Online Temperature Measurement Method for SiC MOSFET Device Based on Gate Pulse

In this article, a new online temperature measurement method for silicon carbide power metal–oxide–semiconductor field-effect transistors (
mosfet
s) is proposed that uses the linear relationship between the drain–source current (
I_ds
) and the temperature of power electronic devices. The temperature-sensitive characteristics of the transfer characteristic curve of these
mosfet
s are studied. The results show that, under different applied gate voltages, the effects of temperature on the change in the
I_ds
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 the accurate junction temperature measurements of power
mosfet
s. 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
I_ds
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.