Design Considerations for High-Voltage High-Current Bi-Directional DC Solid-State Circuit Breaker (SSCB) for Aerospace Applications

Design of a high-voltage and high-current solid-state circuit breaker (SSCB) for aerospace applications is highly challenging, as the overall system should comply with the most stringent operating environment. In addition, the implemented power semiconductor devices within the SSCB would require excellent thermal performance and efficiency with minimised conduction losses as they always operate during on-state and only break current when there is a fault. The newer generation of the more electric aircraft architecture has a proposed DC link voltage of 2.4 kV (+/- 1.2 kV) which is much higher than the presently used DC link voltage of 540 V (+/- 270 V). The proposed DC SSCB would be rated at 2.4 kV with a nominal current rating of 100 A and would be used for protection and controllability to protect the aircraft’s DC grid transmission network. A brief overview of the different elements of a DC SSCB have been discussed here followed by a discussion about the different viable bi-directional SSCB topology configurations. The thermal simulations were carried out in PLECs, which provide the conduction losses and junction temperature dynamics for different switch (Si devices and SiC MOSFETs) types and topologies. Moreover, different figures of merit such as conduction losses, semiconductor weight, and power density are also discussed.