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The purpose of this paper is to present the application of the loss approximation method for non-oriented electrical steel developed by the authors. A new model of a toroidal sample with dimensions ensuring high uniformity of the field was presented.

A critical analysis of the methods used was carried out. Based on these considerations, the authors proposed their own loss approximation method, which allows obtaining high accuracy in a wide range of induction and frequency. The proposed method is based on the assumption that for a certain frequency range losses can be describe by two terms formula. For a fixed value of the peak flux density Bm, the graph of specific loss divided by the frequency should have the form of a straight line. Then, the obtained coefficients for different Bm are the basis for approximation with the power function.

The comparison of measurement and approximation results shows that the method allows to obtain very good accuracy in a wide range of induction and frequency.

More detailed studies on the impact of cutting on a larger number of samples with different geometrical dimensions are needed.

Application of the new method provides a better approximation of the curve of the loss and thus a more accurate calculation of the core loss in the electrical machines.

The paper presents the application of the loss approximation method for non-oriented electrical steel developed by the authors. A new model of a toroidal sample with dimensions ensuring high uniformity of the field was presented. It is shown that the approximation introduced allows for high accuracy in a wide range of frequency and magnetic flux density.

The purpose of this paper is to present a methodology of identification and calculating vibrations of power transformers caused by magnetostriction.

All calculations are based on finite element approach. Electromagnetic model uses 2D time stepping solution in nonlinear continuum of the core accompanied with equivalent representation of overlapping areas. Structural model is 3D with special representation for laminated core limbs. Theoretical results are compared with experimental ones obtained as operational deflection shapes from vibration measurements.

Tensor representation of magnetostriction stress enables calculation of equivalent forces acting on arbitrary chosen parts of laminated core. These forces converted into amplitude and phase of Fourier spectrum and introduced into structural model make possible to get displacement field with reasonable accuracy.

Assumption of magnetic isotropy of the transformer core is the main simplification during analysis.

It was proved that small deformation of the core structure originated from assembly technology may be the reason of substantial growth of the vibration level.

This paper provides a step‐by‐step explanation of how to get core vibration starting from magnetic field distribution.