35 kV穿墙套管放电故障分析及解决措施

35 kV through the Wall Casing Discharge Fault Analysis and Solutions

CMJ2-35型穿墙套管是一种典型的极不均匀电场分布的绝缘结构,在高电压电场作用下容易发生放电,长期放电容易造成绝缘结构损坏,继而引发事故。通过交流耐压试验和对套管绝缘结构进行理论分析,得到存在较大的空气气隙是套管放电的技术原因。增强母线厚度减少放电空气气隙、增加电场屏障提高击穿电压是改进该穿墙套管的有效技术措施,对于用户,改封闭式开关柜为敞开式结构,是彻底解决穿墙套管放电比较容易实施的方案。电网设备放电故障的消除能直接减少大量的电量损失,避免了继发停电事故,有效提高电网安全运行水平。

CMJ2-35 wear casing wall is a typical insulation structure with non-uniform electric field distribution. It is easy to discharge under the action of high voltage electric field. Long-term discharge is easy to cause damage to the insulation structure and then cause accidents. Through the AC withstand voltage test and the theoretical analysis of the insulation structure of the casing,it is found that the large air gap is the technical reason of the casing discharge. The effective technical measures to improve wear casing wall are to increase the thickness of the bus to reduce the air gap and increase the electric field barrier to increase the breakdown voltage. For users, changing the closed switch cabinet to an open structure is an easy solution to the wear casing wall discharge.The elimination of the discharge fault of the power grid equipment can directly reduce a large amount power loss, avoid the secondary power outage, and effectively improve the safe operation level of the power grid.