SiC MOSFET Model And Analysis Of Short Circuit Characteristics

Silicon carbide(SiC)plays a leading role in semiconductor materials because of its wide band gap,strong breakdown electric field,high saturation rate and high thermal conductivity.Therefore,SiC MOSFET has the advantages of high frequency,high voltage,high temperature resistance,high power density and so on.It has gradually become the key research object in the industry and applied in many power electronic occasions.In this paper,the modeling and short circuit characteristics of SiC MOSFET are studied.Taking C2M0080120D SiC MOSFET of Cree company as an example,the static and dynamic characteristic models of SiC MOSFET are established.For the static characteristics,the fitting parameters are extracted mainly according to the device data manual,and the two static characteristics modeling methods based on MOS LEVEL 3 model and MOS LEVEL 1 model based on model editor are compared.The experimental results show that the method of using level 1 MOSFET model built in PSpice and modifying the model parameters is more accurate;For the dynamic characteristic modeling,a non-segmented,continuous and differentiable equation is used to model the nonlinear capacitance CGD,and a modeling method based on the relationship between depletion layer width and CDS is proposed for the nonlinear capacitance CDS,which is verified by the experiment of double pulse test platform.The results show that,compared with other models,the relative deviations of the simulation waveform and the experimental waveform of the proposed model are reduced by 12%,and the relative deviations of current rise slope,current fall slope,voltage rise slope and voltage fall slope are reduced by 2%,21%,20%and 47%,respectively,which verify the accuracy of the PSpice simulation model.On the premise of accurate PSpice simulation model,aiming at the possible parasitic inductance,internal parasitic capacitance and external parameters on SiC MOSFET in practical application,their influence of the dynamic characteristics is analyzed and obtained.The results show that the value of the common source parasitic inductance has the greatest influence on the dynamic characteristics of the device because it exists in both the power circuit and the drive circuit.Finally,two kinds of short-circuit types of SiC MOSFET are introduced,and the influence of different parameters on the short-circuit characteristics of SiC MOSFET is studied.Through a series of work such as modeling,parameter extraction,simulation comparison and experimental verification,the modeling method proposed in this paper for SiC MOSFET is effective and feasible,which provides a reference for the design and application of SiC MOSFET Power electronic system.