A Novel Application of Harmonics Spread Spectrum Technique for Acoustic Noise and Vibration Reduction of PMSM Drive

This paper presents experimental investigation study of Acoustic Noise and Vibration (ANV) reduction in Permanent Magnet Synchronous Motor (PMSM) drives with a novel application of `harmonics spread spectrum technique'. In order to reduce the ANV of PMSM drives, the Random Pulse Width Modulation (RPWM) method is applied which distributes the power of harmonic noise in a wide range of discrete frequency spectrum. Furthermore, in-depth theoretical analysis is presented about the way RPWM improves torque ripples, vibration and acoustic noise in PMSM drives. The theoretical and experimental results obtained are used to draw the operational concept of the power electronics converters to reduce ANV; which is produced by PMSM drive. Time and frequency-domain analysis are carried out to examine the effects of change in the operating parameters such as pulse-width, etc. of the power electronics converters on the ANV. A small-scale laboratory set-up was developed for PMSM drive with low cost acoustic chamber for experimental investigations. Experimental results show significant reduction in ANV and torque ripples of the PMSM drive with the application of RPWM technique.