35kV并联电容器组群爆故障分析及其零序差流保护的参数整定

Analysis on colony fusing failure of 35 kV parallel capacitors and parameters set on its zero sequence difference current protection

针对接连发生的35kV双星接线并联电容器群爆事故,计算分析了由于电容器组内部元件击穿引起的电容器过电压分布情况。零序差流保护是通过检测双星接线电容器组的中性线不平衡电流来判断电容器组内部是否发生故障,最后提供了带内熔丝的双星零序差流保护的正确整定计算方法,对现在执行的整定值进行了修正。

In order to make it clear for explosion accidents of 35 kV double-star parallel capacitors occurred frequently,this paper calculates and analyzes the distribution of overvoltage casued by breakdown of elements within the capacitor bank.Shunt capacitor zero sequence difference current protection can judge whether the breakdown of internal capacitor elements exists in banks by detecting neutral line unbalanced current.At last,it gives the setting method of double-star zero sequence difference current protection and modifies the working setting value.