基于全工作域驱动模式动态配置的Si/SiC混合器件开关策略OA

The Si/SiC hybrid switch(Si/SiC HyS)is composed of a low-current SiC metal oxide semiconductor field effect transistor(MOSFET)and a high-current Si insulated gate bipolar transistor(IGBT)in parallel.It has attracted much attention because of its excellent performance of low switching loss and high switching speed of MOSFET and the low cost advantage of IGBT.However,the switching rates of MOSFET and IGBT are quite different.During the switching transient process under heavy load,MOSFET and IGBT are prone to the problem of peak current exceeding the limit,which threatens the reliable operation during the full working domain of the HyS.This paper proposes a switching strategy for Si/SiC HyS based on dynamic configuration of gate mode in full working domain.Firstly,the influence mechanism of the gate voltage on the switching transient current distribution of Si/SiC HyS is analyzed in detail,and the mathematical model of the peak current with respect to the gate voltage is established.Considering the current stress constraint,the whole working domain is divided into three load intervals.Guided by the principle that the turn-on and turn-off overcurrent ratios are capped at 1,this study takes the minimum loss of HyS as the optimization objective to dynamically optimize the driving sequence and gate voltage across different load intervals.Finally,the experimental results show that compared with the traditional strategies,the proposed switching strategy can achieve lower loss while ensuring that MOSFET and IGBT are free from overcurrent vulnerabilities in the whole working domain.