基于导通电阻测量的SiC MOSFET结温在线监测方法OA

Junction temperature is a key indicator of the health status of SiC MOSFET,and real-time monitoring of junction temperature is an important foundation for condition monitoring,health management and lifetime prediction.The real-time monitoring of junction temperature was investigated based on the on-resistance,a static thermal parameter of medium and high-voltage SiC MOSFETs.Firstly,the correlation between on-resistance and junction temperature was analysed.Secondly,the theoretical analysis,simulation and experimental verification of the working principle and parameter design of the online measurement circuit of turn-on voltage drop were carried out.Finally,the models of junction temperature,on-resistance and load current of SiC MOSFETs were calibrated offline based on the double-pulse experiment.A BUCK converter platform was built to verify the feasibility and applicability of the proposed junction temperature online measurement scheme under two different working conditions.