一起串补MOV的故障分析

Fault analysis of metal oxide varistor for series compensation capacitor banks

对一起串补MOV设备在运行过程中发生的故障进行了分析。对串补MOV进行外观检查、电气试验,分析了MOV的设计要求,分析了故障录波,开展了故障仿真分析,发现某支MOV在区外故障时发生故障,导致了电容器组对故障MOV放电,MOV过电流保护动作,而GAP拒触发保护动作。针对此次故障提出不可随意更换单支MOV,及早整组更换运行年限久、性能裂化的MOV设备,以提高设备的运行可靠性。

A fault of metal oxide varistor( MOV) for series compensation capacitor banks during the operation is analyzed in this paper. The MOV is checked by visual inspection and electrical test,and the wave of fault recorder is analyzed incorporating with the simulation. The fault is due to the discharge of the capacitor,because the MOV is broke down while the phase-phase grounding fault appears. According to this fault,two improvement measures( change MOV not at will,replace MOV with a long history and performance degradation) are presented,so as to improve and enhance operation and maintenance situation of the MOV.