A Permanent Magnet Concentrated-Flux Synchronous Reluctance Motor With Torque Improvement for Autonomous Ship Propulsion

This paper focuses on the design and optimization of a permanent magnet concentrated-flux synchronous reluctance motor (PMC-SynRM) used in unmanned ship propulsion. To meet the performance and stability requirements of propulsion motors, the proposed PMC-SynRM is designed with an asymmetric rotor structure, featuring asymmetric configurations of flux barriers and permanent magnets (PMs), which contributes to a concentrated-flux effect that can greatly improve the air gap flux density, magnetic torque, and power factor. Meanwhile, the maximum magnetic and reluctance torque are superimposed at the same current phase, thereby improving the utilization of torque components for high torque density and low torque ripple. The influence of asymmetric rotor parameters on the torque performance is analyzed, and the multi-objective optimization algorithm is employed to optimize the torque quality. The effectiveness and stability of the proposed design are highlighted by comparing to the conventional permanent magnet synchronous reluctance motor (PM-SynRM). Finally, the prototype of the proposed PMC-SynRM is manufactured and the test is carried out to verify the motor performance.