Research and Simulation Analysis of Systematic Voltage Fluctuation in DC Commutation Failure

The failure of high-power DC commutation leads to large fluctuations in the voltage of the transmitting end grid, which brings great harm to the safe and stable operation of the transmitting end grid. In this paper, the detailed analysis of PMU data is carried out for the voltage fluctuation events of the transmitting end caused by the frequent DC commutation failure in recent years. By constructing a simulation model in BPA and RTDS, the fault back-tracking of the voltage fluctuation of the power supply with the commutation failure is carried out. The simulation results show that the main cause of the fluctuation is caused by the timing coordination and the delay of the rectification side AC filter. This is of great significance for reducing voltage fluctuations in the case of subsequent DC system commutation failure, and it also has great significance for maintaining safe and stable operation of the power grid.