Core seal assembly, core coil assembly and sealing method

Abstract

A sealed core coil assembly, comprising a coil assembly, a core assembly and an expandable sealing member, the coil assembly having an inner coil and an outer coil, the inner coil having an inner surface, an outer surface, an upper surface and a lower surface, the outer coil having an inner surface, an outer surface, an upper surface and a lower surface, the core assembly comprising a core column and a core window of a magnetically permeable material, the core column and the core window having an inner side surface, and the expandable sealing member comprising a fillable or evacuable inner cavity. The expandable sealing member is disposed between one or more inner side surfaces of the core column and one or more inner surfaces of the inner coil, between the outer surface of the inner coil and the inner surface of the outer coil, and between the upper and lower surfaces of the inner and outer coils and the inner side surface of the core window. A core coil assembly, a sealing assembly and a sealing method are provided, and many other aspects are also provided.

Description

Technical Field

[0001] The present application relates to transformers for power distribution, and more particularly to apparatus, assemblies, and methods for sealing between components in dry-type transformers. Background Art

[0002] Transformers are used during power distribution to increase or decrease voltage levels. To transmit power over long distances, transformers may be used to increase the voltage and decrease the current of the power being transmitted. The reduced current level reduces resistive power losses from the cables used to transmit the power. When the power is to be consumed, a transformer may be employed to reduce the voltage level of the power and increase the current of the power to a level specified by the end user.

[0003] One type of transformer that may be employed is a dry submersible transformer, as described, for example, in U.S. Pat. No. 8,614,614, the disclosure of which is hereby incorporated by reference herein for all purposes. Such transformers may be used underground, in cities, etc., and may be designed to withstand harsh environments, such as water exposure, humidity, contamination, etc. Improved apparatus, assemblies, and methods for submersible and other dry transformers are desirable. Summary of the invention

[0004] In some embodiments, a core-coil assembly of a dry-type transformer is provided. The core-coil assembly includes a coil assembly, a core assembly, and an expandable sealing member, wherein the coil assembly has an inner coil and an outer coil, wherein the inner coil has an inner surface, an outer surface, an upper surface, and a lower surface, and the outer coil has an inner surface, an outer surface, an upper surface, and a lower surface; the core assembly includes a core column and a core window of a magnetically permeable material, wherein the core column and the core window have an inner side surface; the expandable sealing member includes an inner cavity that can be filled or evacuated, and the expandable sealing member is arranged at:

[0005] Between one or more inner surfaces of the core and the inner surface of the inner coil,

[0006] between the outer surface of the inner coil and the inner surface of the outer coil, and

[0007] Between the upper and lower surfaces of the inner and outer coils and the inner surface of the core window.

[0008] In some embodiments, a core coil assembly is provided. The core coil assembly includes a coil assembly, a core assembly, and an expandable sealing member, wherein the coil assembly includes a plurality of coils, each of which has an outer peripheral surface; the core assembly includes at least one core column of a magnetically permeable material and a core window, the core window having an inner side surface; each of the expandable sealing members includes a fillable or evacuable inner cavity, and the sealing material is inserted between the outer peripheral surfaces of the plurality of coils in the core window and between the inner side surface of the core window and the plurality of coils.

[0009] In some embodiments, a core-coil assembly is provided, which includes a core assembly of a magnetically permeable material, a coil assembly, and an expandable sealing member, wherein the core assembly has a core window with an inner surface; a portion of the coil assembly is located in the core window, and the coil assembly includes an end surface; the expandable sealing member is disposed between the inner surface of the core window and the end surface of the coil assembly, and the expandable sealing member includes an inner cavity.

[0010] In another embodiment, a method for sealing a core coil assembly is provided. The method includes providing a core assembly having a core window; providing a coil assembly, a portion of which is located in the core window; providing an expandable sealing member including an inner cavity in a gap in the core window not occupied by the coil assembly; and increasing the volume of the inner cavity to expand the outer dimension of the sealing member to seal the gap.

[0011] Other aspects, features and advantages of the present disclosure will become apparent from the following detailed description illustrated by a plurality of example embodiments and implementations. The present disclosure is also capable of other and different embodiments, and several details thereof may be modified in various aspects. Therefore, the drawings and description are considered to be illustrative in nature, and not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings described below are for illustrative purposes only and are not necessarily drawn to scale. These drawings are not intended to limit the scope of the present invention in any way. Where possible, the same or similar reference numerals are used throughout the drawings to represent the same or similar parts.

[0013] Figure 1 A side plan view of a submersible dry transformer including a plurality of core-coil assemblies according to one or more embodiments provided herein is shown.

[0014] Figure 2A A perspective view of a coil assembly including an inner coil and an outer coil according to one or more embodiments provided herein is shown.

[0015] Figure 2B A perspective view of an inner coil of a coil assembly according to one or more embodiments provided herein is shown.

[0016] Figure 2C A perspective view of an outer coil of a coil assembly according to one or more embodiments provided herein is shown.

[0017] Figure 3A Shown is a side plan view of an example embodiment of a core assembly according to one or more embodiments provided herein.

[0018] Figure 3B A cross-sectional partial side view of an example embodiment of a core coil assembly including a core assembly and a coil assembly according to one or more embodiments provided herein is shown.

[0019] Figure 3C A cross-sectional partial top view of an example embodiment of a core-coil assembly according to one or more embodiments provided herein is shown.

[0020] Figure 4A Shown is a cross-sectional side view of an embodiment of an expandable sealing member according to one or more embodiments provided herein.

[0021] Figure 4B According to one or more embodiments provided herein, Figure 4A An enlarged cross-sectional end view of an embodiment of an expandable sealing member taken along section line 4B-4B.

[0022] Figure 4C Shown is a cross-sectional side view of another embodiment of an expandable sealing member having a side port according to one or more embodiments provided herein.

[0023] Figure 4D According to one or more embodiments provided herein, Figure 4C An enlarged cross-sectional end view of an embodiment of an expandable sealing member taken along section line 4D-4D.

[0024] Figure 4E An enlarged cross-sectional end view of an embodiment of an expandable sealing member including an extended side port according to one or more embodiments provided herein is shown.

[0025] Figure 5A A cross-sectional side view of an embodiment of an expandable sealing member having a filling device coupled thereto and shown in a non-expanded configuration is shown in accordance with one or more embodiments provided herein.

