PRODUCTION OF HIGH OR MEDIUM VOLTAGE WINDINGS FOR OIL-IMMERSED TRANSFORMERS AND THE WINDINGS THUS PRODUCED

摘要

The invention relates to oil-immersed power or electric power distribution transformers for which the size of the high (or medium) voltage windings is to be reduced. The invention essentially consists in removing the normal oil paper that is used as a dielectric barrier which separates the layers of spirals of lead wire and replacing said paper with a structure comprising a stack of flat wafers which are formed by concentric axial layers of close spirals of coiled wire, without the insertion of a barrier therebetween, and which are obtained from a round or almost round enamelled wire which is sticky or at least heat-adhesive. Each of said wafers has a maximum height which is calculated according to the dimensions of the wire, the selected inter-spire voltage and the safety electric arcing prevention voltage gradient specific to the relevant transformer.