Fault Location During Power Swing Using Local Measurements

Power swings can occur due to disturbances in power system, including faults on transmission lines, loss of generation, and switching of transmission lines which are heavily loaded. The phenomenon is characterized by generators accelerating relative to one another. Maloperation of distance relay during power swing is prevented using Power Swing Blocking function in modern relays. Further, accurate operation of distance protection for faults during power swing is ensured by Power Swing Unblock function. Clearance of faults during power swing, to ensure continuous supply of power requires accurate fault location identification. Existing phasor-based fault location methods fail in this scenario, due to the unstable nature of the phasors estimated using traditional phasor estimation algorithms. The paper presents the shortcomings of existing fault location solutions for faults during power swing and presents a new time-domain based single-ended fault location solution for the same. The performance of the algorithm is verified using IEEE 39-bus system modelled in PSCAD.