Rotor Topology Optimization for Interior Permanent Magnet Machines Considering Manufacturability

Rotor topology optimization becomes a critical tool in interior permanent magnet (IPM) machine design for better performance and material utilization. Existing optimization methods mainly focus on electromagnetic performance, neglecting manufacturability during the optimization process. In this paper, a novel derivative-free design method is proposed for rotor topology geometrical optimization of IPM machines, which can consider manufacturability robustness. Explicitly expressed elementary components (ECs) are developed for the representation of the material distribution. Projective transformation and Boolean operations are employed to improve the diversity of material distribution. Geometrical constraints are applied to guarantee the manufacturability without introducing additional computational burden. The comparison between optimized results obtained from the proposed and conventional NGnet methods verify that the proposed method can effectively enhance electromagnetic performance of IPM machines while securing manufacturability, using finite element analysis. A prototype has been manufactured and experimentally tested for validation.