Design and Testing of a Modular High-Speed Permanent-Magnet Machine for Aerospace Propulsion

High-power-density megawatt-scale surface permanent magnet (SPM) machines are strong candidates for future aircraft electric propulsion applications. Additional power density and fault tolerance benefits can be gained by designing the machine as an Integrated Modular Motor Drive (IMMD) that breaks the machine into multiple three-phase modules, each with its own dedicated power electronics. This paper discusses development of a 1 MW SPM machine for an IMMD configuration with a rated speed of 20,000 rev/min. A lower-power demonstrator version of this machine (200 kW) has been built to retire key technical risks and to validate machine models for the final design. The materials, components, and performance of this demonstrator machine are reviewed. The machine test configuration is described, and initial test results are presented that exhibit promising agreement with performance predictions provided by simulations and analytical models. Finally, fault tolerance benefits of the modular stator design are experimentally demonstrated.