Influence of Nozzle Expansion Angle on the Breaking Performance of Ultra-high Voltage SF6 Circuit Breaker

In order to ensure that the ultra-high voltage SF 6 circuit breaker has good breaking performance, the two nozzle structures respectively using one expansion angle and two expansion angles are designed. The flow field distribution during the breaker breaking process is obtained by numerical simulation, and the influence of the two kinds of expansion angle design structures on the breaking performance are compared and analyzed. The several different design structures of one expansion angle are also researched, and the recommended interrupter structure is verified by short-circuit breaking test. The results of simulation and test show that, compared with the two expansion angle structure, the interrupter using one expansion angle structure has better breaking performance, which is of great significance to the design of ultra-high voltage SF6 circuit breaker nozzle.