[0026] Figure 5B A cross-sectional side view of an embodiment of an expandable sealing member having a filling device coupled thereto and shown in an expanded and filled configuration is shown in accordance with one or more embodiments provided herein.

[0027] Figure 5C A cross-sectional side view of an embodiment of an expandable sealing member having a decoupled filling device and shown in an expanded, filled, and cured configuration is shown in accordance with one or more embodiments provided herein.

[0028] Figure 6 A cross-sectional side view of an embodiment of an expandable sealing member having an evacuation and fill apparatus coupled thereto and shown in a collapsed configuration prior to filling is shown in accordance with one or more embodiments provided herein.

[0029] Fig. 7A A cross-sectional side view of an embodiment of an expandable sealing member shown in a collapsed configuration having an evacuation apparatus including a vacuum pump coupled thereto according to one or more embodiments provided herein is shown.

[0030] Figure 7B Shown is a cross-sectional side view of an embodiment of an expandable sealing member shown in a collapsed configuration (under vacuum) and decoupled from a vacuum pump in accordance with one or more embodiments provided herein.

[0031] Figure 7C Shown is a cross-sectional side view of an embodiment of an expandable sealing member shown in an expanded configuration (upon vacuum release) and decoupled from an evacuation device in accordance with one or more embodiments provided herein.

[0032] Fig.7D A cross-sectional side view of an embodiment of an expandable sealing member shown in a collapsed (non-expanded) configuration and having a vacuum pump decoupled therefrom according to one or more embodiments provided herein, wherein collapse and removal of the vacuum pump can be performed at a location away from the expansion sealing member for sealing.

[0033] Fig. 7E Shown is a cross-sectional side view of an embodiment of an expandable sealing member shown in an expanded configuration and having a cavity filled with a fill material according to one or more embodiments provided herein.

[0034] Figure 7F Shown is a cross-sectional side view of an embodiment of an expandable sealing member shown in an expanded and filled configuration according to one or more embodiments provided herein.

[0035] Figure 7G Shown is a cross-sectional side view of an embodiment of an expandable sealing member shown in expanded and occluded configurations according to one or more embodiments provided herein.

[0036] Fig. 8AShown is a cross-sectional side view of an embodiment of an expandable sealing member that is compressed and then end-plugged according to one or more embodiments provided herein.

[0037] Figure 8B According to one or more embodiments provided herein, Fig. 8A Side plan view of an expandable sealing member.

[0038] Figure 8C A cross-sectional view taken along section line 8C-8C according to one or more embodiments provided herein is shown. Fig. 8A An enlarged cross-sectional end view of an expandable sealing member of the present invention and illustrating a non-rectangular cross-sectional shape that can preferentially contract in one direction.

[0039] Fig.8D A diagram showing preferential contraction in one direction according to one or more embodiments provided herein FIG. 8A to FIG. 8C An enlarged cross-sectional end view of an expandable sealing member.

[0040] Fig. 9A Shown is a cross-sectional side view of an embodiment of a blow molded expandable sealing member according to one or more embodiments provided herein.

[0041] Fig. 9B According to one or more embodiments provided herein, Fig. 9A Side plan view of an expandable sealing member.

[0042] Fig. 9C According to one or more embodiments provided herein, Fig. 9A A cross-sectional end view of the expandable sealing member taken along section line 9C-9C and illustrating another non-rectangular shape that can preferentially contract in one direction.

[0043] Fig.9D According to one or more embodiments provided herein, Figures 9A-9C End view of the expandable sealing member.

[0044] Fig.9E A diagram showing preferential contraction in one direction according to one or more embodiments provided herein is shown. 9A to 9D End view of the expandable sealing member.

[0045] Fig.10 A flow chart is shown of a method for sealing a core-coil assembly according to one or more embodiments provided herein. DETAILED DESCRIPTION

[0046] As described above, submersible dry transformers may be used underground and / or in other environments where the transformer may be exposed to water, humidity, contaminants, etc. Such transformers are typically connected to deliver multi-phase power, such as 2-phase or 3-phase power. Common three-phase configurations include transformer assemblies connected, for example, in delta and wye configurations.

[0047] According to one or more embodiments described herein, a submersible dry-type transformer, a core coil assembly, and a method for sealing a core coil assembly are provided, thereby providing improved manufacturing time. In the prior art, a foam strip element is used to seal between the outer portion of the low-voltage inner coil and the high-voltage outer coil of the coil assembly and the core window, and also between the low-voltage inner coil and the high-voltage outer coil. These foam strips are compressed during installation, for example, when the foam strip is in place, the low-voltage inner coil is inserted on the core column. Of course, in order to maintain a proper seal, the thickness of the foam strip is slightly thicker than the gap it seals. In this way, during the assembly method of the core coil assembly, the insertion of the low-voltage inner coil on the core column may be quite difficult, and may take a relatively large force to complete. In addition, it may be difficult to keep the foam strip element in place during the assembly of the foam strip element, that is, the foam strip element tends to slide along the low-voltage inner coil. Similarly, the seal between the low-voltage inner coil and the high-voltage outer coil may have the same problem: that is, inserting the high-voltage outer coil on the low-voltage inner coil requires a large force and the problem of properly positioning while maintaining the seal. Similar problems are encountered when sealing the core windows above and below the coil assembly.

[0048] Therefore, according to one or more embodiments of the present disclosure, a method and apparatus are provided that can improve the ease of assembly of a core coil assembly and a sealing element and / or the sealing effectiveness of a core window.

[0049] In some embodiments, a core coil assembly of a dry-type transformer is provided. In some embodiments, the core coil assembly includes an expandable sealing member, which includes a fillable or evacuable or both fillable and evacuable inner cavity. The fillable or evacuable sealing member seals the core window, and specifically, seals between one or more side surfaces of the core column and the inner surface of the low-voltage inner coil, between the outer surface of the low-voltage inner coil and the inner surface of the high-voltage outer coil, and between the top and bottom of the coil assembly and the inner surface of the core window.

