Improving performance of ring-winding axial flux permanent magnet motor based on harmonic analysis approach

Recent advancements in the design of permanent magnet motors have attracted considerable interest; however, many of these innovative motors are still in their developmental stages and encounter a variety of design challenges. This paper addresses the pressing need for further refinement of these motor topologies, particularly focusing on the ring-winding axial flux permanent magnet (RWAFPM) motor, which suffers from significant cogging torque ripple. The study begins with a thorough analysis of cogging torque harmonics to pinpoint the dominant harmonics impacting the RWAFPM motor's performance. By identifying the sources of these harmonics, the paper proposes effective strategies for their mitigation. A novel stator core configuration and winding layout are introduced, and the impact of stator shifting on harmonic reduction is explored. The findings reveal that substantial improvements can be achieved through cost-effective modifications to the manufacturing process. Specifically, the research demonstrates a remarkable decrease in ripple torque from 44.5 to 6.1, an enhancement in efficiency from 86.7 to 90%, and a 37.7% decrease in copper usage. The validity of these results is established through the use of 3D finite element modeling complemented by experimental measurements, highlighting the effectiveness of the proposed solutions in optimizing RWAFPM motor performance.