Development of High-Power DC Solid-State Power Controllers Using SiC FETs for Aircraft Electrical Systems

The growing demand for improved interruption performance characteristics in emerging aircraft high-voltage direct current (HVDC) electrical networks motivates the rapid development of solid-state power controllers (SSPCs). This article presents a comprehensive design procedure for a 270 V 300 A SSPC utilizing discrete SiC cascode devices. Due to the high fault current and limited power of single switches, parallel SiC FETs are essential for interrupting high fault currents in SSPCs. Consequently, the challenge of current balancing among parallel devices is addressed in this paper by adopting a passive current balancing strategy based on an irregular-shaped busbar. Furthermore, considering the voltage spikes arising from the power loop parasitic inductance and TVS characteristics during fault interruption, an RC-TVS-based transient voltage mitigation circuit is proposed to suppress these peak voltages. Moreover, thermal models for overload and short-circuit conditions were developed to optimize the thermal management system to ensure reliable operation of the SSPC. Finally, a prototype of 270 V/300 A SSPC has been built to validate the key characteristics of the proposed high power SSPC.