A GOVERNMENT OF WEST BENGAL ENTERPRISE

A PROJECT ON

LILUAH 132/33/25 KV SUBSTATION

PRESENTED BY:- PRABHAT KUMAR (EE/11/012)

ARIJIT DAS (EE/11/015)

DIPTESH KOLEY (EE/11/033)

-:ACKNOWLEDGEMENT:-We had a great pleasure in expressing our sincere gratitude to

the TPO of our college and Mr. D.Bose, GM(HR &

A),W.B.S.E.T.C.L for allowing summer training at Liluah

132/33/25 KV substation.

We are greatly thankful to Mr. Rakesh Kundu, assistant engineer

of Liluah transmission(O & M) substation for his immense help

and suitable guidance during training period.

We are also thankful to all other staffs of substation for their day

to day help and assistance.

SINGLE LINE DIAGRAM OF LILUAH

132/33/25 KV

ELECTRICAL BUSBAR

ELECTRICAL BUSBAR

It is the collector of electrical energy at one location at constant voltage

Types:- 1. Rigid type: - made up of aluminium alloy tubes of 50 to 250 mm diameter and supported on post insulator with clamps and connector.

2. Flexible type:- made up of A.C.S.R. conductor and supported at both ends by strain insulators clamps and conductors.

Acts as common point when a number of generator or feeder operating at same voltage is to be connected together.

TYPES OF ARRANGEMENT

1. Single busbar system

2. Duplicate busbar system

3. Triple busbar system

PROTECTIVE SCHEME IN

POWER SYSTEM The capital investment involved in a power system for the

generation, transmission & distribution of electrical power is so great that proper precaution must be taken to ensure that the equipment not only operate as nearly as possible to peak efficient but also that it is protected from accident .

There are two main components of protection scheme:

1. Protective relay.

2. Circuit breakers.

1. Protective relay:- A relay is an automatic device which senses an abnormal condition in an electrical circuit and closes its contacts.

There are two operating principle of relay:

I. Electromagnetic induction.

II. Electromagnetic attraction.

Relays used for line protection :

(a) Earth fault relay (b) over current relay (c) distant protection relay

(d)Zone protection relay

Relays used for transformer protection:

(a)Earth fault relay. b) Over current relay. (c) buchholz relay

(d)differential relay (e)back up earth fault relay (f)restricted earth

fault relay (g)high temp relay (g)high temp relay (h)supervision relay.

2.CIRCUIT BREAKER-

• Isolate the faulty part of the power system in case of abnormal

condition.

•A protective relay detects the abnormal condition & sends a tripping

signal to circuit breaker. After receiving that relay trips the circuit and

circuit breaker isolates the faulty part

•In normal condition, the two contacts(fixed and moving) remain in

closed position

CLASSIFICATION-

1. Oil circuit breaker

2. Air blast CBs

3. Sulphur hexafluoride CBs

4. Vacuum CBs

PROTECTION AGAINST LIGHTNING

The most commonly used devices for protection

against lightning surges are:

1. Earthing screen.

2. Overhead ground wires.

3. Lightning arrester or surge diverters.

ISOLATOR

An Isolator is a disconnecting switch being operated under the condition of no load negligible current.

Used for disconnecting the circuit breaker from the circuit and to isolate the electrical circuit at the time of maintenance work and repair.

Interlocking arrangement are generally provided in the isolators.

TYPES:-

1. Vertical break type single, double and triple pole insulator

2. Horizontal two rotating post, centre break insulator

3. Horizontal break ,centre rotating double break insulator

4. Extra high voltage column insulator

CAPACITOR BANKThese capacitors have an important role to investigate the

behavior of the breaker towards the restricting voltage.

1. Controls and improves the voltages.

2. Removes the reactive components of VARS component of the

power which is not desirable.

3. Improves power factor.

Capacitor

s

POWERLINE CARRIER COMMUNICATION

(PLCC) Protection signaling, speech and data transmission for

system operation and control, management information system etc. are predominantly met by PLCC .

It is the most economical and reliable method of communication because of higher mechanical strength and insulation of high voltage power-lines which contribute to the increased reliability of communication and lower attenuation over the longer distances involved.

PLCC Equipments-

a) Wave trap

b) Coupling capacitor

c) Line Matching Unit(LMU)

d) Protective equipments.

BATTERY Provide unit charge to the entire system & behaves as back-up

charging system

In Liluah 132 KV substation these units provide control voltage of 220

VOLT DC back-up of entire system.

Makers- Amra Raja Make

Charging & discharging is needed to keep it healthy.

Battery Charger:

SL. No. : 4/2008/2

AC Input: 415± 10%

Ph: 50 Hz

DC Output to charge: 250 V

AH:110 A

Cells at quick/boost: 2/2.7

A.P.L.: 60 A

Trickle/float: 2.15/2.3

V.P.C.: 1602 /480 M

EARTH TRANSFORMER

An Earth Transformer is

connected in those areas

where earth point is not

available like a system

connected to delta side of

electrical power

transformer, an artificial

neutral point is createdusing earth transformer.

