Reactor Protection

REACTOR PROTECTION PREPARED BY GOPALA KRISHNA PALEPU ADE/MRT(PROTECTION) [email protected], Mobile:9440336984

MAIN-1 & MAIN-2 PROTECTION FOR SHUNT REACTOR ADOPTED IN ONE AND HALF CIRCUIT BREAKER SCHEME PREPARED BY GOPALA KRISHNA PALEPU ADE/MRT(PROTECTION)

BASICS OF SHUNT REACTOR 1. TYPES OF REACTORS : A. BASED ON REACTOR CONNECTION i. SHUNT REACTOR. ii. SERIES REACTOR. B. BASED ON REACTOR LOCATION i. BUS REACTOR ii. LINE REACTOR C. BASED ON CONTROL i. 3-PH OIL IMMERSED REACTOR WITH GAPPED IRON CORE. ii. THYRISTOR CONTROLLED REACTOR (STATIC VAR COMPENSATOR) (APTRANSCO UTILISING SHUNT REACTORS FOR BUS & LINE IN 400KV NETWORK) 2. NEED OF SHUNT REACTOR: A. LINE REACTOR SHUNT REACTORS ARE USED IN ORDER TO COMPENSATE FOR THE CAPACITIVE SHUNT REACTANCE OF TRANSMISSION LINES. THE REACTOR IS CONNECTED PARALLEL TO THE LINE. THE LOCATION OF REACTOR IS OUT GOING SIDE OF LINE i.e AFTER CIRCUIT BREAKER. LENGTH OF LINE IS MORE THERE MAY BE VOLTAGE IS RAISING DUE TO FARANTI EFFECT(CAPACITANCE) DURING CHARGING. IN CASE OF ZONE-2 (OPEN JUMPER) FAULT, THE FAULT CLEARED BY REMOTE END IS FAST, BUT THIS END IT WILL TAKE TIME DELAY DUE TO ZONE-2. DURING THIS TIME, VOLTAGE MAY RAISING. SO, LINE REACTOR IS USED FOR CONTROLLING THE SWITCHING OVER VOLTAGES AND SAFEGUARD THE OPERATING EQUIPMENT. NORMALLY IT IS ALWAYS IN SERVICE. NORMALLY BOTH ENDS LINE REACTORS ARE PROVIDED. THE ELECTRICAL INTERLOCK IS PROVIDED THAT IF REACTOR ISOLATOR CLOSSED POSITION ONLY WILL GIVE PERMIT TO CLOSE THE LINE ISOLATOR. SIMILARLY FOR OPENING REACTOR ISOLATOR THE LINE ISOLATOR SHOULD BE IN OPEN POSITION. NEUTRAL REACTOR CONNECTED BETWEEN THE STAR POINT OF EHV SHUNT REACTOR AND THE GROUND, LIMITS THE SECONDARY ARC CURRENT TO A LOW VALUE OF AROUND 10 AMPS TYPICALLY FOR 400KV SYSTEM TO ENSURE COMPLETE DE-IONISATION OF ARC PATH WHEN EHV SYSTEM DEVELOPS A SINGLE LINE TO GROUND FAULT. ARC EXTINCTION DURING LINE SINGLEPHASE AUTORECLOSE DEAD TIME IS ASSISTED BY THIS NEUTRAL REACTOR.

3.

4.

