基于大电流通态压降的IGBT功率模块结温监测方法的研究

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

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。

Insulated gate bipolar transistor(IGBT)is a key factor that limits the reliability and costs of electric vehicles(EVs).Junction temperature monitoring can improve the power density of IGBT power modules,improve the system reliability,and reduce costs.In this paper,a junction temperature monitoring method for IGBT power modules is proposed based on the on-state voltage drop at high current.First,the relationship between on-state voltage drop and junction temperature is analyzed.Then,an on-state voltage drop junction temperature calibration circuit is designed,which is further verified based on the small current on-state voltage drop.Finally,the relationship between junction temperature and on-state voltage drop is fitted using a mathematical model and a neural network model,respectively,and the junction temperature is predicted based on these two models.Results show that the on-state voltage drop at high current can accurately measure the junction temperature.