High Impedance Fault Classification in UPFC Compensated Double Circuit Transmission Lines using Differential Power Protection Scheme

Abstract

Detection of high impedance faults is a unique challenge to power system engineers as they are a constant threat to public safety and are not sensed by conventional relays due to the low magnitudes of fault currents. In this paper a novel scheme is presented for high impedance fault detection in UPFC compensated transmission lines using synchronized power measurement from both ends of the line. The proposed scheme uses the magnitude of the difference of apparent power at the sending and receiving end bus to detect and classify faults. The scheme is immune to fault resistance, fault inception angle and location of fault in the line. Simulated results of high impedance faults in a 400kV double circuit transmission line have been presented which demonstrate that this scheme can effectively distinguish between internal and external fault and accurately classify high impedance faults.