B. BUS REACTOR THE REACTOR IS CONNECTED PARALLEL TO THE BUS i.e LIKE A FEEDER/LINE. DURING LIGHTLY LOADED CONDITIONS THERE MAY BE POSSIBULITY OF RAISING BUS VOLTAGES. FOR SAFEGUARD THE OPERATING EQUIPMENT BUS REACTORS ARE UTILISING. NORMALLY IT IS NOT IN SERVICE. WHENEVER THE VOLTAGE RAISES TO 4%TO 5% MORE THAN THE RATED VOLTAGE THIS MAY BE KEPT IN SERVICE AND 2% TO 3% LESS THAN THE RATED VOLTAGE THIS MAY BE KEPT OUT OF SERVICE. SELECTION OF REACTOR A. LINE REACTOR NORMALLY LINE REACTORS ARE PROVIDED IF THE LINE IS MORE OR EQUAL TO 250KM. IN APTRANSCO NETWORK MAXIMUM LENTH OF LINE IS 350KM. AS PER SYSTEM STUDIES RECOMANDATIONS IF LINE LENGTH IS 250KM TO 300KM 50MVAR REACTOR IS TO BE USED. IF MORE THAN 300KM 63MVAR REACTOR IS TO BE USED. B. BUS REACTOR NORMALLY BUS REACTORS ARE PROVIDED IF THE SUBSTATION BUS VOLTAGE IS RAISING 5% MORE THAN THE RATED VOLTAGE DURING LIGHTLY LOADED CONDITION. BASED ON THE SYSTEM STUDIES RECOMANDATIONS BUS REACTORS ARE TO BE PROVIDED. CALCULATIONS ARE REQUIRED FOR PROVIDING BUS REACTOR. IN THIS THERE IS NO STANDARDISATION. LOCATION OF REACTORS WITH CAPACITY IN APTRANSCO A. LINE REACTOR 1. 400KV KALAPAKA-KHAMMAM 1 AT BOTH ENDS – 63MVAR 2. 400KV KALAPAKA-KHAMMAM 2 AT BOTH ENDS – 63MVAR B. BUS REACTOR 1. 400KV KALAPAKA SS – 2 X 50 MVAR 2. 400KV NUNNA SS(PGCIL BAYS) – 1 x 63 MVAR

5.

6.

7.

8.

9.

PURPOSE OF SHUNT REACTOR PROTECTION THE PURPOSE OF THE PROTECTION RELAYING IS TO DISCONNECT THE REACTOR AND LIMIT DAMAGE IN CASE OF INTERNAL SHORT CIRCUITS, EARTH FAULTS, INTERTURN FAULTS AND OVER VOLTAGE OR OVER LOAD.THE REACTOR FORMS CERTAIN IMPEDENCE FOR RATED FREQUENCY, AND AS IT IS SHUNT CONNECTED, AS OVER LOAD MAY BE CAUSED BY OVER VOLTAGE OR HARMONICS IN VOLTAGE AND CURRENT. PROTECTION DEVICES INBUILT OR MOUNTED ON REACTOR A. OIL IMMERSED REACTOR USUALLY HAVE A GAS DETECTOR AND OIL SURGE. DETECTOR (BUCHHOLZ ALARAM & TRIP DEVICES), WHICH ARE EXCELLENT FOR DETECTING INTERNAL FAULTS. B. TEMPARATURE MONITORS FOR OIL & WINDING PROVIDE GOOD OVER LOAD PROTECTION. C. PRESSURE RELIEF DEVICE IS PROVIDED TO SAFE GUARD THE REACTOR FROM HIGH PRESURES. REACTOR DIFFERENTIAL PROTECTION IT IS WIDELY USED AS INSTANTANEOUS PROTECTION FOR SHORT CIRCUIT FAULTS WITH IN THE DIFFERENTIAL ZONE. THIS IS TREATED AS MAIN-1 PROT FOR REACTOR. IT CAN BE OF HIGH IMPEDENCE TYPE OR OF A SENSITIVE CURRENT STABILISED TYPE. HIGH IMPEDENCE DIFFERENTIAL PROTECTION RELAYS REQUIRE AN EQUAL CT TURNS RATIO ON THE PHASE AND NEUTRAL SIDE. SENSITIVITY IS 5% OF NOMINAL REACTOR CT CURRENT. BACK-UP PROTECTION A VARIETY OF RELAYS ARE AVAILABLE. A. OVER CURRENT & EARTH FAULT PROTECTION. ( 50, 50N, 51, 51N, 67, 67N - ANY COMBINATION OF THESE) B. UNDER IMPEDENCE / DISTANCE ( Z<)(21R). C. NEUTRAL DISPLACEMENT PROTECTION (Un>). RESTRICTED EARTH FAULT PROTECTION IF, FOR SOME REASON, A SENSITIVE DIFFERENTIAL PROTECTION NOT CHOOSEN A RESTRICTED EARTH FAULT PROTECTION CAN BE UTILISED.

