An Experimental Investigation of Acoustic Noise and Vibration of PMSM Induced by Power Electronics Converters

Abstract

— This article presents an experimental and theoretical investigation of acoustic noise and vibration (ANV) produced by permanent magnet synchronous motor (PMSM)-based electric drive. The principal sources of ANV in PMSM are the natural frequency of oscillations for a structure, magnetostrictive push–pull forces, aero-dynamical and aero-mechanical forces, and the interaction of time and space harmonics in airgap flux density and armature flux density. Initially, a structural mathematical model of PMSM has been developed to determine the structural natural frequency component in the ANV pattern emitted from the PMSM. Later an analytical electrical model has been designed to assess the torque performance of the machine. Interaction of the torque ripple with the natural frequency oscillation has been demonstrated to establish the net acoustic pressure levels. Power electronic converter injects the time harmonics into the PMSM drives, which can be addressed by employing suitable control algorithms. To investigate the ANV of PMSM drive, a mathematical model of PMSM is developed and analyzed. The physical phenomenon responsible for ANV induced by Maxwell forces in the machine has been discussed extensively. Time-domain and frequency domain analysis is used to show the effects of changing the operating parameters of the power electronic converters on the ANV. The main focus of this work is to build a better understanding and to draw an operational concept of ANV produced by PMSM drive from deduced theoretical and experimental investigations. The experimental investigations are performed on a low-cost laboratory setup of PMSM drive and acoustic chamber to validate the theoretical deductions. Furthermore, a numerical techniques-based design approach for a reduction in ANV for PMSM drive is presented in this article. This approach reduces the space harmonics in the airgap flux density wave by altering the number of slots in PMSM. Hence, the effective torque pulsation reduction has also been reported.