小开距下直流真空断路器介质恢复试验及分析

介绍了一种能在小开距下分断高上升率短路电流的方法,并就其真空介质恢复特性展开试验研究。设计了等效真空介质恢复试验方案,从燃弧能量与零电压恢复时间两方面对真空介质恢复过程进行分析,得到直流真空断路器短路分断控制方法的设计依据。研制了额定1 000V/800A直流真空断路器试验样机,可在小于1ms内成功分断上升率约为20A/μs的短路电流,并将电流峰值限制在8kA以内。试验结果证明了所提出的小开距下分断高上升率短路电流的方法有效、可行。

Dielectric Recovery Experimentation and Analysis of DC Vacuum Circuit Breaker Interrupting in Short Contact Gap

A method of switching off high di/dt fault circuit current in short contact gap was presented and its vacuum dielectric recovery characteristic was studied. An equivalent experiment circuit of the vacuum dielectric recovery process was conducted. And the effect of arcing energy and zero voltage recovery period on vacuum dielectric recovery was analyzed, from which the design basis of the vacuum breaker in breaking off the short circuit current was achieved. A prototype of 1 kV/800 A breaker was developed and the cutting off fault circuit current test with di/dt of 20 A/μs was performed. The test results show that the breaker is able to limit the short circuit current to be below 8 kA within 1 ms, which proves the feasibility of the proposed method.