A Novel Real-Time Junction Temperature Monitoring Circuit for SiC MOSFET

Abstract

Junction temperature is a critical parameter for indicating the health condition of power devices in converters. Temperature sensitive electrical parameters (TSEPs) provide a viable method for extracting junction temperature of power devices in real-time operation. However, a few studies focus on practical implementations methods for SiC devices. This paper proposed a novel real-time junction temperature monitoring circuit for SiC MOSFET based on its quasi-threshold voltage (quasi-V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) without complex circuits and current sensors. Furthermore, the effects of load current and DC bus voltage on junction temperature of SiC MOSFET extraction are analyzed. The experimental result shows that the quasi-V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> of SiC MOSFET extracted by the proposed measurement circuit has a sensitivity of -4.37mV/°C and is independent of load current.