Research on A 252kV SF6 self-blast circuit breaker re-ignition based on CFD simulation

In recent type tests, a 252kV SF6 self-blast circuit breaker re-ignites several times after interruption. In order to solve this problem, through CFD simulation of the gas flow field in the interrupter on load, the pressure, temperature and velocity after current zero are analyzed carefully. The conclusion is that, due to the upstream pressure decreased quickly after current zero and will lower than downstream pressure, the downstream hot gas returns to the upstream resulting in the re-ignition. Based on CFD simulation two optimal structure is proposed, and is verified by simulation.