Preliminary Safety Assessment of the Propulsion Power Management System of a Hybrid-Electric Regional Aircraft

The development and the technological demonstration of Hybrid-Electric Propulsion Systems (HEPSs) represent fundamental steps towards more sustainable air transports, especially with reference to regional applications. Beyond performance aspects, the reliability and safety of the electrical power devices integrated in the HEPSs are still far to be substantiated, especially with reference to Li-Ion batteries and fuel cells. In addition, due to the presence of multiple power paths, a safety-critical element of all HEPSs is the power management system, defining the torque split among sources and monitoring the health-state of subsystems. This work presents the preliminary Functional Hazard Assessment of the power management system of a 2-MW HEPS with hydrogen fuel cells for regional aircrafts, developed within the context of the EU-funded AMBER project, launched in 2023 and part of the Clean Aviation program. The activity conducts to the identification of the most critical failure conditions of the HEPS power management system, which can bring up to hazardous consequences (depending on the mission phase), and to the proposal of possible enhancements of the system architecture aiming to mitigate or eliminate the failure effects.