Reducing Permanent Magnet Volume in a PMSM Using Optimization Algorithms

The paper presents a two-step approach to reduce the volume of the rare-earth permanent magnets (PMs) used in a small power permanent magnet synchronous machine (PMSM) with 36 stator slots and 12 rotor surface-mounted PMs. In the first step, half of the PMs with the same polarity were replaced with steel, resulting in a machine with half the number of PMs but the same number of magnetic poles. In the second step, the shape of the PMs was optimized to ensure that the new motor produces the same torque as the initial PMSM. Finally, other optimization criteria were used to enhance the torque–magnet volume ratio of the newly designed PMSM. The study was conducted using Finite Element Method (FEM) models and specific optimization algorithms. To validate the models, both COMSOL Multiphysics and Altair Flux software were used, and the results were compared.