陶瓷密封直流接触器温升计算及优化

Temperature Rise Calculation and Optimization of DC Contactor with Ceramic Seal

建立电动汽车及其充电桩用300 A直流接触器的几何模型,基于COMSOL软件进行三维有限元电磁场和稳态热分析仿真,分析不同因素对接触器温升的影响。在对热源进行等效处理时,着重考虑触头系统中的接触电阻和电磁系统中的线圈电阻对温升的影响。在仿真时考虑接触器内部及其与外部环境之间的热传导、热对流、热辐射,根据热相似理论计算各个外表面的对流散热系数。利用所建立的模型,研究连接铜板的横截面积、触头间的接触压力、外壳材料、线圈线径对温度场分布的影响,并提出改善温升特性的优化设计意见,为接触器小型化和大容量的设计提供参考。

In order to analyze the influence of different factors on temperature rise of the contactor,a geometric model of 300 A DC contactor for the electric vehicle and its charging pile was established,and the simulation of three-dimensional finite element electric field and steady-state thermal analysis based on COMSOL software was carried out.When using equivalent treatment for the heat source,the effects of contact resistance in the contact system and coil resistance in in the electromagnetic system on the temperature rise were emphatically considered.Meanwhile,the heat conduction,convection and radiation heat dissipation between the contactor and the external environment were also consider for simulation,and the heat convection coefficients of different outer surfaces were calculated according to the heat similarity theory.By using the built model,this paper studies the influence on the temperature field distribution of the factors such as cross-sectional area of the copper plate,contactor pressure,shell materials and coil diameters.The paper also proposes suggestions for optimization design to improve temperature rise characteristics so as to provide references for the design of the miniaturization and large capacity of the contactor.