Topology optimization of a PMSM based on a local method to gain lightweight structure and better operation

In this study, a Topology Optimization procedure has been applied to a 3-phase permanent magnet synchronous machine (PMSM) to gain a lighter weight motor with lower torque ripple and cogging torque, while the average torque maintains at a reasonable level with a novel local method, named Local Importance Measure (LIM). The validity of this method is checked with an electrical machine's permanent magnet and rotor part to reduce production costs, permanent magnet and material consumption, and reach a better motor performance. To give more freedom to the designers, replacing the conventional parameter optimization, topology optimization is used. To overcome continuous grey optimization with intermediate material characteristics, a discretized binary method is applied. The electromagnetic field is calculated by using the 2D finite element software FEMM, and the optimization is processed via Matlab. The results verified the method's validity in reaching to a machine design with lower torque ripple and cogging torque, which causes less vibration and acoustic noise. In addition, an improvement in the flux linkage and back-EMF waveform is gained. It is shown that the proposed method can be extended to different kinds of electromagnetic devices, with different objective functions.