Abstract: A method of manufacturing a transformer is provided. The method includes forming a disc-wound coil by forming a first conductor layer, a second conductor layer and a layer of cooling ducts between the first and second conductor layers. The first and second conductor layers each have a plurality of disc windings arranged in an axial direction of the disc-wound coil. Each of the disc windings includes a conductor wound into a plurality of concentric turns.

Abstract: The present invention is directed to a method of forming a transformer having a stacked core, which includes upper and lower yokes and first and second outer legs. The core also includes one or more inner legs. Each of the upper and lower yokes is formed from a stack of plates and has a rectangular cross-section. Each inner leg is formed from a stack of plates and has a cruciform cross-section. Each of the first and second outer legs is formed from a stack of plates and may have a cruciform cross-section.

Abstract: The present invention is directed to a method of making a transformer having a stacked core, which includes top and bottom yokes and first and second outer legs. The core also includes an inner leg that is formed from a pair of stacked plates, which abut each along a seam that extends in the longitudinal direction of the inner leg. Each of the upper and lower yokes may be formed from a single stack of plates, or a plurality of stacks of plates. Each of the inner and outer legs may also be formed from a single stack of plates, or a plurality of stacks of plates. The cross-section of the core may be rectangular or cruciform.

Abstract: A transformer and a method of manufacturing the same are provided. The transformer includes a coil assembly mounted to a leg of a core. The coil assembly includes a low voltage coil and an insulation spool disposed over the low voltage coil. The insulation spool is composed of an insulating material and includes a plurality of guide strips defining a plurality of series of aligned notches. A high voltage coil is mounted to the insulation spool and includes a plurality of disc windings disposed in the series of aligned notches, respectively. Each of the disc windings comprises alternating concentric conductor layers and insulating layers. The conductor layers each have a width to thickness ratio of greater than 20:1.

Abstract: A method of manufacturing a transformer is provided. The method includes forming a disc-wound coil by forming a first conductor layer, a second conductor layer and a layer of cooling ducts between the first and second conductor layers. The first and second conductor layers each have a plurality of disc windings arranged in an axial direction of the disc-wound coil. Each of the disc windings includes a conductor wound into a plurality of concentric turns.

Abstract: The invention is directed to a transformer and a method of manufacturing the same, wherein the transformer has a cylindrical disc-wound coil that includes a layer of cooling ducts disposed between first and second conductor layers. The first and second conductor layers each have a plurality of disc windings arranged in an axial direction of the disc-wound coil. Each of the disc windings includes a conductor wound into a plurality of concentric turns.

Abstract: The present invention is directed to a transformer having a stacked core, which includes upper and lower yokes and first and second outer legs. The core also includes one or more inner legs. Each of the upper and lower yokes is formed from a stack of plates and has a rectangular cross-section. Each inner leg is formed from a stack of plates and has a cruciform cross-section. Each of the first and second outer legs is formed from a stack of plates and may have a cruciform cross-section.

Abstract: The present invention is directed to a transformer having a stacked core, which includes top and bottom yokes and first and second outer legs. The core also includes an inner leg that is formed from a pair of stacked plates, which abut each along a seam that extends in the longitudinal direction of the inner leg. Each of the upper and lower yokes may be formed from a single stack of plates, or a plurality of stacks of plates. Each of the inner and outer legs may also be formed from a single stack of plates, or a plurality of stacks of plates. The cross-section of the core may be rectangular or cruciform.

Abstract: An internal heating method for drying, gelling and final curing of epoxy resin insulation systems used for encapsulating dry type cast distribution transformer coils is disclosed. The internal method uses a Direct-Current (DC) power source to control and supply DC current to resistively heat the transformer coil encapsulated with a liquid resin under vacuum in a mold. DC current is applied to a given coil based on its conductor cross-sectional area and its epoxy resin quantity to achieve a specified temperature for drying, gelling and final curing. The temperature, controlled by DC resistive heating is maintained for a given period for each step.