변압기 보호용 비율차동계전기의 전류보상 알고리즘 분석 및 고장유형 식별로직 개발

Abstract

In order to protect transformers, the ratio differential relay is widely adopted based on the differences in magnitudes and phases of currents on both sides of the transformer. Since the implementation method varies depending on ratio differential relay manufacturer, there exist some differences in the operation results of the protective relay and eventually the facility operator may have difficulties in analyzing the cause of the fault. In this paper, various electrical faults are simulated by modeling a wye-delta transformer, and the operation results of the protective relays are categorized patterned. Based on these results, a logic circuit is proposed to identify a failure in transformer fault. The fault type identification function and the operation stability of transformer is improved.