35 kV并联电抗器分闸过电压故障实例分析及防治

Case analysis and prevention of opening overvoltage fault of 35 kV Shunt Reactor

针对电网运行中产生的切除并联电抗器的分闸操作过电压问题,以一起35 kV真空断路器切除并联电抗器的分闸操作过电压故障实例为基础,根据故障前后设备运行情况、故障录波实测数据和设备损坏检查情况,得出故障原因为电抗器开关上、下极间绝缘子的绝缘相对薄弱,真空泡内的电弧被拉断后,极间外绝缘无法承受较高的过电压水平,A、B相极间发生绝缘闪络。根据过电压产生机理,提出电抗器侧安装阻容吸收器、增加系统出线等防治建议。

In view of the opening operation overvoltage problem of removing shunt reactor during power grid operation,based on an example of opening operation overvoltage fault of removing shunt reactor by 35 kV vacuum circuit breaker,according to the equipment operation before and after the fault,the measured data of fault recording and equipment damage inspection,it is concluded that the cause of the fault is that the insulation of the insulator between the upper and lower poles of the reactor switch is relatively weak.After the arc in the vacuum bubble is broken,the external insulation between the poles cannot withstand a high overvoltage level,and insulation flashover occurs between the poles of phase A and B.According to the mechanism of overvoltage,some prevention suggestions such as installing resistance capacitance absorber on the reactor side and increasing system outgoing line are put forward.