MTR 중성점 접지에 초전도 전류제한기 적용시 지락과전류계전기 동작 분석

The fault current has increased due to growth of distributed generations for the large power demand in power distribution system. To solve some problem such as excess of the circuit breaker's cut-off ratings, the superconducting fault current limiter(SFCL) has been progressed. However, the operational characteristics of the relay is changed by SFCL. Therefore, the proper impedance for the SFCL should be selected to keep protective coordination with the SFCL when SFCL is introduced on the neutral line of main transformer in distribution system. In this paper, the proper normal conducting resistance was suggested to solve the problem in case of the protection coordination with SFCL.