Dry-type transformer and method of manufacturing
AssigneeSquare D Company
InventorsDilip R. Purohit, Timothy A. Soter, Jeewan Puri
Life of this patent
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Abstract
A dry type transformer has an iron core, high voltage windings embedded in cast resin, and low voltage windings resin encapsulated. The low voltage winding is constructed with flexible sheet conductors. Insulating material includes an apparatus to secure the windings in place during a vacuum and pressure resin impregnation process. The result is a coil that exhibits high short circuit protection due to the tightly bond conductors comparable to completely resin encased molded transformers at a substantially reduced cost.
Claims18
A dry-type transformer having a plurality of phases, said transformer comprising;
- a. an iron core having a leg for each of said plurality of phases;
- b. a cylindrical solid cast resin high voltage coil functioning as a primary winding for each of said plurality of phases;
- c. a cylindrical resin encapsulated low voltage coil functioning as a secondary winding for each of said plurality of phases;
- d. wherein said low voltage coil includes multiple turns of a conductor sheet material coincident with an insulating sheet material and further including means for forming cooling channels interposed in said multiple turns;
- e. wherein said low voltage coil includes means for bonding each of said multiple turns of conductor sheet material with an adjacent turn of said multiple turns of conductor sheet material, said bonding means to prevent movement of said conductor sheet material during short circuit conditions;
- and
- f. wherein for each of said plurality of phases, said low voltage coil is placed over and around said leg of said iron core, and said high voltage coil is placed over and around said low voltage coil.
A dry-type transformer having a plurality of phases, said transformer comprising:
- a. an iron core having a leg for each of said plurality of phases;
- b. a cylindrical solid cast resin high voltage coil functioning as a primary winding for each of said plurality of phases and including termination means for connecting to a high voltage AC source;
- c. a cylindrical resin encapsulated low voltage coil functioning as a secondary winding for each of said plurality of phases and including termination means for outputting a lower AC voltage;
- and
- d. wherein for each of said plurality of phases, said low voltage coil is placed over and around said leg of said iron core, and said high voltage coil is placed over and around said low voltage coil.
A method of manufacturing a dry-type transformer having a plurality of phases, said method comprising:
- a. forming an iron core having a leg for each of said plurality of phases;
- b. forming a cylindrical high voltage coil using a solid cast resin method for each of said plurality of phases, said high voltage coil functioning as a primary winding for each of said plurality of phases and including termination means for connecting to a high voltage AC source;
- c. forming a cylindrical low voltage coil using resin encapsulated method for each of said plurality of phases, said low voltage coil functioning as a secondary winding for each of said plurality of phases and including termination means for outputting a lower AC voltage;
- and
- d. placing said low voltage coil over and around said leg of said iron core for each of said plurality of phases;
- and
- e. placing said high voltage coil over and around said low voltage coil for each of said plurality of phases.
Dependencies are inferred from the claim text.