Aluminum and its future in power transformers

DURING THE EARLY 1940´s copper was in short supply in many countries, with the result that aluminum came into use in power transformer windings as a means of conserving copper. Since that time, there has been a continued interest in aluminum for transformer use. Considerable literature has been published on the use of aluminum in reactors, dry-type transformers, and distribution transformers. Less data has been available on the use of aluminum in power transformers above 10,000 kva. It is these larger sizes that are now under study.