真空断路器弧后等离子体探针诊断系统

Probe Diagnostic of Post-Arc Plasma System for Vacuum Circuit Breaker

真空断路器弧后阶段残余等离子体电子密度是表征弧后微观特性的重要参量。本文分析了探针诊断方法的工作原理,提出了一种基于电子饱和区的真空电弧弧后残余等离子体电子密度探针诊断方法。设计了探针结构、探针控制单元和数据处理系统,研制了基于单探针的真空断路器弧后残余等离子体诊断系统。利用可拆卸式真空灭弧室搭建了诊断实验平台,系统研究了开断电流、触头结构、测量位置等因素对弧后电子密度空间分布的影响。研究表明:真空断路器弧后等离子体探针诊断系统测量的弧后初始电子密度范围在10^(10)-10^(11)cm^(-3),衰减时间为30-40μs,变化规律与弧后鞘层理论一致,并与国内外其他诊断方法的测量结果进行对比,验证了探针诊断方法的可行性和有效性,为真空电弧弧后电子密度的诊断提供了一种有效、简便的方法。

The residual plasma electron density is an important parameter to characterize the post-arc microcosmic characteristics of the vacuum circuit breaker.In this paper,the working principle of the probe diagnosis method is analyzed,and a probe diagnosis method based on the electron saturation region of vacuum arc residual plasma is proposed.The probe structure,probe control unit and data processing system are designed,and the diagnosis system of residual post-arc plasma of the vacuum circuit breaker based on a single probe is developed.A diagnostic experiment platform was built by using a detachable vacuum arc extinguishing chamber,and the influence of breaking current,contact structure and measuring position on the spatial distribution of post-arc electron density was systematically studied.Research shows that:the initial electron density measured by the postarc plasma probe diagnostic system of the vacuum circuit breaker is in the range of 10^(10)-10^(11) cm^(-3),and the decay time is 30-40μs.The variation law is consistent with the back-arc sheath theory,and the comparison with the measurement results of other diagnostic methods at home and abroad verifies the feasibility and effectiveness of the probe diagnosis method.It provides an effective and simple method for diagnosing electron density after the vacuum arc.