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KR-102964147-B1 - coil for transformer assembly

KR102964147B1KR 102964147 B1KR102964147 B1KR 102964147B1KR-102964147-B1

Abstract

As a coil (2) for a transformer core (100), the coil extends circumferentially around a longitudinal axis. The coil includes a foil winding array and a conductor element. The foil winding array extends circumferentially around a longitudinal axis and has four edge regions. The conductor element (8) partially covers at least one of the edge regions (72, 74, 76, 78) of the foil winding array (6). The conductor element allows for a reduction in the electric field generated during the operation of the transformer assembly at the edge of the foil winding array. In this way, performance improvements in partial discharge tests and lightning strike tests can be achieved.

Inventors

  • 노게스 안토니오
  • 로이 카를로스
  • 가르시아 빅토르 마누엘
  • 무리요 라파엘
  • 세브리안 로레나
  • 모라타 필라르
  • 무뇨스 페르난도

Assignees

  • 히타치 에너지 리미티드

Dates

Publication Date
20260512
Application Date
20220330
Priority Date
20210330

Claims (14)

  1. As a coil (2) for a transformer assembly (4), The above coil (2) extends circumferentially around the longitudinal axis (L), and A foil winding array (6) that extends circumferentially around the longitudinal axis (L) and has four edge regions (72, 74, 76, 78); and It includes conductor elements (8, 8') that at least partially cover the edge regions (72, 74, 76, 78) of the foil winding array (6), and The above conductor element (8, 8') is a single piece element that extends cylindrically around the longitudinal axis (L) in a closed ring-shaped manner, and The above conductor element (8, 8') includes a first conductor element (8) and a second conductor element (8'), and The first conductor element (8) covers the first edge region (72) and the second edge region (74), and the second conductor element (8') covers the third edge region (76) and the fourth edge region (78) correspondingly, and A coil (2) for a transformer assembly (4), wherein the coil (2) has an extension (H) along the longitudinal axis (L), the foil winding array (6) has an extension (h) along the longitudinal axis (L), and the extension (h) of the foil winding array (6) is at least 75% of the extension (H) of the coil (2).
  2. In Article 1, The above conductor element (8, 8') is a coil (2) for a transformer assembly (4) that completely covers the above edge regions (72, 74, 76, 78).
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  5. In Article 1, The above foil winding array (6) has a first end surface (62), a second end surface (64), a radially inward surface (66), and a radially outward surface (68) with respect to the longitudinal axis (L), The first end surface (62) and the radially inward surface (66) are connected through the first edge region (72) among the four edge regions (72, 74, 76, 78), and The second end surface (64) and the radially inward surface (66) are connected through the second edge region (74) among the four edge regions (72, 74, 76, 78), and The first end surface (62) and the radially outward surface (68) are connected through the third edge region (76) among the four edge regions (72, 74, 76, 78), and The second end surface (64) and the radially outward surface (68) are connected through the fourth edge region (78) of the four edge regions (72, 74, 76, 78), forming a coil (2) for a transformer assembly (4).
  6. In Article 5, The above foil winding array (6) comprises a conductor member (10) and an insulating member (12), and the radially inward surface (66) and/or the radially outward surface (68) is at least partially formed by the conductor member (10), for a coil (2) for a transformer assembly (4).
  7. In Article 5, The above conductor element (8, 8') is a coil (2) for a transformer assembly (4) that is in direct contact with the radially inward surface (66) or the radially outward surface (68) of the foil winding array (6).
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  9. In Article 1, The above conductor element (8, 8') is a coil (2) for a transformer assembly (4), made of metal, for example, aluminum.
  10. In Article 1, The conductor element (8, 8') is a bent metal foil element, and the metal foil element has a thickness between 0.1 mm and 0.5 mm or between 0.2 mm and 0.4 mm, a coil (2) for a transformer assembly (4).
  11. In Article 1, The conductor element (8, 8') has a curled edge region (82), and the conductor element (8, 8') covers at least partially or completely the edge region (72, 74, 76, 78) of the foil winding array (6) by the curled edge region (82), a coil (2) for a transformer assembly (4).
  12. A transformer assembly (4) comprising a coil (2) of any one of claims 1 to 2, 5 to 7, and 9 to 11.
  13. As a conductor element (8, 8') for at least partially covering the four edge regions (72, 74, 76, 78) of the foil winding array (6) of the coil (2) for the transformer assembly, The coil (2) extends circumferentially around a longitudinal axis (L), and the conductor element (8, 8') is a curved metal foil element including a curled edge region (82), and The above conductor element (8, 8') is a single-piece element configured to extend cylindrically around the longitudinal axis (L) in a closed ring-shaped manner, and The above conductor element (8, 8') includes a first conductor element (8) and a second conductor element (8'), and The first conductor element (8) covers the first edge region (72) and the second edge region (74), and the second conductor element (8') covers the third edge region (76) and the fourth edge region (78) correspondingly, and The above coil (2) has an extension (H) along the longitudinal axis (L), and the above foil winding array (6) has an extension (h) along the longitudinal axis (L), and the extension (h) of the above foil winding array (6) is at least 75% of the extension (H) of the above coil (2), a conductor element (8, 8').
  14. A method for manufacturing a first conductor element (8) and a second conductor element (8') to at least partially cover four edge regions (72, 74, 76, 78) of a foil winding array (6) of a coil (2) for a transformer assembly, The first conductor element (8) is an element covering the first edge region (72) and the second edge region (74), and the second conductor element (8') is, correspondingly, an element covering the third edge region (76) and the fourth edge region (78), and The first conductor element (8) and the second conductor element (8') are curved metal foil elements including a curled edge region (82), and The method includes the step of pushing or pulling a metal foil element through a forming tool to form the curled edge region (82) of the first conductor element (8) and the second conductor element (8'), and A method for manufacturing a first conductor element (8) and a second conductor element (8'), wherein the coil (2) has an extension (H) along a longitudinal axis (L), the foil winding array (6) has an extension (h) along the longitudinal axis (L), and the extension (h) of the foil winding array (6) is at least 75% of the extension (H) of the coil (2).

