Experimental verification of radial force control for a PMSM self-bearing motor drive

This paper presents a radial force control scheme for self-bearing operation of a surface permanent magnet synchronous motor. The control scheme is based on a self-bearing motor which consists of separate torque and suspension windings. Torque winding produces rotational torque, and the suspension winding produces radial force for rotor levitation. Calculated winding currents are combined internally in the controller. Thus, only a set of winding is required to produce controllable radial force and rotational torque. Analysis, implementation, and experimental verifications of the proposed scheme are presented.