基于米勒平台电压的SiC MOSFET结温监测及校正方法

Junction temperature monitoring and correction method for SiC MOSFET based on Miller plateau voltage

基于导通米勒平台电压的碳化硅金属-氧化物-半导体场效应晶体管(SiC metal-oxide-semiconductor field effect transistor,SiC MOSFET)结温监测方法受到功率回路负载电流和驱动电路电阻等参数的影响,会造成很大的测量误差。文中以降压变化电路中的SiC MOSFET为研究对象,研究了负载电流和驱动电阻、电感对导通米勒平台电压的影响,并进行了多组校准试验,建立了新的结温监测方法。试验验证了文中提出的结温监测及校正方法的有效性,且最大误差小于6.9℃。文中提出的结温检测方法可在具有不同负载电流和驱动电阻的变换器中准确获取结温信息。

The junction temperature monitoring method based on the Miller platform voltage of the SiC metal-oxide-semiconductor field effect transistor(SiC MOSFET)is affected by parameters such as the load current of the power circuit and the resistance of the driving circuit,which can cause significant measurement errors.In this paper,the effects of the load current and drive resistance and inductance on the conduction Miller plateau voltage of SiC MOSFET in Buck changing circuit are investigated,and several sets of calibration experiments are conducted to establish a new junction temperature monitoring method.The experiments verify the effectiveness of the proposed junction temperature monitoring and calibration method,and the maximum error is less than 6.9℃.The proposed junction temperature monitoring method can accurately obtain junction temperature information in converters with different load currents and driving resistances.