SCC DATE:

GENERATOR
GENERATOR EXCITER FIELD FIELD CURRENT(A)
STATOR AVR CONTROL EXCITER FIELD CURRENT(mv) Q Axis coil volt
CURRENT(A) VOLTAGE(Uc) VOLTAGE(V) [60mv=200A) (0-40V=0-8000A)
1000
2000
4000
6000
8000
10000
12000
14000
16000
19407

OCC DATE:

GENERATOR GENERATOR
STATOR EXCITER FIELD FIELD CURRENT(A)
VOLTAGE AVR CONTROL EXCITER FIELD CURRENT(mv) Q Axis coil volt
(KV) VOLTAGE(Uc) VOLTAGE(V) [60mv=200A) (0-40V=0-8000A)
0
1
2
4
6
8
10
12
14
16
18
20
21
Remarks

Remarks
 500 MW GENERATOR TESTING PROCEDURE FOR FIRST SYNCHRONIZATION

OBJECTIVE:
TO CARRY OUT GENERATOR SHORT CIRCUIT TEST,CURRENT OPERATED RELAYS DYANAMIC
TESTING,OPEN CIRCUIT TEST,VOLTAGE OPERATED RELAYS DYNAMIC TESTING,SYNCHRONIZATION
CIRCUIT CHECK,PROTECTION TRIP OF GENRATOR CIRCUIT BREAKER AND SYNCHRONIZATION

PREPARATIONS:
1 The following measurement circuits are to made through for monitoring and taking readings
A) Generator voltage- RY,YB,BR
B) Generator current- R,Y,B
C) Excitation Voltage
D) Excitation Current
E) Generator field current(Q-AXIS coil voltage)
F) Active power
G) Reactive Power
H) Power factor
I) Energy meter

2 Synchronising cirucits and protection circuits are also to be kept ready alongwith recommended
settings set in the protection relays

3 Testing/measuring equipments to measure PMG voltage(3 Ph AC),Main Exciter(DC) and PMG's Phase
sequence and frequency in AVR are to be kept ready

4 Winding resistance for PMG&ME are to be measured to check the healthiness of PMG&ME

PREPARED BY:RMS SHEET 3 OF 12

 500 MW GENERATOR TESTING PROCEDURE FOR FIRST SYNCHRONIZATION

5 No trip should persist from GRP&turbine panel and in DAVR

6 Gen PTs are to be ensured racked in and bust duct is pressurised with air

7 21 KV R,Y,B terminals of Generator at 8.5 mtrs must be shorted with the shorting bar provided.

8 Mechanical system readiness

a) Stator water cooling system is to be kept on line.Online conductivity monitoring made ready
b) Rotor cooling is to be confirmed by parameters of H2 temp
c) Generator slot,stator core,tooth temps are to be monitored in control room
d) Rotor earthfault circuit to be tested and kept online
e) Fire protection system of GT must be kept online

9 Following modifications are to be carried out for testing and to be normalized before synchronization
a) Excitaion system on manual internal mode
b) Auto channels to be kept in blocked condition
c) Field breaker closing from ATRS to be inhibited
d) Auto sync circuit output to be isolated from GCB closing circuit
CJJ10 X09 -18
X09 -19
e) Generator Trip to turbine trip to be isolated
GRP3 TB1-63,64
TB1-65,66
TB1-67,68
f) LBB links are to be kept out to avoid 400 kV HVCB TRIP
GRP-3 TB2-9,10(MAIN CB)
TB2-11,12(TIE CB)
g) 186A1/286A1,186C/286C trip from GR1,2 to be kept out to avoid 400 kV HVCB TRIP
GR1 L1,L2,L5,L6,K1,K2,K5,K6
GR2 L1,L2,L5,L6,K1,K2,K5,K6

g) Interlock between switchyard and Field circuit breaker are to be isolated if required
h) GT Trf,Overall differential&Gen diff protection to be kept in service AFTER ENSURING THE STABILITY AT AROUND 10 KA.

10 AT standstill condition,test rotor earthfault and 100% stator earthfault circuit with 20 Hz Gen
a) earth the main exciter star point slip ring terminal at main exciter ROTOR EARTH FAULT SIMULATION
b) earth the NGT 1.1 terminal at NGT 100% STATOR EARTH FAULT SIMULATION

11 a) AT 3000 RPM,measure PMG VOLTAGE,Frequency and Phase sequence.

