中文摘要：

以风电变流器可靠性评估为应用背景，文中提出一种结温迭代数值计算方法。基于电热比拟理论讨论了IGBT模块在一个开关周期内的结温计算方法，并通过迭代算法计算了IGBT模块的工频周期结温。以1．8MW单机直驱风力发电系统为例，将该方法与Infineon．IPOSIM电热仿真和解析方法对比。与电热仿真相比，在保证结温精度的情况下，迭代数值计算方法显著缩短了计算时间；与解析方法相比，迭代法考虑了器件的电热耦合关系，提高了结温计算精度。文中还分析了电热参数对结温计算的影响。计算结果表明，文中提出的结温迭代算法计算精度较高，计算速度快。

英文摘要：

With the application background of reliability evaluation in wind power converters, a junction temperature iterative numerical calculation method for insulated gate bipolar transistors （IGBT） was proposed in this paper. The proposed junction temperature calculation method calculated the switching cycle junction temperature of IGBT modules based on the electrical-thermal analogy firstly, and then the entire line frequency junction temperature were further calculated by means of an iterative algorithm. The calculation accuracy and speed performance of the presented method were evaluated through a case study of a 1.8 MW wind power converter, and also compared with the results obtained from the electrical-thermal simulation and analytical calculation solutions. The results show that the presented method not only ensures calculation accuracy, but also greatly reduces the calculation time compared with the electro-thermal simulation method. In contrast with the analytical junction temperature method, the presented method exhibits much higher accuracy. Finally, the effects of the variation of the electrical-thermal parameters on the junction temperature calculation were also analyzed. The calculation results show that the presented iterative algorithm can calculate junction temperature accurately and fast.