A Method of Preventing Blackout Caused by Relay

계전기 동작에 의한 광역정전 방지방안

This paper presents an vulnerability index for hidden failure of protective relays in transmission system. The bad influence can be quantized by an vulnerability index. When there is mis-operation, no-operation or mis-setting, power flow can be quantized by an index. According to the index, relays can be resetting. So the wide area blackout can be prevented.