Electric Field Distribution Characteristics of High-Voltage Vacuum Cup-Type Contacts Based on the Finite Element Method

With the development of vacuum circuit breakers towards high voltage and large capacity, the insulation issues inside the vacuum interrupter have become increasingly prominent. The geometric structure of the contact system directly determines the electric field distribution within the interrupter, thereby affecting the insulation withstand level of the equipment. Based on the finite element analysis software COMSOL, this paper establishes a three-dimensional electrostatic field simulation model for a certain type of high-voltage vacuum cup-type axial magnetic contact. By solving Laplace's equation, the potential distribution and electric field strength distribution under the power frequency voltage of 252 kV in the open state are numerically calculated and analyzed. The simulation results indicate that the electric field distribution of the contact system exhibits significant inhomogeneity. The maximum electric field strength is concentrated at the edge of the contact cup root and the sharp corners of the slots, with a magnitude reaching 2.51×10⁷ V/m. Based on the results of quantitative simulation analysis, this paper discusses the physical mechanism of electric field distortion from the perspective of electrostatic field theory, providing a theoretical basis for the structural design of high-voltage vacuum switching equipment.