中文摘要：

近年来,35 kV电网中真空断路器开断并联电抗器时发生了多起事故,原因不明。采用数据统计的方法,对现场燃次数最高达128次,三相重燃过程持续时间最长达5ms,试验的大量结果进行了总结和分析。经统计,单次开断中重后重燃相瞬态恢复电压上升率可高达13kV/s,无保护情况下相间过电压可超过8.0pu,相对地过电压均可超过4.0pu。结果表明,三相多次重燃和相间过电压是此类事故的主要原因。基于电路理论分析并揭示了三相多次重燃过程的产生、发展和结束机制,即工频电流首先过零相的预期瞬态恢复电压幅值高,导致电弧重燃,重燃产生的高频电流经电缆的相间耦合导致其他两相发生强制熄弧。强制熄弧相预期瞬态恢复电压的幅值和初始上升率都极高,继而引发三相多次重燃过程,并产生可达相对地过电压幅值的2倍的相间过电压。

英文摘要：

Accidents occurred frequently in the 35 kV power system in recent years when vacuum breaker switched off shunt reactors.However,the reason is not clear.Through data statistics,detailed summary and analysis were carried out on the numerous results of field test.Statistic results shows that there can be 128 reignitions during a break operation,the three phase reignition process can last to 5 ms,the RRRV of the latter reignition phase can be as high as 13 kV/ms,the inter-phase overvoltage can beyond 8.0 pu and the phase to ground overvoltage can beyond 4.0 pu.The statistics results show that the main reason of such accidents is three phase multi-reignitiion and inter-phase overvoltage.Based on circuit theory,the mechanism of the whole process of the three phase multi-reignition was analyzed and revealed.The magnitude of the prospective transient recovery voltage is high enough to lead arc reignition,the high frequency current generated by the reignition can be coupled into the other two phases and cause forced arc extinguish.The magnitude and RRRV of the phase of forced arc extinguish are both extremely high,then excite the multi-reignition process andgenerate the inter-phase overvoltage which is twice in magnitude to phase to ground one.