沙尘环境下棒–板间隙的雷电冲击击穿特性

Effect of Sand and Dust on Lightning Pulse Breakdown Characteristics in Bar-plate Air Gap

沙尘天气会威胁高压输变电外绝缘的安全运行,因此有必要加强相关的研究。为此通过建立人工沙尘放电试验平台,开展了沙尘环境下棒–板间隙雷电冲击击穿特性试验,选用石英砂来模拟现实中的沙尘环境,对比分析了不同间隙距离下,沙尘间隙和空气间隙的雷电击穿电压。结果表明:沙尘环境下,间隙的雷电冲击击穿电压会降低,降低幅度最多可达15%。但试验研究发现,存在例外的一小段间隙距离区段,沙尘条件下的负雷电冲击击穿电压反而会升高,升高幅度最多可达20%。对于大间隙,沙尘对放电的影响将随着间隙距离的增大而减弱。对试验结果与现象,应用流注理论、表面光致电离等机理进行了分析。相关结论为沙漠地区输电线路运维提供了参考。

Dust weather threatens the safe operation of high-voltage power transmission and insulation, so it is necessary to strengthen relevant research. Therefore, through the establishment of an artificial sand and dust discharge experimental platform, the experiment of lightning-impact breakdown characteristics of rod-plate gap under dust environment was carried out. Quartz sand was selected to simulate the dust environment in reality, and the breakdown voltages of the air gap and dust gap were analyzed under different gap distances. The results show that, under the dust environment, the lightning breakdown voltage of the gap will be reduced, and the reduction can be up to 15%. However, the experimental study reveals that there is an exception of a small gap distance section, the negative lightning impulse breakdown voltage under sand and dust conditions will increase, up to 20%. For large gaps, the effect of dust on the discharge will decrease as the gap distance increases. The experimental results and phenomena were analyzed by streamer theory, surface photoionization and other mechanisms. The relevant conclusions provide a reference for the operation and maintenance of transmission lines in desert areas.