Thermal Analysis of the Main Power Transistor in Direct Current Solid-State Power Controllers

With the continuous rise in aircraft power level and power density, the junction temperature of the main power transistor SiC MOSFET in the DC solid-state power controller (SSPC) has an increasingly prominent impact on the reliability of the SSPC, significantly affecting the safe and reliable operation of more-electric/all-electric aircraft. In this paper, a three-stage Foster thermal network model was established for the MOSFET of model C2M0025120D. The junction temperature change curve of this thermal network model under various working conditions was measured using PLECS, and the simulation results were compared with those of the Ansys transient thermal simulation. The results indicate that the error of the simulation results is within 5%, and the accuracy of the thermal network parameters is relatively high. The thermal network parameters measured in this paper can reveal the thermal characteristics of the DC SSPC under normal and abnormal working conditions and are of great significance for the development of effective thermal management and fault prevention strategies, thereby providing a scientific basis for enhancing the reliability and safety of the DC SSPC.