ABSTRACT The purpose of this paper is to enumerate and evaluate the different technical and economical aspects of using amorphous metals (or metallic glasses), characterized by lower specific losses, as magnetic materials in power transformer cores. For a fair comparison between the conventional iron-cored and these recently suggested metallic glass-transformers, an optimal transformer design procedure based on minimizing the total annual cost of both alternatives is applied to get the optimal transformer dimensions in both cases for certain transformer power and voltage ratings. This optimized objective function will take into consideration the effect of different design factors such as the specific costs of power and energy losses and the used active core (iron or metallic glasses) and winding materials (copper or aluminium), as well as the way of loading the transformer (load factor). After comparing the minimum total annual cost of both cases, taking into account the possible future increase in the specific iron cost and the expected decrease in the specific cost of metallic glasses resulting from the use of industrial mass production techniques, it is shown that during the next decade' the suggested amorphous core materials will be more economical than the conventional silicon steel. This statement was found to depend strongly on the transformer load factor. The next step will be the comparison of the electrical parameters and performance indices in both cases. The efficiencies are already (indirectly) included in the economical comparison, so that a special attention is paid to other indices such as the leakage reactances, no-load currents, short-circuit voltages … etc.
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