Using Genetic Algorithms for Optimal Electromagnetic Parameters of SPM Synchronous Motors

Abstract

The permanent magnet synchronous motors (PMSMs) have been widely used in industrial applications due to the high efficiency, reliable performance and different shapes and sizes. Based on the arrangement of permanent magnets (PMs), the PMSM can be split into two primary types, i.e., surface-mounted permanent magnet (SPM) motors and interior permanent magnet (IPM). For the SPM motor, PMS are mounted on the rotor surface, while the IPM has the magnets embedded into the rotor. The use of PMs for the PMSMs has eliminated the necessity for excitation currents, thanks to the high flux density and significant coercive force. The resulting absence of excitation losses plays a key role in enhancing overall efficiency. This research, introduces a multi-objective optimal design strategy for a surface-mounted PMSM, with the primary goal of achieving maximum efficiency while minimizing material costs. The optimization is carried out through the application of a genetic algorithm. In addition, a finite element method is proposed to validate a comprehensive assessment and comparison of the variances between the initial design and optimal design. The proposed methods are applied to the practical problem of 5.5 kW SPMSM. The FEM and calculation results showed that the motor’ s efficiency increased 0.5% and material cost decreased 15.2$ after the optimization process, both are the expected results.