A New Hybrid Permanent Magnet Synchronous Reluctance Machine With Axially Sandwiched Magnets for Performance Improvement

This paper proposes a new hybrid permanent magnet synchronous reluctance machine (HPM-SynRM) with axially sandwiched magnets for improving machine performance including airgap flux density, back electromotive force, torque, torque ripple, efficiency, and power factor. The significant feature of the proposed machine is the configuration of axially integrating two kinds of independent and symmetrical rotors with a specific assembling angle, such that it can make full use of the magnetic torque and the reluctance torque for efficient production of the total torque. Meanwhile, the proposed machine greatly improves the PM utilization for high magnetic torque, and releases the stress condition of SynRM rotors for more proper design of ribs, thus to further improve the torque, efficiency, and power factor, especially when compared to the conventional PM-SynRM with the same machine specifications and operating conditions. The design of the proposed machine, including the PM optimization using the Kriging method and genetic algorithm, rib width and assembling angle design using the finite element method (FEM), has been first discussed in detail. Then, the advantages of the proposed machine are highlighted by quantitatively comparing to a conventional PM-SynRM by the FEM. Finally, the proposed machine is manufactured to validate its high performance by experiments.