Design and electromagnetic performance analysis of a new stator-permanent magnet bearingless machine

In the paper, a new stator-PM bearingless machine (SPMBM) is proposed. Its suspending winding, armature windings and PMs are in the stator, while no PMs or windings are in the rotor. The paper theoretically analyzed topology and operating principle of the proposed three-phase 12/8 poles SPMBM. The magnetic field analysis model was established based on finite element method (FEM). Hence, the corresponding magnetic characteristics, including magnetic field lines, air gap magnetic density, suspension force, and electromagnetic torque are deduced. The relationship between suspension force and winding currents and angles were calculated. The calculation results indicate the proposed new structure of SPMBM has a good suspension and rotation performance. The studied results build a base for further motor structure optimization and rotating control.