HI JBARTOS,THE POWER SWING RELAY IS

[ckavamba]

HI JBARTOS,THE POWER SWING RELAY IS INCORPORATED IN THE DISTANCE RELAY.IN THE DISTANCE RELAY ONE CAN EITHER SET THE POWER SWING RELAY TO "TRIP" OR "BLOCK" DEPENDING ON THE DIRECTION OF THE SWING IN THE SYSTEM.NOW MY QUESTION WAS TO FIND OUT THE CRETERIA USED IN SELECTING THE POWER SWING SETTINGS.SORRY MAYBE MY QUESTION WAS NOT CLEAR.PLEASE HELP.

 

[jbartos]

Typically, distance relays protect transmission lines against transmission line faults. They may have some blind sectors to block the trips. The swing bus, accepting power swings from the system, is not supposed to be tripped or isolated else it would not be needed. Then, the only option left is to block swings to the swing bus, rather than to trip the swing bus, and let other bus or buses to be tripped.