Simulation of No-load Medium Recovery Characteristics of CO2 Circuit Breaker

CO2 is considered as one of the most potential SF6 substitute gases due to its good arc quenching performance, low global warming potential (GWP), stable physical and chemical properties and low price. Gas medium recovery characteristics largely determine the interruption performance of high voltage circuit breakers. Therefore, it has great significance to research the medium recovery characteristics of CO2 circuit breaker for guiding the design of the circuit breaker. In this paper, a CO2 circuit breaker model is established based on a 40.5kV SF6 circuit breaker. The no-load flow field of the CO2 circuit breaker is analyzed by Fluent software. The pressure distribution of CO2 is obtained under different contact gap, and the influencing factors are analyzed. The electric field of the circuit breaker is analyzed by Ansoft Maxwell software, and the distribution of electric field strength and potential is obtained under different stroke. On this basis, the no-load medium recovery characteristics of CO2 circuit breaker are calculated by streamer theory.