Terminals Voltage Frequency Phase Sequence
RY
YB
BR
b) Measure the spill currents in relay panel,AVR,load Transducer and T&AVT panel

SHORT CIRCUIT TEST

a) AT 3000 RPM,If spill currents are successfully measured in all terminals as per spill current
measurement sheet,Close FB and raise Excitation for SCC test
b) Raise gen current up to 1000 amps and check the Gen differentail protection
protection by shorting CT secondary.
e) Raise current for Check the field fialure,Dead machine relays and impedance relays.
f) Bypass/block the Dead machine protection,field failure and impedance protection.
Relays
Sl No Protection Methodology operated I Value Remarks
operation

SHORT ANY PHASE TO NEUTRAL

Iset= 0.1 In
Gen diffl(87G-GR1) GRP-1 : N.SIDE - TB1-1,2,3,4 186A2/286A2
(In=5 A)
PH.SIDE - TB1 - 6,7,8,9

1
SHORT ANY PHASE TO NEUTRAL
Gen diffl(87G-GR2) GRP-3 : N.SIDE - TB1-1,2,3,4 186A2/286A2
Iset= 0.1 In
PH.SIDE - TB1 - 6,7,8,9 (In=5 A)

Iset= 0.09 In
Dead machine protection (GR1) Raise the current to the set value 186A1/286A1 (In=5 A) t=1
sec

Iset= 0.09 In
Dead machine protection (GR2) Raise the current to the set value 186A1/286A1 (In=5 A)
t=1 sec

PREPARED BY:RMS SHEET 4 OF 12

 500 MW GENERATOR TESTING PROCEDURE FOR FIRST SYNCHRONIZATION

I2th.set= 0.07 In
186C/286C (In=5 A)
I2th.k=6.3
Interchange R,Y Currents and raise the
Negative Phase sequence(46G1) current to the set value
GRP-1 : N.SIDE - TB1-1,2,3,4 I2th.set= 0.07 In
(In=5 A)
186A1/286A1
I2th.k=6.3 t=1
sec
3
I2th.set= 0.07 In
186C/286C (In=5 A)
I2th.k=6.3
Interchange R,Y Currents and raise the
Negative Phase sequence(46G2) current to the set value
GRP-3 : N.SIDE - TB1-1,2,3,4 I2th.set= 0.07 In
(In=5 A)
186A1/286A1
I2th.k=6.3 t=1
sec

reduce the set value to ≤ 100% and raise Iset= 1.1 In

Overcurrent (51G1) the current to the set value. ALARM (In=5 A) t=2
sec

Iset= 1.1 In
reduce the set value to ≤ 100% and raise
Overcurrent (51G2) ALARM (In=5 A) t=2
the current to the set value. sec

Remove field CB trip.operate Iset= 0.05 In

50 LBB (GR1) 186A2/186D.Raise the current to the set 186A1/286A1 (In=5 A)
value. t=0.3 sec
5
Remove field CB trip.operate Iset= 0.05 In
50 LBB (GR2) 186A2/186D.Raise the current to the set 186A1/286A1 (In=5 A)
value. t=0.3 sec
g) Raise the current in steps and Take readings as given in SCC table.

h) Note the spill current in all differential protection and shaft voltage and Temperatures of GEN and GT

PREPARED BY:RMS SHEET 5 OF 12

 500 MW GENERATOR TESTING PROCEDURE FOR FIRST SYNCHRONIZATION

OPEN CIRCUIT TEST

a) After SCC& 21 kV shorting normalization

b) Measure the spill voltage in all PT circuits.

c) Create 1 phase earth fult at SPVT cubicle. Check the 95% Stator earth fualt protection and
Interturn fault protection.

d) Remove the the 1 phase earthing at SPVT cubicle

Normalise all the protection and settings. Close feid breaker and slow raise the Gen voltage in step
as per table up to 100 % voltage.
e) Find SCR(Gen field current at Rated voltage/Generator field current at Rated current)

f) Check PT voltages at all circuits and measure Gen Shaft voltage.

