Audible noise of power transformers

TRENDS in power-system design require installations of large power transformers in thickly populated areas. These trends have been brought about by increasing capacities of existing stations and by transforming power closer to the ultimate customer than has been done in the past.
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As a result, power-transformer manufacturers have been asked to build low-noise-level designs for these installations. Simultaneous with these new requirements being placed on them, manufacturers have been developing new materials, processes, and material applications; and to advance the art, certain of these improvements are being incorporated in designs. Themanufacturer then finds himself faced with the problem of designing for low noise levels and, at the same time, improving his product in quality, cost, and dependability. The way in whichthese two parts of the problem are related will be shown in this article.