Optimization of Electromagnetic Noise for PMSMs Considering Space–Time Phase Superposition of Various Force Harmonics

Noise is one of the main design considerations for permanent-magnet synchronous machines (PMSMs) in plenty of applications. Noise reduction is usually conducted by optimizing the main air-gap magnetic force due to their strong correlation. However, it has been proved that the noise is induced by the synthesizing effect of various force configurations and harmonics, which makes it quite complicated for noise reduction. In this article, a noise optimization method considering various force configurations and harmonic phase differences is proposed to improve the design efficiency and accuracy of PMSMs. The proposed method is based on the semi-analytic method which is more efficient than the finite element method (FEM). The superposition approach of different force configurations and spatial harmonics is theoretically analyzed and then integrated into the semi-analytical method (SAM) in order to obtain a high-accuracy and high-efficient noise prediction model. Thereafter, an optimization algorithm is utilized and the optimized scheme can be obtained. This result is also compared with that of the conventional noise reduction method to highlight the superiority of the proposed method. Finally, the experiment is performed to verify the optimization result.