[0050] The inflatable sealing member including a fillable or evacuable inner cavity is configured so that it can have a size smaller than the gap that it will initially fill, and can then expand to fill the gap size between the sealed components. In some embodiments, the cavity of the inflatable sealing member is filled with material (e.g., silicone under pressure) to expand the inflatable sealing member to fill the gap. Once filled, the filling material can be cured in place. In other embodiments, a vacuum can be applied to the cavity of the inflatable sealing member so that at least some parts of the inflatable sealing member shrink / bend, thereby producing a size smaller than the gap. The vacuum can then be released to allow the inflatable sealing member to seal the gap. After this, the cavity can also be optionally filled with a suitable material. Since the size of the inflatable sealing member is smaller than the size of the gap, it is not necessary to assemble various units (low-voltage inner coil to core column, high-voltage outer coil to low-voltage inner coil and coil assembly to core window) against the force of the sealing member. The inflatable sealing member can be easily positioned and accurately positioned during the assembly method.

[0051] Here is the reference in this article Figure 1-Figure 10 These and other embodiments of an expandable sealing member including a cavity, a sealing apparatus, a core-coil assembly, and a dry-type transformer including the expandable sealing member are described.

[0052] Figure 1 is a front plan view of a dry-type transformer 100 according to an embodiment provided herein. The dry-type transformer 100 shown is a three-phase transformer, but in other embodiments, transformers with different numbers of phases (e.g., single-phase or two-phase) may be used. A dry-type transformer as used herein refers to a transformer that includes a high-voltage coil and a low-voltage coil that are not immersed in an oil bath contained within a housing. Such dry-type transformers 100 have significant advantages because they do not utilize oil that may escape the housing and cause contamination or may ignite during extreme events. In addition, the coils are directly exposed to the environment so that the cooler can be operated by cooling with air or water (when immersed).

[0053] As an example, the dry-type transformer 100 may include a core assembly 102 mounted between an upper frame portion 104U and a lower frame portion 104L. An insulating sheet (not shown) may be provided to insulate the front and rear sides of the core assembly 102 from the respective front and rear portions of the upper frame 104U and the lower frame 104L. The core assembly 102 may be composed of a plurality of laminations of magnetic material. Example magnetic materials include magnetically permeable materials such as iron, steel, amorphous steel or other amorphous magnetically permeable metals, silicon steel alloys, carbonyl iron, ferrite ceramics, and more specifically, laminated layers of one or more of the above materials, etc. In some embodiments, laminated ferromagnetic metal materials with a high cobalt content may be used. Other suitable magnetic metals and magnetically permeable materials may be used.

[0054] like Figure 1 and FIG. 3A to FIG. 3C As shown, the core assembly 102 may include a plurality of interconnects, which may include one or more core columns and, in the depicted embodiment, include vertical core columns 102L, 102C, and 102R. The vertical core columns 102L, 102C, and 102R may be assembled with top and bottom core legs 102T, 102B to form the core assembly 102. The construction may include a stepped overlap between the various components of the core assembly 102. For example, the construction of the core assembly 102 may be as shown in US 4,200,854 or US8,212,645. Other overlapped constructions of the core assembly 102 or even a wound core construction may be used. When assembled, bolted together, and painted, the core assembly 102 may include two core windows 102W as shown.

[0055] Each core window 102W includes a side surface 102S and is limited by the side surface. Two core windows 102W are shown in the depicted embodiment. However, it should be appreciated that the method and apparatus described herein are applicable to a core assembly having only one core window and including two core posts, wherein one or two coil assemblies are arranged on their corresponding core posts. In addition, in the depicted embodiment, core posts 102L, 102C, 102R are shown as being vertically oriented. However, other orientations are also possible.

[0056] In some embodiments, within the dry-type transformer 100 , each of the core legs 102L, 102C, and 102R may be surrounded by a coil assembly (ie, coil assemblies 106 , 108 , 110 ). Figure 2A An example core assembly is shown.

[0057] Figure 2A 1 shows a perspective view of an example coil assembly 106. The coil assembly 106 is shown and described herein by way of example, and the coil assemblies 108, 110 may be the same or substantially the same as the coil assembly 106. Figure 2B to Figure 2C As best shown, the coil assembly 106 includes a low voltage inner coil 112 and a high voltage outer coil 114, which can be concentric when installed with the low voltage inner coil 112. The low voltage inner coil 112 can be electrically isolated from the core assembly 102 and also electrically isolated from the high voltage outer coil 114. For example, the low voltage inner coil 112 can be surrounded by an insulating material such as a molded resin. Similarly, the high voltage outer coil 114 can also be surrounded by an insulating material such as a molded resin. Example insulating materials can include any suitable solid insulation, such as epoxy resin, polyurethane, polyester, silicone, etc.

[0058] Reference again Figure 1 A and also refer to FIG. 3A to FIG. 3B, the coil assemblies 106, 108, 110 and the core assembly 102 can be separated by expandable sealing members 116a-116n, wherein at least some, preferably all, of each expandable sealing member include a cavity. Prior art foam sealing sheets are described in US 8,614,614 entitled "Submersible Dry Transformer", the disclosure of which is hereby incorporated by reference for all purposes. The expandable sealing members 116a-116n can be any suitable compliant insulating material including a cavity 440, and operate together to seal the unoccupied plane of the core window 102W of the core assembly 102 to prevent the formation of a water loop when submerged.

[0059] exist FIG. 3B to FIG. 3C , inflatable sealing members 116c-116d, 116g-116n are shown aligned along the center plane 115 of window 102W. Other inflatable sealing elements 116a-116b and 116e-116f can be aligned along the same center plane 115. Such planar aligned inflatable sealing members 116a-116n prevent the formation of a water loop (which acts like an electrical short circuit). As shown, inflatable sealing members 116h, 116i, 116l and 116m are included between the low-voltage inner coil 112 and the high-voltage outer coil 114. Inflatable sealing members 116g, 116j, 116k and 116n are included between the low-voltage inner coil 112 and the side surfaces of the core column 102L, 102C, 102R and are aligned along the center plane 115. Inflatable sealing members 116c and 116d are included between high voltage outer coils 114 and may be aligned along center plane 115. Likewise, inflatable sealing elements 116a-116b and 116e-116f are included between upper and lower surfaces of core window 120W and side surface 102S and may be aligned along center plane 115.

