Investigation of induced anisotropy in silicon alloy cores based on magnetic domain structure

Abstract

In this study induced anisotropy inside the specimen applying external magnetic field was investigated by means of surface domains in grain-oriented Fe-3%-Si transformer sheets. Bar (closure)-type domains and lancets on the sheet surface were observed by magneto-optical Kerr microscopy. Moreover, in specimens with standard Epstein geometry, crystal orientations of grains in a chosen spot were examined via EBSD analyses and compared with Kerr images. On the other hand, deterioration in flux density distribution depending on induced anisotropy in the core joints of square-shape transformer was simulated using ANSYS simulation software. Therefore, it is found a proportional connection between the reactions of surface domains under influence of transverse magnetic field and power losses of certain steels. Components of power losses of single steel sheet and of a transformer core made of actual steel sheet have been theoretically and empirically compared with this proportional connection.

Keywords

• Magnetic domains,induced anisotropy,electrical steels,power losses

Silisyum alaşımlı çeliklerde indüklenen anizotropinin manyetik domain yapısına göre incelenmesi

Abstract

Bu çalışmada grainleri yönlendirilmiş Fe-%3-Si transformatör çeliklerinde, dışarıdan uygulanan manyetik alan yoluyla malzemenin içinde uyarılan anizotropi enerjisi, yüzey domainleri vasıtasıyla incelenmiştir. Malzemenin yüzeyindeki bar tipi ve çivi-benzeri manyetik domainler, manyeto-optik Kerr mikroskobuyla görüntülenmiştir. Ayrıca, standart Epstein geometrisine sahip numunelerde, seçili bölgedeki grainlerin kristal yönelimleri, EBSD analiziyle araştırılmış ve Kerr görüntüleriyle karşılaştırılmıştır. Öte yandan, ANSYS benzeşim programıyla kare tipi bir transformatör çekirdeğinin eklem bölgelerinde, indüklenmiş anizotropiye bağlı akı dağılımındaki bozulmalar simüle edilmiştir. Böylelikle, enine manyetik alan etkisi altında, yüzey domainlerin vereceği tepkiler ile çeliklerdeki güç kayıpları arasında orantısal bir bağ bulunmuştur. Bir elektrik çeliği ve bu çelikten oluşturulmuş bir transformatör çekirdeğinde oluşan güç kayıplarının bileşenleri, bu orantısal bağ ile hem teorik hem de deneysel olarak karşılaştırılmıştır.

Keywords

• Manyetik domain,indüklenmiş anizotropi,elektrik çelikleri,güç kayıpları

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