Research On Large Capacity Sic MOSFET And Its Application In Inverter

Silicon carbide(SiC),which is a new type of wide bandgap semiconductor material,has attracted much attention due to its excellent performance.Compared to traditional silicon power devices,SiC devices which have low switching loss,high switching frequency and high temperature resistance and other good characteristics,have been promoted and applied rapidly in the high-performance power converter,and SiC devices will meet the requirements of the power electronic technology's development in the future.Therefore,it is of great significance to study the characteristics of SiC devices and its application in the converters.This paper focuses on the SiC MOSFET,and analyzes the physical and electrical properties of SiC devices in detail,and the characteristics differences are discussed between SiC devices and silicon devices in static and dynamic performance respecetively.Based on that,the PSpice simulation model for SiC MOSFET is established,and this paper describes detailedly the steps in the process of parameter extraction and specific modeling.Meanwhile,the temperature controlled power supply is introduced to compensate the temperature characteristics of the SiC power MOSFET.And then the accuracy and validity of the model is verified by the simulation and double pulse test.Moreover,this paper discusses the application of SiC MOSFET inverter,and it points out the problems of crosstalk in SiC devices and the voltage oscillation in the deadtime,and explains the mechanism for those problems.According to theoretical analysis and circuit simulation,a reasonable solution is given,and the effectiveness of the solution is verified by experiments.Finally,the loss of three-phase inverter based on SiC MOSFET is analyzed and calculated,and the differences of switching frequency and temperature characteristics are compared between SiC devices and silicon devices.Finally,the experiments are carried out which verifiy the superiority of SiC MOSFET inverter.