Note down the Temperatures of Generator and GT for winding,core and air
g) Protections during OCC
Relays
Sl No Protection Methodology operated V. Value Remarks
operation
Earthing at SPVT cubicle and slowly raise the
Vn set=11 V
95% Stator E/F - GR1 voltage to the set value. GRP- 186A2/286A2
t=0.2 sec
3 : TB1-29,31
1
Earthing at SPVT cubicle and slowly raise the
Vn set=11 V
95% Stator E/F - GR2 voltage to the set value. 186A2/286A2
t=0.2 sec
GRP-3 : TB1-29,31
V>1 = 115.5 V t=
ALARM
Reduce the set value and raise the voltage to 2 sec
Over Voltage - 59G1 the set value
GRP-1 : TB1-24,25,26,27 V>2 =154 V
186A2/286A2
t= 0 sec
2
V>1 = 121 V t=
Reduce the set value and raise the voltage to 186A2/286A2
6 sec
Over Voltage - 59G2 the set value
GRP-1 : TB1-41,42,43,44 V>2 = 154 V t=
186A2/286A2
0 sec
F<1 = 48.5 HZ t=2.5
ALARM
sec
Under frequency - 81G1UF Reduce the turbine speed to the set value
F<2 = 47.5 HZ t=2.0
186C/286C
sec
7
F<1 = 48.5 HZ t=2.5
ALARM
sec
Under frequency - 81G2UF Reduce the turbine speed to the set value
F<2 = 47.5 HZ t=2.0
186C/286C
sec

Reduce the set value and raise the turbine F>1 = 51.5 HZ t=2.0
Over frequency - 81G1OF ALARM
speed to the set value sec
8
Reduce the set value and raise the turbine F>1 = 51.5 HZ t=2.0
Over frequency - 81G2OF ALARM
speed to the set value sec

V/F =1.05 vn/fn

ALARM
t= 20 sec
Reduce the set value and raise the 1)V/F =1.06 vn/fn
Over fluxing - 99G1
voltage/reduce the turbine speed TMS=0.4 sec
186A2/286A2
2)V/F=1.4vn/fn
t=1 sec
7
V/F =1.05 vn/fn
ALARM
t= 20 sec
Reduce the set value and raise the 1)V/F =1.06 vn/fn
Over fluxing - 99G2
voltage/reduce the turbine speed TMS=0.4 sec
186A2/286A2
2)V/F=1.4vn/fn
t=1 sec

P<1=5W T=
low forward power(37G1) build up 21 KV and close GCB 186A2/286A2 10 SEC (WITH
GCB CLOSE)
8
P<1=5W T=
low forward power(37G2) build up 21 KV and close GCB 186A2/286A2 10 SEC (WITH
GCB CLOSE)

AVR CHECKING

PREPARED BY:RMS SHEET 6 OF 12

 500 MW GENERATOR TESTING PROCEDURE FOR FIRST SYNCHRONIZATION

De excite the machine and normalise the Manual chanel internal mode.
Reduce the over voltage protection to 105 % and Excite mahine through manual channel.
Check the change circuit of auto channel after cheking the matching circuit.
Check the Auto channel flashing after PID tuning
check the manual channel and auto chennel from ECP.
Check the V/Hz limiter.
Normalise all protections and the settings.

Synchronization circuit check

Normalise the turbine interlocks.

CFA01
21 KV VT-2 PT SUPPLY: TBK-23,24(R&N)
21 KV VT-4 PT SUPPLY: TBK-27,28(R&N)
SKE 11 CHECK SYNC RELAY SETTINGS
Phase angle difference ±10 °
Percentage Voltage difference 4%
Percentage Slip 0.22

Time Setting 0.5

ECP
CHECK SYNC SWITCH SELECTION FOR GCB MAN SYNC
CFA01 ECP
TBK-5 (INC) 1TBC-40
TBK-6 (RUN) 1TBC-41
TBK-7 (COMM) 1TBC-42
AT 12'0 CLOCK POSITION,
VOLTAGE BETWEEN 1TBC-40&1TBC-41 OF ECP SHALL BE ZERO AND CHECK SYNC PERM AVAILABLE
PHASE SEQUENCE OF GENERATOR PT SIGNALS:FORWARD

SYNCHRONIZATION
1 Excite the machine and develop 21KV voltage at Generator terminals.
2 Adjust the voltage & speed from ECP and get synchronising 12'O clock position using Voltage Raise\Lower PBs & Speed Raise\ Lower PBs.
3 Close GCB at 12'O clock position.