Description

coil for transformer assembly The present disclosure relates to a coil for a transformer assembly, and more specifically, to a coil for a transformer assembly comprising a foil winding arrangement. The present disclosure also relates to a transformer assembly comprising such a coil. A transformer is a passive electrical device that transfers electrical energy from one electrical circuit to another, or to multiple circuits. A transformer typically comprises a ferromagnetic core having rims extending between a first yoke and a second yoke. Coils are wound around the rims. A changing current in any one of the coils generates a changing magnetic flux in the core, which induces a changing electromotive force across any other coil wound around the core. The coil of the base comprises a foil winding array, wherein the foil winding array comprises multiple turns of foil wound around the longitudinal axis of the rim. Radial “inter-turn insulation” is provided between the turns. The coil may comprise a single foil winding array, wherein the foil essentially has a length along the longitudinal axis corresponding to the length of the coil. Alternatively, the coil may comprise multiple groups of foil winding arrays, each foil winding array forming a “disk” such that multiple foil disks are formed arranged along the longitudinal axis. The coil further includes an insulating element, for example made of epoxy resin, that surrounds the foil winding array. Accordingly, the foil winding array exhibits a first end plane and a second end plane with respect to the longitudinal axis, wherein the first end plane and the second end plane extend between the radially inward surface of the foil winding array and the radially outward surface of the foil winding array, respectively. Typically, the edges formed by these faces of the foil winding array are not electrically shielded. WO 2012/000983 A1 relates to an electric shielding device placed at an axial distance from the winding to increase the dielectric strength of a transformer. The electric shielding device covers the general cross-sectional area of the winding. It is necessary to provide coil and transformer assemblies having enhanced performance features. According to the present disclosure, a coil for a transformer assembly is provided. The coil extends circumferentially about a longitudinal axis. The coil comprises a foil winding array and a conductor element. The foil winding array extends circumferentially about a longitudinal axis and has four edge regions. The conductor element covers at least one of the edge regions of the foil winding array at least partially. The conductor element allows for a reduction in the electric field generated during the operation of the transformer assembly at the edges of the foil winding array. In this way, improved performance in partial discharge tests and lightning strike tests can be achieved. Furthermore, if a solid insulator is used between the low-voltage and high-voltage windings, the achieved reduction in dielectric stress allows for improved performance regarding dielectric aging. Consequently, a reduction in separation distance can be achieved overall. Various embodiments may preferably implement the following features: Preferably, the conductor elements are arranged and designed to electrically shield or screen the foil winding array. Preferably, the conductor elements extend cylindrically around a longitudinal axis, particularly in a closed ring-shaped manner. The coil may further include an insulating element, for example made of epoxy resin, that surrounds both the foil winding array and the conductor element. Preferably, the insulating element completely surrounds the foil winding array and/or the conductor element. The transformer assembly may be a dry-type transformer assembly. Preferably, the conductor element completely covers at least one of the edge regions. This further enhances the reduction of the electric field. Preferably, the coil has an extension (H) along the longitudinal axis, and the foil winding array has an extension (h) along the longitudinal axis, wherein the extension (h) of the foil winding array is at least 75% of the extension (H) of the coil. For example, the extension (h) of the foil winding array is at least 80% or at least 85% of the extension (H) of the coil. For example, the foil winding array may be the only foil winding array of the coil. Alternatively, the coil preferably has an extension (H) along the longitudinal axis, and the foil winding array has an extension (h') along the longitudinal axis, wherein the extension (h') of the foil winding array is less than 50% of the extension (H) of the coil, preferably less than 30% of the extension (H) of the coil. For example, the extension (h') of the foil winding array is less than 20% or less than 10% of the extension (H) of the coil. For example, the foil winding may form a so-called foil disk. The coil may include a plurality of coil disks. The