Oil-filled pole-mounted transformer

Abstract

To provide an oil-filled pole transformer in which an arrester capable of reducing a manufacturing cost is built-in.SOLUTION: An oil-filled pole transformer is an oil-filled transformer including: a content of a transformer having an iron core and a wiring wound to the iron core; and a container housing the content of the transformer: an upper fastening metal fitting attached to an upper direction of the content of the transformer; and a content hanging metal tool that connects a content fixing sheet provided to an inner wall of the container. An arrester attachment structure is provided to the content hanging metal tool of an upper part of the content of the transformer. The arrester attachment structure is arranged to between an attachment part with the content attachment sheet of the content hanging metal tool and an attachment part of the upper fastening metal tool attachment part of the content hanging metal tool.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an oil-immersed pole-mounted transformer with a built-in arrester. [Background technology]

[0002] Distribution transformers, such as pole-mounted transformers that change the voltage to supply electricity over distribution lines, are primarily composed of a transformer body having an iron core and windings wound around the iron core, and an outer box that houses the transformer body.

[0003] Some distribution transformers have an arrester (surge protector) inside the transformer as a lightning protection measure, and in such transformers, the arrester must be installed in the oil or gas space above the inside of the tank.

[0004] The structure is such that the arrester mounting bracket with the arrester attached is attached to the internal mounting bracket that attaches the transformer internals (iron core, primary coil, secondary coil, upper and lower fastening brackets) to the tank.

[0005] For example, Patent Document 1 discloses an invention for a gas-insulated transformer in which an inert gas with higher dielectric strength than air is sealed as an insulator, and a gapless arrester connected to the line end of the transformer coil is built into the sealed gas.

[0006] Specifically, an internal mounting bracket (a U-shaped cross-section bracket in the figure located between the iron core 6 and the tap changer 7) is attached to the short side of the top fastening bracket inside the transformer, and the arrester mounting bracket is attached to the internal mounting bracket, thereby realizing the arrester to be built into the tank.

[0007] Patent Document 2 discloses an invention for a transformer in which a common mounting bracket bent into an L shape is attached to a terminal block above the transformer winding inside a tank filled with insulating oil, SF6 gas, or other insulator, and three-phase lightning arresters connected to high-voltage side leads led from the overhead line through a switch are fixed to the common mounting bracket. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 61-190910 [Patent Document 2] Japanese Patent Application Publication No. 1-222417 Summary of the Invention [Problem to be solved by the invention]

[0009] The gas-insulated pole-mounted transformer in Patent Document 1 has an arrester mounting bracket attached to the inner mounting bracket on the short side, which improves workability, but if the insulation method is changed to oil insulation, manufacturing costs will increase.

[0010] The arrester in Patent Document 1 is attached above the attachment position of the fixing bolt for fixing the contents of the internal mounting bracket of the gas-insulated pole-mounted transformer to the tank.

[0011] In gas-insulated pole transformers, an inert gas is sealed inside the tank as an insulator, so the arrester can be covered with inert gas no matter where it is installed inside the tank. However, since the arrester in an oil-filled transformer is placed in oil, a certain amount of oil is required to reach a certain depth below the oil surface. If the arrester mounting bracket is installed so that it extends upward from the inner mounting bracket, the arrester position will be higher, and the amount of insulating oil required will increase.

[0012] As described above, when the invention of the gas-insulated pole transformer of Patent Document 1 is applied to an oil-filled transformer using insulating oil, there is a problem in that the manufacturing cost is high.