[0060] Therefore, in one embodiment, a core coil assembly 200 is provided, which includes a core post (e.g., any one of the core posts 102L, 102C, 102R) and a first coil (e.g., any one of the inner coils 212), which is accommodated around the corresponding core post (e.g., any one of the core posts 102L, 102C, 102R) and forms a gap between them. The core coil assembly 200 also includes an expandable sealing member (e.g., any one of the expandable sealing members 116g, 116j, 116k, 116n) containing a cavity 440, thereby sealing the gap between the corresponding core post and the corresponding first coil.

[0061] The core coil assembly 200 may also include a second coil (e.g., an outer coil 214) surrounding the first coil (e.g., the inner coil 212) and providing another gap between the first coil and the second coil, and another inflatable sealing member (e.g., one of the inflatable sealing members 116h, 116i, 1161, 116m) including a cavity 440, thereby sealing the gap between the first coil and the second coil.

[0062] In another embodiment, a core coil assembly 200 (see FIG. 3A to FIG. 3C ), the core coil assembly 200 is configured with a sealed end of the coil assembly. The core coil assembly 200 includes a core assembly 102 of a magnetically permeable material and a coil assembly (e.g., coil assemblies 106, 108, 110), the core assembly 102 having one or more core windows 102W with an inner surface 102S, and the coil assembly includes an end surface (e.g., end surfaces 244, 246, 248, 250) in at least one core window 102W, and preferably in all core windows. The core coil assembly 200 also includes an inflatable sealing member (e.g., inflatable sealing members 116a, 116b, 116e, 116f) disposed between the inner surface 102S of the core window 102W and the end surfaces 244, 246, 248, 250 of the coil assembly, the inflatable sealing member including an inner cavity.

[0063] Now refer to Figure 1 and FIG. 2A to FIG. 2B Each of the coil assemblies 106, 108, 110 of the transformer 100 may be provided with a high voltage terminal 118, which may be positioned at the top front of the corresponding coil assembly 106, 108, 110. The low voltage inner coil 212 ( Figure 2B ) can be disposed on the back side of the coil assembly 106, 108, 110. For example, Figure 2A As best shown, the high voltage terminal 118 can be located at the top front of the columnar front extension 226E of the coil housing 226, which includes insulation around the corresponding high voltage outer coil 214. The low voltage terminal 219 can be located at the rear of the low voltage inner coil 212. However, the high voltage terminal 118 and the low voltage terminal 219 can be located at other positions. The high voltage terminal 118 provides power connection to the high voltage outer coil 214 of the corresponding coil assembly 106, 108, 110. A connector (not shown, such as a sealed plug connector) can be provided to facilitate the sealed connection of the high voltage terminal 118 to the cable (not shown). The low voltage terminal 219 can be used to make a Y-shaped connection (not shown) and the like. Other suitable sealed electrical connections are also possible.

[0064] like Figure 1 and FIG. 2A to FIG. 2CAs best shown in FIG. 1 , transformer 100 may also include triangle connections 120A, 120B, and 120C between the corresponding high-voltage outer coils 114 of coil assemblies 106, 108, and 110. For example, triangle connections 120A, 120B, and 120C may include shielded cables. As shown, each of triangle connections 120A, 120B, and 120C may be connected to an upper triangle terminal 122 and a lower triangle terminal 124 of the high-voltage outer coil 114 of each of coil assemblies 106, 108, and 110. The electrical connection may be a sealed connection. The upper triangle terminal 122 and the lower triangle terminal 124 may extend horizontally (as shown) from the columnar front extension 226E of the coil housing 226. For example, in some embodiments, the upper triangle terminal 122 and the lower triangle terminal 124 may extend outward from the front 226F of the columnar front extension 226E.

[0065] The high voltage outer coil 114 of each of the coil assemblies 106, 108, 110 may include a ground terminal 128. For example, a ground conductor 129 (e.g., a braided cable) may be connected between the corresponding ground terminal 128 of the high voltage outer coil 114 and the lower frame 104L. A common ground strap 130 may be attached to the lower frame 104L and may provide grounding. Each of the coil assemblies 106, 108, 110 may include a tap switch assembly 132. The tap switch assembly 132 allows the voltage across the corresponding coil assembly 106, 108, 110 to be adjusted, typically by repositioning the movable bridge element to adjust the + / - voltage of approximately the rated voltage value.

[0066] Additional details regarding the general construction of a submersible dry transformer 100 that may be used in accordance with one or more embodiments provided herein are described in previously mentioned US 8,614,614 and US 9,355,772, the entire contents of which are hereby incorporated by reference for all purposes.

[0067] According to a broad embodiment of the present disclosure, a core coil assembly (e.g., core coil assembly 106) of a dry-type transformer is provided. The core coil assemblies 108 and 110 can be the same or substantially the same. The core coil assembly 106 has: an inner coil (e.g., a low voltage inner coil 212), the inner coil having an inner surface 232 and an outer surface 234; and an outer coil 214, the outer coil 214 having an inner surface 236 and an outer surface 238. As will also be further described herein, each of these surfaces 232, 234, 236, 238 can be cylindrical at the location to be sealed.

[0068] The core coil assembly 106 further includes a core assembly 102, which includes a core column 102L made of a magnetically permeable material and a core window 102W. The core column 102L and the core window 102W have a side surface 102S. The side surface 102S defines the inner periphery of the core window 102W.

[0069] The core coil assembly 106 also includes expandable sealing members 116a, 116e, 116g and 116h, and may include 116c when there is more than one coil assembly (e.g., coil assemblies 106, 108), wherein each expandable sealing member 116a, 116e, 116g, 116h and 116c includes a fillable or evacuable inner cavity 440. Figure 4A and Figure 4B A first representative example of an inflatable sealing member 116g is shown. The inflatable sealing member 116g can be made of a suitable material, such as an elastomeric material. Suitable elastomeric materials include nitrile, fluorocarbon, ethylene propylene diene monomer rubber (EPDM), butadiene rubber, silicone, neoprene, fluorosilicone, hydrogenated nitrile rubber (HNBR), thermoplastic elastomer (TPE), and natural rubber. Other suitable flexible materials can be used. The inflatable sealing member 116g can be molded into any suitable shape. For example, Figure 4A and Figure 4B The expandable sealing member 116g shown in FIG. 4 may include an open end 441 and a closed end 442 and may be, for example, injection molded, transfer molded, or compression molded. The expandable sealing member 116g includes suitable dimensions capable of sealing corresponding gaps between components of the transformer assembly 100.

