Quantification of magnetostriction for analysis of vibration of electrical machine cores

Magnetostriction in non-oriented electrical steel is a source of vibration of electrical machine cores. This paper covers measurements of magnetostriction in a disc sample of non-oriented electrical steel under unidirectional and two-dimensional magnetisation conditions, close to those occurring in electrical machine stator cores for use in analysis of core vibration. A comparison with magnetostriction measured in conventional Epstein strips is presented. The characterisation of magnetostriction of the disc sample provides better versatility under closer magnetisation conditions present in machine cores.