真空灭弧室冲击电压作用下的击穿统计特性研究

Statistical Property of Electric Breakdown in Vacuum Interrupters under Impulse Stress

本文实验测取了实际真空灭弧室在雷电冲击电压下的静态击穿统计特性。根据实验结果，引入一个特征参量ｘ来描述电场应力的作用，指出真空灭弧室的绝缘击穿是在电场应力达到一定值后才有可能发生。借助击穿弱点的概念，从间隙击穿的微观过程出发，推导了击穿累积概率分布特性，并对理论结果和击穿机理做了分析。最后，对ｘ参数的物理意义进行了初步探讨。

The statistical property of electrical breakdown in vacumm interrupters under impulse stress is experimentally studied. A characteristic parameter x is introduced to describe the applied stress, and the breakdown may be initiated only when the value of x has reached its critical point. In terms of the weak point and based on the microporocesses of breakdown,the statistical property is analysed, the Weibull distribution law is derived. The physical meaning of x is discussed.