Impact of Structural Variation in SiC MOSFETs on TSEP Performances for Temperature Estimation

The accurate monitoring of the temperature of silicon-carbide (SiC) MOSFETs during operation in power electronic converters is crucial. The use of temperature-sensitive electrical parameters (TSEPs) to enable online real-time temperature monitoring is a promising technique in this field. However, previous studies have not fully considered how the structural differences in devices affect the selection of parameters to be monitored and the accuracy of the monitoring results. This article presents a comprehensive study of TSEPs of SiC MOSFETs with different gate structures. The physical mechanisms governing the variation of TSEPs with various device temperatures are analyzed in detail and validated through the double-pulse tests. This comparative research reveals the affecting mechanism of device temperature on typical TSEPs in SiC MOSFETs with different gate structures and provides guidance on TSEP selection in terms of sensitivity and linearity to achieve better accuracy of device temperature measurement. The findings have significant practical implications for the safety-critical application scenarios.