A Study on Operation Zone of Adaptive Distance Relay on Transmission Line Connected UPFC Between Kangjin and Jangheung

UPFC가 연계 된 강진-장흥 송전선로 보호용 거리계전기의 동작특성에 관한 연구

This paper presents an apparent impedance calculation procedure for distance relaying of transmission line involving FACTS (Flexible AC Transmission System) devices, particularly the UPFC (Unified Power Flow Controller), between Kangjin and Jangheung in Korea. With the changes of UPFC's parameters, the measurement and protective range (trip boundaries) of the adaptive distance relay can also be changed. So, it is the most important part in the field of system protection to analyze the operating characteristic of relaying system. The presence of UPFC significantly affects the trip boundaries which are also adversely affected by fault resistance combined with remote end infeed. This paper presents the apparent impedance calculations and the distance relay setting characteristics for faults involving the UPFC in the KEPCO system.