DC Protection in Series-Hybrid-Electric Aircraft Propulsion Systems with Ultra-fast Momentary Circuit Interrupter and Fault Detection Algorithm

The onboard system of aircraft is increasingly going through an electrification transformation, driven by the goal of meeting CO2 emission reduction targets. This increases challenges regarding the electrical faults and the safety operation of the aircraft’s onboard Electrical Power Distribution System (EPDS). To address this, we propose a new topology of Momentary Circuit Interrupter (MCI) as a Fault Current Limiter (FCL) in combination with a Fault Detection Algorithm (FDA) for fault current limiting and short-circuit protection in an aircraft EPDS. A MCI with FCL is designed to hold the fault current to rated values or rapidly reduce the rising DC fault current of the EPDS to near-zero amperes. Also, a FDA is developed to locate the fault for rapid isolation and clearing by a fast DC Circuit Breaker (DC CB). The Simulink model of a series-hybrid-electric aircraft propulsion system is simulated with the developed MCI with FCL and FDA. The simulation results validate the effectiveness of the MCI with FCL in limiting or reducing the fault current to near zero amperes (in ~10 µs) and the FDA in locating and clearing the fault via a CB.