大电流条件下真空接触器温升特性的试验测量与仿真分析

This paper established a test platform for measuring temperature rise characteristics of vacuum contactor under high current condition. The temperature rise characteristics of vacuum contactor under different current levels were measured and analyzed by experimental setup. Temperature rise curves of the specified positions were obtained through a series of experiments. The temperature rise rules under different currents of the vacuum contactor were discussed, especially the overload current capacity. A 3D simplified model based on electro-thermal coupling theory was built by the COMSOL Multiphysics software and four cases with different current (800~2 500A) were calculated for the contacts and main circuit of the vacuum contactor. The influence of load current on temperature rise process was analyzed according to the numerical simulation results under different conditions, and the effect of natural convection on heat dissipation was considered during the calculation. The simulated temperature behaviors including temperature field and Joule heat generation power density distribution were presented. The experimental data agree well with the calculation, which verifies the mathematical model. This paper can provide a reference for thermal design of high-power vacuum contactor.