Design of a Dipole Internal Permanent Magnet Bearingless Motor for Flux-weakening Control

In this paper we present the design of a new interior permanent magnet (IPM) bearingless slice motor that facilitates flux-weakening control for high-speed operations. The motor consists of a dipole IPM rotor with ferrite magnets, a 12-tooth stator core, 12 concentrated coils grouped into quadruple 3-phase windings, and four 3-phase inverters. We discuss the design process for the prototype and show test results demonstrating stable levitation in the flux-weakening region.