Multi-material topology optimization for the PMSMs under the consideration of the MTPA control

Abstract

This study proposes multi-material topology optimization to develop a high-torque permanent magnet synchronous motors (PMSM). For the purpose, it is necessary to simultaneously optimize a structural design and current phase angle. Particularly, it is important to determine the optimal geometry of permanent magnet with the corresponding multiple iron webs and bridges. However, due to a high design complexity, many researchers have conducted topology optimization with a predetermined and fixed geometry for permanent magnet. To overcome the above limitation, this study develops the multi-material topology optimization that can simultaneously determine the optimal multi-material distribution (permanent magnet, silicon steel, and air in this study) and a design-dependent MTPA current phase angle through two design stages. In the first stage, the complicated design patterns and the corresponding MTPA current phase angle are simultaneously optimized. Note that the optimal permanent magnet is determined with optimal multiple iron webs and bridges in this stage. The electromagnetic and structural finite element analyses are performed to evaluate the torque and structural compliance, respectively, at every iteration. In the second stage, an optimized design determined in the first stage is elaborated to be structurally safe and manufacturable. Finally, the optimized PMSM design is manufactured to validate the potential of the proposed method.