Performance Improvement of Ferrite-Assisted Synchronous Reluctance Machines Using Asymmetrical Rotor Configurations

This paper proposes novel ferrite-assisted synchronous reluctance machines (FA-SynRMs) having the merit of highly improved machine performance including torque, efficiency, and power factor. The particular superiority of the proposed FA-SynRMs is the utilization of an asymmetrical rotor configuration that contributes to the full use of torque components by allowing the magnetic and reluctance torques to reach their maximum values near or at the same current phase angles. To provide visible insights into the contribution, a frozen permeability method is utilized to separate the torque into the reluctance torque and the magnetic torque based on a 2-D finite-element method by the aid of JMAG-Designer. For highlighting the advantages of the proposed models, a conventional FA-SynRM with symmetrical rotor configurations is adopted for comparison under the same operating conditions. As a result, it is demonstrated that the proposed design is effective in improving the performance of FA-SynRMs.