微米尺度气隙放电击穿电压及放电路径的分析  

Analysis on breakdown voltage and discharge path in micro scale air gap discharge

作　　者：贾斌 赵来军[1] 陈芸 李彦森 孙岩洲[1] JIA Bin;ZHAO Laijun;CHEN Yun;LI Yansen;SUN Yanzhou(School of Electrical Engineering and Automation,Henan Polytechnic University,Jiaozuo 454003,China)

机构地区：[1]河南理工大学电气工程与自动化学院,河南焦作454003

出　　处：《绝缘材料》2023年第7期102-108,共7页Insulating Materials

基　　金：国家自然科学基金资助项目(11405044)。

摘　　要：为分析微米尺度下气隙的击穿放电特性,本文搭建了微米尺度放电实验平台,在电极间距为1~100μm的范围内,研究气隙击穿特性随气压p和电极间距d的变化。当调节气压或电极间距,使得击穿电压到达最低点后,发现击穿电压曲线出现平台期,并且对于不同的外界条件,平台期的长度范围也有较大的区别。通过微米尺度电场的数值模拟,发现电极边缘的电场仍处于较高范围,在此范围内仍可达成自持放电,碰撞电离过程可以通过较长路径而非极板间的最短距离来达到电极间的击穿,使得击穿电压维持在最低点,从而形成平台期;而当电极间距小于10μm时,离子增强场致发射机制参与击穿,击穿电压最低点由平台期继续下移。阴极离子数密度不仅对电极间距敏感,同时还受到外界气压的影响,产生的离子增强场会增强场致发射的强度,进一步降低击穿电压。综合分析气压和电极间距,传统Paschen定律在微米尺度范围不再适用,击穿电压不再由电极间距d和所处气压p的乘积决定。In order to analyze the breakdown discharge characteristics of air gap at micrometer scale,a microgap discharge experimental platform was built to study the change of breakdown characteristics of air gap with the air pressure and electrode spacing in the range of electrode spacing between 1−100μm.When the air pressure or electrode spacing was adjusted to make the breakdown voltage reach the lowest point,it was found that the breakdown voltage curve appeared a plateau,and corresponding to different external conditions,the length range of plateau was different.Through the simulation of microscale electric field,it was found that the electric field at the edge of electrodes was still in a higher range,within the range the self-sustaining discharge can still achieve.The collisional ionization process can reach breakdown between the electrodes through a longer path rather than the shortest distance,so that the breakdown voltage maintained at the lowest point,thus the plateau period was formed.When the electrode spacing was less than 10μm,the ion-enhanced field emission mechanism was involved in the breakdown,and the lowest point of breakdown voltage continued to decrease from the plateau period.The number density of cathode ions was not only sensitive to the electrode spacing,but also influenced by the external air pressure,and the generated ion-enhanced field would enhance the intensity of field emission and further reduce the breakdown voltage.Combined with the analysis of air pressure and electrode spacing,the traditional Paschen’s law is no longer applicable in the micro-scale range,and the breakdown voltage is no longer determined by the product of the electrode distance d and the pressure p.

关 键 词：微米间隙 变气压 平台期 长路径击穿 离子增强场致发射 

分 类 号：TM852[电气工程—高电压与绝缘技术]