双极性加载脉冲源中储开关同步击穿特性

Synchronous Breakdown Characteristic of Transfer Switches in a Bipolar Pulse Generator

采用2级压缩回路和双极性脉冲叠加技术可以获得高电压快脉冲,但这对脉冲源各级开关同步特性要求较高。为研究初级源对中间储能电容器充电时间约120 ns时中储开关击穿特性对脉冲源运行的影响,文中分析了一种双极性加载脉冲源对中储开关同步击穿的要求,通过实验获得了自触发预电离中储开关在相应充电时间下的击穿电压、时延及抖动特性,并根据实验数据计算了正、负极性脉冲下中储开关击穿时延差值的概率分布。结果表明,该双极性脉冲源需要控制中储开关击穿时延差值小于10 ns;自触发预电离中储开关在0.2~0.7 MPa氮气中、不同极性脉冲下的击穿时延抖动均小于3 ns;取99.99%置信区间时,气压0.5~0.7 MPa时正、负极性中储开关击穿时延差值小于10.8 ns。该结果可作为考核中储开关同步特性和分析峰化电容器绝缘裕度设计要求的参考。

High voltage pulse with fast rise time can be generated by two-stage compression circuit and superposition of bipolar pulses, but it requires good synchronization of switches in every stage of the generator. To investigate the influences of transfer switches’ synchronization on the operating characteristics of pulse generator when the charging time of transfer capacitor is about 120 ns, the requirements for transfer switches’ synchronization were analyzed, meanwhile, the breakdown voltage, time delay and jitter characteristics of a self-triggered pre-ionization transfer switch under corresponding charging time were obtained by experiments, and the probability distribution of breakdown time delay difference of transfer switch under positive and negative pulses was calculated based on experimental data. The results indicate that the breakdown time delay difference of transfer switches should be smaller than 10 ns in our bipolar pulse generator. The breakdown time delay jitter of transfer switch is no more than 3 ns under positive and negative pulses when the operating gas is nitrogen and gas pressure varies from 0.2 MPa to 0.7 MPa. The breakdown time delay difference of positive and negative transfer switches is smaller than 10.8 ns(taking 99.99% confidential interval under 0.5~0.7 MPa gas pressure). These results can be used as a reference for checking the synchronous breakdown characteristic of transfer switches and analyzing the requirements for peak capacitor’s insulation design.