change main T.L = 0.249 Mw .The losses after change main T.L = 0.236 Mw .
T2(400KVA)to T40(630KVA)
T8(400KVA)to T34(630KVA)
T7(400KVA)to T47(630KVA)
T2T40T8T34T7T47Bus# 13737383630
L.F before10733104399844L.F after655364596070
Voltage before
387393387394388393
Voltage after
391390391392392389
influence of Load factor correctioninfluence of Load factor correction. . Some transformers are over loaded T2,T7,T8… while others are
operating at light load as T40,T34 , T47. To have a good transformer loading the load factor should be greater than 0.6 In order to make the transformer works on a better efficiency
We make the following correction and we show the influence
Two connection points , change main T.LTwo connection points , change main T.L, , P.f improvement and load factor correction without P.f improvement and load factor correction without
ring configurationring configuration. .
SUMMARY OF TOTAL GENERATION, LOADING & DEMAND
MW Mvar MVA % PF ======= ======= ========= ========== Swing Bus(es): 6.942 3.919 7.972 87.1 Lagging Generators: 5.000 2.000 5.385 92.8 Lagging Total Demand: 11.942 5.919 13.329 89.6 Lagging --------- --------- --------- -------------- Total Static Load: 11.693 5.096 Apparent Losses: 0.249 0.823
I swing 209 AI gen 93 A
Bus
#
Voltage
nom
Voltage
act
bus20.4000.397
Bus50.4000.391
Bus60.4000.392
Bus70.4000.389
Bus80.4000.389
Bus90.4000.388
Bus100.4000.390
Bus110.4000.388
Bus120.4000.389
Bus130.4000.389
Bus140.4000.388
Bus150.4000.386
Bus160.4000.390
Bus170.4000.387
Bus180.4000.388
Bus200.4000.389
Bus210.4000.389
Bus
#Voltage
nom
Voltage
act
Bus220.4000.388
Bus230.4000.390
Bus240.4000.391
Bus260.4000.392
Bus280.4000.391
Bus290.4000.391
Bus300.4000.386
Bus310.4000.390
Bus320.4000.387
Bus340.4000.388
Bus350.4000.388
Bus360.4000.390
Bus370.4000.389
Bus380.4000.389
Bus
#Voltag
e
nom
Voltage
act
Bus390.4000.386
Bus400.4000.386
Bus420.4000.391
Bus430.4000.390
Bus450.4000.388
Bus460.4000.390
Bus480.4000.384
Bus490.4000.390
Bus500.4000.387
Bus510.4000.391
Bus520.4000.389
Bus540.4000.388
Bus550.4000.390
Bus560.4000.396
Two connection points , change main T.L , P.f Two connection points , change main T.L , P.f improvement and load factor correction improvement and load factor correction with ringwith ring
configurationconfiguration. .
SUMMARY OF TOTAL GENERATION, LOADING & DEMAND
MW Mvar MVA % PF
========= ========= ========= ============== Swing Bus(es): 7.222 2.291 7.577 95.3 Lagging Generators: 5.000 2.000 5.385 92.8 Lagging Total Demand: 12.222 4.291 12.954 94.3 Lagging --------- --------- --------- -------------- Total Static Load: 12.051 3.559 Apparent Losses: 0.172 0.732..
Comparison between voltages of
1. the origin case . 2. voltage level improvement case . 3. Two connection points without ring. 4 . Two connection points , change main T.L , P.f improvement and load
factor correction without ring configuration . 5 . Two connection points , change main T.L , P.f improvement and load
factor correction with ring configuration .
Two connection points , without ring
Two connection points , change main T.L
without ring
Two connection points , change main T.L , P.f improvement and load factor correction without ring configuration
Two connection points , change main T.L , P.f improvement and load factor correction with ring configuration
losses0.2490.2360.2170.172
When we put rings We noticeThat the voltages increases in average and the losses decrease
The optimum case Two connection points , change main T.L , P.f improvement and load factor correction with ring configurationBecause: ** less losses and best voltages
Low Tension analysis:
Most of the power losses …. Voltage drop happens on the low voltage network … That because of high currents … Analysis will be over the longest feeder of a certain Transformer which is T 23 … T 23 has three feeders and loaded by 465 A Three feeders •Feeder 1 = 134 KVA •Feeder 2 = 122 KVA•Feeder3 = 98.5 KVA
We note that drop voltages in low tension between We note that drop voltages in low tension between ( 2.5-5)%( 2.5-5)%
As shown in the next pictureAs shown in the next picture