MASTER TRIP RELAY OPERATIONS ( 186 - GROUP 1 AND 286 - GROUP 2)

1 A1 - All trips ( Turbine, 21KV GCB, Field Breaker Trips, Main & Middle Breaker trips)
2 A2 - Only Turbine, 21KV GCB, Field Breaker Trips
3 C - Only Switch Yard Breakers Trips( Main & Middle Breakers)
4 D - Only 21KV GCB & Field Breaker Trips

PREPARED BY:RMS SHEET 7 OF 12

 SPILL CURRENT MEASUREMENT
SL NO CT NO RATIO PANEL TERMINALS READINGS(mA) PURPOSE REMARKS
CJJ10 X05 -1
3 LOAD
CT-2 (0.2S)
1 22000/5 A 5 MEASUREMENT
16

GRP-1 TB1- 1
2 GROUP-1
2 CT-3(PS) 22000/5 A
3 PROTECTION
4

GRP-3 TB1-1
2 GROUP-2
3 CT-4(PS) 22000/5 A
3 PROTECTION
4

GRP-1 TB1-6
7 GROUP-1
4 CT-5(PS) 22000/5 A
8 PROTECTION
9
GRP-3 TB1-6
7
5 CT-6(PS) 22000/5 A
8 GROUP-2 PROTECTION
9

CJJ10 X05-17
19
21 LOAD
MEASUREMENT
26
6 CT-7(0.2S) 22000/5 A
DVR TY-50
54
58 DVR CH-1
60

GRP-2 TB1-40
41
ENERGY METER
42
43

T&AVT TBE-07
10
METERING
13
5
7 CT-8(0.2S) 22000/5 A
CJJ10 X05-27
29 LOAD
31 MEASUREMENT
36

DVR TY-62
66
DVR-CH2
70
72

M/S.APGENCO M/S. BHEL

 CURRENTS @ 1000 A,19407 AMPS
SL NO CT NO RATIO PANEL TERMINALS @ 1000 A @ 5000 A @ 10000 A @15000 A @19407 A
CJJ10 X05 -1
3
1 CT-2 (0.2S) 22000/5 A
5
16

GRP-1 TB1- 1
2
2 CT-3(PS) 22000/5 A
3
4

GRP-3 TB1-1
2
3 CT-4(PS) 22000/5 A
3
4

GRP-1 TB1-6
7
4 CT-5(PS) 22000/5 A
8
9
GRP-3 TB1-6
7
5 CT-6(PS) 22000/5 A
8
9

CJJ10 X05-17
19
21
26
6 CT-7(0.2S) 22000/5 A
DVR TY-50
54
58
60

GRP-2 TB1-40
41
42
43

T&AVT TBE-07
10
13
5
7 CT-8(0.2S) 22000/5 A
CJJ10 X05-27
29
31
36

DVR TY-62
66
70
72

M/S.APGENCO M/S. BHEL

PURPOSE REMARKS

LOAD
MEASUREMENT

GROUP-1
PROTECTION

GROUP-2
PROTECTION

GROUP-1
PROTECTION

GROUP-2 PROTECTION

LOAD
MEASUREMENT

DVR CH-1

ENERGY METER

METERING

LOAD
MEASUREMENT

DVR-CH2

M/S.APGENCO M/S. BHEL

SL NO VT NO RATIO PANEL TERMINALS SPILL @ 2KV @ 5KV
TB1-24
25
1 GRP -1
26
27
X03 - 1
VT-1(0.2/3P) 21000/110V 4
2 CJJ - 10
7
10
TY - 46
3 AVR 47
48
TB1 - 41
42
4 GRP -1
43
44
TY - 41
5 AVR 42
VT-2(0.2/3P) 21000/110V
43
TBK - 23
6 T & AVT
24
X03 - 11
7 CJJ - 10 13
15
TB2 - 1
2
8 GRP - 1
3
4
X03 - 18
9 VT-3(0.2) 21000/110V CJJ - 10 20
22
TBE - 1
2
10 T & AVT
3
4
TB2 - 22
23
11 GRP - 1
24
VT-4(0.2/3P) 21000/110V
25
TBK - 27
T & AVT
12 28
@ 10KV @ 12KV @ 15KV @ 21KV PURPOSE REMARKS

GR-1 RELAY

FREQUENCY & LOAD

TRANSDUCER,LOAD
SHEDDING

AUTO CH - 1

GR - 2 RELAY

AUTO CH - 2

SYNCHRONISING

LOAD
TRANSDUCER

METERING

LOAD
TRANSDUCER

METERING

SYNCHRONISING,
59 NGT

SYNCHRONISING