22396525 part i sld bb layout

7/28/2019 22396525 Part I Sld Bb Layout

1/50

1

Presentation on

SUB STATION BASIC : PARTI

Single Line Diagram

Bus Bar Arrangement

Sub Station Layout


2/50

2

IntroductionThe economics of generation of electrical energy and

the huge demands for power in the modern timesrequires creation of bigger POWER STATIONS.The power stations may be far from the load centre /consumers and so long high voltage transmissionlines are necessary for transfer of bulk power from

power station to different load centres. In between power station and ultimate consumers anumber of transformation and switching stations areto be created. Such stations are known as Sub Station.


3/50

3

Concept of Power System


4/50

4

What is Sub Station ?A SUBSTATION is a subsidiary station of an electricity

Generation, Transmission and Distribution systemwhere voltage is transformed from high to low or viseversa using transformers. Electric power may flowthrough several substationsbetween generating plantand consumer, and may bechanged in voltage inseveral steps.A Step-up transformer increases the voltage andproportionally decreases the current, while a step-down transformer decreases the voltage andproportionally increases the current for domestic andcommercial distribution.


5/50

5

House Electrification

DISTRIBUTION BOARD

3- & 1- MCBsBUS BAR STRIPS

SOURCE CABLE (Incoming)

3- LOAD CABLE (Outgoing)


1-

LOAD CABLE (Outgoing)



6/50

6

General Arrangement

LIGHTNING ARRESTOR

POTENTIAL

TRANSFORMER

TR. LINE

(INCOMER / OUTGOING)

TR. LINE

(INCOMER)

CURRENT TRANSFORMER

WAVE TRAP

EARTH SWITCH

ISOLATOR

CIRCUIT BREAKER

ISOLATOR

CAP. VOLTAGE TRANSFORMER POWER

TRANSFORMER

SUBSTATION

BUS

BAR


7/50

7

Single Bus Bar Scheme

BUS BAR

SUB STATION POWER STATION LOAD CENTRE

Faulty

Faulty


8/50

8

Advantage & DisadvantageSINGLE BUS BAR (UPTO 33kV SS)Advantages Lowest cost Small land area required Easily expandable Simple in concept and operationDisadvantages Lowest reliability Failure of a circuit breaker causes loss of the feeder Bus fault causes loss of the entire substation


9/50

9

ImprovementMain Disadvantage ? Loss of the entire Sub Station in case of Bus fault.Requirement ? Avoid loss of entire bus i.e., entire Sub Station in Bus

fault.How to Achieve ? By Sectionalizing the Single Bus Bar.Arrangement ? Sectionalisation of Single Bus Bar Arrangement.


10/50

10

Sectionalization of Single Bus Bar Scheme

BUS SECTION - I BUS SECTION - II


Faulty

Faulty

SECTIONALIZING CB


11/50

11

Advantage & DisadvantageSECTIONALIZATION BUS BAR (33kV & 66kV SS)Advantages Flexible operation Higher reliability than single bus scheme Isolation of bus sections for maintenance Loss of only part of the substation for a bus faultDisadvantages Loss of circuit for breaker failure A sectionalized bus arrangement has a higher costthan a single bus scheme asadditional circuit breakerand isolators are required for sectionalizing


12/50


13/50

13

Main and Transfer Bus Bar Scheme

MAIN BUS I

SUB STATION POWER STATION

TRANSFER BUS

LOAD CENTRE

Faulty

Faulty

TRANSFER BUS

COUPLER (TBC)


14/50

14

Advantage & DisadvantageMAIN & TRANSFER BUS BAR (132kV SS)Advantages Circuit breaker outage / maintenance does not disruptthe service of feeder / circuit Reasonable in cost Fairly small land area Easily expandableDisadvantages Bus Fault causes disruption of service of entire substation An additional circuit breaker is required for bus tie


15/50

15

ImprovementMain Disadvantage ? Bus fault in a sub station having more nos. of circuits

causes greater interruption of power. In Main andTransfer Bus Bar arrangement bus fault results loss ofentire sub station i.e., all circuits.Requirement ? Avoid loss of too many circuits in case of bus fault.How to Achieve ? By providing another Main Bus for connection ofcircuits.Arrangement ? Double Main Bus Bar Arrangement.