[0070] In the case of the expandable sealing member 116g, the gap to be sealed is the gap between the core column 102L and the inner coil 112, wherein the gap extends along the length of the inner coil 112. In a first embodiment configured to be pressurized and expanded, the expandable sealing member 116g includes a thickness dimension T, which is slightly smaller than the gap dimension of the gap to be initially sealed in a free state. Applying pressure to the cavity 440 will expand the dimension T and thus expand to seal the gap. The internal dimension D of the cavity 440 and the width W of the expandable sealing member 116g are selected so that applying appropriate pressure can cause the expansion of the dimension T. A rectangular cross-section is shown, but other cross-sectional shapes can also be used. For example, one or more of the surfaces to be sealed can be formed as non-planar, but can be actuated by including a cylindrical arc seal along the length L instead. In some embodiments, the sidewalls can be non-planar to allow preferential expansion along the position of the core window 102W. The cavity 440 is shown as a circular cross-section, however, other cross-sectional shapes can be used.

[0071] exist FIG. 3B to FIG. 3CIn the depicted embodiment, a core coil assembly 200 is shown. The core coil assembly 200 includes coil assemblies (e.g., 106, 108, 110), each of which includes a plurality of coils (e.g., an inner coil 112 and an outer coil 114), each of the plurality of coils having an outer peripheral surface (including surfaces 232, 234, 244, and 246 of the inner coil 212, and including surfaces 236, 238, 248, and 250 of the outer coil 214). The core coil assembly 200 also includes the core assembly 102 ( Figure 3A ), the core assembly 102 includes one or more core windows 102W formed therein. The core window 102W may include two core columns (core columns 102L and 102C define the left and right sides of the left core window 102W, and core columns 102C and 102R define the left and right sides of the right core window 102W) all made of magnetically permeable material and at least two core legs (for example, core legs 102T and 102B define the top and bottom sides of the core window 102W). The core window 102W includes an inner side surface 102S defining its inner periphery.

[0072] In addition, the core coil assembly 200 includes an inflatable sealing member (e.g., 116a-116n), each inflatable sealing member including a fillable or evacuable inner cavity 440, which is inserted between the outer peripheral surfaces of multiple coils (e.g., coils 212, 214) within the core window 102W, and between the inner surface 102S of the core window 102W and the multiple coils (e.g., coils 212, 214).

[0073] like FIG. 3B to FIG. 3C As best shown in FIG. 1 , an inflatable sealing member 116g may be provided and seal between the inner side surface 102S of the stem 102L and the inner surface 232 of the inner coil 112. Likewise, inflatable sealing members 116j and 116k having substantially the same configuration as inflatable sealing member 116g may be provided to seal between the respective side surfaces 102S of the stem 102C and the inner surface 232 of the inner coil 112 in the plane 115 of the core window 102W. Inflatable sealing member 116n may have substantially the same configuration as inflatable sealing member 116g and may be provided to seal between the side surface 102S of the stem 102R and the inner surface 232 of the inner coil 112 in the plane 115 of the core window 102W.

[0074] Similarly, expandable sealing members 116h, 116i, 1161 and 116m, which may have substantially the same configuration as expandable sealing member 116g, may be provided to seal between the outer surface 234 of the inner coil 112 and the inner surface 236 of the outer coil 114 in the plane 115 of the core window 102W.

[0075] In another sealing area, an expandable sealing member 116c and an expandable sealing member 116d, which may have substantially the same configuration as expandable sealing member 116g, may be provided to seal between the outer surface 238 of the outer coil 114 in the plane 115 of the core window 102W.

[0076] In additional sealing areas above and below the inner coil 112 and the outer coil 114, expandable sealing members 116a, 116b and 116e, 116f may be provided, and the expandable sealing members 116a, 116b and 116e, 116f may have FIG. 4C to FIG. 4E The expandable sealing members 116a, 116b, 116e, 116f are configured to seal in the plane 115 of the core window 102W between the upper surface 244 and lower surface 246 of the inner coil 112 and the upper surface 248 and lower surface 250 of the outer coil 114 and the corresponding inner side surfaces 102s of the core legs 102T, 102B forming the core window 102W.

[0077] In the case of a single phase transformer having only one core window, a primary core leg surrounded by a core assembly, a return core leg, and top and bottom core legs interconnecting the primary and return core legs, then additional gaps are sealed. In the case of a single phase transformer, all of the following gaps within the plane of the core window are sealed: 1) the gap between the inner coil 212 and the outer coil 214, 2) the gap between the inner coil 112 and the primary core leg, 3) the gap between the core legs and the top and bottom of the coil assembly, and additionally 4) the gap between the outer surface of the outer coil 214 and the inside surface of the return leg.

[0078] The inflatable sealing member 116a includes some of the same features and configurations as the previously described inflatable sealing member 116g. However, in this embodiment, the port at the open end 441 is eliminated and replaced with a closed end 442, and a side port 452 is provided on the non-sealing side of the inflatable sealing member 116a. This embodiment of the inflatable sealing member 116a can be blow molded. Any suitable blow moldable conformable material can be used, such as TPE. In some embodiments, the side port 452 can be provided from, for example, Figure 4E The non-sealed side surface of the body of the expandable sealing member 116a' in the embodiment of the present invention is extended to allow easy access and connection. Optionally, the expandable sealing member 116a can be formed by the following operations: extrusion; and then cutting to length L; cutting side ports 452; and filling the corresponding open ends 441 with sealants or plugs.

[0079] Obviously, both types of expandable sealing members 116a, 116g may take the form of an expandable tube having a length L, a width W and a thickness T. The molded or extruded dimension of the thickness T may be configured to be smaller than the gap dimension G of the gap to be filled.

[0080] Figure 5A Sealing assembly 500 is shown including core coil assembly components to be sealed; the core coil assembly components are disposed in spaced relationship defining a gap of dimension G. The core coil assembly components to be sealed may be inner coil 112 and a core leg, such as core leg 102L of core assembly 102 as shown.

