伪火花放电开关的实验研究

Experimental Investigation of the Pseudospark Switch

设计了典型参数下的伪火花放电开关,进行了空气介质下的放电实验研究.测量了伪火花开关耐受电压与气压关系曲线,确定了产生伪火花放电的气压范围.研究表明,当间隙距离和孔径均为3mm时,开关的伪火花放电气压范围为4～29Pa.实验发现,在伪火花放电和普通辉光放电之间存在一气压阈值,在本文实验条件下,该点的气压为29Pa,此时开关放电电压为2kV.测得了单间隙伪火花开关耐受电压的上限值(40kV),并对此现象进行了理论分析.计算了开关的放电电流密度和电流上升陡度,当导通电流为93kA时,其电流密度大于1 7×104A/cm2,电流上升陡度大于7 8×1010A/s,反峰系数为90%.最后,分析了伪火花开关的设计要点与性能影响因素.

A prototype pseudospark switch was designed, and the experiments in air were carried out. The discharge curve was measured; and the critical pressure between pseudospark and glow discharge was determined. When the gap distance is 3 mm, the gas pressure producing pseudospark discharge is from 4 Pa to 29 Pa. The current densities and rate of current rise were calculated from experimental data. The factors influencing the switch characteristics were discussed. The prototype switch has maximum holdoff voltage of 37 kV, maximum peak current of 93 kA, current reversal of 90% and rate of current rise of 78×1010 A/s.