Design of a Novel Homopolar Bearingless Slice Motor With Reluctance Rotor

This paper presents the first prototype of a novel class of bearingless slice motors whose main difference from other examples of this motor topology is the absence of permanent magnets in the rotor. A homopolar permanent-magnetic-bias air-gap field is generated by stator magnets and enables passive stabilization of three degrees of freedom. This drive concept features special operational behaviors that distinguish it from other state-of-the-art bearingless drives. A prototype motor was optimized and fabricated, and measurements were conducted to verify finite-element simulation results and to prove the functionality of the drive and its nonlinear control scheme.