Hybrid Optimization Method for Additively Manufactured Permanent Magnet Synchronous Motors

This paper presents a new two-step optimization process for the rotor of a multilayer Interior Permanent Magnet Synchronous Motor (IPMSM), using additive manufacturing (AM) to create a layered rotor made from alternating soft magnetic materials (SMM) and permanent magnet (PM) layers. The process starts with parametric optimization (PO), to determine the optimum number and dimensions of the PM layers, leading to a solid baseline design. The second step was topology optimization (TO), using the NGnet method to achieve the optimum rotor geometry, mainly to reduce demagnetization risk. The TO was run using different mesh element sizes to investigate the mesh refinement effect on the design. The final rotor design that was optimized is characterized by a higher torque density, improved use of PM material, and a lower risk of demagnetization when compared to the baseline design. The optimization process presented in this paper provides a valuable approach for the design of high performance IPMSM rotors and subsequent manufacture through additive manufacturing.