Digital Distance Relay with Adaptive Protection Zone

Adaptive보호범위를 가진 송전선로 보호용 디지털 거리계전기

This paper presents the adaptive setting method of distance relay under the single line ground fault. The apparent impedance measured at the relaying point and actual impedance is different because of fault resistance and various prefault loading condition. For a resistance earth fault detection, relay setting zone is adaptively changed with measured load current and bus voltage at the relaying point to avoid maloperation.