Preliminary Assessment of a Highly Flexible HTS Drive for Electric Aircraft

Abstract

The push for the Energy Transition and the electrification of emerging applications, particularly those that already include cryogenics, has stimulated new developments in electric machines with high-temperature superconducting (HTS) materials in their components. Electric aircraft enabled by HTS-based systems, such as motors and energy distribution cables, are highlighted among those applications. In this context, there is an urgent need for machines with specific powers ranging from 15 to 30 kW/kg, which can leverage the inherent compactness and low weight of HTS motors. This work presents an electromechanical drive built by an axial-flux type motor with an HTS rotor, where the latter uses HTS REBCO tapes. The drive enables the electronic changing of the number of magnetic poles generated by a double stator with conventional windings. Consequently, the rotor must dynamically reconfigure its distribution of currents in the tapes to adapt to different numbers of poles. The prototype of the polyphase power electronics converter for the drive is also introduced. It allows for generating 24 voltages with frequency, voltage, and phase shift defined by the user according to the desired number of poles. Despite its increased complexity, the converter and the motor allow for improved performance compared to conventional drives. Preliminary experimental results are presented to support the discussion and outline prospects for the proposed concept in the framework of electric aircraft applications.