Si IGBT/SiC MOSFET Hybrid Switching Model And Application

With the rapid development of modern industrial automation,the increasingly complex working conditions and application environments make the development direction of power electronic converters tend to be high frequency,high power density and high reliability.Power electronic devices are the key factors affecting power electronic converters,however,conventional pure Si IGBT or SiC MOSFET converters cannot satisfy both performance and cost requirements.On this basis,the Si/SiC hybrid switch composed of Si IGBT and SiC MOSFET in parallel combines the advantages of the two devices,and has the characteristics of high operating frequency,low switching loss,and low conduction loss,which is suitable for medium and high power applications.development provides new ideas.In order to further study the characteristics of the Si/SiC hybrid switch,the Si IGBT and SiC MOSFET models were established based on LTspice,and the Si/SiC hybrid switch model was constructed to study the shunt characteristics and temperature characteristics of the Si/SiC hybrid switch.Firstly,the research background of this paper,the modeling of SiC MOSFET and Si IGBT and the research status of Si/SiC hybrid switch at home and abroad are introduced,and then the theoretical basis of SiC MOSFET and Si IGBT modeling is introduced,and then the models of SiC MOSFET and Si IGBT are constructed respectively.The modeling of SiC MOSFETs mainly includes channel current modeling and bulk diode modeling,based on the SPICE level-1 channel current model of MOSFET,replacing the traditional constant mobility with a mobility model that can reflect the trap of SiC/Si O2 interface,the body diode model of SiC MOSFET is established by lumped charge theory.Starting from the physical structure of IGBT,the Si IGBT model is established by combining the equivalent circuit model and the mathematical model,and the internal conductance modulation effect of the Si IGBT is simulated by using the voltage control current source.Finally,the SiC MOSFET model and Si IGBT model are verified by using the device data sheet and experimental results,which confirms the rationality of the model and can accurately reflect the dynamic and static characteristics of the device.The Si/SiC hybrid switching model is constructed using the Si IGBT and SiC MOSFET models.In the single-pulse simulation circuit,the effect of the SiC/Si O2interface state density(Q_trap)of the SiC MOSFET on the shunt characteristics of the hybrid switch is studied.The results show that with the decrease of Q_trap,the shunt point of the Si/SiC hybrid switch increases significantly,Increased shunt time.The current distribution of Si/SiC hybrid switches at different temperatures is studied,and an experimental platform is built to verify that the hybrid switches have good temperature characteristics in the full load range.