[0081] Furthermore, in some embodiments, the core coil assembly components to be sealed may be the inner coil 112 and the outer coil 114 spaced apart to form a gap of dimension G. In some embodiments, the core coil assembly components to be sealed may be the outer coil 114 of one coil assembly 108 and the outer coil 114 of another coil assembly (e.g., coil assembly 106 or 110), which are spaced apart to form a gap of dimension G. In another embodiment, the core coil assembly components to be sealed may be the inner coil 112 and the outer coil 114 and the core assembly 102, wherein the top surfaces 244, 248 of the inner coil 112 and the outer coil 114 are spaced apart from the side surface 102S of the top core leg 102T above the top surfaces 244, 248 to form a gap of dimension G. Similarly, in another embodiment, the core coil assembly components to be sealed can be the inner coil 112 and the outer coil 114 of the core assembly 102, wherein the bottom surfaces 246, 250 of the inner coil 112 and the outer coil 114 are spaced apart from the side surface 102S of the bottom core leg 102B of the core assembly 102 below the bottom surfaces 246, 250 to form a gap of size G.

[0082] Additionally, the seal assembly 500 includes an expandable sealing member 116g that occupies the gap, and in all embodiments the expandable sealing member 116a includes an inner cavity 440. The other gaps to be filled are filled by the expandable sealing members 116a-116f and 116h-116m.

[0083] In addition, the sealing assembly 500 may include an expander / contractor device 554, which includes a port connector 555, which is connected to the cavity 440, for example by sealing to the port. The port connector 555 can be a short section of any suitable size and shape to achieve a sealed connection. For example, the external shape of the port connector 555 can include a tapered taper or other suitable shape thereon so that a strong insertion into the port seals the port around the outside of the port connector 555. Optionally, the expander / contractor device 554 can include a valve 557 and a quick disconnect connector 558 so that the pump 556 can be removed and used to seal another gap together with another expandable sealing member.

[0084] The seal assembly 500 may include optional components for achieving expansion of the expandable seal member. In some embodiments, a positive pressure pump 556 ( Figure 5A In other embodiments, a vacuum pump 660 is provided (see Figure 6 A to Figure 6 B). Refer to 5A to Figure 5C The positive pressure pump 556 is configured to pump the filling material 562 from the filling material supply device 564 into the cavity 440 by applying positive pressure. The filling material supply device 564 is interconnected with the port connector 555 through a valve 557.

[0085] This positive pressure from the positive pressure pump 556 operates to expand and bend the expandable sealing member 116g having a thickness of the unexpanded (molded) dimension T1 into the gap of dimension G and thereby seal the gap, as shown in FIG. Figure 5B As shown. The filler material 562 can then be cured into a suitable solid or semi-solid material. For example, the filler material 562 can be any material that maintains a sealing force against the surface of the sealed core coil assembly when cured under pressure. For example, the filler material 562 can be a curable polymer, such as a curable silicone material. For example, the filler material 562 can be a room temperature curable two-part silicone, such as available from Wacker Chemie AG of Munich, Germany. RT, etc. After curing, the port connector 555 can be removed and a sealed core coil assembly 500S is obtained.

[0086] In another embodiment, the sealing assembly 600, 700 may include a vacuum pump 660, such as Figure 6 and FIG. 7A to FIG. 7GAs shown. The vacuum pump 660 is configured to evacuate and contract the cavity 440 of the inflatable sealing member 116g′, and then release the vacuum and expand the inflatable sealing member 116g′ into the gap of dimension G. Therefore, in this embodiment, the initial (molded) dimension T of the inflatable sealing member 116g′ is initially formed to be larger than the gap dimension G. Evacuation reduces the thickness T to a value T1 that is less than dimension G, so that the inflatable sealing member 116g′ can be easily inserted into the gap and adjusted in position therein. Once properly positioned in the plane of the core window 102W, the vacuum can be released, and the inflatable sealing member 116g′ can bend and expand due to its inherent stored energy, and be sealed to the gap of dimension G.

[0087] As in Figure 6 As can be seen in the figure, the sealing assembly 600 can include an expander / contractor device 654, which includes a vacuum pump 660, a valve 657 and a port connector 655 configured to evacuate and contract the cavity 440 of the expandable sealing member 116g'. The port connector 655 may include a T-shaped connector coupled to the open end. The expander / contractor device 654 can also include a filling assembly, which includes a positive pressure pump 556, a valve 557 and a filling material supply device 564.

[0088] When the cavity 440 is evacuated and the thickness T is contracted to the thickness T1 by the operation of the vacuum pump 660, the valve 657 is closed. Then the valve 557 is opened and the positive pressure pump 556 is operated to provide the filling material ( Figure 6 660 and the positive pressure pump 556 so they can be used for another gap filling operation at a different location. As before, both valves 557, 657 interconnected to the port connector 655 are configured to be in a closed position after the filling material flows into the cavity 440. The filling material can then be cured in place.

[0089] FIG. 7 shows an embodiment in which the expander / contractor device 754 includes a port connector 755, an integral valve 757 interconnected to the vacuum pump 660. In this embodiment, after the expander / contractor device 754 is evacuated so that the thickness T is reduced to a dimension T1 that is less than the gap dimension G, the vacuum can be removed / turned off and the expandable sealing member 116g′ can be allowed to expand to seal the gap. In an embodiment such as Figure 7B In some embodiments shown, the vacuum pump 660 may be disconnected by using the quick disconnect coupler 558. Thereafter, the valve 757 may be opened to expand the expandable sealing member 116g'.

[0090] Thus, it is apparent that, according to some embodiments, a sealing assembly (e.g., sealing assembly 500, 600, 700) is provided. The sealing assembly includes core coil assembly components (e.g., one or more coils 212, 214 and core assembly 102) disposed in a spaced relationship defining a gap (e.g., having a gap dimension G); an inflatable sealing member (e.g., one of inflatable sealing members 116a-116n) occupying the gap, the inflatable sealing member including cavity 440. The sealing assembly (e.g., sealing assembly 500, 600, 700) also includes an inflator / contractor device (e.g., inflator / contractor device 554, 654, 754) including a port connector (e.g., 555, 655, 755) connected to cavity 440 and one of a pump (e.g., positive pressure pump 556) or a vacuum device (e.g., vacuum pump 660):

[0091] The pump is configured to pump fill material (e.g., fill material 562) into cavity 440 and expand the expandable sealing member into the gap,

[0092] The vacuum device is configured to evacuate the cavity 440 and thereafter release the vacuum to allow the expandable sealing member to expand into the gap.

