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US 4,906,960 AGranted
Distribution transformer with coiled magnetic circuit
AssigneeHydro-Quebec
InventorNicolai Alexandrov
Life of this patent
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AssigneeHydro-Quebec
InventorNicolai Alexandrov
Estimating the term…
A distribution transformer and a method of making same. The transformer has at least one closed magnetic circuit in the form of a hollow toroidal coil made from ferro-magnetic steel ribbon. An electric circuit is formed by a primary winding and a secondary winding each constituted by one or more sub-assemblies in the form of a double pancake. These double pancakes are juxtaposed and molded together in a solid insulating material to form a rigid insulating frame on which the magnetic circuit is wound to form one or more magnetic coils. The rigid insulating frame, which is constituted by the primary and secondary windings and the insulating material, also includes therein conduits capable of circulating a cooling fluid through the windings whereby to provide heat exchange to cool the assembly of the electrical and magnetic circuits.
A distribution transformer comprising an electric circuit formed by primary and secondary windings electrically insulated from one another and constituted by at least two sub-assemblies insulated between each other and juxtaposed and retained together to form a rigid insulating frame, cooling means disposed at the interior of said rigid frame for circulating cooling liquid fluid, and a magnetic circuit wound about at least one section of the rigid frame, said magnetic circuit being constituted by at least one hollow coil of superimposed layers of a ferromagnetic flat metallic ribbon consisting of one of silicon steel having an oriented crystal structure and amorphous steel and having a high relative magnetic permeability, and means including a plate upon which said coil rests to support the weight of said coil on a wound edge with its axis oriented vertically to thereby substantially eliminate mechanical stresses on said layers of metallic ribbon.
Dependencies are inferred from the claim text.