Estudo de aplicações da liga Fe78b13Si9 amorfa em núcleos de transformadores de baixa potência.

Abstract

The object of this thesis is to evaluate the performance of transformer cores designed and built from the amorphous alloy FeygB^Siq. A simple transformer equivalent circuit is used to carry out these investigations. The main focus is on the effect of the magnetic material on the total loss on the excitation current. A finite difference method is used to help the design of two single-phase transformer prototypes, with the following rated values: 100 VA and 1,0 kVA, 220V/T10V, 60 Hz. The as-cast material structure were examined using X-ray diffractometer. These amorphous cores are annealed in an argon atmosphere, under a DC magnetic field applied along the ribbon length for inducing uniaxial anisotropy. The crystallization behaviour was examined by differential scanning calorimetry (DSC) and no one crystallization was observed. The achieved results are compared with test data obtained on two commercial silicon-steel transformers with the same rated values. It is shown amorphous cores are more efficient than silicon-steel cores.