An amorphous core transformer: design and experimental performance

The main aspects related to the design and experimental implementation of a 1 kVA, 220 V/110 V, 60 Hz amorphous metal core transformer (prototype) are presented. The core material is the amorphous alloy Fe78B13Si9. This as-cast core was annealed at 380 °C for 1 h in an argon atmosphere, under a DC magnetic field applied along the ribbon length to induce an uniaxial anisotropy. After having been annealed, samples of the core material were examined by differential scanning calorimetry (DSC) and by X-ray diffraction and no crystallization was observed. Experimental tests are presented to compare the amorphous core transformer performance with that of a commercial transformer with the same ratings values, but built with a steel core. In comparative terms, the amorphous core transformer presented lower active losses and lower excitation power than the commercial steel core transformer.