Magnetisation-induced mechanical resonance in electrical steels

Extensive research has been carried out over the years to reduce the acoustic noise resulting from vibration of electromagnetic cores mainly caused by magnetostriction. This paper presents the results of a basic experimental study of magnetostriction in strips of grain oriented electrical steel commonly used in electromagnetic cores which gives an important new understanding of the phenomenon. Results suggest that a transformer core assembled from laminations of grain-oriented electrical steel around 0.3 m long would resonate at a magnetising frequency of 1.5 kHz which could result in excessive vibration and noise. (c) 2007 Elsevier B.V. All rights reserved.