Characterization of Electro-Thermal Coupling Behaviors and Safe Operating Area of SiC MOSFET Modules in Pulsed Power Applications

With the development of high-temperature packaging technology, silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (
mosfet
s) can operate under high-temperature conditions with junction temperatures exceeding 175 °C, providing a solution for pulsed power applications facing instantaneous high currents and significant temperature fluctuations. However, the electro-thermal coupling behaviors and safe operating area (SOA) of SiC
mosfet
s in a wide temperature range are unclear, and there is a lack of guiding principles for SiC module packaging and heat dissipation design in pulsed power applications. In this article, an electro-thermal coupling model of SiC
mosfet
modules is established. The electrical model over a wide temperature range (25 °C–375 °C) is built in Simulink, and the thermal finite element model is established in COMSOL, while MATLAB script is used to implement interaction between the two models. Then, detailed analyses are conducted on the electro-thermal coupling behaviors of SiC
mosfet
modules. Besides, the impact of packaging on the SOA of SiC
mosfet
modules is researched. In addition, a transient junction temperature measurement method of SiC
mosfet
s is proposed by using the
on
-state resistance
R
_ds(on)
as the temperature-sensitive electrical parameter. Finally, the discharge experiments of the capacitor bank through resistive loads are carried out under short pulse and long pulse, respectively, and the experimental results are consistent with the model.