Effect of Permanent Magnet Material Properties on Cogging Torque of PMSM

Abstract

This study explores how the material properties of permanent magnets (PM) influence on the cogging torque of surface-mounted Permanent Magnet Synchronous Motors (PMSMs) using Finite Element Method (FEM)-based numerical analysis. A 2D model of the PMSM is created in Ansys Maxwell to evaluate the behavior of the machine under no-load conditions. The cogging torque is one of the significant problems of the PMSM due to causing torque ripple, vibration, and acoustic noise and affects the motor performance. Therefore, it is desired to be minimized and various methods are used for this. As one of them, in this study, the examination of the effects of permanent magnet material properties on the cogging torque is proposed. The analyses of magnetic flux density distribution, cogging torque, and magnetic flux density in the air gap are carried out for four distinct magnet materials. The simulation results reveal that the magnets with higher strength exhibit greater cogging torque, and air gap magnetic flux density, whereas weaker magnets result in lower values. These outcomes highlight the importance of optimizing magnet material for improved PMSM performance with low cogging torque. Thus, the magnet materials should be considered to design an optimal PMSM by improving efficiency and reducing the cogging torque.