Multi-Material Topology Optimization with Continuous Magnetization Direction for motors design

Permanent magnet-assisted synchronous reluctance motors (PMSynRM) have a significantly higher average torque than synchronous reluctance motors. Thus, determining an optimal design results in a multi-material topology optimization problem, where one seeks to distribute ferromagnetic material, air and permanent magnets within the rotor in an optimal manner. In this paper, we propose the use of density-based distribution scheme, which allows for continuous magnetization direction. A filter using K-mean clustering is used to determine the magnetization angle final distribution accounting for technical feasibility. As for the ferromagnetic material interpolation, a novel interpolation scheme inspired by the topological derivative is established. A comparison with several interpolation schemes is proposed. Finally, the design of the electrical motor is proposed to maximize the torque value.