[0093] like Fig.7D As can be seen in FIG. 1 , in some embodiments, the expandable sealing member 116g′ can be evacuated by the vacuum pump 660 at a general location away from the gap, the valve 757 is closed and the quick disconnect coupler 558 is disconnected, thereby leaving only the half 558A of the coupled quick disconnect coupler 558. Thus, the expandable sealing member 116g′ is now movable and can be moved into position to seal the gap as desired.

[0094] In some embodiments, cavity 440 may remain unfilled. Alternatively, cavity 440 may be filled with filler material 562 by inserting a filler tool 759 (e.g., a tube) into cavity 440 and filling from a canister 760 of filler material 562. Filler tool 759 may be withdrawn from cavity 440 when filling begins. Figure 7F 1 and 2 show an end-filled expandable sealing member 116g′ that fills and seals the gap. As another option, the end of the expandable sealing member 116g′ can be inserted with a plug 762 that includes a plug member or a plug of a sealant material (e.g., silicone) that meets the requirements. Other suitable insertion techniques can be used.

[0095] Various configurations and manufacturing methods may be used for the expandable sealing members 116a-116n and 116g'. For example, cross-sectional shapes other than rectangular may be used.

[0096] like FIG. 8A to FIG. 8DAs shown, an embodiment of an inflatable sealing member 816 including a non-rectangular cross-section and an extruded and inserted configuration is shown. The inflatable sealing member 816 can be used with any of the vertically oriented inflatable sealing members 116a-116n and 116g'. As shown, the inflatable sealing member 816 includes an extruded body 816B formed by extruding a compliant material (e.g., TPE) and installing an end plug 862 therein. The end plug 862 can be as described above. The inflatable sealing member 816 includes a recessed side that allows the inflatable sealing member 816 to expand and / or contract preferentially in the thickness direction when pressure or vacuum is applied. For example, in Fig.8D , where application of vacuum shrinks the thickness to a dimension T1 that is less than T. In some embodiments, a port connector (eg, port connector 755) can include an elongated configuration rather than a cone to allow for each to be collapsed.

[0097] like 9A to 9D As shown, an embodiment of an expandable sealing member 916 including a non-rectangular cross-section and a blow-molded configuration is shown. The expandable sealing member 916 can be used for any of the vertically oriented expandable sealing members 116a-116m and 116g'. As shown, the expandable sealing member 916 includes a blow-molded body 916B formed by blow-molding a desired material (e.g., TPE) in a mold to form a composite body 916B and ports therein. Other cross-sectional shapes are also possible, but thinner sidewalls allow for a preferred shrinkage direction, such as Fig.9E shown.

[0098] Other configurations can be implemented where the port is provided on the non-sealing side of the expandable sealing member. For example, a fill port can be cut on the non-sealing side of the extrusion body 816B and the other end can also be inserted. In an alternative to the expandable sealing member 916, for example FIG. 4C to FIG. 4E As shown, ports can be blow molded on one side. In some embodiments, the expandable sealing member can include a sealant on these sealing end faces to help form a permanent seal and minimize the movement of the expandable sealing member in the gap. Other suitable configurations of the expandable sealing member are also possible, as long as they can expand or contract, or can expand and contract both.

[0099] In a broad aspect, a core coil assembly 100 is provided. The core coil assembly 100 includes a coil assembly, which includes a plurality of coils (for example, an inner coil 112 which may be a low voltage coil and an outer coil 114 which may be a high voltage outer coil), each of the plurality of coils having an outer peripheral surface (including an inner surface, an outer surface, an upper surface, and a lower surface). The core coil assembly 100 also includes a core assembly 102, which includes at least one core column of magnetically permeable material and one or more core windows 102W, the core window 102 having an inner surface. In practice, a return path for the magnetic circuit is used, and is typically another core column. In the described embodiment, three core columns (core columns 102L, 102C, 102R) are included. In the case of a single-phase transformer, only two core columns can be used.

[0100] The core coil assembly 100 includes an inflatable sealing member (e.g., similar to the inflatable sealing members 116a-116n and 116g′). At least some of the individual inflatable sealing members (e.g., inflatable sealing members 116a-116n and 116g′), preferably each inflatable sealing member includes a fillable or evacuable cavity 440. The inflatable sealing member is inserted between the outer peripheral surfaces of the plurality of coils within the core window 102W (e.g., between the inner coil 112 and the outer coil 114), between the inner side surface 102S of the core window 102W and the plurality of coils (e.g., between the ends of the inner coil 112 and the outer coil 114 and the top and bottom core legs 102T, 102B), and between the inner coil 112 and the core column (e.g., core columns 102L, 102C, 102R).

[0101] In some embodiments, a method 1000 for sealing a gap between components such as a core coil assembly 200 in a dry-type transformer is provided. The method 1000 includes, in 1002, providing a core assembly (e.g., core assembly 102) having a core window (e.g., core window 102W and in some embodiments, multiple core windows 102W), and in 1004, providing a coil assembly (e.g., coil assembly 106, 108 and / or 110), a portion of the coil assembly residing in the core window 102W. The method 1000 also includes, in 1006, providing an expandable sealing member (e.g., in fact, multiple expandable sealing members 116a-116n, 116g′) including an inner cavity (e.g., inner cavity 440) in the gap (of dimension G) in the core window 102W not occupied by the coil assembly. The method 1000 also includes, in 1008, increasing the volume of the inner cavity 440 to expand the outer dimension (T or T1) of the expandable sealing member to seal the gap. In one embodiment, the dimension (T) is expanded to fill the gap of dimension G by increasing the pressure in lumen 440 during the filling operation. In another embodiment, increasing the volume of lumen 440 to expand the outer dimension (T1) of the expandable sealing member includes releasing the vacuum in lumen 440, thereby expanding the dimension to fill the gap of dimension G.

[0102] Although the present disclosure is primarily described with respect to submersible three-phase dry-type transformers, it will be appreciated that the disclosed expandable sealing members and assemblies may also be used with other types of transformers (eg, single-phase transformers) or coil assemblies.

