直流叠加脉冲电压下FLTD气体开关击穿特性

分析了直流叠加脉冲电压(定义为复合电压)下次级感应电压触发快脉冲直线变压器驱动源(FLTD)中气体开关击穿延时过程,给出了击穿延时的估算公式。初步实验研究了FLTD用三电极气体开关在复合电压作用下的击穿特性,结果表明:在±70kV直流充电电压叠加300kV/30ns快脉冲电压的复合电压作用下,气体开关的击穿延时小于相同工作系数下常规触发方式的击穿延时,采用SF6气体绝缘时,击穿延时较常规触发方式减小了17%~30%;采用N2绝缘时,减小了约50%,开关工作系数为55%时,击穿延时抖动小于5ns;理论估算的复合电压下击穿延时与实测结果基本吻合。

Breakdown characteristics of gas spark switch for fast linear transformer driver under DC and pulse combined voltage

The breakdown delay processes of gas switches under combined voltages of DC and pulse voltages in the faster linear transformer driver (FLTD) are analyzed. A formula is presented to estimate the delay time. The three-electrode gas switches used in the present FLTD were preliminarily tested under combined voltages to investigate the breakdown characteristics by experiment. The experimental results indicate that, as applying the combined voltage of 70 kV DC voltage and 300 kV/30 ns fast pulse voltage, the delay time of switches under the combined voltages is smaller than that of normal trigger method. When gas switches are insulated by SF6, the delay time decreases by 17%-30%. While the delay time decreases by 50% with N2 as the dielectric. At the working coefficient of 55%, the jitter is less than 5 ns. Moreover, the estimated delay time is in close agreement with the experimental result.