On-line Temperature Measurement Method for SiC MOSFET Device based on Gate Pulse

In this paper, a new online temperature measurement method for SiC power metal-oxide-semiconductor field-effect transistors (MOSFETs) is proposed that uses the linear relationship between the drain-source current(Ids) and the temperature of power electronic devices. The temperature-sensitive characteristics of the transfer characteristic curve of these MOSFETs are studied. The results show that under different applied gate voltages, the effects of temperature on the change in the Ids are different; under the same gate voltage, the drain-source current of each device maintains a good linear relationship with the temperature, which can be used to perform accurate junction temperature measurements of power MOSFETs. Based on this characteristic, by superimposing a pulse on the gate, characterizing the instantaneous current produced by this superimposed pulse, and combining this characteristic with the relationship between the Ids change and temperature, detection of the device's operating temperature under actual working conditions is realized. Furthermore, a related circuit is designed to reduce the influence of changes in the electrical bias on the system stability during temperature measurements. In addition, the measurement results are verified via infrared thermal imaging, and the results show that the proposed method has good practicability.