An optimal phase control method for the suppression of phase sequence exchange impulse current and voltage

Abstract

Phase sequence exchange (PSE) is an emerging emergency control method for power systems. However, PSE will generate impulse current and voltage. In this research, to suppress the impulse of PSE, a phase control method for zero-current opening and equal-voltage closing is adopted, and verified via both physics and experiments. First, an equivalent circuit is established, and the differential equations are solved to validate that this phase control method is the optimal method for the suppression of the impulse current and voltage in PSE. Then, the action sequence scheme and calculation method of the phase control method are advanced. Finally, based on the real-time digital simulation system (RTDS), a PSE prototype was used to carry out impact experiments. The results verify that the performance of the optimal method is the best compared to those of other control methods, the requirement for the sampling frequency is low, and there is almost no additional cost. In the two experiments, the first peak of the impulse current was found to be reduced by 47.49% and 33.28% on average, respectively, and the first peak of the impulse voltage was found to be reduced by 14.89% and 44.10% on average, respectively.