设计了一种新型的同轴三电极结构, 仿真计算结果表明开关在充电及触发时电场最大值区域均匀性良好。引入循环吹气系统能够控制放电产物的流向, 减小对开关绝缘结构内壁的污染, 可在提高气体绝缘恢复能力的同时延长开关绝缘外壳寿命。在重频实验条件下(±40 kV/20 kA/0.1 Hz)进行了寿命考核实验, 目前单个开关寿命考核实验已大于17.2万发次, 开关工作稳定, 自击穿电压特性和触发延时抖动特性良好。

Except for the integrated charge transferred, the effective area of discharge electrode and pollution of discharge spatters on insulator shell are major limiting factors to the gas spark switch lifetime. After theoretic analysis, increasing electrode area with uniform discharge can improve switch lifetime effectively. We have designed a new three-coaxial-electrodes structure, whose electric field simulation results show nice uniformity in both charging state and triggering state. Meanwhile, a circulative gas path can control the splash direction of discharge spatters to reduce the pollution of insulator’s inner wall, and enhance the gas insulation recoverability to prolong switch’s lifetime. We have carried out the experiments under the repetitive condition (±40 kV/20 kA/0.1 Hz). Result shows that this long-lifetime gas spark switch works stably, whose self-breakdown voltage characteristic and trigger delay jitter characteristic are both as good as expected, and single switch has worked more than 13.7×105 shots.