SPWM模式下逆变器中IGBT结温的快速评估方法

Rapid Assessment Method of IGBT Junction Temperature in Inverter Under Sinusoidal Pulse Width Modulation

为了提高采用正弦脉冲宽度调制(SPWM)方式的逆变器中绝缘栅双极晶体管(IGBT)结温的仿真计算速度,采用高斯赛德尔迭代法对IGBT结温计算进行了研究。分析了开关周期的结温计算方法,然后使用迭代算法计算了工频周期的结温,并且将该计算方法与利用电热耦合模型仿真得出的结温和利用光纤测量实验得到的结温进行对比。结果表明:在保证精度的同时,同样是获取40 s时间的结温,仿真大约需要15 min时间,而结温迭代算法只需要20 s时间,其计算速度要比仿真快将近50倍。结温迭代法计算速度的提高,满足了逆变器中IGBT模块长期结温评估的要求,对于完成IGBT的寿命预测具有重要意义。

In order to improve the simulation speed of insulated gate bipolar transistors （IGBT） junctions in sinusoidal pulse width modulation （SPWM）, the Gauss Seidel iteration method was applied in the study of the IGBT junction tem- perature computation. The method of calculating the junction temperature of the switching period was analyzed, and then the iterative algorithm was used to calculate the junction temperature of power frequency cycle. Moreover, a comparison was conducted for the junction temperature obtained by this method, electro-thermal coupling model simulation, and op- tical fiber measurement experiment. The results show that, to obtain a 40 s junction temperature, it takes 15 min for the simulation method while the iterative calculation method only needs 20 s under the same accuracy, namely, the computa- tion speed can increase by nearly 50 times. The increased computation speed by using iteration method can meet the requirements of long-term evaluation for junction temperature of IGBT module in inverter, which is significant for the life prediction of IGBT.