SHUNT REACTOR (BUS & LINE) (ONE AND HALF CIRCUIT BREAKER SYSTEM ) BUS-1

BUS-2

1-89

IL INTER LOCK FACILITY: WHEN 1-89R CLOSES ONLY PERMIT TO CLOSE 1-89L AND 1-89L OPENS ONLY PERMIT TO OPEN 1-89R.

3-89

1-52CB 1-CT

3-52CB P2

P2

3 3-CT

3

P1

P1

1-89A

.

UUU

1-PH NEUTRAL GROUNDING REACTOR

UUU

IL

LINE SHUNT REACTOR

2-CT

1-89L

2-89A

2-52CB

P2

2-89B 3-89R

UUUU

.

P1

3

1-89R

3-89A

LINE 1

BUS SHUNT REACTOR

REACTOR BUSHING CT INFORMATION CAPACITY OF 400KV REACTORS : 50, 63, 80, 125 MVAR Sr NO 1

SHUNT REACTOR ITEM

400KV / LINE SIDE

CORE-2 CORE -3 CORE-4

3 RCT IN OHMS 1 OHM

1 OHM

CLASS OF ACURACY

PS

PS

PURPOSE

87 R DIFF

64 R REF1

200V

1000500250V

1000500250V

1.0 CL AND 10 – 5 – 10 – 5 BURDEN – 2.5 10 VA 1 OHM 2.5

PS

OHM

OHM

PS

PS

FOR 21L2 FOR 21L1 21 R /TEED-1 / /TEED-2 / MET IMP BBM BBC

Parameters of WTI CT for each winding shall be provided by the contractor

200V

5

CORE-1

2000- 2000200/1 200/1 200/1 1000- 1000- 200/1 WTI 200/1 200/1 500/1 500/1 NEUTRAN BUSHING CT : CORE-1 : BEFORE STAR FORMATION IN RYB PHASES

VKNEE FOR PS 2 & VA FOR 200V MET

4

LINE SIDE EARTH SIDE

STAR / NEUTRAL SIDE

CORE-1 CORE -2 CORE-3 CORE-4 CORE-5

RATIO

NGR

CORE-1

CORE-2

200/1

200/1

200V

200V

200V

200V

1 OHM

1 OHM

1 OHM

1 OHM

PS

PS

PS

PS

87 R DIFF

64 R REF1

64 R REF2

64 R REF1/2

SHUNT REACTOR PROTECTION ONE & HALF BREAKER SYSTEM

CORES

LINE

BUS

DOUBLE BUS & TRANSFER BUS SYSTEM LINE

BUS

400KV SIDE CORE-1

87R – 3Ph, 2Wdg REACTOR DIFFERENTIAL RELAY EITHER LOW or HIGH IMPEDANCE TYPE.

CORE-2

64R - REACTOR RESTRICTED EARTH FAULT PROTECTION OF1-POLE HIGH IMPEDANCE TYPE.(REF1)

CORE-3

21R – 3Ph, REACTOR BACKUP IMPEDANCE RELAY OF SUITABLY SHAPED CHARECRESTICS EITHER SINGLE / DOUBLE ZONE TYPE.

