200kV小型低电感气体开关

为减小脉冲功率源装置的体积,对场畸变三电极轨道气体开关和两电极轨道气体开关结构进行了小型化低电感设计,采用电磁场仿真软件对局部结构进行优化,对初步设计的触发开关和自击穿开关在不同气压(0~0.3MPa)和不同气体介质(N2,SF6,以及二者混合)条件下的击穿电压及导通电感等进行了研究。研究表明:小型触发开关和自击穿开关在0~0.3MPa气压范围内自击穿电压随气压具有较好的线性关系;相同气压下SF6气体的自击穿电压约为N2气体的两倍;N2与SF6压力按3∶2混合的自击穿电压约为纯SF6气体的0.8~0.9倍;内部充入0.25MPa气压的SF6气体时,触发开关和自击穿开关均可在190kV左右正常工作。根据实验中出现的开关沿面击穿现象,对开关的沿面绝缘能力进行了优化设计,并得到了实验验证。另外通过短路放电测试,得到触发开关电感约22nH,自击穿开关电感约20nH,开关导通电流大于20kA,多次放电后电极烧蚀痕迹分布均匀。

200 kV small gas switches with low inductance

A small tri-electrode gas switch and a small two-electrode gas switch are designed. Experiments for self-breakdown voltages of two-electrode gas switches and operating voltages of tri-electrode gas switches have been carried out in different conditions. The inductances of these switches have also been tested. The experimental results show the relation between self-breakdown voltages and gas pressures (0~0.30 MPa, relative) is nearly linear. The self-breakdown voltage of two-electrode gas switches with 11.9 mm gap and full of 0.25 MPa SF6 is up to 190 kV. The self-breakdown voltage by linear extrapolation can be up to 210 kV while the gap is 11.9 mm and inner SF6 pressure is 0.30 MPa. Operating voltages for tri-electrode gas switches with 11 mm total gap can be ranged from 90 kV to 200 kV by adjusting inner SF6 pressure from 0 to 0.30 MPa. Short circuit experiments reveal that the inductance of the two-electrode switch is about 20 nH and the one of the tri-electrode switch is about 22 nH. Thus the results tested for inductances are close to the values calculated.