Design a novel asymmetric chamfered on consequent-pole vernier permanent-magnet machine for electric propulsion vessel

This article proposes a novel asymmetric chamfering consequent-pole Vernier permanent magnet (CPVPM) rotor topology of torque enhancement and torque ripple reduction for electric propulsion vessels. The rotor structure is featured by the asymmetric chamfered structure applied on the CP adjacent to the PMs. It is demonstrated that without any modification of high price and limited storage of rare-earth PM materials employed for the rotor, the torque density of the machine with an asymmetric chamfering can be effectively increased. The influence of key asymmetric chamfered parameters of the CPVPM machine on torque and torque ripple characteristics are investigated. Then, the presented asymmetric chamfered machine, along with a prior symmetric chamfered machine, has been meticulously designed and globally parametrically optimized. Both machines share identical specifications, including stator dimensions, rotor diameter, and permanent magnet (PM) utilization. Moreover, the mechanical characteristics and efficiency of the proposed motor are analyzed comprehensively. Finally, our investigation indicates that even a minor refinement in the novel asymmetric chamfered structure can further mitigate flux leakage issues, elevate torque density, and reduce torque ripple.