[EVER] Analysis of noise reduction in a low speed and high torque PMSM with tooth concentrated windings

AuthorsJean Le Besnerais ; G. Brando ; A. Dannier ; A. Del Pizzo ; L.P. Di Noia ; R. Rizzo ; L. Castellini ; M. D’Andrea
StatusPublished in: Ecological Vehicles and Renewable Energies (EVER), 2016 Eleventh International Conference
Date6-8 April 2016
Keywords Tooth Concentrated Windings, Acoustic Noise in Electric Machines, Resonance in Permanent Magnet Machines


The paper deals with acoustic noise in permanent magnet synchronous motors (PMSM) with tooth concentrated armature windings. In particular, the noise emitted by this kind of motors is investigated with reference to high-torque low-speed applications. In these cases, due to the high number of poles, the stator yoke is usually thin and it is characterized by low natural frequencies that could lead to undesired amplifications of mechanical resonance phenomena. The paper analyzes the effects of variations of stator yoke thickness on vibrations and noise emitted by the machines. The aim is to investigate the relation between noise emission and stator yoke thickness without any other variation of the machine configuration. The analysis is led by the mathematical model of PMSM, used to characterize analytically the time behavior of the radial forces that excite the machine vibrations; FEM analysis and numerical extrapolation of the machine acoustic response are performed by the software MANATEE.

Preprint and full paper

The full paper can be found on IEEE.


This article shows in particular the effect of yoke dimensions on electromagnetic noise and vibrations of electrical machines. Changing the stator dimensions has several effects on vibro-acoustics:

  • change of the static response due different average yoke width to diameter ratio
  • change of the static response due to different teeth/yoke coupling behaviour with respect to radial and tangential force
  • change of the dynamic response due to change of the natural frequency
  • change of the radiating surface due to change of the outer diameter
  • change of the modal radiation factor due to change of the radiating surface geometry

All these effects can be studied in MANATEE.