[0103] The foregoing description discloses only example embodiments. Modifications of the above-described devices, components, and methods that fall within the scope of the present disclosure will be apparent to those of ordinary skill in the art. For example, although the examples discussed above are shown for dry-type transformers, other embodiments according to the present disclosure may be implemented for other devices. The present disclosure is not intended to limit the present invention to the specific devices, components, and / or methods disclosed, but rather, the present invention is intended to cover all modifications, equivalents, and alternatives that fall within the scope of the claims.

Claims

1. A core-coil assembly of a dry-type transformer submersible in water, comprising: A coil assembly having an inner coil and an outer coil, the inner coil having an inner surface, an outer surface, an upper surface and a lower surface, the outer coil having an inner surface, an outer surface, an upper surface and a lower surface; A core assembly, comprising a core post of magnetically permeable material and a core window, the core post and the core window having inner side surfaces; as well as An expandable sealing member comprising a fillable or evacuable cavity, the expandable sealing member being located: between one or more inner side surfaces of the core column and the inner surface of the inner coil, between the outer surface of the inner coil and the inner surface of the outer coil, and Between the upper and lower surfaces of the inner and outer coils and the inner surface of the core window, The cavity of the expandable sealing member is filled with a solid insulating material of suitable quality to seal the gap between the surfaces where the expandable sealing member is located, thereby inhibiting the formation of a conductive water loop in the sealed gap between the surfaces where the expandable sealing member is located during the submerged operation of the dry-type transformer.

2. The core-coil assembly according to claim 1, wherein: The expandable sealing member includes an expandable tube.

3. The core-coil assembly according to claim 1, wherein: The expandable sealing member includes an open end and a closed end.

4. The core-coil assembly according to claim 1, wherein: The cavity is filled with a curable polymer.

5. The core-coil assembly according to claim 4, wherein: The curable polymer includes silicone.

6. The core coil assembly of claim 3, comprising a T-connector coupled to the open end.

7. The core-coil assembly according to claim 1, wherein: The expandable sealing member including the cavity is disposed between an inner side surface of the stem and an inner surface of the inner coil.

8. The core-coil assembly according to claim 1, wherein: The expandable sealing member including the cavity is disposed between an outer surface of the inner coil and an inner surface of the outer coil.

9. The core-coil assembly according to claim 1, wherein: The expandable sealing member including the cavity is disposed between top surfaces of the inner and outer coils and an inner side surface of the core window.

10. The core-coil assembly according to claim 1, wherein: The expandable sealing member including the cavity is disposed between bottom surfaces of the inner and outer coils and an inner side surface of the core window.

11. The core-coil assembly according to claim 1, wherein: The expandable sealing member including the cavity is disposed between an outer surface of the outer coil and an outer surface of another outer coil.

12. The core-coil assembly according to claim 1, wherein: The expandable sealing member including the cavity is configured to seal between an inside surface of the second core window of the core assembly and a surface of the second coil assembly and also between respective surfaces of the second coil assembly.

13. A core-coil assembly of a dry-type transformer submersible in water, the core-coil assembly comprising: A coil assembly including a plurality of coils, each of the plurality of coils having an outer peripheral surface; a core assembly comprising a core window of magnetically permeable material and at least one core post, the core window having an inner side surface; and Inflatable sealing members, each of which includes a fillable or evacuable cavity, the inflatable sealing members being inserted between: between the outer peripheral surfaces of the plurality of coils in the core window, and Between the inner surface of the core window and the plurality of coils, The cavity of each of the expandable sealing members is filled with a solid insulating material that meets the requirements to seal the gap between the surfaces where the expandable sealing members are located, thereby inhibiting the formation of a conductive water loop in the sealed gap between the surfaces where the expandable sealing members are inserted during the immersed operation of the dry-type transformer.

14. A sealing assembly comprising: core-coil assembly components disposed in a spaced relationship defining a gap; an expandable sealing member configured to occupy the gap, the expandable sealing member comprising a cavity; An expander / contractor device comprising a port connector coupled to the chamber and further comprising a pump or vacuum device: The pump is configured to pump filler material into the cavity and expand the expandable sealing member into the gap, The vacuum device is configured to evacuate the cavity such that when the vacuum is released, the expandable sealing member expands into the gap.

15. The sealing assembly of claim 14, further comprising a valve interconnected to the port connector, the valve being configured to close after fill material flows into the cavity.

16. The seal assembly of claim 14, further comprising a fill material supply interconnected to the port connector.

17. A core-coil assembly of a dry-type transformer submersible in water, the core-coil assembly comprising: core column; a first coil received around the core leg and forming a gap; as well as An expandable sealing member includes a cavity for sealing the gap between the core leg and the first coil, the cavity of the expandable sealing member being filled with a solid insulating material that meets the requirements, thereby inhibiting the formation of a conductive water loop in the sealed gap during the submerged operation of the dry-type transformer.

18. The core-coil assembly according to claim 17, wherein: The expandable sealing member can be expanded by applying pressure to the cavity or can be deflated by applying a vacuum to the cavity.

19. The core-coil assembly of claim 17, further comprising: a second coil surrounding the first coil and providing a further gap between the first coil and the second coil; and an additional expandable sealing member including a cavity for sealing a gap between the first coil and the second coil.

20. The core coil assembly of claim 19, further comprising an additional expandable sealing member disposed between an inner side surface of the core window and end surfaces of the first coil and the second coil, the additional expandable sealing member comprising a cavity.

21. A core-coil assembly of a dry-type transformer submersible in water, the core-coil assembly comprising: A core assembly of magnetically permeable material having a core window with an inner surface; a coil assembly, a portion of which is located in the core window, the coil assembly comprising an end surface; and An expandable sealing member is arranged between the inner surface of the core window and the end surface of the coil assembly, and the expandable sealing member includes a cavity, and the cavity of the expandable sealing member is filled with a solid insulating material that meets the requirements to seal the gap between the surfaces where the expandable sealing member is located, thereby inhibiting the formation of a conductive water loop in the sealed gap between the surfaces where the expandable sealing member is located during the immersion operation of the dry-type transformer.

22. A method of sealing a core-coil assembly, comprising: providing a core assembly having a core window; providing a coil assembly, a portion of the coil assembly residing in the core window; providing an expandable sealing member including a cavity in a gap in the core window not occupied by the coil assembly; as well as The volume of the cavity is increased to expand the outer dimensions of the expandable sealing member to seal the gap.

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