Research On Current Sharing Technology Of SiC MOSFET Parallel Module

At present,due to the development of intelligent power systems and the Internet of energy,power electronic equipment has attracted a great deal of attention.The presence of power switching devices is critical,and the development of power switching devices has affected the development of power electronics devices.Current power switching devices are basically silicon-based semiconductors and their derivatives such as MOSFETs and IGBTs.However,as a new generation of wide bandgap semiconductor devices,SiC has received a great deal of attention due to its excellent characteristics in high voltage and high power applications.The use of SiC MOSFETs in power devices such as charging pile inverters can significantly increase power density and equipment efficiency.This paper focuses on the research of SiC MOSFET driving and paralleling current sharing circuits.Firstly,in this paper,the device structure and working principle of SiC MOSFET are introduced.At the same time,using a power analyzer to measure the static characteristics of the CREE SiC MOSFET C2M0280120D experiment,and then models its characteristics.After that,the corresponding model parameters of SiC MOSFET C2M0280120D are given,the modeling and experimental measurements are compared.The result shows that the modeling results are basically consistent with the actual measurements.Secondly,the difference between traditional Si power MOSFET driver circuit and IGBT driver circuit and SiC MOSFE.T driver circuit is analyzed,and a dedicated driver circuit is designed according to the switching characteristics of SiC MOSFET.The detailed description of the drive voltage,resistance selection,and the specific calculation of the drive current and drive power,and signal isolation and pretreatment of the drive signal.Then,in the design of parallel current sharing scheme,through the analysis of device dispersion,power loop parameters,driving circuit parameters,temperature and other factors,a grid resistance compensation combined coupled inductor current sharing method is proposed according to the LTSpice simulation results.This method reduces the current unbalance from 10.9%to 1.47%compared to using traditional coupled-inductor method that only reduced to 2.58%.Finally,a dual-pulse test bench is built to verify the performance of different resistance drive circuits for driving single-tube SiC MOSFETs.Then the parallel current sharing experiment is carried out.By gate current resistance compensation combined with the coupling current sharing method The current unbalance of the device dispersion,drain inductance,driving resistance,driving voltage,and gate inductance are respectively reduces from 10.12%,14.86%,10.97%,19.2%,and 16.16%to 2%,3.89%,2.87,3.15%,and 3.34%,which verified that the gate resistancecompensation combined coupled inductor has good current sharing.Compared with the existing method of current sharing between series resistance and coupled inductance,the method is close to practical application,and the current sharing effect is good and more reliable and stable.