Abstract:The bearingless flux-switching permanent magnet motor (BFSPMM) places the permanent magnets on the stator side of the motor, providing an excellent heat dissipation path and fundamentally solving the problem of demagnetization of the rotor permanent magnets at high speeds, ensuring reliability under high-temperature conditions. Meanwhile, it combines the high power density and high torque characteristics of flux-switching motors with the non-contact and wear-free advantages of bearingless technology, theoretically enabling multi-degree-of-freedom active suspension of the rotor. As the core of the next-generation high-speed electric spindle, it will directly enhance the processing accuracy and efficiency of high-end CNC machine tools. In flywheel energy storage systems, it can achieve ultra-high-speed operation, significantly increasing energy storage density. Additionally, in special fields such as aerospace, semiconductor manufacturing, and life sciences, which have strict requirements for pollution-free and ultra-high-speed operation, it has irreplaceable potential and is one of the key technologies driving the upgrade of future high-end equipment. However, conventional BFSPMMs can only achieve two-degrees-of-freedom (2-DOF) magnetic levitation for the rotor. To address this limitation, this article constructs a novel Bearingless Flux-Switching Permanent Magnet Motor with Five Degrees of Freedom (5-DOF-BFSPMM) by employing two BFSPMMs and one axial magnetic bearing, and proposes a high-performance cooperative levitation control strategy for five-degree-of-freedom control. Two BFSPMMs are coaxially arranged and installed with a 3° circumferential offset to cancel their cogging torques mutually. Based on the unique structure of the motor, the 5-DOF dynamic model of the 5-DOF-BFSPMM rotor is derived. Furthermore, leveraging this dynamic model, a cooperative levitation control strategy is proposed, which decouples the rotor′s translational displacements and tilting angles. Experimental results show that the proposed cooperative levitation control strategy successfully achieves high-performance magnetic levitation control for all five degrees of freedom in the 5-DOF-BFSPMM. Specifically, the steady-state radial displacement ripple is reduced by 41.9%, and the radial disturbance amplitude is suppressed by 32.9%.