Effect of grounded shield on electric field distribution for solid insulation vacuum circuit breaker

In the tendency of high capacity and structure miniaturization, 40.5kV solid insulation vacuum circuit breakers have been widely used in electrical distribution networks. In order to investigate the effect of the grounded shield on insulating performance, the electric field distribution of a solid insulation vacuum circuit breaker was calculated by finite element analysis software. Taking a 40.5kV solid insulation vacuum circuit breaker for example, the electric field distribution of some critical areas was concerned such as the area near main shield. Meanwhile, the electric field distribution between the embedded pole and the earth is presented. The results showed that the grounded shield might aggravate the electric field strength inside the embedded pole. The effect on the electric field in the vacuum interrupter was calculated and the grounded shield might increase the electric field intensity. The comparison results are available for reference to optimization design of insulating structure for a 40.5kV solid insulation vacuum circuit breaker.