基于多物理场耦合的压接型IGBT功率循环应力特性仿真分析  

Simulation and Analysis of Power Cycle Stress Characteristics of Press-pack IGBTs Based on Multiphysics Coupling

作　　者：鲁宇加 焦超群[1] 陈蕊 袁文迁 张秀敏[1] LU Yujia;JIAO Chaoqun;CHEN Rui;YUAN Wenqian;ZHANG Xiumin(School of Electrical Engineering,Beijing Jiaotong University,Beijing 100044,China;State Grid Jibei Electric Power Research Institute,Beijing 100045,China)

机构地区：[1]北京交通大学电气工程学院,北京100044 [2]国网冀北电力有限公司电力科学研究院,北京100045

出　　处：《高电压技术》2024年第9期4195-4206,共12页High Voltage Engineering

基　　金：国家自然科学基金(52377001)。

摘　　要：压接型IGBT器件广泛应用于高压柔性直流系统中。由于在功率循环实验以及实际运行中,器件不同材料之间存在的热膨胀效应会显著影响机械应力,其难以通过实验仪器获取,进而造成疲劳寿命预测困难以及不准确,因此需要研究与实际相符的高精度仿真模型计算器件内部的应力参数。首先,分析了影响IGBT器件有限元模型准确性的物理特性,并提出考虑IGBT芯片动态电导率的高精度IGBT电-热-力多物理场耦合模型。其次,通过器件饱和压降、结温以及Von Mises应力对所搭建模型进行实验对比分析,验证了模型的准确性。最后,利用所提出的多物理场耦合模型仿真分析了压接型IGBT器件在工况以及功率循环过程中的应力变化特性,提出“额外应力差”这一概念以表征IGBT在功率循环中应力存在的特殊变化规律并分析了额外应力差的产生机理,明确应力特性对在研究寿命预测等问题时具有的意义。Press-pack IGBTs are extensively utilized in flexible HVDC systems.Because the thermal expansion effect between different materials of the device will significantly affect the mechanical stress in the power cycle and actual op-eration,it is difficult to obtain the mechanical stress by the experiments,resulting in difficult and inaccurate prediction for fatigue life.Therefore,it is necessary to study a high-precision simulation model consistent with the reality to calculate the internal stress parameters of the device so as to address issues such as life prediction difficulties and inaccurate fore-casts.Firstly,the physical characteristics that affect the accuracy of the FEM of IGBT are analyzed,and a high-precision electrical-thermal-mechanical multiphysics IGBT model is proposed,in which the dynamic conductivity of IGBT chips is taken into consideration.Secondly,the accuracy of the model is verified by experimental comparison and analyses of the saturation voltage drop,junction temperature,and Von Mises stress.Finally,the stress variation characteristics of the IG-BTs during the power cycling are analyzed by using the Multiphysics model proposed in this paper.The concept of“extra stress difference”is proposed to characterize the special change law of the stress of IGBT in the power cycle and to ana-lyze the generation mechanism of extra stress difference.The significance of stress characteristics in the study of life prediction is expounded.

关 键 词：压接型IGBT 动态应力特性 额外应力差 应力寿命预测 有限元仿真 电-热-力多物理场耦合 

分 类 号：TN322.8[电子电信—物理电子学]