Analysis and Control of Multiphase Permanent-Magnet Bearingless Motor With a Single Set of Half-Coiled Winding

In this paper, a multiphase bearingless motor (MBLM) with a single set of half-coiled winding is proposed, with advantages such as simpler construction and capability of fault-tolerant operation, comparing with the traditional BLM with dual groups of three-phase windings. The magnetomotive force distribution of the half-coiled winding is analyzed. Then, the winding configuration of a five-phase permanent-magnet bearingless motor is introduced, and the inductance of the MBLM is deduced by the modified winding function approach and verified by finite-element analysis. Furthermore, the control system is proposed based on the derived voltage model, torque model, and suspension force model, considering rotor eccentricity. Finally, static and dynamic experiments are provided on a prototype motor to verify the validity of the analysis.