Six-Axis Rotor Magnetic Suspension Principle for Permanent Magnet Synchronous Motor with Control of the Positive, Negative and Zero-Sequence Current Components

A novel magnetic levitation principle, applicable for two- and four-pole high-speed permanent magnet synchronous motors, is presented. The drive consists of two half-motors, in which two asymmetric star-connected windings are arranged. An additional active magnetic bearing part is inserted to control the axial displacement. The two coils of the axial magnetic bearing are fed by the zero-sequence current components of the star-connected windings. The proper control of the positive, the negative, and the zero-sequence currents permits to set the torque, the radial levitation forces and the axial levitation force, respectively.