串联真空灭弧室工频预击穿电流的自均压作用  

Self-voltage Sharing Effects of Power Frequency Prebreakdown Current Flowing Through Vacuum Interrupters in Series

作　　者：阮江军[1] 舒胜文[1] 黄道春[1] 吴高波[1] 刘兵[1] 黄国栋[1] 

机构地区：[1]武汉大学电气工程学院,武汉430072

出　　处：《高电压技术》2010年第6期1353-1358,共6页High Voltage Engineering

基　　金：国家"十一五"科技支撑计划(2009BAA19B05);国家电网公司重大科技项目(SG0846)~~

摘　　要：为给多断口真空断路器的开发提供理论和试验依据,进行了小开距下单断口和三断口真空灭弧室的工频电压击穿试验。工频电压击穿试验结果表明,三断口真空灭弧室的各断口电压分布在总电压的上升过程中得到了一定的改善,设计了双断口真空灭弧室的工频电压分布试验验证了该结论。真空灭弧室在工频电压作用下会同时流过容性电流和预击穿电流,故引入了预击穿电流对上述试验现象进行分析,提出了串联真空灭弧室的工频预击穿电流具有自均压作用。仿真得到的场致发射电流和试验得到的预击穿电流波形基本一致,表明真空短间隙的击穿主要是由场致发射引起的。而真正决定断路器开断成败的是暂态恢复电压,指出了多断口真空断路器不能仅依靠这种自均压作用,还需配置合理的均压措施。To provide some theoretical and experimental bases for the development of multiple-break vacuum circuit breakers （VCB） in series,power frequency voltage breakdown tests of single and triple-break vacuum interrupters （VI） in series with a short gap length were carried out.After deriving from the test results,a phenomenon was found that the voltage distribution of each break was improved to a certain extent as the total voltage rising,and then the conclusion was proved by experimental results of power frequency voltage distribution in double-break VI in series.Both capacitive current and prebreakdown current will flow through VI when applying a high power frequency voltage across them.Thus,the power frequency prebreakdown current was introduced to analyze the above test phenomenon,a self-voltage sharing effect of prebreakdown current flowing through VI in series was proposed.The simulation results of field emission current are consistent with test results of prebreakdown current,indicating that the breakdown of short vacuum gap is mainly caused by the field emission.In fact,the success interruption of VCB depends on transient recovery voltage （TRV）.Therefore,for multiple-break VCB in series,it is necessary to take some reasonable measures of voltage sharing such as shunt grading capacitors,rather than relying solely on the self-voltage sharing effects.

关 键 词：串联真空灭弧室 工频预击穿电流 自均压 工频击穿电压 电压分布 均压措施 

分 类 号：TM561.2[电气工程—电器]