CORE-4

21L2

87 TEED-2

21L2

(M_CT+T_CT–R_CT)

(M_CT, T_CT, R_CT)

(M_CT+T_CT – R_CT)

21L1

87 TEED-1

21L1

(M_CT+T_CT–R_CT)

(M_CT, T_CT, R_CT)

(M_CT+T_CT – R_CT)

CORE-5

M_CT: Main CT, T_CT: Tie CT, R_CT: Reactor CT

87 BBC/BB-2 87 BBM/BB-1

SHUNT REACTOR PROTECTION CORES

ONE & HALF BREAKER SYSTEM LINE

BUS

DOUBLE BUS & TRANSFER BUS SYSTEM LINE

BUS

STAR / NEUTRAL SIDE CORE-1

METERING OF REACTOR

CORE-2

WINDING TEMPARETURE OF REACTOR

CORE-3

87R – 3Ph, 2Wdg REACTOR DIFFERENTIAL RELAY EITHER LOW / HIGH IMPEDANCE TYPE.

CORE-4

64R - REACTOR RESTRICTED EARTH FAULT PROTECTION OF1-POLE HIGH IMPEDANCE TYPE .(REF1)

NEUTRAL GROUNDING REACTOR SIDE CORE-1

64 REF1

--

64 REF2

--

CORE-2

64 REF1

--

64 REF 1 / 2

--

3

3

CORE -2

3 3

3 3

CORE -4

3

3

3

CORE -5

UUU

UUU

UUU

3 3 3

3

CORE -3

3

3

3 3 3

LINE SHUNT REACTOR

3 3

CORE -4

.

CORE -1 CORE -2

CORE -1

UUU

3 3

1-PH NEUTRAL GROUNDING REACTOR

CORE -3

3

3 3

REACTOR BUSHING CT INFORMATION

3

3

CORE -1

CORE -2

3 3 3

3 3 3

3

3

3

CORE -5

UUU

UUU

UUU

CORE -3

3 3 3

3

CORE -3

3

3

3 3 3

BUS SHUNT REACTOR

CORE -2

3

3 3

REACTOR BUSHING CT INFORMATION

3 3

3

3

CORE -4

CORE -1

CORE -4

.

CORE -1 CORE -2

ONE & HALF BREAKER LINE & BUS SHUNT REACTOR PROTECTION SCHEME 87BB1 BUSBAR-1 79 CVT VBB1

VL1

21M1 VBB1

25

VL1 / VL2 OR VBB2

BF 87L

21M2

VL1

CVT

VL1 FEEDER1 / LINE1

79

UUU 64R 21R

79 25

PROTECTION OF BUS REACTOR 21R BUSBAR-2

87BB2

64R

TEED-2 VBB1/VBB2

VL2 / VL1 OR VBB1 CVT VBB2

87R

UUU TEED-1

BF

OR

VL1/VBB1/VBB2

25

BF

VBB2

UUU

VL1 / VBB1 VL2 / VBB2

87R

FOR REACTOR PROTECTION & METERING VOLTAGE SELECTION RELAYS FOR BUS-1, BUS-2& LINE ARE PROVIDED .

