Numerical Analysis of the Contribution of Magnetic Forces and Magnetostriction to the Vibrations in Induction Machines

Inhalt:
Magnetic forces and the magnetostriction effect both contribute to the vibrations and noise of electromechanical devices. In this paper, the contribution of these causes to the vibrations is analysed numerically by using the finite element method for both the magnetic and the mechanical calculations. The magnetic forces are calculated analytically and the magnetostriction is calculated by making use of magnetostriction measurements, conducted in a special test setup. Calculations are made on a two-pole and a four-pole induction machine (IM). When considering only the main components of the deformations, analysis of the results reveals that in the case of the two-pole IM, the contributions of the magnetic forces and the magnetostriction add up, while in the case of the four-pole IM the respective contributions substract. We can conclude that the contributions of the magnetic forces and the magnetostriction to the vibrations of an electromechanical device, can either add up or substact, depending on the geometry of the device and the deformation mode.