철도 차량용 피뢰기의 뇌 충격전류에 의한 열화 특성

A railway arrester consisting of ZnO varistors for railway vehicles is deteriorated by repeated protection operation against impulse voltage. A line to ground fault may occur if the deteriorated arrester is not removed. It is therefore essential to analyze the deterioration condition of arrester to evaluate its integrity assessment and residual life. This paper described the deterioration process of arrester by lightning impulse current in order to ensure the criterion of integrity assessment. An accelerated aging test was carried out by standard lightning impulse current of 8/20μs. The changes of leakage current and reference voltage with applied times were analyzed.