Feasibility Study of High Temperature Superconducting Machines for Electric Aircraft

The rapid advancements in the aviation transport sector require stringent benchmarks for emissions, noise, and fuel efficiency in commercial aircraft, thereby escalating the significance of electric propulsion aircraft technologies. High temperature superconducting (HTS) synchronous machines, standing out for their high power density and efficiency, are key enablers for the practical and commercial application of electric propulsion aircraft. This paper introduces the design of a 20 MW-class HTS synchronous generator and analyzes its feasibility for electric propulsion aircraft from an electromagnetic perspective. The design process undergoes multi-objective optimization, aiming for minimal active mass and maximal efficiency to achieve an optimal power density. The rotor of this generator employs REBCO HTS-tapes in the field winding, operating at 20 K with liquid hydrogen (LH2) cooling. The stator consists of nonmagnetic teeth and Litz wire armature winding. The generator's power density and efficiency are calculated considering armature windings made of copper and high purity aluminum, respectively. Different cooling mediums, such as direct water and LH2, are also discussed. The results show that using high purity aluminum armature winding with LH2 cooling can greatly improve power density and efficiency.