An accurate technique for supervising distance relays during power swing

Power swing is a power system transient phenomenon that arises due to several reasons including line switching, outage, sudden increment or decrement in load, faults, etc. Unnecessary tripping during and unnecessary blocking for faults occur result distance relay maloperation. Several cascaded outages major worldwide blackouts have occurred maloperation of relays. This paper proposes technique supervising relays swing. The proposed online discriminates real accurately. It relies on constructing locus diagram the current voltage differences (∆I-∆V) between two ends protected line. estimated at every frequency cycle continuously monitor state by utilizing synchrophasor measurements sending receiving tested two-area, four-machine under different locations zone-1 zone-2 regions relays, fault resistances, inception angles slip frequencies using MATLAB software. simulation results proved superior improvement performance handling unblocking actions.