Today is...
Tuesday, July 16, 2019
Welcome to Control.com, the global online
community of automation professionals.
Featured Video...
Featured Video
A tutorial introduction to programming using the QuickBuilder Programming Environment.
Our Advertisers
Help keep our servers running...
Patronize our advertisers!
Visit our Post Archive
Generator Differential Protection Operation During Connecting Generator to the Network
Differential relays operation during failed attempt to close the generator circuit breaker

A 64 MW, 13.8 KV generator is connected to a 13.8 to 115 KV step up transformer. It has two differential protection relays. One of them on the load side is connected to the generator bushing CTs, and the other to the breaker bushings at the load side. During attempt to close the Gen breaker, both of the differential relays operated. There is an ambiguity about the proper synchronization between gen and network voltages. Does anybody have any idea why the differential relays are operated?

Any comment is appreciated.