特高压（UHV）变电站在站用电切换过程中，调相机循泵电机会出现冲击电流过大导致多级跳闸的情况。为研究切换策略，首先定量分析失电残压的频率和幅值随时间的变化，并进行相关仿真研究。其次对重合闸时的瞬态进行研究，通过仿真模型得到冲击电流随时间的变化规律，发现冲击电流的最大值略滞后于相位相反的点，最小值略滞后于相位相同的点，且该滞后的量取决于失电残压的衰减速率，提出一种基于失电残压和电源电压幅值差的切换方法。针对仿真结果进行分析，为维护人员提供一定的参考依据，尽可能降低投切过程中的冲击电流，避免切换失败。

In the process of power switching in ultra-high voltage (UHV) substation, the electric shock current of the synchronous condenser circulating water pump will be too large, leading to the situation of multistage tripping. In order to study the switching strategy, the frequency and amplitude of the residual voltage are quantitatively analyzed over time, and relevant simulation studies are carried out. The transient state of reclosing is studied, and the change law of impulse current with time is obtained through simulation. According to the simulation, it is found that the maximum value of the shock current lags slightly behind the point with opposite phase, the minimum value lags slightly behind the point with same phase, and the lag depends on the decay rate of the loss residual voltage. On this bases, a switching method based on the difference between the loss residual voltage and the amplitude of the supply voltage is proposed. The simulation results are analyzed to provide some references for maintenance personnel, so as to reduce the impulse current in the switching process as much as possible and avoid switching failure.

国家自然科学基金项目(51577050)；国网江苏省电力公司科技项目(J2019114)；111引智计划项目（B14022）