The numerical calculation and optimization design of electric field for the high voltage SF6 circuit breaker arc-quenching chamber

The electric field in the arc-quenching chamber of high voltage SF₆ circuit breaker has been calculated using Finite Element Method (FEM). The distributions of equal electric potential line and electric field strength have been analyzed and figured, and the main factors which affect internal insulation of the chamber have been evaluated. Moreover, the inverse problem optimizing the chamber structure has been studied. The shapes of contacts and nozzle are selected as optimization variables. The minimum of maximal electric field strength is regarded as optimized function, which provides some theoretical basis for the overall design of high voltage SF₆ circuit breaker.