[0013] An object of the present invention is to provide an oil-immersed pole-mounted transformer with a built-in arrester that can reduce manufacturing costs. [Means for solving the problem]

[0014] The above object is achieved by an oil-filled pole-mounted transformer having a transformer interior having an iron core and a winding wound around the iron core, and a container for accommodating the transformer interior, the transformer interior being provided with an upper fastening bracket attached above the transformer interior, and an interior suspension bracket provided on the inner wall of the container for connecting an interior fixing seat, the interior suspension bracket being provided with an arrester mounting structure on the upper part of the transformer interior, the arrester mounting structure being arranged between the mounting portion of the interior suspension bracket with the interior mounting seat and the mounting portion of the interior suspension bracket with the upper fastening bracket mounting portion. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide an oil-immersed pole-mounted transformer that can be manufactured at reduced costs. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram of a transformer to which the present invention is applied; [Figure 2a] 1 is a schematic plan view of the inside of a transformer to which the present invention is applied; [Figure 2b] 1 is a schematic diagram of the front of the upper part of the inside of a transformer to which the present invention is applied. [Figure 3a] FIG. 1 is a schematic plan view of a transformer to which the present invention is applied, in which a spacer is added to the upper portion of the interior thereof. [Figure 3b] FIG. 1 is a schematic front view of a transformer to which the present invention is applied, with a spacer added to the upper portion of the interior thereof. [Figure 4] 1A and 1B are three-view diagrams of an upper fastening fitting to which the present invention is directed. [Figure 5] 1 is a three-view diagram of an internal hanging fitting to which the present invention is directed. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing for explaining the embodiments, the same components are given the same names and symbols as much as possible, and repeated description thereof will be omitted. [Example]

[0018] A schematic diagram of a transformer to which the present invention is applied is shown in Fig. 1. As shown in Fig. 1, the transformer to which the present invention is applied has a container consisting of a tank 11 and a cover 10, and the container houses a transformer internals 12 consisting of an iron core 13 and a winding wound around the iron core 13.

[0019] It is desirable that the container be sealed. In addition, when the tank 11 and the cover 10 are integrated, they may be collectively referred to as an outer box. In the following embodiments, the transformer will be described as an oil-filled transformer, which has insulating oil, a liquid for insulating and cooling the transformer body, inside the outer box.

[0020] 1 is a schematic diagram of a transformer to which the present invention is applied. A transformer body 12 having an iron core sandwiched between an upper fastener 14 and a lower fastener 15 and a winding wound around the iron core is contained in a tank 11.

[0021] The top fastening bracket 14 is fixed to the inner suspending bracket 16 with bracket fixing bolts and nuts 24. The inner suspending bracket 16 has a U-shaped structure consisting of a horizontal long side and vertical short sides bent at both ends in the opposite direction to the transformer inner suspending bracket 12.

[0022] An insulator base 28 is installed near the center of the long side, and an arrester 17 is fixed with bolts toward the insulator base 28 on the side of the short side closer to the transformer contents 12, and a metal fitting fixing bolt 25 is arranged above the arrester to fix the contents hanging metal fitting 16 to the tank 11.

[0023] In this embodiment, an example of fixing to the tank 11 with bolts is described, but bolts are not necessarily required, and a contents fixing seat for hanging the contents hanging fitting 16 on a receiver protruding inward from the tank 11 may also be provided.

[0024] The arrester 17 must be covered with insulating oil for insulation, and in this example, it is sufficient if the insulating oil is filled up to the dashed line indicated by 30.

[0025] 2a is a schematic plan view of the upper part of the transformer interior to which the present invention is applied. Interior slings 16 are attached to top fastenings 14, and an insulator base 28 is installed in the center of the interior slings 16. Arresters 17 are fixed horizontally to both the left and right ends of the interior slings 16, and are installed so that the tips of the insulator bases 28 and the arresters 17 are at a predetermined distance.

[0026] In this embodiment, a method is described in which the bolt protruding from the arrester 17 is fixed with a nut, but since the installation method depends on the specifications of the arrester 17, the internal hanging fitting must have an arrester installation structure that meets the installation specifications of the arrester 17.

[0027] 2b is a schematic diagram of the front of the upper part of the transformer interior to which the present invention is applied. The arrester 17 is fixed to the vertically bent ends of the interior hanging bracket 16 at the positions close to the transformer interior 12, with bracket fixing bolts 25 installed at the top. Since the arrester 17 needs to be covered with insulating oil, installing it as close to the transformer interior 12 as possible can reduce the amount of insulating oil required.

