Abstract:

Due to the uneven distribution of electric fields in low voltage circuit breakers,the partial discharge and even fire accidents are prone to occur during the actual operation.Therefore,the analysis and optimization design of electric fields in circuits breaker have become an important research topic.The low voltage circuit breakers on the DC side of inverters in a certain photovoltaic power station are taken as the research objects.The finite element software is used to analyze the electric field distribution under different voltage levels and different contact gaps.The structural optimization design is conducted on the weak insulation points of the circuit breaker.Finally,by comparing the maximum electric field intensity before and after optimization,it is demonstrated that the proposed optimized structure reduces the possibility of breakdown discharge.

Key words: low voltage circuit breaker, electric field analysis, contact gaps, structural optimization