用于电动汽车功率模块热分析的紧凑型热网络模型

Compact Thermal Network Model for Thermal Analysis of Power Modules in Electric Vehicle

由于恶劣的运行环境,IGBT模块成为电动汽车驱动系统最薄弱的环节。功率模块的失效主要由温度因素引发。为了尽可能准确地预测芯片结温,文中提出一种适用于电动汽车功率模块热分析的紧凑型热网络模型。首先在ANSYS/ICEPAK中搭建包含水冷散热系统的功率模块有限元模型。然后,提出一种考虑上下桥臂热耦合的3D紧凑型热网络模型,并详细地叙述热网络模型参数提取的步骤。最后,3D紧凑型热网络模型的仿真结果与有限元仿真模型高度吻合并且实验结果表明,所提出的热网络模型能够准确预测电动汽车中功率模块的结温。与有限元模型相比,所提出的热网络模型减少仿真时间,适用于功率模块的寿命估计和结温在线计算。

Insulated gate bipolar transistor(IGBT) modules have become the most fragile component in electric vehicle drive systems due to the harsh operating environment. The failure of the relevant power module is mainly caused by temperature-related factors. To predict the chip junction temperature as accurately as possible, a compact thermal network model suitable for the thermal analysis of electric vehicles was proposed. The finite element model of IGBT modules containing a water-cooled system was built in ANSYS/ICEPAK firstly. Then a 3 D compact thermal network model considering the thermal coupling of the upper and lower bridge arms was proposed and the steps of parameter extraction of the thermal network model were described in detail. Finally, the simulation results of the 3 D thermal network model are in good agreement with the finite element simulation model. and experimental results shows that the proposed thermal network model can accurately predict the junction temperature of power module in electric vehicles. Compared with the finite element model, the proposed thermal network model reduces simulation time and is suitable for lifetime estimation and on-line junction temperature prediction for power module.