Three-Dimensional Modeling and Optimization Analysis of Internal Electric Field in 40.5 kV Switchgear

Metal enclosed switchgear has the advantages of easy maintenance and high reliability, and is widely used in medium voltage power system. Combined with the demand of power system and supply and distribution system, and the overall structure scheme of switchgear, in this paper, three-dimensional simulation model of internal electric field in switchgear was established by using Auto CAD and Maxwell 3D, and the electric field distribution inside the switchgear was simulated and analyzed. According to the results of electric field analysis, the corresponding optimization measures were designed for the parts with the most concentrated electric field distribution and weak insulation strength. By modifying the insulating sleeve model of the bus bar compartment, adjusting the thickness of the insulating sleeve in the circuit breaker compartment, the internal electric field distribution of the switchgear was optimized. On the basis of simulation analysis, lightning impulse tests, power frequency withstand tests, etc., of the sample switchgear were carried out according to the relevant standards. The results showed that the switchgear met the insulation requirements, the electric field optimization and the overall structure of the switchgear were reasonably arranged.