COMPLEX MAGNETIC CHARACTERISATION OF IRON-SILICON TRANSFORMER SHEETS

István Mészáros

   Different transformer lamination alloys were studied by non-destructive magnetic methods in the present work. Nine different commercial grades were compared. The investigated alloys were strongly different quality products but all of them were so-called electro-technical steels produced for laminated iron core production. Seven of them were non-oriented and two of them were grainoriented with cube texture. All of them contain silicon alloying to improve their magnetic properties. In this study the so called hyperbolic model of magnetization was applied for the experimental magnetization curves. It was proved that the applied model is excellent for describing mathematically the experimental magnetization curves. However, the application of the model is useful for evaluating the measured data as well. The model assisted data evaluation can provide not only the classical magnetic parameters but new information like the ratio of irreversible and reversible components of magnetization as well. Therefore, it can help the better understanding of the connection between the magnetic parameters and their microstructural background and can extend the application possibilities of magnetic measurements.

Keywords: T(x) model, minor loops, magnetisation curve, irreversible magnetization, power loss

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