LINE/BUS REACTOR DIFFERENTIAL PROTECTION (LOW IMPEDANCE DIFFERENTIAL PROTECTION) CT MB

P2 P2 P2

RET 670

CT MB

CTR: 200/1A

3 3 3

CORE-1

1S2

1S2

1S2

1S1

1S1

1S1

ACTIVE

START

3S1

3S1

3S2

3S2

3S2

3 3 3

R-CT HV BUSHING

3S1

TRIP

P2 P2 P2 R-CT

CLASS: PS

STAR BUSHING

DISPLAY

CORE-3 CTR: 200/1A

CLASS: PS

C

E

NORMALLY LOW / HIGH IMPEDENCE DIFFERENTIAL RELAY IS USED FOR BUS / LINE REACTOR DIFFERENTIAL PROTECTION

IN CASE OF REACTOR BUSHING CT P2 IS AWAY FROM REACTOR & P1 IS TOWARDS REACTOR

LINE/BUS REACTOR DIFFERENTIAL PROTECTION (HIGH IMPEDANCE DIFFERENTIAL PROTECTION) P2 P2 P2 R-CT HV CORE-1

3 3 3

BUSHING CT

RET 670 1S2 1S2 1S2 ACTIVE START

TRIP

1S1 1S1 1S1

CTR: 200/1A

CLASS: PS P1 P1 P1

DISPLAY C E

P1 P1 P1 R-CT STAR CORE-3 CTR: 200/1A

3S1 3S1 3S1

3 3 3

BUSHING CT

3S2 3S2 3S2

CLASS: PS

P2 P2 P2

NORMALLY LOW / HIGH IMPEDENCE DIFFERENTIAL RELAY IS USED FOR BUS / LINE REACTOR DIFFERENTIAL PROTECTION IN CASE OF REACTOR BUSHING CT P2 IS AWAY FROM REACTOR & P1 IS TOWARDS REACTOR

LINE/BUS REACTOR REF PROTECTION (NGR IS NOT AVAIALBLE) P2 P2 P2 R-CT HV CORE-2

3 3 3

BUSHING CT

RET 670 2S2 2S2 2S2 ACTIVE START

TRIP

2S1 2S1 2S1

CTR: 200/1A

CLASS: PS P1 P1 P1

DISPLAY C E

P1 P1 P1 R-CT STAR CORE-4 CTR: 200/1A

4S1 4S1 4S1

3 3 3

BUSHING CT

NORMALLY HIGH IMPEDENCE VOLTAGE/CURRENT OPERATED SINGLE POLE RELAY IS USED FOR BUS / LINE REACTOR RESTRICTED EARTH FAULT PROTECTION. PRESENTLY NUMERICAL DIFFERENTIAL RELAYS HAVING IN BUILT FUNCTION OF 2 REF OR 2 SEF PROTECTIONS.

4S2 4S2 4S2

CLASS: PS

P2 P2 P2

IN CASE OF REACTOR BUSHING CT P2 IS AWAY FROM REACTOR & P1 IS TOWARDS REACTOR

LINE REACTOR REF PROTECTION (NGR IS AVAIALBLE) P2 P2 P2 R-CT HV CORE-2

3 3 3

BUSHING CT

RET 670 2S2 2S2 2S2 ACTIVE START

TRIP

2S1 2S1 2S1

CTR: 200/1A

CLASS: PS P1 P1 P1

DISPLAY C E

P1 P1 P1 NGR-CT EARTH CORE-2 CTR: 200/1A

2S1 2S1 2S1

3 3 3

BUSHING CT

NORMALLY HIGH IMPEDENCE VOLTAGE/CURRENT OPERATED SINGLE POLE RELAY IS USED FOR BUS / LINE REACTOR RESTRICTED EARTH FAULT PROTECTION. PRESENTLY NUMERICAL DIFFERENTIAL RELAYS HAVING IN BUILT FUNCTION OF 2 REF OR 2 SEF PROTECTIONS.

2S2 2S2 2S2

CLASS: PS

P2 P2 P2

IN CASE OF REACTOR BUSHING CT P2 IS AWAY FROM REACTOR & P1 IS TOWARDS REACTOR

LINE REACTOR 2 NOs REF PROTECTIONS (NGR IS AVAIALBLE) P2 P2 P2

P2 P2 P2

CT MB R-CT HV CORE-2

3 3 3

BUSHING CT

RET 670 2S2 2S2 2S2 ACTIVE START

TRIP

CTR: 200/1A

CLASS: PS P1 P1 P1

E

R-CT STAR CORE-4 CTR: 200/1A

4S1 4S1 4S1

3 3 3

BUSHING CT

4S2 4S2 4S2

CLASS: PS

P2 P2 P2

1S2

1S2

1S1

1S1

1S1

DISPLAY C

P1 P1 P1

1S2

3 3 3

2S1 2S1 2S1

NORMALLY HIGH IMPEDENCE VOLTAGE/CURRENT OPERATED SINGLE POLE RELAY IS USED FOR BUS / LINE REACTOR RESTRICTED EARTH FAULT PROTECTION. PRESENTLY NUMERICAL DIFFERENTIAL RELAYS HAVING IN BUILT FUNCTION OF 2 REF OR 2 SEF PROTECTIONS.

