The Research And Optimization On Parasitic Parmeters In A 6kW Half Bridge Power Module

Power module(PM)has the advantages of high resistance to high voltage,high current density,and high integration.It is widely used in intelligent home application,transportation and industrial automation.Due to the rapidly switching of the power module,the instantaneous voltage and current overshoot caused by the module parasitic parameters affect the reliability of the system.Therefore,the research and analysis of the power module parasitic parameters are paid more and more attention.In this paper,according to the current half-bridge power module products,first of all,the power module parasitic parameters of domestic and foreign scholars research status has been studied.The equivalent circuit model with high precision of half-bridge power module is proposed,and the parasitic parameter extraction platform is constructed by ANSOFT.Next,the DC brushless motor system is taken as an example to verify the accuracy of the model.By the state equation of the power module's switch,the quantitative relationship the parasitic parameter and its voltage overshoot is deduced.By using Matlab,the waveform of voltage overshoot is calculated,and compared with the measured waveform.Then,according to the relationship between voltage overshoot and its parasitic parameters,the optimization scheme of the power half-bridge module is proposed from the viewpoint of reducing the self-inductance and mutual inductance of the module,and the half-bridge power module is redesigned.Finally,the new half-bridge power module's reliability is verified.Through the study of the parasitic parameters of the power half bridge module,it provides effective guidance for the optimization and analysis of the parasitic parameters of the power module.The experimental results show that the error rate is less than 5%in the DC brushless motor system with DC voltage of 60V and bus current of 100A.The proposed parasitic parameter optimization scheme,the overall parasitic inductance decreased by about 30%.Power over half bridge module internal power tube drain-source voltage overshoot reduced by 15V,lower power tube drain-source voltage overshoot reduced by 30V,gate-source coupling voltage overshoot reduced by 1.8 V.