Optimal Design of Outer Rotor Spoke Motors Considering Practical Slot-Filling Factor Based on the Manufacture Process

Abstract

The slot-filling factor is a critical parameter in motor design, as it is closely associated with key factors such as magnetomotive force and efficiency. Conventional design methods often rely on fixed estimates of the slot-filling factor, resulting in discrepancies between predicted and actual performance. This paper proposes a method for estimating the slot-filling factor, considering slot geometric variations and manufacturing factors specific to outer rotor motors. The effectiveness of the proposed method is demonstrated by comparing the optimized design results with those obtained using a fixed slot-filling factor. The results highlighted the limitations of the conventional approach and demonstrated the superiority of the proposed method. Additionally, the proposed slot-filling factor estimation method is validated by comparing the predicted winding layout with the actual motor's winding layout through X-ray imaging of the manufactured motor. Furthermore, the performance of the predicted optimal design model is validated by comparing it with experimental data.