Sains Malaysiana 43(6)(2014): 909–914

Simulation and Statistical Approaches on Electrical Steel’s Magnetic Behaviour under

Unidirectional Single Sheet Tester

(Pendekatan Simulasi dan Statistik ke atas Kelakuan Magnet Keluli Elektrik di bawah

Satu Arah Penguji Kepingan Besi Tunggal)

NOOR ASHIKIN MOHD RASHID* & WAN NOR LIZA WAN MAHADI

Electromagnetic Radiation and Devices (EMRD), Block E, Department of Electrical Engineering

Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia

Received: 27 March 2013/Accepted: 2 December 2013

ABSTRACT

Evaluation of magnetic properties of electrical steel is vital in improving the quality of electrical machinery since it is used as magnetic cores for transformers, motors and generators. A double yoke single sheet tester (SST) was modeled using two identical C-cores wound with copper wires at limb side in horizontal arrangement. The magnetic properties for electrical steels, grade M4 and M19 were tested under a frequency of 50 Hz with the current ranging from 0.2 to 2.4A. The effects of the sample dimension and anisotropy on magnetic measurements were investigated. Evaluation on specimen dimensions indicate that the non-uniformity of sample magnetization in overhang sample can attribute to the flux leakage between the yoke legs. The stray flux is also increased with the overhang sample. However, the so-called fit-in sample which is fitted nicely between the yoke end poles can minimize the effect of stray flux. One way ANOVA and T-test were used as statistical methods and executed at the 5% significance level. It is statistically proven that the magnetic properties of both magnetic materials are influenced by their anisotropy.

Keywords: Anisotropy; magnetization; single sheet testerelectrical steel; stray flux

ABSTRAK

Penilaian sifat magnet keluli elektrik penting dalam meningkatkan kualiti jentera elektrik kerana ia digunakan sebagai teras magnet untuk transformer, motor dan penjana. Penguji kepingan besi tunggal (SST) yang diperbuat daripada dua teras-C yang sama saiznya, dililit dengan wayar tembaga di bahagian teras anggota secara mendatar. Sifat magnet keluli elektrik, gred M4 dan M19 diuji pada frekuensi 50 Hz dengan arus pada kadar 0.2 kepada 2.4A. Kesan dimensi sampel dan anisotropi ke atas pengukuran magnet dikaji. ANOVA satu hala dan ujian T digunakan sebagai kaedah statistik pada tahap kesignifikanan 0.05. Hasil statistik membuktikan sifat magnet untuk bahan magnet dipengaruhi oleh anisotropi bahan. Penilaian ke atas dimensi sampel menunjukkan ketidakseragaman pemagnetan sampel dalam sampel terjuntai yang mengakibatkan kebocoran fluks di kaki dening. Fluks yang terkeluar bertambah dengan penggunaan sampel terjuntai. Walau bagaimanapun, penggunaan sampel yang padan di antara hujung kaki dening berupaya mengurangkan kesan fluks yang terkeluar.

Kata kunci: Anisotropi; kebocoran fluks; keluli elektrik; pemagnetan; penguji kepingan besi tunggal

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*Corresponding author; email: ashikin_rashid @yahoo.com