适用于SiC MOSFET的漏源电压积分自适应快速短路保护电路研究OA北大核心CSTPCD

SiC MOSFETs have been widely used in various power electronic converters because of their high breakdown voltage,high switching speed,and low switching loss.However,since the short-circuit withstand time of SiC MOSFETs is only 2～7 μs and will be shortened with the increase of bus voltage,a fast and reliable short-circuit protection circuit has become one of the key technologies for their popularization and application.In order to deal with short-circuit faults at different bus voltages,this paper proposes a drain-source voltage integration-based adaptive fast short-circuit protection method(DSVI-AFSCPM).The protection performance of the proposed DSVI-AFSCPM is studied under hard switching fault(HSF)and fault under load(FUL).Furthermore,the action mechanism of different bus voltages on DSVI-AFSCPM is studied.At the same time,the influence of SiC MOSFET operating temperature on its response speed is explored.Finally,an experimental platform is built to test the protection performance of the proposed DSVI-AFSCPM at different bus voltages and operating temperatures under conditions of HSF and FUL.The experimental results show that the DSVI-AFSCPM proposed in this paper has excellent protection speed adaptability at different bus voltages,namely,the higher the bus voltage,the faster the short-circuit protection speed.And its response speed is less affected by the operating temperature of SiC MOSFET.Under the two short-circuit conditions,the operating temperatures change from 25℃to 125℃,and the short-circuit protection time doesn't change more than 90 ns.Therefore,this paper provides technical support for the reliable use of SiC MOSFET at different bus voltages.