The Influence of Nozzle Structures on Asymmetric Interrupting Performance of High Voltage SF₆ Circuit Breakers

The nozzle structure of the circuit breaker interrupter chamber plays a crucial role in regulating the flow of arc blowing gas during the breaking process, directly impacting the recovery characteristics of the intermediate and subsequently influencing the breaking capability of the circuit breaker. This study focuses on analyzing the impact of downstream straight length, throat straight length, and throat width on circuit breaker performance using simplified enthalpy flow physical simulation for a 126kV pressurized air circuit breaker. The findings indicate that while the first and second downstream straight lengths have minimal influence on circuit breaker performance, throat straight length and width significantly affect its breaking ability. Increasing the linear length of the throat appropriately can enhance circuit breaker performance, and increasing throat width initially enhances and then diminishes its breaking ability. These results are highly significant for investigating factors affecting SF<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> circuit breaker opening and breaking performance, providing theoretical support for structural design improvements in circuit breaker nozzles.