Simulation and Analysis of Small Capacitive Current Interruption of a 550kV Single-Break SF6 Circuit Breaker

The prediction of breakdown voltages in capacitive switching tests of high-voltage circuit breaker is a challenging issue [1] . In order to analyze the small capacitive current interrupting ability of a 550 kV single-break SF6 circuit breaker, based on mass, momentum, energy conservation equation and Laplace equation, the no-load air flow field and electric field are calculated by finite volume method. According to current beam theory [2] , the critical breakdown voltage curve and the breakdown margin when arcing time is 0 ms, 0.5 ms and 1 ms are calculated and analyzed. The results show that the minimum value of breakdown margin appears in the throat gap.