Effect of mechanical stress on different iron loss components up to high frequencies and magnetic flux densities

Abstract

Purpose The purpose of this paper is to study the variation of the specific iron loss components of electrical steel sheets when applying a tensile mechanical load below the yield strength of the material. The results provide an insight into the iron loss behaviour of the laminated core of electrical machines which are exposed to mechanical stresses of diverse origins. Design/methodology/approach The specific iron losses of electrical steel sheets are measured using a standardised single-sheet tester equipped with a hydraulic pressure cylinder which enables application of a force to the specimen under test. Based on the measured data and a semi-physical description of specific iron losses, the stress-dependency of the iron loss components can be studied. Findings The results show a dependency of iron loss components on the applied mechanical stress. Especially for the non-linear loss component and high frequencies, a large variation is observed, while the excess loss component is not as sensitive to high mechanical stresses. Besides, it is shown that the stress-dependent iron loss prediction approximates the measured specific iron losses in an adequate way. Originality/value New applications such as high-speed traction drives in electric vehicles require a suitable design of the electrical machine. These applications require particular attention to the interaction between mechanical influences and magnetic behaviour of the machine. In this regard, knowledge about the relation between mechanical stress and magnetic properties of soft magnetic material is essential for an exact estimation of the machine’s behaviour.

Magnetic Properties of Silicon Steel after Plastic Deformation

“…The influence of residual stress is considered only in a small subset of the proposed cutting models, and the models that do incorporate the effect of stress in the cutting model do not consider the effect of different frequencies of the applied magnetic field. Unrelated to the cutting models, material models have been proposed that correlate the applied mechanical stress to the magnetic properties of silicon steels for uni-directional magnetization [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ] and multi-directional magnetization [ 16 , 17 , 18 , 19 ]. These models are based on measurements of the effect of externally applied stress within the elastic or plastic region while external mechanical load was present.…”

Complete and accurate modular numerical computation scheme for multi‐coupled electric drive systems

“…In various scientific studies, this model has been used to calculate the losses in electrical machines. It can be combined with the continuous local cut-edge model or other variants, for example the general dependency of mechanical stress described in Section 6 [17]. In [13], the effect of texture and grain size on the iron loss components has been studied.…”

Equivalent Strain and Stress Models for the Effect of Mechanical Loading on the Permeability of Ferromagnetic Materials

“…On the other hand, the same effects can be utilized for harvesting electrical energy from mechanical vibration [2], [3]. Complex multiaxial strains and stresses may occur in such applications, but identification measurements are most commonly available only under uniaxial stress parallel to the magnetic field [4]- [5]. A simple way to account for the multiaxial loadings in modeling tools is to reduce them to equivalent uniaxial strains [6] or stresses [7]- [8] for which permeability measurements are available.…”