220 kV GIS母线电压互感器放电故障分析

Discharge Fault Analysis of 220 kV GIS Bus TV

介绍一起GIS母线电压互感器放电引起母线跳闸的故障,通过故障前母线电压波动情况,初步判断跳闸前电压互感器存在匝间或层间绝缘异常,进一步对该电压互感器试验检查分析,确定该故障原因为电压互感器绕组内部匝间或层间短路,短路电流产生的热量导致层间薄膜和漆包导线漆膜烧熔,短路范围逐渐扩大,向一次绕组接地屏方向发展,最终导致绕组内部导线对一次绕组接地屏放电,导致母线跳闸。针对该故障提出防范措施,确保电网安全稳定。

It introduces a fault of bus tripping caused by GIS bus TV discharge.Through the voltage fluctuation of the bus before the fault,it preliminarily judges that the TV has abnormal turn or layer insulation before tripping.Further test and analysis of the TV shows that the fault is caused by short circuit between inter-turns or inter-layers in the coil of the TV.The heat generated by the short-circuit current causes the interlayer film and the paint film of the enamelled wire to melt.The short-circuit scope gradually expands to the primary coil grounding screen,and finally leads to the discharge of the internal wire of the coil to the primary coil grounding screen,resulting in bus trip.In view of this fault proposed preventive measures to ensure the safety and stability of the power grid.