Influence of Field Weakening Control on Electromagnetic Force and Electromagnetic Vibration of SPMSMs

A 50kW surface mounted permanent magnet synchronous motor (SPMSM) is used to explore the influence of field weakening control on electromagnetic force and vibration characteristics of SPMSMs. The air gap magnetic flux density was calculated by 2-dimensional (2-D) finite element method (FEM).The Maxwell stress tensor method (MSTM) was employed to analyze the motor's radial and tangential electromagnetic force density. By using the 2-D fast Fourier transformation, the time and spatial harmonics of the radial and tangential electromagnetic force were decomposed. In the meanwhile, vibration characteristics under different phase angles of armature current with field weakening control of the SPMSM were analyzed by the mode superposition method based on a multi-physics model. The results show that the phase angle of the armature current has a significant influence on the electromagnetic excitation force harmonics. It's effective to use the field weakening control to reduce the electromagnetic vibration of SPMSMs. This research will contribute to electromagnetic design and field weakening control strategies of SPMSMs.