[0028] 4 is a three-view diagram of the top fastening fitting to which the present invention is applied. It has an insulator base fixing hole 29, a fixing band hole 18, and an inner hanger fixing hole 21.

[0029] 5 is a three-view diagram of the internal suspension bracket to which the present invention is applied. Insulator base fixing holes 29 and internal suspension bracket fixing holes 21 are provided on the long sides, and arrester mounting holes 22 and internal fixing holes 23 are provided on the short sides. [Example]

[0030] Example 2 will be explained using Figures 3a and 3b. Figure 3a is a schematic plan view of a transformer to which the present invention is applied, in which a spacer 27 has been added to the upper part of the interior. The difference from Figure 2a is that a spacer 27 has been added to the attachment part of the arrester 17 to the short side of the top fastening bracket 14. The arrester 17 must be installed at a specified distance from the insulator base 28.

[0031] In a large-capacity transformer, the diameter of the tank 11 also becomes larger, so it becomes necessary to adjust the distance between the arrester 17 and the insulator base 28 to an appropriate distance by inserting a spacer 27. For this reason, the spacer 27 is placed between the arrester 17 and the internal hanging bracket to adjust the distance between the arrester 17 and the insulator base 28. A washer, nut, or the like may be used as the spacer 27.

[0032] Furthermore, since the insulator base 28 may not be installed exactly in the center of the tank, it is desirable to make it possible to adjust the distance between the arrester 17 and the insulator base for each arrester mounting portion.

[0033] 3b is a schematic front view of the transformer interior to which the present invention is applied, with a spacer 27 added to the top. Even when the spacer 27 is added, the arrester 17 can be installed at a position lower than the metal fitting fixing bolts 25 that fix the transformer interior 12 to the tank 11, thereby reducing the amount of insulating oil. [Explanation of symbols]

[0034] 10 Cover, 11 Tank, 12 Transformer internals, 13 Core, 14 Top fastening bracket, 15 Bottom fastening bracket, 16 Internal suspension bracket, 17 Arrester, 18 Fixing band hole, 19 Internal fixing seat, 21 Internal suspension bracket fixing hole, 22 Arrester mounting hole, 23 Internal fixing hole, 24 Bracket fixing bolt and nut, 25 Bracket fixing bolt, 26 Tap changer base, 27 Spacer, 28 Insulator base, 29 Insulator base fixing hole, 30 Insulating oil

Claims

1. An oil-filled transformer having a transformer body having an iron core and a winding wound around the iron core, and a container for accommodating the transformer body, The transformer includes an upper fastening fitting attached to the top of the transformer contents, and a contents hanging fitting provided on the inner wall of the container for connecting the contents fixing seat, The inner suspension bracket at the upper part of the transformer is provided with an arrester mounting structure, The arrester mounting structure is an oil-filled pole-mounted transformer that is arranged between the mounting portion of the internal suspension bracket with the internal mounting seat and the mounting portion of the internal suspension bracket with the upper fastening bracket mounting portion.

2. In claim 1, The arrester mounting structure of the oil-immersed pole-mounted transformer is an arrester fixing hole located below the mounting portion of the internal hanging bracket and the internal mounting seat extending upward.

3. In claim 2, An oil-immersed pole-mounted transformer in which an arrester is attached horizontally in the arrester fixing hole.

4. In claim 3, An oil-immersed pole-mounted transformer in which an arrester is attached to the arrester mounting structure via a spacer so that the arrester mounting position can be adjusted.

5. In claim 4, The contents hanging fittings have attachment portions for attachment seats on both ends, The arrester mounting structure is provided between the mounting portion and the upper fastening fitting, An oil-immersed pole-mounted transformer in which a fixed distance is maintained between the insulator base and the arrester mounted on the arrester mounting structure.

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