Torque Ripple Minimization for Bearingless Synchronous Reluctance Motor

A bearingless synchronous reluctance motor (BSRM) is a new type of bearingless motors with numerous advantages. The conventional BSRM with a salient-pole rotor is easy to manufacture at the cost of low output torque and high torque ripple. In this paper, a new rotor structure with multilayer flux barrier of the BSRM is proposed to improve performances of torque and levitation force. The key is to optimize flux-barrier layer number, flux-barrier thickness, and magnetic guide thickness. This new rotor structure is compared with the conventional one, confirming the validity of the proposed design. The experimental results show that the proposed BSRM can achieve stable operation with satisfactory levitation performance.