多种手段联合判断GIS闪络故障原因及分析

Multiple Methods to Judge and Analysze Fault Cause of Gas Insulated Switchgear

针对某变电站500 kV气体绝缘金属封闭开关设备(GIS)开展现场交接试验过程中出现击穿的问题,通过闪络定位仪、气体分析仪及绝缘检测等多种手段对故障间隔气室进行定位,查找故障点,判断故障原因。解体后发现GIS内部导电杆上有明显的磕碰痕迹,改变了导电杆周围电场的分布规律,导致耐压过程中导电杆周围电场发生畸变,在导电杆上发生沿面放电,出现绝缘击穿现象。此次故障的发现及分析,为之后的交接试验及现场安装提供了经验。

In allusion to the breakdown problem existing in a substation’s500kV gas insulated switchgear(GIS)during the onsite handover test,the fault gas compartment was located by means of flashover locator,gas analyzer and insulation detector etc,the fault point was searched and the cause of the fault was judged.After disintegration,it was found that there were obvious bump marks on the conductive rods inside the GIS and the distribution of the electric field around the conductive rods was changed.As a result,the electric field around the conductive rods was distorted during discharge and creeping discharge occurred on the conductive rods,resulting in dielectric breakdown.The discovery and analysis of this fault provided precious practical experience for the handover test and onsite installation later.