多通道伪火花放电开关及其半导体表面放电触发器研究

Coaxial multichannel pseudospark switches and semiconductor flashover triggering technique

本文设计了典型参数下的同轴式三通道伪火花放电开关及其氧化锌表面放电触发器,进行了空气介质下的放电实验研究,测量了开关的放电曲线,给出了产生伪火花放电的气压范围,计算了开关的放电电流上升陡度,并与相同尺寸下的单通道伪火花开关进行了比较,试验结果表明,采用多通道结构后,开关的长期通流能力由单通道的40kA提高到120kA,电路的电流上升陡度也有很大提高(15%～20%),而电极烧损则大大降低。同时首次采用氧化锌半导体设计了开关的表面放电触发器。实验表明,对耐受电压37kV的伪火花开关,在气压不变的条件下,开关的可触发开关电压可低至440V;在30～2kV的放电电压下,放电电流的时延及其抖动分别为(100～500ns)和(20～50ns)。

A fundamental problem of pseudospark switch(PSS) is erosion in the borehole area. One way to reduce erosion is to distribute the electric current in several discharge channels. In this paper, a prototype coaxial 3channel pseudospark switch is designed, and experiments in air have been carried out. Discharge curve is measured;and the critical pressure between pseudospark and glow discharge is determined. The rate of current rise is calculated from experimental data. The prototype switch has max. holdoff voltage of 37kV, max. peak current more than 120kA, current reversal of 90% and rate of current rise of 9.8×1010A/s.A semiconductor (ZnO) surface flashover trigger is presented in the first time. This trigger unit provides an excellent delay(100～500ns)and jitter(20～50ns) performance at the switch voltage of 30～2kV. The emitted plasma electron density is high enough to trigger switches reliably down to switcher voltage of 440V.