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Numerical and Experimental Analysis of Torsional Vibration and Acoustic Noise of PMSM Coupled With DC Generator

The magnetic field inside a machine is responsible for the mechanical excitation of the stator structure, generating vibrations and thus, audible noise. In this article, the Permanent Magnet Synchronous Motor (PMSM) is driven by using sinusoidal pulsewidth modulation technique and then an investigation (cause and effect) of Acoustic Noise and Vibration (ANV) is presented. An equivalent lumped parametric modeling of end-to-end coaxially coupled shafts between PMSM and DC generator along with effective modal mass and modal participation factor accuracy enhancement technique is presented to predict the torsional vibration. The modal analysis approach is used to analyze the torsional vibration response, which is used to estimate the source of acoustic noise, and a mathematical approach is presented at the end to calculate ANV of electric drives. Theoretical and experimental investigations are carried out on a 1.07- kW, 4-poles, 36-slots, 3-phase PMSM drive. Analytical and numerical results are validated by experimental studies.