16/50

16

Double Main Bus Bar Scheme

MAIN BUS I

MAIN BUS II


Faulty

Faulty

BUS COUPLER (BC)

Single Bus Scheme Mode


17/50


18/50

18

ImprovementMain Disadvantage ? Double Main Bus arrangement is an alternative toMain & Transfer Bus scheme. In both cases, the

investment is same. The only difference is that inDouble Main Bus the outage of Bus Bar and in Main &Transfer Bus the outage of Breaker is prioritized. Interruption of Power during Isolator operation.Requirement ? Both Bus fault and Circuit Breaker outage are to betaken care off.How to Achieve ? By using one of the Main Buses as Main Cum TransferBus.Arrangement ? Double Main Cum Transfer Bus Bar Arrangement.


19/50

19

Double Main Cum Transfer Bus Bar Scheme

BUS I CUM

TRANSFER

BUS II


Faulty

Faulty

BC

Single Bus Scheme Modeain and Transfer Bus Scheme Mode


20/50

20

Advantage & DisadvantageDOUBLE MAIN CUM TRANSFER BUS BAR (220kV SS)Advantages Bus Bar outage / maintenance does not disrupt theservice of any feeder / circuit Circuit Breaker outage does not cause disruption ofservice of that feeder Reasonable in cost Fairly small land area Easily expandableDisadvantages Additional Isolator in each circuit increases the cost


21/50

21

ImprovementMain Disadvantage ? Double Main Cum Transfer Bus Bar arrangementoutage of Circuit Breaker and Bus together causes lossof faulty Circuit Breaker feeder. Interruption of Power during Isolator Operation.Requirement ? Avoid loss of feeder in case of simultaneous outage ofCircuit Breaker and a Main Bus.How to Achieve ? By providing separate transfer Bus along with DoubleMain Buses.Arrangement ? Double Main and Transfer Bus Bar Arrangement.


22/50

22

Double Main and Transfer Bus Bar SchemeSUB STATION POWER STATION LOAD CENTRE

BUS I

BUS II

TRANSFER BUS

Faulty

Faulty

BC

TBC

INTERRUPTION

Single Bus Scheme Modeain and Transfer Scheme Mode


23/50

23

Advantage & DisadvantageDOUBLE MAIN AND TRANSFER BUS BAR (220kV SS)Advantages Bus Bar outage / maintenance does not disrupt theservice of any feeder / circuit Circuit Breaker outage does not cause disruption of

service of that feeder Maintenance of Bus and CB does not interrupt supplyDisadvantages Additional Isolator and Circuit Breaker required fortransfer Bus tie.


24/50

24

ImprovementMain Disadvantage ? Interruption of Power during Isolator operation. Interruption of Power is likely to cause majordisturbance if the feeders are important and heavilyloaded.Requirement ? Avoid interruption of important and heavily loadedfeeders during bus fault or outage of Circuit Breaker.How to Achieve ? By connection of circuits for double feed throughCircuit Breakers and avoid Isolator switching.Arrangement ? One and a Half Breaker Bus Bar Arrangement.


25/50

25

One and a Half Breaker Bus Bar SchemeBUS I BUS II

MAIN CB MAIN CBTIE CB

MAIN CB MAIN CBTIE CB

SUB STATION

POWER STATION

LOAD CENTRE

Faulty Faulty

Faulty

Faulty


26/50

26

Advantage & DisadvantageONE & HALF BREAKER BUS BAR (400kV SS)Advantages Flexible operation High reliability Can isolate either main bus for maintenance withoutdisrupting service Can isolate any circuit breaker for maintenancewithout disrupting service Double feed to each circuit Bus fault does not interrupt service to any circuits All switching done with circuit breakersDisadvantages One-and-a-half breakers are required per circuit


27/50

27

ImprovementImportant In transmission system the highest reliable Bus Bar

Arrangement adopted by POWERGRID is One and aHalf Bus Bar Scheme. However, where bulk powerevacuation without alternative path is concerned,further reliable arrangement may be adopted.What Arrangement ? Connection of circuits in Double Bus Bar Arrangementwhere each circuit will have a spare Circuit Breaker inservice.Where can be used ? In large Generating Plants where implication ofgeneration outage is much higher than the cost ofCircuit Breakers.


