Low voltage coil and transformer
AssigneeABB Research Ltd.
InventorsStephane SCHAAL, Patricia GONZALEZ, Francisco ARAUZO
Life of this patent
Estimating the term…
Abstract
To improve its fire resistance, the winding of a low voltage coil for a dry transformer is, at its circumferential surface, covered by a wrap made up of four turns of a protective foil comprising a layer consisting of woven glass fibers impregnated with silicone resin with an admixture of mica. An inner part winding and an outer part winding are separated by a gap comprising twelve rectangular aluminium tubes as spacers. At a lower end, the end face of the winding is covered with a protective cover comprising epoxy resin.
Claims18
A low voltage coil for a transformer, with a winding made from a conductive foil and an insulating foil forming a plurality of turns where two subsequent turns of conductive foil are in each case separated by at least one turn of insulating foil, wherein the circumferential surface of the winding is at least partially covered by a fire resistant protective layer.
A dry type transformer comprising:
- a low voltage coil having a winding made from a conductive foil and an insulating foil forming a plurality of turns where two subsequent turns of conductive foil are in each case separated by at least one turn of insulating foil;
- a core with at least one leg surrounded by the said low voltage coil;
- and
- a high voltage coil surrounding the said at least one leg and said low voltage coil.
Dependencies are inferred from the claim text.