一起并联电容器装置损毁故障分析

Damage Fault Analysis on High Voltage Shunt Capacitor

某500 kV变电站并联电容器装置经AVC自动投运后发生故障损毁,为查明故障的具体原因并避免今后类似故障再次发生,分析人员从参数校核、谐波、保护动作、过电压、返厂解体等多方面对电容器故障过程及原因进行了综合分析和推断,通过分析依次排除了参数、谐波、保护、过电压等因素,最终认为故障是由投运后个别电容器内部绝缘缺陷引发整组电容器三相短路故障。通过本文的介绍可为今后类似并联电容器装置故障分析提供了一定的借鉴意义。

The fault of shunt capacitor for certain 500 kV substation was happened after auto switching through AVC.In order to find out the specific cause of the fault and avoid recurrence of similar failure,the comprehensive analysis and inference on the fault process and cause are carried out by the analysts from such aspects as parameters validation,harmonics,protection action,overvoltage and disassembly at the manufacture.Throughout analysis,such factors as parameters,harmonics,protection,overvoltage are eliminated in turn.Finally,it is thought that the fault is the three-phase short-circuit fault of the complete set of capacitors due to internal insulation fault of individual capacitor after operation.The introduction in this paper can provide a certain reference for the fault analysis of similar shunt capacitors.