Module Development of a High-Power-Density High-Efficiency Cryogenic Solid State Circuit Breaker for Electrified Aircraft Propulsion

Solid state circuit breaker (SSCB) with high efficiency and high gravimetric power density is required for Electrified Aircraft Propulsion (EAP). A cryogenically cooled GaN device based SSCB module is developed for EAP system. The SSCB module is suitable for medium voltage direct current (MVDC) applications and is designed with low-weight modular cold plates. Each module is rated for 750V, 100A and achieves a power density of 329 kW/kg. The design of the SSCB module structure, thermal design, and insulation design are discussed. Experimental results of interrupting an over-current fault of ~10x of the rated current by the SSCB module is provided to validate its operation at cryogenic temperature.