P1 P1 P1 NGR-CT BUSHING CT CORE - 1 & 2 CTR: 200/1A

CLASS: PS

P1 P1 P1

CT MB

2S1

2S1

2S1

2S2

2S2

2S2

3 3 3

P2 P2 P2

LINE/BUS REACTOR B/U IMPEDANCE PROTECTION

P2 P2 P2

IR3 / A311 IY3 / A331 IB3 / A351

R-CT HV CORE-3 CTR: 200/1A

3 3 3

BUSHING CT

CT MB

3S2

3S2

3S2

3S1

3S1

3S1

IN3 / A371

REL 670 ACTIVE START

TRIP

CLASS: PS

DISPLAY C

VR11 / E111 VY11 / E131 VB11 / E151 VN11 / E171 CVT SELECTION BUS-1 CVT / BUS-2 CVT / LINE CVT CORE-1 VA : 200

E

CLASS: 3P

LINE REACTOR PROTECTION FOR LINE (MAIN-1 PROTECTION) P2 P2 P2

IR5 / A511 IY5 / A531 IB5 / A551

1-CT CTR: 2000-1000-500/1A

3 3 3

CORE-5

CT MB

5S4

5S4

5S4

5S2

5S2

5S2

IN5 / A571

REL 521 ACTIVE START

TRIP

VR11 / E111 VY11 / E131 VB11 / E151 VN11 / E171 1-CVT

CLASS: PS

DISPLAY

CORE – 1 200VA CLASS: 3P

C

2-BCT CTR: 2000-1000-500/1A

3 3 3

CORE-5

5S2

5S2

5S2

5S4

5S4

5S4

CLASS: PS

P2 P2 P2 LR-CT 400KV CTR: 2000-1000-500/1A

3 3 3

CORE-5

5S4

5S4

5S4

5S2

5S2

5S2

CLASS: PS P1 P1 P1

E

LINE REACTOR PROTECTION FOR LINE (MAIN-2 PROTECTION) P2 P2 P2

IR4 / A411 IY4 / A431 IB4 / A451

1-CT CTR: 2000-1000-500/1A

3 3 3

CORE-4

CT MB

4S4

4S4

4S4

4S2

4S2

4S2

IN4 / A471

REL 316 ACTIVE START

TRIP

VR21 / E211 VY21 / E231 VB21 / E251 VN21 / E271 1-CVT

CLASS: PS

DISPLAY

CORE – 2 200VA CLASS: 3P

C

2-BCT CTR: 2000-1000-500/1A

3 3 3

CORE-4

4S2

4S2

4S2

4S4

4S4

4S4

CLASS: PS

P2 P2 P2 LR-CT 400KV CTR: 2000-1000-500/1A

3 3 3

CORE-4

4S4

4S4

4S4

4S2

4S2

4S2

CLASS: PS P1 P1 P1

E

BUS REACTOR TEED-1 PROTECTION {BAY3&2}

P2 P2 P2

IR5 IY5 IB5

3-CT CTR: 2000-1000-500/1A

3 3 3

CORE-5

5S4

5S4

5S4

5S2

5S2

5S2

CLASS: PS

IN5

RET 670 P1 P1 P1 P2 P2 P2

IR5 IY5 IB5

2-CT CTR: 2000-1000-500/1A

3 3 3

CORE-1

1S4

1S4

1S4

1S2

1S2

1S2

CLASS: PS

IN5

ACTIVE START

TRIP

DISPLAY C

P1 P1 P1

E

P2 P2 P2 BR-LCT CTR: 2000-1000-500/1A

CLASS: PS

IN1 4S4

4S4

4S4

4S2

4S2

4S2

3 3 3

CORE-5

IB1 IY1 IR1 P1 P1 P1

IT WORKS ON CIRCULATING CURRENT PRINCIPLE AND IT IS HIGH IMPEDENCE DIFFERENTIAL RELAY. TEED-1 PROTECTION FOR BAY 2&3 AND THE FOLLOWING CTs & CORES ARE USED 3-CT(CORE-5), 2-CT(CORE-1) & BR-CT (CORE-5) ARE STARRED AND CONNECTED TO TEED-1 PROTECTION

