Analysis Of Frequency Converter IGBT Electric-thermal Model And Design Of Cooling System

With the development of power electronic technology and device packaging technology,the miniaturization and integration degree of high-power electronic device enhances unceasingly,so that the capacity of the frequency converter is increased significantly.Designing the frequency converter's heat dissipation system has become the key to improve its performance.While the power devices of existing frequency converter are mainly adopted in the IGBT module,the most part of its heat is caused by the power losses of IGBT(Insulated Gate Bipolar Transistor)modules,so the heat dissipation problem of frequency converter mainly depends on the IGBT modules.In this paper,I start from analyzing the electricthermal model of IGBT,combining the theory of heat dissipation of IGBT chip and the working process of the frequency converter,and then take a frequency converter composed of the six IGBT modules(Fuji IGBT: 2MBI600VN-120-50)as an example.I achieve the further study of the heat dissipation problem and verify it.First,this paper introduces the working principle of the frequency converter and the basic theory of IGBT.And the working process of the IGBT modules in the frequency converter is analyzed.Then on this basis of that,I analyses the electrical model of IGBT,studies the working characteristic of IGBT and its equivalent thermal model.The whole equivalent thermal circuit model of its inverter circuit is deduced.Then,in view of the specific frequency converter and IGBT modules,a cooling system meeting the requirements is designed.And the corresponding system-level model in Icepak is established.The simulation research on the heat dissipation of the model is carried out,and the heat dissipation problem is analyzed by simulation results.Finally,I set up the experimental platform of IGBT modules in the frequency converter with cooling system and conduct the experiments.The cooling capacity of the cooling system is studied by comparing the experimental results with simulation results.The conclusions prove the thinking from analyzing the electronic-thermal model for IGBT power modules to designing of the frequency converter's cooling system is correct.