Granted Patent B2

US 9,111,677 · App. 13/639,287 · Granted Aug 18, 2015

Abstract

Claims (40)

1. A method of manufacturing a dry, open wound power distribution transformer comprising:

(a.) providing a ferromagnetic core;

(b.) providing a cylindrical insulation barrier having a plurality of circumferentially spaced and radially-extending comb structures, each comb structure comprising a plurality of teeth, wherein the teeth of the comb structures form a series of gap rings arranged along an axial length of the insulation barrier, each of the gap rings comprising a series of circumferentially arranged gaps;

(c.) forming a winding over the insulation barrier, the winding comprising a plurality of serially connected discs arranged in an axial direction of the winding, wherein the forming of the winding comprises forming each disc by:

winding a conductor and an insulating strip around the insulation barrier, inside one of the gap rings, to form a radially-inner section of the disc comprising a plurality of concentric and alternating layers of the insulating strip and the conductor, wherein each pair of adjacent layers in the radially-inner section are in contact with each other;

disposing a plurality of spacers around the circumference of the radially-inner section; and

winding the conductor and the insulating strip around the spacers to form a radially-outer section of the disc comprising a plurality of concentric and alternating layers of the insulating strip and the conductor, wherein each pair of adjacent layers in the radially-outer section are in contact with each other, and wherein the radially-outer section is separated from the radially-inner section by a plurality of spaces arranged in a circumferential configuration;

d.) applying an insulating varnish to the winding; and

e.) mounting the winding to the ferromagnetic core.

2. The method of claim 1 , wherein the forming of the winding is performed such that the spaces in the discs between the radially-inner and radially-outer sections are aligned from disc to disc so as to form a plurality of cooling channels that axially extend through all of the discs.

3. The method of claim 2 , wherein the winding of the conductor and the insulating strip to form the radially-inner section of each of the discs is performed so that the radially-inner sections of the discs have the same number of layers.

4. The method of claim 1 , wherein each spacer extends between a pair of the teeth.

5. The method of claim 4 , wherein each spacer comprises a body having opposing ends with notches formed therein, respectively, and wherein for each spacer disposed between a pair of the teeth, portions of the teeth are disposed in the notches of the spacer, respectively.

6. The method of claim 1 , wherein the spacers are located between the comb structures.

7. The method of claim 6 , wherein each spacer is hollow and has a rectangular cross-section.

8. The method of claim 1 , wherein the step of disposing the spacers around the circumference of the radially-inner section of each the discs comprises providing a piece of tape having a plurality of the spacers secured thereto in a spaced-apart manner and winding the piece of tape around the circumference of the radially-inner section.

9. The method of claim 1 , wherein the conductor is a foil conductor having a width to thickness ratio of greater than 20:1.

10. The method of claim 1 , wherein the transformer is a three phase transformer and the winding is a first winding, and wherein the method further comprises forming second and third windings and mounting the second and third windings to the ferromagnetic core.

11. The method of claim 10 , further comprising enclosing the first, second and third windings in a ventilated outer housing.

12. The method of claim 1 , wherein the winding is a high voltage winding and wherein the method further comprises disposing the high voltage winding over a low voltage winding so that the low voltage winding is disposed within and radially inward from the high voltage winding.

13. A method of manufacturing a dry, open wound power distribution transformer comprising:

(a.) providing a ferromagnetic core;

(b.) providing a cylindrical insulation barrier having a plurality of circumferentially spaced and radially-extending comb structures, each comb structure comprising a plurality of teeth, wherein the teeth of the comb structures form a series of gap rings arranged along an axial length of the insulation barrier, each of the gap rings comprising a series of circumferentially arranged gaps;

(c.) forming a winding over the insulation barrier, the winding comprising a plurality of serially connected discs arranged in an axial direction of the winding, wherein the forming of the winding comprises forming each disc by:

winding a conductor and an insulating strip around the insulation barrier, inside one of the gap rings, to form a radially-inner section of the disc comprising a plurality of concentric and alternating layers of the insulating strip and the conductor, wherein each pair of adjacent layers in the radially-inner section are in contact with each other;

disposing a plurality of spacers around the circumference of the radially-inner section and wherein each spacer extends between a pair of the teeth; and

winding the conductor and the insulating strip around the spacers to form a radially-outer section of the disc comprising a plurality of concentric and alternating layers of the insulating strip and the conductor, wherein each pair of adjacent layers in the radially-outer section are in contact with each other, and wherein the radially-outer section is separated from the radially-inner section by a plurality of spaces arranged in a circumferential configuration;

d.) applying an insulating varnish to the winding; and

e.) mounting the winding to the ferromagnetic core.

14. The method of claim 13 , wherein each spacer comprises a body having opposing ends with notches formed therein, respectively, and wherein for each spacer disposed between a pair of the teeth, portions of the teeth are disposed in the notches of the spacer, respectively.

15. A method of manufacturing a dry, open wound power distribution transformer comprising:

(a.) providing a ferromagnetic core;

(b.) providing a cylindrical insulation barrier having a plurality of circumferentially spaced and radially-extending comb structures, each comb structure comprising a plurality of teeth, wherein the teeth of the comb structures form a series of gap rings arranged along an axial length of the insulation barrier, each of the gap rings comprising a series of circumferentially arranged gaps;

(c.) forming a winding over the insulation barrier, the winding comprising a plurality of serially connected discs arranged in an axial direction of the winding, wherein the forming of the winding comprises forming each disc by:

winding a conductor and an insulating strip around the insulation barrier, inside one of the gap rings, to form a radially-inner section of the disc comprising a plurality of concentric and alternating layers of the insulating strip and the conductor, wherein each pair of adjacent layers in the radially-inner section are in contact with each other;

disposing a plurality of spacers around the circumference of the radially-inner section and wherein the spacers are located between the comb structures; and

winding the conductor and the insulating strip around the spacers to form a radially-outer section of the disc comprising a plurality of concentric and alternating layers of the insulating strip and the conductor, wherein each pair of adjacent layers in the radially-outer section are in contact with each other, and wherein the radially-outer section is separated from the radially-inner section by a plurality of spaces arranged in a circumferential configuration;

d.) applying an insulating varnish to the winding; and

e.) mounting the winding to the ferromagnetic core.

16. The method of claim 15 wherein each spacer is hollow and has a rectangular cross-section.

Assignments (6)