NPC三电平中IGBT焊料层多物理场耦合失效分析

Multi-physics coupling failure analysis of IGBT solder layer in NPC three-level circuit

针对传统的多物理耦合分析建模方式需要试验来提取参数,同时电物理参数的提取难度大,静态功耗的计算正确性难以保证、耗费了人力物力等问题,提出一种利用IGBT动态模型来分析焊料层多物理场耦合失效的方法。首先对IGBT模块进行动态仿真,使用Simplorer软件计算NPC三电平逆变器的动态功耗;然后使用动态功耗在ANSYS软件中进行三维有限元建模;最后利用三维有限元模型求解出电-热-力多物理耦合失效分析的解。分析功耗仿真结果可知,逆变器内侧IGBT的功耗要比外侧IGBT高,有限元分析结果验证了动态模型可以准确仿真三电平逆变器功耗不均衡问题。分析三维有限元耦合仿真结果可知,与传统IGBT电-热耦合仿真相比,结温仿真模型误差减小了10%。电-热-力多物理场耦合模型可以更好的显示IGBT焊料层存在缺陷时的多场应力状态。研究结果表明,该方法操作简单,动态功耗求解结果和多物理耦合应力分析结果准确度较高。

For traditional multi-physical coupling analysis modeling methods,experiments are needed to extract parameters,at the same time,the extraction of electrical physical parameters is difficult,and the calculation accuracy of power consumption is difficult to guarantee,it is greatly costing manpower and resources. A method for analyzing multi-physics coupling failure of solder layer by using IGBT dynamic model is proposed. Firstly,the IGBT module is dynamically simulated,and the Simplorer software is used to calculate the dynamic power consumption of the NPC three-level inverter,then use dynamic power to perform 3D finite element modeling in Ansys software,finally,the solution of the electric-thermal-force multi-physical coupling failure analysis is solved by using the threedimensional finite element model. Analyze the power simulation results show that the power consumption of the IGBT inside the inverter is higher than that of the outer IGBT,and the finite element analysis results verify that the dynamic model can accurately simulate the inverter power imbalance problem. Analysis of 3 D finite element coupling simulation results show that compared with the traditional IGBT temperature simulation model,the error of the junction temperature simulation model is reduced by 10%. The electro-thermal-force multi-physics coupling model constructed in this paper can better display the multi-field stress state of IGBT solder layer defects. The research results show that the method is simple to operate,the dynamic power solution results and the multi-physical coupled stress analysis results are more accurate.