内置电子式传感器后ZW20开关局部放电研究

Research on Partial Discharge of ZW20 Switch After Built-in Electronic Sensor

基于静电场分析研究ZW20型柱上开关局部放电是绝缘结构优化设计的主要手段之一。文中通过静电场分析获得其电场分布云图,通过理论分析指出:出线套管密封圈附近,电流传感器与出线套管之间及绝缘盒与出线套管之间空气域电场强度超过空气的介电强度是局部放电的关键原因。而后根据静电场复合绝缘理论,提出一种出线套管内铜棒与绝缘盒动端、静端新型的连接方式,并在其内部增设法兰屏蔽罩的优化方案。通过静电场分析可知优化后关键位置气隙电场强度明显降低,并通过试验测试进行验证,从理论及工程实际中验证了此优化方案的可行性。

The research of ZW20 switch based on electrostatic field analysis is one of the main method for the optimi-zation design of the insulation structure. In this paper,the electric field distribution is obtained depending upon elec-trostatic field analysis. The theoretical analysis that: it is the key reason for partial discharge that the electric field strength of air domain nearby the sealing ring,between the electronic current transformer and the outlet bushing,be-tween the insulating box and the outlet bushing exceeds the dielectric strength of air. According to the theory of elec-trostatic field composite insulation,a new type of connection method between copper rod in bushing and moving end and static end of insulating box is proposed,and an optimum scheme of flange shielding cover is added in bushing. It is concluded that the electric field strength of the air gap in the key position decreases obviously after optimization,and it is verified by test,the feasibility of the optimization measures in theory and engineering can be confirmed.