基于绝缘栅双极型晶体管(IGBT)模块的实际结构, 建立了开关电源IGBT模块有限元等效热分析模型和双热阻模型。在开关电源实际工作情况下进行温度测量实验, 结合实际运行时的电压电流曲线, 给出模块的总损耗。仿真拟合出热特性主要参数瞬态热阻, 与厂商数据手册提供的实测热阻曲线进行对比, 两者曲线基本一致, 验证了有限元热分析等效模型合理。分别将有限元等效模型与双热阻模型进行稳态热仿真, 与实验对比分析, 得到实际工况下IGBT模块温度场分布及芯片结温。分析双热阻模型的优缺点, 并提出了改进方案。

Based on the actual structure of an IGBT module, the finite element equivalent thermal analysis model and the double thermal resistance model of the IGBT switch power supply are established. The total loss of the module is calculated by using the voltage-current curve and temperature measurement experiment results under the circumstance of actual work of the switching power supply. The transient thermal resistance which is the main parameter of the thermal characteristics is simulated. By comparing with the measured thermal resistance curve provided by the manufacturer’s data sheet, the consistence of both curves indicates that the finite element equivalent thermal analysis model is reasonable. The thermal distribution and chip junction temperature of the IGBT module are achieved under actual working state by experimental comparison and analysis, based on the steady state thermal simulation of the finite element analysis model and double thermal resistance model. The advantages and disadvantages of double thermal resistance model are analyzed, and an improvement program is proposed.