基于流固物理场的电机逆变器功率模块散热结构优化设计

Optimized Design of Heat Dissipation Structure for the Motor Inverter Power Module Based on the Fluid Solid Physical Field

散热设计在电机逆变器功率模块研制过程中至关重要,温升是影响逆变器功率模块散热的关键因素。为了探究其温升特性,建立了一种基于流固物理场的电机逆变器功率模块结构模型,采用有限元分析法对功率模块的3D温度场和流体场进行了计算,分析了功率模块内部温度场及湍流流线的分布情况。在此基础上,进一步分析了导热胶脂参数、环境温度、风扇面积及格栅面积对功率模块温升的影响,得到一种优化后的功率模块流固物理场结构模型。结果表明,考虑空气流场的流固物理场模型能分析电机逆变器功率模块内部的温度,也可确定影响其温升的关键性因素。经优化后,在环境温度为20℃和125℃下,该模型能分别有效降低电机逆变器功率模块23.1%和10.01%的温度。该研究为电机逆变器功率模块的封装热设计提供了参考,同时为功率模块结温的在线估算提供了依据。

Heat dissipation design is crucial in the development process of motor inverter power modules,and temperature rise is a key factor affecting the heat dissipation of the inverter power module.In order to investigate its temperature rise characteristics,a structural model of the motor inverter power module based on the fluid solid physical field was established.The 3D temperature field and fluid field of the power module were calculated by using finite element analysis method,and the distributions of the internal temperature field and turbulent flow lines of the power module were analyzed.Based on this,the influences of thermal grease parameters,ambient temperature,fan area and grid area on the temperature rise of the power module were further analyzed,and an optimized fluid solid physical field structural model of the power module was obtained.The results show that the fluid solid physical field model con-sidering the airflow field can analyze the temperature inside the motor inverter power module and identify the key factors affecting its temperature rise.After optimization,the temperature of the motor inverter power module can be effectively reduced by 23.1%and 10.01%at the ambient temperature of 20℃and 125℃,respectively.This study provides a reference for the package thermal design of the motor inverter power module,and also provides a basis for the online estimation of the junction temperature of the power module.