Structural and Electromagnetic Rotor Topology Optimization of a PM-Assisted Synchronous Reluctance Motor Using Commercial Software

This contribution addresses the combined structural and electromagnetic topology optimization of the rotor in a permanent magnet-assisted synchronous reluctance machine. A finite element approach is employed to evaluate the responses. Once the sizes and positions of the magnets in the rotor are fixed, the optimization domain is extended exclusively to the elements made of soft material. The optimization algorithm is based on the density method, already implemented within the commercial software chosen as the pre and post-processor. Some important tips on the structural analysis set-up are provided to best exploit the combined topology optimization, in order to obtain a feasible design. Two different approaches in terms of optimization objectives and constraints are analyzed. The first one minimizes the volume, while the second one maximizes the mean torque. Redesign is carried out for both topological results to obtain manufacturable geometry. The second approach identifies a solution with a mean torque increased by 7.5%, a torque ripple reduced by 11.7%, albeit at the cost of a volume increased by 9.6% compared to an existing design used as a benchmark.