Axial-flux superconducting motor to enable zero emission aviation

To achieve a zero-emission aviation, aerospace is evolving towards electrified propulsion using clean electricity or hydrogen as an energy source. Achieving a 20–40 MW electrical powertrain for commercial aircraft requires multi-MW scale machines with power densities above 20 kW/kg. High temperature superconductors (HTS) offer a ground-breaking and transformative way to increase the power density of electrical machines, as the current carrying capability can be more than 200 times that of room temperature conductors and more than 80 times that of cryogenic normal-state conductors. As a result, superconducting machines have become a key research focus for aviation. This presentation summarizes the ongoing research efforts in the Applied Superconductivity Laboratory at the University of Strathclyde, where two large development projects for HTS motors ( 200 kW and 100 kW) are underway. Firstly, the steady/transient testing results of a partially axial-flux HTS motor are presented as a proof-of-concept testing to validate our design methodology. The motor consists of two permanent magnet rotors and a HTS stator. Secondly, the design methodology is used for a detailed design of a 200 kW fully axial-flux HTS motor. Our design will focus on maximizing the machine power density and efficiency using both HTS rotor and HTS stator. Preliminary testing results for both HTS rotor and HTS stator will be presented, with a focus on reducing AC loss of HTS stator and charging of the HTS rotor. The design and preliminary testing results for the motor cooling system will also be presented. The 200 kW demonstrator will be commissed by 2024.