Research On Modeling And Dynamic Characteristics Of High Power Sic Modules

Si(silicon)is the main material of power electronic devices.The research and development of silicon materials have reached the limits of properties.Therefore,the research on wide band gap semiconductors has become an inevitable trend.With more and more research available,semiconductor devices are gradually transitting from traditional silicon to silicon carbide.Among them,silicon carbide MOSFETs have advantages such as high temperature,high frequency and high efficiency.Firstly,in order to evaluate the static and dynamic characteristics of silicon carbide devices in practical applications.This paper first establishes a pspice model for the Infineon1200V/100 A silicon carbide half-bridge module(FF11MR12W1M1_B11).Three static characteristics modeling methods are given,and their advantages and disadvantages are compared.The voltage control current source model is proposed to establish the static characteristic model.The results show that the model based on the temperature variable fitting the static parameters has a higher matching degree with the actual device characteristics in a wide temperature range and the dynamic characteristics are based on the fitting of the nonlinear capacitor.The nonlinear capacitor is described by a current source with capacitance I-V characteristics,and the Pspice simulation model of the half-bridge module is established by the Spice.Then,the accuracy of the model is verified based on the double pulse test platform,and the error phenomenon in the experiment is analyzed to prove the accuracy of the established model.Secondly,due to the high-frequency characteristics of silicon carbide devices,they are more sensitive to loop parasitic parameters during operation.For example,under the influence of parasitic parameters,there will be high current and voltage overshoot in the dynamic process of the device,which will directly lead to the device damaged.Therefore,the effects of the driving loop and the power loop on the parasitic parameters are studied respectively,and the influence of the parasitic parameters of each part on the dynamic performance of the device is obtained.The results show that the common source parasitic inductance exists in both the power loop and the driving loop which is the greatest impact on device dynamics.Finally,various factors that cause the current imbalance of the silicon carbide MOSFET are analyzed,including external circuit parameters,internal device parameters,and temperature.The equivalent oscillating circuit model with parasitic parameters is establishedfor turn-on and turn-off transients respectively.The oscillating phenomenon of complex and multi-parasitic parameters is simplified by an equivalent RLC circuit,which simplified the complexity of SiC devices in practical applications.