真空断路器开断并联电抗器过电压试验研究

针对国内35kV与20kV系统真空断路器开断并联电抗器系统事故多发情况,开展35kV系统工况下的现场试验,分析了开断后的暂态过程及过电压的机理,并在实验室进行了20kV系统真空断路器在额定电流下投切电抗器的截流试验,研究截流值和过电压规律。结果表明:截流过电压幅值远小于重燃过电压,多次重燃过电压是真空断路器开断并联电抗器频繁出现高过电压的主要原因;在系统典型额定工况下,300A负载电流下的截流值比100A负载电流下小,真空断路器的截流值随着开断电流的增大而减小的理论在系统额定电流下同样成立。

Research on Overvoltage Test of Vacuum Circuit Breaker Switching-Off Shunt Reactor

As overvoltage failures frequently occur in vacuum circuit breakers switching-off shunt reactors of 35 kV or 20 kV power system, the field tests were carried out in the operating condition of 35 kV power system. This paper analyzed the transient process caused by the opening operation and the overvoltage mechanism.The chopping current test of vacuum circuit breaker switching off shunt reactors was carried out under rated current condition in the laboratory. This paper researched the chopping current value and the overvoltage regulation. The results show that the overvoltage of chopping current is much smaller than multiple reignition overvoltage, and multiple reiguition overvoltage is the main reason of overvoltage failures of vacuum circuit breakers switching-off shunt reactors. In the typical conditions of power system, the chopping current of 300 A load current is smaller than that of 100 A load current. The theory that the chopping current value of vacuum circuit breakers decreases with the increase of breaking current is completely true at rated high current.