Electro-thermal Based Junction Temperature Estimation Model And Thermal Performance Analysis For IGBT Module

The insulated gate bipolar transistor(IGBT)is widely applied in high-power occasions such as power converters and motor drives for its fast switching speed,high voltage resistance as well as input impedance and low output impedance.While the switching frequency of k Hz-level and high-power running state make it produce a lot of power loss as working,resulting in the rise and fluctuation of chip junction temperature(T_j)which is closely related to the device failure and safe operation.The current measure is to dearing the module or match a large heatsink of the inverter.But,excessive derating will reduce the application of the power module,and unreasonable thermal design will increase the system's weight.Thus,accurate T_j estimation of the high-power IGBT module is of critical importance for monitoring the health of the device and increasing its reliability in industrial application.However,due to the coupling between electric and thermal,as well as the real-time changes of the operating conditions of the module in practical applications,the prediction of the junction temperature of the IGBT power module becomes a challenge.With Infineon FF600R06ME3 power module as the research object,this paper proposed an electro-thermal based junction temperature estimation model through the research of the working principle of IGBT devices,power module loss calculation and heat transfer characteristics.In addition,we explored the thermal performance of it,which provided the basis for the reliability and thermal design optimization of IGBT module.Firstly,based on the structural characteristics and working principle of IGBT,the generic power loss calculation model is established with full study about the influence rule of temperature,gate resistance and other factors on the loss.And then the thermal path and the form of the module are analyzed.According to the transient thermal impedance curve in the data sheet,the fourth-order Foster thermal resistance network model is fitted.Thus,the coupling of the loss and thermal resistance model in matlab/Simulink is implemented,realizing the set up of module and system-level junction temperature predictive model which can be applied in a specific working point.Then,three circuit parameters are selected as examples for simulation and the accuracy of the model was verified as the results compared with Infineon's IPOSIM simulation software and ANSYS temperature field,Then the relationship between the thermal performance and the parameters of module package structure as well as circuit is researched,providing ensurance of rational thermal design.Additionally,based on the actual application,the modifiled junction temperature estimation model which can be applied to the working condition is established,and the changes of junction temperature and loss during a deceleration condition can be simulated.And the accuracy of the proposed model is further verified by comparison with inverter losses in the bench test,which provide a reliable theoretical basis for the research of IGBT power module reliability verification,reasonable thermal design as well as condition monitoring and related control.