基于传热动力学作用特征的IGBT结温预测数学模型

Junction Temperature Prediction Mathematical Model of IGBT Based on the Characteristics of Thermal Dynamics

提出一种基于传热动力学作用特征建立绝缘栅双极型晶体管(IGBT)结温预测模型的建模方法。针对目前IGBT结温预测模型无法灵活应用于多时间尺度仿真与快速计算模式的问题,通过将简单(阶跃)信号下得到的动力学作用分量应用于复杂(PWM)信号下,建立IGBT结温预测数学模型。基于经典Cauer传热RC网络结构,建立针对阶跃功率输入信号的IGBT结温预测数学模型。提出采用自然解耦的方法,对IGBT传热动力学特性进行研究,建立传热动力学作用分量的准确表征。在此基础上,采用自然解耦与精确补偿的方法,建立针对PWM脉冲功率输入信号的IGBT瞬态结温预测数学模型。仿真与实验结果验证了模型的正确性与准确性。所建IGBT结温预测数学模型对于查明IGBT器件的传热动力学作用机理,实现结温的快速有效仿真与计算,建立IGBT传热多时间尺度数学模型具有重要的理论意义和应用价值。

Based on the characteristics of thermal dynamics, a method of insulated gate bipolar transistor （IGBT） thermal mathematical modelling is proposed. The model of IGBT junction prediction temperature can’t be flexibly applied to the multi-time simulation and fast calculation. Thus, the thermal mathematical model against step power signal is established based on the RC network structure of Cauer heating theory. The method of natural decoupling is proposed to investigate the characteristics of thermal dynamics. And then the interaction mechanism of thermal dynamics is found out. Accordingly, the characterization of thermal dynamics component is established. On this basis, the mathematical models of transient junction temperature and the junction temperature fluctuation against PWM pulse power signal are established, using the method of natural decoupling and accurate compensation. The dynamical characteristics of junction temperature are studied under different signals including amplitude, period and duty ratio. The results of simulations and experiments verify the rightness and accuracy of the models. It is useful to find out the operation rules of junction temperature and interaction mechanisms of thermal dynamics, realize the fast and effective simulation, and set up the multi-timescale thermal mathematical model.