变电站投切电容器组过电压研究

投切补偿电容器组电力系统最常发生的内部过电压,以贵州某变电站为原型,建立了仿真计算模型。操作过电压仿真研究中,断路器模型起着关键性作用,在分析了真空断路器开断时交流电弧物理过程的基础上建立了断路器的仿真模型,大大提高了仿真精度。仿真计算结果表明：投、切电容器组过程中电容器上承受的过电压幅值较小,不会对电容器造成威胁,但会在电容器入口端产生较高的对地过电压;在切除电容器组过程中发生断路器两相重燃时,由于断路器相间电压较高,将会在重燃相产生上千安的涌流,对电容器组的通流能力要求较高。

Overvoltage Research When Switching Capacitor Bank in Substation

Switching compensating capacitor bank and switching transformer are two kinds of the main causes of overvoltage and failure of electrical equipment.The causes of the above-mentioned overvoltage are analyzed.The simulation model is constructed using ATP-EMTP simulation program based on a substation in Guizhou.The simulation results show that the overvoltage endured by capacitors is small during switching compensating capacitor bank,but the overvoltage to earth of the interface is much greater with 3.0 p.u.amplitude.It is a risk for compensating capacitor bank when two phases are re-closed.