A study on Fault Calculation and Coordination of Relays in Distribution System

배전계통의 고장계산 및 보호계전기 협조에 관한 연구

Recently, the scale of distribution system is being enlarged by increasing power demand. When system fault occurs, fault currents and damage power facilities increase, so system stability decreases. Effective prevention of system from fault extention becomes influential as a subject in distribution system operation. In this study, exact settings of relays are obtained from program for fault calculation and coordination of relays in distribution system. In order to make smooth coordination between relays even when power system conditions vary, operation time and sensitivity of relays are optimized. As a result, reliability of distribution system is increased with rapid and exact operation of relays when fault occurs.