Abstract: A high voltage electrical winding for shell form transformers is disclosed that reduces eddy current and circulating current losses within the winding. The winding is fabricated from an elongated conductor bundle that is spirally wound into a plurality of turns. The conductor bundle is formed from a multiplicity of enamel coated elongated conductor strands arranged in side by side relation. Each of the conductor strands has a rectangular cross section with a thickness of less than approximately 40 mils between contacting surfaces. The strand's cross sectional height is preferably less than 120 mils. The conductor strands are mounted side by side such that their respective contact surfaces abut. The conductor bundle is preferably wrapped in an adhesive tape to give the bundle some structural support and to provide insulation between winding turns. The disclosed winding also has very good mechanical strength and impulse distribution.

Abstract: A power transformer characterized by inner and outer low voltage winding sections and a high voltage winding section disposed therebetween. The low voltage windings are comprised of a plurality of pancake coils, and the high voltage winding are comprised of a plurality of conductor strands spirally wound for a plurality of coil layers. The low and high voltage winding sections are laterally spaced with the low voltage windings disposed in side-by-side positions and adjacent to the high voltage windings. The high voltage windings having a smaller turn height than the low voltage windings and having conductor strands of smaller gauge than the pancake coils of the low voltage windings.