Holistic approach for cryogenic cooling system design of 3 MW electrical aircraft motors

This paper discusses the holistic approach for determining a viable cryogenic cooling system for a 3 MW fully superconducting motor. The unprecedented power density requirement above 10 kW/kg for electrically propelled aircraft necessitates the development of a superconducting motor and possibly a superconducting generator as well. Only a fully-superconducting synchronous motor can achieve the ambitious high-energy density required by electrical aircraft propulsion. We propose a cooling scheme design of the motor where the field winding coil is located in the rotor at 50 K and the stationary armature is energized in a liquid hydrogen bath around 20 K to maximize the power density as a compact structure. Each cryostat for the superconducting rotor or stator is independently designed driven by its own topology of cooling configuration to minimize the weight of the required refrigeration system. The innovative design of the superconducting rotor especially considers a dedicated cryocooler mounted on the rotating axis. This paper intends to provide a consolidated concept design of cryogenic cooling for 3 MW-scale electrically propelled aircraft engines.