Sl.no Specifications Earthing Transformer 1 Earthing Transformer 2

1. Makers name GEC GEC

2. Std IS3151-1982 IS2026-1977

3. KVA Rating 100 100

4. Volts at no load HV:33KV,LV:415V HV:33KV,LV:415V

5. Amperes rating HV:1.75A,LV:139A HV:1.75A,LV:139.3A

6. Phases 3 3

7. Types of Cooling ON AN ON AN

8. Frequency 50 Hz 50 Hz

9. Vector group ZNyn-11 ZNyn-11

10. Impedance volt 4.5077% 3.796%

11. Earth fault current 550 A for 30 sec 287 amp for 30 sec

12. Year of mfg. 1990 1986

TRACTION TRANSFORMER(132KV/25KV)

It is used to supply the Indian Railways. The Railways use 25 KV Single

phase line, so the Traction Transformer takes 2 phase 132 V Input supply

and gives 2 phase 25 KV Output out of which one phase is grounded and

made neutral and other phase is used by the Indian Railways.

Serial

no.

Specifications Traction Transformer 1 & Traction

Transformer2

1. Maker’s Name Crompton Greaves Ltd.

2. MVA Rating 12.5/18.75

3. MVA (As per I.S) 13.5/20

4. KV Rating (at no load) H.V=132 KV;L.V=15KV

5. Line Current(Amps) H.V=102/151.5amp;L.V=500/750amp

6. Output Phase Single

7. Frequency(Hz) 50Hz

8. Type of cooling ON AN/ON AF

9. Total Oil(ltrs/kg) 15300/12900

10. Total Mass(Kg) 47600

11. Untanking Mass Core & winding=18900 kg

Bell tank=4200 kg

12. Heaviest Package With oil=33500 kg

Without oil=24800 kg

13. Hot Spot temperature Ref<1150C

14. Ambient temperature 45OC

15. Insulation level (H.V./L.V.) LI650AC275/LI250AC95

16. Guaranteed temperature rise of oil(0C) 50

17. Guaranteed temperature rise of winding(0C): 50

18. Maker’s w.o no.: T8174

19. Maker’s sl no.: 24749

20. Customer reference No.: LOI REF PLN/TRACTION/TRANS/491

21. Year of mfg: 06-04-1987

STATION SERVICE TRANSFORMER

Station Service Transformer converts HV 33 KV TO LV 400KV which is used by the Substation for its own needs like to run the air conditioner, fans and to run the control panel and relay panel.

Specifications-

Maker’s Name: - Transmake Electrical Pvt. Ltd.

STD:- IS2026 & 1180

KVA Rating:-100

Volts at no load:-HV-33KV & LV-400V

Current at no load(A):-HV-1.75 & LV-144.34

Phase:-3

Diagram:- TW/100/33

Sl. No.-94311

Type of cooling:- ON AN

Frequency:- 50 Hz

Impedance:- 4.1%

Vector Group:- DYn11

Core & Winding weight:- 430 Kg

Weight of oil:- 260 Kg

Total weight:- 930 Kg

Oil quantity:- 300 Ltrs

Year Of Mfg:- 12/2002

Guaranteed Max temp. rise in oil:450C

POWER TRANSFORMER-3NAMEPLATE PARTICULARS:

Maker’s Name: - Bharat Heavy Electricals Ltd.

MVA Rating: - 30/40/50

Vector Symbol: - YnD1

Phase: - 3

Frequency: - 50 Hz

Type of cooling: - ON AN/ON AF/OF AF

Diagram Drg. no:-14561950473

Sl. No.:- 2013511

Year of mfg:- 2001

OLTC With oil, transport with oil heaviest package:- 50

Tonnes

Complete transformer including oil:- 97 Tonnes

Bil: HV:- 550 kvp & LV:-170 kvp

Impedance volts(at 750C):- 12.5 ± 13%

KV(No load):- HV-132 KV & LV-33 KV

Amps:- HV-218.95 & LV-875.81

At taps: normal tap(9b)

POWER TRANSFORMER-4SPECIFICATION:

Maker’s Name:- ABB

Ref. Std: IS2026

Sl. No.: AAA-003

Year of mfg:- 2008

Frequency:- 50 Hz

Type of cooling:- ON AN/ON AF/OF AF

% Impedance Voltage HV/LV:

Nominal Power(ON AN/ON AF/OF AF):-30/40/50 MVA

Nominal voltage:- HV-132 KV & LV-33 KV

OLTC Type:- EASUNMR

Rated current:- 350 A

Insulation Ground:- 725 KV

Step Voltage:- 953 V

Control Voltage:- 110 V

Variation:- +10% to -10% of HV

No. of steps:- 16

Temp. rise of oil/winding:- 500C/550C

Vector Group:- YDn1

Short circuit current(max duration 3 sec):- HV=1.749 KA &

LV=6.99 KA

Tap No. Guaranteed at N tap Actual (after test)

Tap 1

12.5% (± 10%)

12.14%

Tap 9b 11.64%

Tap 17 11.33%

•% Impedance Voltage HV/LV:

Testing Voltage HV HVN LV

Um(Highest sys V) 145 36

AC(Power frequency) 230 38 70

Lightning Impulse 550 95 170

•Core & Winding Mass:- 45670 Kg

•Tank & Fitting Mass:- 12520 Kg

•Oil Mass:- 17830 kg

•Total Transformer mass:- 76020 Kg

•Transformer mass(oil filled):- 68420 kg

•Total oil quantity:- 20030 litres

•Insulation Level:-

Cooling Fans

POWER TRANSFORMER 4

POWER TRANSFORMER 3

HV

Bushings

Conservator

Radiator Bank

Buchholz

relay

MOG

Oil pump

Earthing Transformer

Oil level indicator