BUS REACTOR TEED-2 PROTECTION CT MB

3-CT CTR: 2000-1000-500/1A

3 3 3

CORE-4

4S4

4S4

4S4

4S2

4S2

4S2

CLASS: PS

CT MB

RET 670 ACTIVE

START

RAICA LBB/BFR

P2 P2 P2

RAICA LBB/BFR

{BAY3&2} P2 P2 P2

2S4

2S4

2S4

2S2

2S2

2S2

3 3 3

TRIP

2-CT CORE-2

DISPLAY

CTR: 2000-1000-500/1A

CLASS: PS

P2 P2 P2 CT MB BR-CT CTR: 2000-1000-500/1A

CLASS: PS

3 3 3

CORE-4

C 4S4

4S4

4S4

4S2

4S2

4S2

E

IT WORKS ON KIRCHOFF’S CURRENT PRINCIPLE & IT IS PERCENTAGE BIASED LOW IMPEDENCE DIFFERENTIAL RELAY. TEED-2 PROTECTION FOR BAY 2&3 IS THE FOLLOWING CTs & CORES ARE USED. 3-CT(CORE-4), 2-CT(CORE-2) & BR-CT (CORE-4) ARE CONNECTED TO TEED-2 PROTECTION.

OVER EXCITATION/FLUX RELAY {FOR LINE & BUS REACTORS} VOLTAGE SELECTION

CVT SELECTION BUS-1 CVT / BUS-2 CVT / LINE CVT CORE-1 VA : 200

CLASS: 3P

RATUB

BUS-1 PT /

V/F RELAY LINE

CORE-1

RATUB V/F RELAY BUS

BUS-2 PT VA : 200

CLASS: 3P

REACTOR MULTI FUNCTION PANEL METERING P2 P2 P2

IR2 / D211 IY2 / D231 IB2 / D251

R-CT STAR CORE-2

3 3 3

BUSHING CT

CT MB

2S2

2S2

2S2

2S1

2S1

2S1

CTR: 200/1A

CLASS: 0.2

IN2 / D271

VR31 / E311 VY31 / E331 VB31 / E351 VN31 / E371 BASED ON SELECTION LINE CVT / BUS-1 CVT / BUS-2 CVT CORE – 3 100VA CLASS: 0.2

CARRIER INTERTRIPPING OF LINE SHUNT REACTOR LINE SHUNT REACTOR PROTECTION TRIPPINGS WILL BE USED AS DIRECT TRIPPINGS OF LINE IN ADDITION TO OTHER TRIPPINGS. BUS SHUNT REACTOR NEED NOT REQUIRE CARRIER INTER TRIPPING FACILITY. 87R REACTOR DIFFERENTIAL RELAY RET 670 21R REACTOR IMPEDENCE RELAY REL 670

ABB NSD 50

LINE PROTECTION COUPLER PANEL-1

DC +VE FROM PANEL

64R RESTRICTED EARTH FAULT RELAY

RET 670 REACTORS INTERNAL FAULTS

G4AD V9LC 2

GROUP-1/A TRIPPINGS

G4AD V9LC 1 87R REACTOR DIFFERENTIAL RELAY RET 670 21R REACTOR IMPEDENCE RELAY REL 670

ABB NSD 50

DC –VE FROM PANEL

LINE PROTECTION COUPLER PANEL-2

DC +VE FROM PANEL

64R RESTRICTED EARTH FAULT RELAY

RET 670 REACTORS INTERNAL FAULTS

G4AD V9LC 2

GROUP-2/B TRIPPINGS

G4AD V9LC 1

DC –VE FROM PANEL