双断口直流真空断路器延时开断仿真分析与实验

Simulation and Experiment on Delay Breaking for Double-break Direct Current Vacuum Circuit Breaker

以30kV双断串联口直流真空断路器为研究对象,建立换流回路拓扑结构,采用连续过渡模型,考虑换流回路元件参数的影响,提出非同步下短路电流及暂态恢复电压计算模型,分析同步以及不同延时时间下(0.1~0.5ms)双断口直流真空断路器开断特性与暂态恢复电压分布差异。搭建机械式双断口直流真空断路器样机实验平台,在4.5kA短路开断电流下进行延时开断实验分析。仿真与实验比对分析的结果表明:由于机构分散性导致双断口直流真空断路器中的某一断口动作延时时,两个断口的暂态恢复电压分布存在差异;断口间暂态恢复电压分配不均,先动作的断口承受更高电压;延时时间0.5ms是成功开断的极限时间;延时时间越长,开断性能越劣化。

For30kV direct current vacuum circuit breaker with double-break in series was taken into consideration,and the commutation circuit topological structure was established. Combining the continuous transition model and the effect of the transfer circuit parameters,the model of short circuit current and transient recovery voltage were proposed for simulating the breaking performance and transient recovery voltage variation under different delay time(0.1-0.5ms)and synchronous breaking conditions.Moreover,an experimental platform for the mechanical double-break direct current vacuum circuit breaker was established.And the delay breaking experiment was analyzed under4.5kA short circuit current interruption.The comparative,analysis with simulation and experimentalresultsshowedthat:whenoneofthe double-break delayed by dispersion,the transient recovery voltage on the double-break was correspondingly different, which led to the unbalanced distribution of transient recovery voltage.And the first triggered break undertook higher voltage. Furthermore,0.5ms delay time was the interrupting limitation for the30kV/4.5kA double-break direct current vacuum circuit breaker.The longer the time delayed,the worse the breaking capacity became.