TANDA THERMAL POWER PROJECT-STAGE II, (2X660 MW)

Switchyard Package (CS-9562-563-2)

SALIENT TECHNICAL FEATURES

1. 400 kV GIS consisting of “One and Half Breaker Scheme” system with the following parameters:

a) Highest system voltage	420 KV rms
b) System Frequency	50Hz
c) Lightning Impulse Voltage
-Phase to earth & between phases	1425 KVp
-Across isolating distance	1425(+240) KV
d) Switching Impulse Voltage
-Phase to earth	1050KVp
-Across isolating distance	900(+345) KV
-Between phases	1575KVp
e) Power frequency withstand for 1(one) min (rms)
-Phase to earth & between phases	650KVrms
-Across isolating distances	815KVrms
f) Max fault level (1 Sec.)	50 kA
g) PD level of GIS	Less than 5 Pico Coulomb

2. 400 kV AIS (Air insulated switchyard) parameters:

The system parameters shall be as under:

Highest system voltage : 420 kV rms

Lightning Impulse voltage : ±1425kVp

Switching impulse voltage : ±1050kVp

Power frequency withstand : 630kV (rms)

for 1 min. (rms) :

Max. fault level (1 sec.) : 50 kA

Minimum creepage distance : 10500 mm

3. 220 kV AIS (Air insulated switchyard) parameters:

The system parameters shall be as under:

Highest system voltage : 245 kV rms

Lightning Impulse voltage : ±1050kVp

Power frequency withstand : 460kV(rms)

for 1 min. (rms) :

Max. fault level (1 sec.) : 40 kA

Minimum creepage distance : 6125 mm