Three Dimensional Electric Field in a Novel Rotary-Gas Nozzle Structure of SF6 Circuit Breaker

In this paper, the novel Rotary-Gas nozzle structure with the advantage of arc extinguishing capacity has been investigated. The 126kV SF₆ circuit breaker is taken as the investigation model and the novel structure with Rotary-Gas Grooves in the upstream nozzle is presented. Using Finite Element Method, it focuses the influence of Rotary-Gas groove on electric field in the arc-quenching chamber. To modify the structure parameters of Rotary-Gas nozzle, such as numbers and angle of Rotary-Gas grooves, the maximum electric field strength in arc-quenching chamber and the electric field distributions of the Rotary-Gas grooves during the interrupting process have been acquired, and compared with that of conventional nozzle. Based on the calculation electric field of Rotary-Gas nozzle, the satisfying results are obtained and illustrated. Moreover, it has been proved that the proposed novel Rotary-Gas nozzle has good insulation performance.