A Multi-Material Topology Optimization Method for Template-Free Design of Synchronous Reluctance Motors

Design optimization of electrical machines, including synchronous reluctance motors (SynRMs), often depends on predefined structures and materials based on the designer's experience, resulting in limited design freedom. To address this problem, this paper proposes a novel topology optimization method that enables automatic generation of the entire motor structure of SynRMs, including the stator and rotor geometries, without relying on predefined templates. First, a multi-material interpolation scheme is developed to represent the winding, core, air and excitation current in the stator structure. Then, to integrate conceptual design, quantitative optimization, and manufacturable geometry processing in a single streamlined stage, a multi-material boundary division technique is introduced for generating smooth boundaries. The simultaneous stator and rotor topology optimization scheme is developed for the template-free design optimization of SynRMs. The developed method creates an optimal structure with an enhanced torque profile without a templated geometry. The effectiveness of the proposed method is validated through both simulation and experimental results of a prototype.