Study on the Analysis and Suppression Methods of Inrush Current in Power Capacitor Switching

The inrush current and over voltage of shunt reactive compensation capacitor bank are generated when the capacitor is switched on, and the inrush current mainly occurs in the process of capacitor closing. The value of inrush current at closing affects the service life of breaker contacts and endangers the safety of power equipment and the stability of power system. Based on ATP/EMTP electromagnetic simulation software, a three-phase equivalent simulation circuit model of 10kV capacitor circuit with series reactor and synchronous closing switch is built, and the problems of capacitor insurge current and over voltage under synchronous closing strategy are analyzed. The simulation analysis of several factors, such as the connection mode of shunt capacitor bank and the reactance rate of series reactor, is carried out to obtain the transient process of inrush current after closing under different conditions. After the analysis and comparison of the simulation results, the inrush current suppression measures based on the research results in this paper are proposed.