Components of Electrical Power Systems in More and All-Electric Aircraft: A Review

Even though achieving carbon-free and reduced NOx emission transportation is a prevailing goal, the aviation industry is in its infancy to arrive at passenger class all-electric aircraft (AEA) properly operating over commercial missions. Challenges are mainly associated with the components of the aircraft electric power system (EPS). Considering today's technologies, power electronics components are not capable to sustain tens of megawatts of required power during the takeoff and meet the aviation limits in terms of size, weight, and cost at the same time. The state-of-the-art electrochemical energy units (EEUs), including battery, fuel cell, and supercapacitor, cannot provide the 25-30-MW thrust power needed for the takeoff, and electrical circuit breakers (CBs) are not able to clear a fault in a large AEA propulsion system, and multimegawatt electric drives/motors can barely be found being able to provide 2-3-MW thrust power, so that they can be employed in a distributed propulsion architecture. Taking mentioned challenges into account, this article aims to tackle challenges associated with protection devices, EEUs, and electric machines in passenger class AEA and present promising solutions using an envisioned medium voltage direct current +/- 5-kV EPS for an AEA, all-electric NASA N3-X aircraft. Based on findings and discussions made through this article, the authors conclude that although technology advancements are essential in all research areas, high-voltage wide bandgap electrical CBs, Li-air and Li-S batteries with >1000-kW/kg specific power, and multimegawatt superconducting electric machines will turn a commercialized passenger class AEA into reality within the next 20-30 years.