28/50

28

Double Breaker Bus Bar SchemeBUS I BUS II

SUB STATION

POWER STATION

LOAD CENTRE

Faulty

Faulty


29/50

29

Advantage & DisadvantageDOUBLE BREAKER BUS BAR (Mega Generating Units)Advantages Flexible operation Very high reliability Isolation of either main bus for maintenance withoutdisrupting service Isolation of any circuit breaker for maintenance

without disrupting service Double feed to each circuit No interruption of service to any circuits from busfault Loss of only one circuit for breaker failure All switching with circuit breakersDisadvantages This configuration carries a high cost Two circuit breakers are required for each circuit.


30/50

30

PHOTOGRAPHS


31/50

31

Photographs

BUSBAR


32/50

32

CIRCUIT BREAKER ISOLATOR AND EARTH SWITCH

Photographs


33/50

33

CURRENT TRANSFORMER POTENTIAL TRANSFORMER

Photographs


34/50

34

LIGHTNING ARRESTER

CAPACITOR VOLTAGE

TRANSFORMER

Photographs


35/50

35

WAVE TRAP TRANSMISSION LINE

Photographs


36/50

36

TRANSFORMER

Photographs


37/50

37

REACTOR

Photographs


38/50

38

Photographs

SUB STATION


39/50

39

LAYOUT & SECTION


40/50

40

DRAWING EXAMPLE : 1

CL-CT

CL-WT

CL-CVT

CL-LA

A

A

B

B

CL-ISO

CL-CB

CL-ISO

CL-LA

CL-TFR.

SLIDE : 1 of 3


41/50

41

Ground LevelLA CVT WT CT ISO & ES CB ISO

SECTION - AA

DRAWING EXAMPLE : 1

SLIDE : 2 of 3

Earth Wire

Gantry


42/50

42

Ground LevelLA CT ISO CB ISO

SECTION - BB

DRAWING EXAMPLE : 1

SLIDE : 3 of 3

Transformer

A B


43/50

43

DRAWING EXAMPLE : 2

SLIDE : 1 of 3

CL-CT

CL-WT

CL-CVT

CL-LA

A

CL-ISO

CL-CB

CL-ISO

CL-LA

CL-TFR.

CL-ISO


44/50

44

SECTION - AA

DRAWING EXAMPLE : 2

SLIDE : 2 of 3

Ground LevelLA CVT WT CT ISO & ES CB ISO ISO

Gantry

Earth Wire


45/50

45

SECTION - BB

DRAWING EXAMPLE : 2

SLIDE : 3 of 3

Ground LevelCT ISO & ES CB ISO ISO

Gantry

LATransformer

Earth Wire


46/50

46


47/50

47

QUESTIONWhat are the different parts of Power System ?What is Sub Station ?What is Single Line Diagram ?Explain BUS BAR ?What do you understand by Bus Bar Arrangement ?What are the limitations of Single Bus Bar Scheme ?What is the advantage of Sectionalisation of Single Bus

Bar over Single Bus Arrangement ?Bus Bar Arrangement for 132kV Sub Station is .


48/50

48

QUESTIONWhat are the limitations of Main & Transfer Bus BarScheme ?How does Double Main Bus Scheme differ from Main &Transfer Bus Arrangement ?What is the difference between Double Main Bus and

Double Main Cum Transfer Bus Arrangement ?What is the Bus Bar Arrangement for Sub Station havingvoltage class 400kV & above ?What is the advantages of One and a half Breaker BusBar Scheme ?What is the advantage & Disadvantage of Two BreakerBus Bar Scheme and where the same is used ?


49/50

49

QUESTIONExplain the purpose of using

(a) Circuit Breaker(b) Isolator(c) Earth Switch(d) Lightning Arrestor(e) Current Transformer(f) Potential Transformer(g) Capacitor Voltage Transformer(h) Wave Trap(i) Power Transformer


50/50

22396525 part i sld bb layout

Documents