雷电侵入波对变电站设备的影响及防范措施

Impact of Lightning Invasion Wave on Substation Equipment and Countermeasures

对广西某35kV变电站进线段绝缘子进行U50%冲击闪络电压试验发现,线路绝缘水平远高于站内主设备耐压水平。线路遭雷击时,雷电侵入波得不到充分衰减,到达变电站后电压水平仍超过站内主变耐压水平,导致主变雷击损害事故频繁发生。为解决该问题,提出在进线段上加装并联可调间隙防雷装置来优化线路与变电站的耐雷冲击水平配合,与传统"堵塞型"防雷方式相比,并联可调间隙防雷装置这一"疏导型"防雷给防雷工作提供了新思路和实践经验。

Investigation on the U50% flashover voltage test on the insulator used on the incoming line in a 35kV substation in Guangxi indicates that line insulation level is much higher than equipments insulation level in the station, which causes the lightning invasion wave on the line is not sufficiently attenuated and the lack of lightning discharge channel, which result in lightning strike that damages the main transformer. In order to solve the problem of lightning strike in the substation, this paper proposes to install the adjustable gap lightning protection device in parallel to the insulators on the incoming line for optimization and coordination with lightning protection level of lines and substation, comparing to the traditional protection, adjustable gap lightning protection device for lightning protection provides a new thought on channelizing the lightning invasion wave to achieve lightning protection.