基于大电流通态压降的IGBT功率模块结温监测方法的研究

绝缘栅双极型晶体管IGBT(insulated gate bipolar transistor)是限制新能源汽车可靠性和成本的关键因素。结温监测能够提升IGBT功率模块的功率密度,提高系统可靠性,降低成本。基于此,提出一种基于大电流通态压降的IGBT功率模块结温监测方法。首先分析通态压降与结温之间的关系,然后设计通态压降结温校准电路,并基于小电流通态压降对校准结果进行验证。最后,分别使用数学模型和神经网络模型拟合结温和通态压降的关系,对基于模型对结温进行预测。结果证明,大电流通态压降能够准确测量结温。

Research on Junction Temperature Monitoring Method for IGBT Power Module Based on On-state Voltage Drop at High Current

Insulated gate bipolar transistor (IGBT) is a key factor of the reliability and cost of EV. Junction temperature monitoring can improve the power density of IGBT power modules, improve system reliability, and reduce costs. This paper presents a method for monitoring the junction temperature of IGBT power modules based on the on-state voltage drop at high current. First, the relationship between the on-state voltage drop and the junction temperature is analyzed, and then the on-state voltage drop junction temperature calibration cir-cuit is designed, which is verified by the small current on-state voltage drop. Finally, the relationship between junction temperature and on-state voltage drop is fitted using mathematical model and neural network model, and the junction temperature is predicted using the two models respectively. The results show that the on-state voltage drop at high current can accurately measure the junction tempera-ture.