Prediction Modeling Of Inverter Temperature Rise And Optimization Design Of HeatSink Fin For Vehicle Electric Drive System

With the boom of the electric vehicle(EV)industry,increasingly higher performance of various components of the EV drive system is pursued,which cause a series of problems such as high power loss density and overheating.Since the inverter IGBT module is one of the core components of EV drive system,the problems of power loss,junction temperature,heatsink efficiency in the inverter IGBT module have received extensive attentions.For the complex and diverse driving conditions of EVs,the constantly changing switching frequency and power output lead to large fluctuations in junction temperature of the module.Therefore,the research on the prediction of the IGBT module power loss and temperaturerise can realize the junction temperature control and thermal management of the module.Meanwhile,the optimization of the heatsink design is crucial to its heat-dissipation efficiency improvement,which plays a significant role in improving the performance of the EV drive system and ensuring its safe operation.In this paper,a new parameterized power loss model for inverter IGBT module under real motor duty cycles is proposed to meet the demand of integrated modeling of electric drive systems.The accurate power loss model is acquired by experimental calibration of its parameters.Then,based on the Green’s function method,a transient temperature-rise model of the IGBT module is deduced.Both the loss model and the temperature estimation model are validated with the tests of an electric drive system conducted on an AVL test platform.Finally,a multi-objective optimization of the heatsink fin is carried out to achieve the low cost,lightweight and high heat-dissipation performance of the inverter.The main research work of this paper is as follows:1.Based on the of space vector pulse width modulation(SVPWM)principle,the calculation method of the power loss of IGBT module is deduced.On this basis,a new parametrized power loss model of IGBT inverters is obtained according to the requirements of integrated modeling of EV drive systems.The parameters of the model is revised and the accurate power loss model is given.Finally,the proposed the new parameterized power loss model of IGBT module is verified by experiments2.According to the heat conduction equation and Green’s function theory,the transient temperature-rise model of IGBT module is derived.Then simulations of a calibrated CFD model of the tested inverter are performed to get the response functions in the analytical model of temperature rise.Then the fast and real-time prediction of IGBT temperature-rise can be accomplished by using the response function and the new parameterized power loss model.Finally,the proposed transient temperature-rise model of IGBT module is verified by experiments.3.The search method SHERPA in the optimization software HEEDs is used to optimize geometry of the heatsink fin.In the implementation of the optimization,the angle of the cone-shaped fins is used as the optimization variable,and the heatsink fin volume and the IGBT module temperature are used as the two optimization objectives.The optimal correlation among the cone angle,the fin volume and the IGBT module temperature are established.Finally,the multi-objective optimization results are analyzed to achieve the lightweight and high heat-dissipation performance of the IGBT module.