Design and Analysis of a Novel Bearingless Flux-Switching Permanent Magnet Motor

Conventional bearingless permanent magnet motors have magnets on their rotor, and their maximum electric loading performance may be restricted by thermal instability and lack of mechanical integrity. To overcome such drawbacks, a novel bearingless motor with magnets, suspension force windings, and torque windings in the stator is proposed; the proposed motor is called bearingless flux-switching permanent magnet motor. First, the structure and winding configuration of the bearingless flux-switching permanent magnet motor are designed and introduced. Second, the operation principle of radial suspension force is illustrated based on the principle of reverse direction magnetization for symmetrical rotor teeth. Third, the corresponding electromagnetic characteristics, including flux field distributions, torque, and controllability of radial suspension forces, are investigated. Finally, the decoupling characteristics between suspension force windings and torque windings are discussed and analyzed comprehensively. High power per permanent magnet volume, good controllability of radial suspension forces, and excellent decoupling characteristics are achieved with the proposed bearingless flux-switching permanent magnet motor. Analytical results are validated through finite-element analysis and experimentation.