oil-filled transformer

Abstract

To provide an oil-immersed transformer with low connection resistance and an internal wiring structure that offers excellent cooling performance. [Solution] An oil-filled transformer having a housing, insulating oil provided in the housing, and windings disposed in the insulating oil, wherein the transformer has a busbar connected to the windings and for electrically connecting the windings to the outside of the housing via an external connection wire, the busbar having a winding connection portion for connecting to the windings, a terminal connection portion for connecting to the external connection wire, and a main wire portion between the winding connection portion and the terminal connection portion, and when viewed from one direction, the busbar is wide at the winding connection portion and the terminal connection portion and thin at the main wire portion.

Description

Technical Field

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[0001] The present invention relates to an oil-immersed transformer.

Background Art

[0002] Oil-immersed transformers are widely used. As an example, Patent Document 1 is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] <00000​​​​​​​​​​​​​​​​​​The present invention provides an oil-filled transformer having busbars suitable for oil-filled transformers.

[0008] Further means and effects of the present invention will become apparent throughout the entire specification below. [Brief explanation of the drawing]

[0009] [Figure 1A] This is a schematic diagram of the busbar before processing. [Figure 1B] This is a schematic diagram of the busbar after processing. [Figure 1C] This is a schematic diagram of Figure 1B from the perspective of the orthogonal plane. [Figure 1D] This is a schematic diagram showing a busbar with holes added to it, as shown in Figure 1B. [Figure 2] This is a schematic diagram of an oil-immersed transformer. [Figure 3A] This is a schematic diagram of the busbar before processing. [Figure 3B] This is a schematic diagram of the busbar after the first processing. [Figure 3C] This is a schematic diagram of the busbar during the second machining process. [Figure 3D] This is a schematic diagram of the busbar after the second processing step. [Figure 3E] This is a schematic diagram of Figure 3D from an orthogonal plane. [Figure 3F] This is a schematic diagram showing a busbar with holes added to it, as shown in Figure 3D. [Figure 4] This is a schematic diagram of an oil-immersed transformer. [Figure 5A] This is a schematic diagram of the busbar during the second machining process, corresponding to Figure 3C. [Figure 5B] This figure corresponds to Figure 3D. [Figure 5C] This figure corresponds to Figure 3E. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings. [Examples]

[0011] FIG. 1 illustrates the structure of a bus bar used in an oil-immersed transformer while following the manufacturing process.

[0012] FIG. 1A shows the state of the metal member before processing. As an example, it is a round bar or square bar metal member. From the perspective of ease of processing, an aluminum material is preferable.

[0013] FIG. 1B is a schematic diagram of the bus bar 1 after processing. By processing, the bus bar 1 has a shape having a main line portion 1A, a terminal connection portion 1B, and a winding connection portion 1C. The terminal connection portion 1B and the winding connection portion 1C are formed by pressurizing or pressing the metal member before processing as shown by PS in FIG. 1B. Thereby, the terminal connection portion 1B and the winding connection portion 1C are in a state thinner than the main line portion 1A.

[0014] FIG. 1C is a schematic diagram when FIG. 1B is viewed from an orthogonal plane. The terminal connection portion 1B and the winding connection portion 1C are in a state wider than the main line portion​​​​​​​​​​​​​​​The ends of the windings are electrically connected to the busbar 1 at the winding connection section 1C. At the terminal connection section 1B, the busbar 1 and the external lead wire 7 are electrically connected. By providing a hole 2 in the terminal connection section 1B, the connection to the external lead wire 7 can be easily made using the fastening member 6.

[0019] As is clear from the diagram, the terminal connection section 1B is wider than the main line section 1A, which reduces connection resistance, ensures a secure connection, and simplifies the connection process.

[0020] The main wire section 1A has a structure in which it is bent or folded below the oil level 5 of the insulating oil. This is for the purpose of electrically connecting the external lead wire 7 and the winding 3. In this case, the main wire section 1A is narrower in width than the terminal connection section 1B and the winding connection section 1C, making it easier to bend or fold. Furthermore, by using aluminum material, in addition to the effect of the shape, the effect of the metal material itself, which facilitates bending or folding, is added.

[0021] Furthermore, the ease of bending or folding allows the bent or folded portion of the main wire section 1A to be reliably positioned below the oil surface 5. This increases the volume or area of ​​the main wire section 1A below the oil surface 5, thereby improving the cooling efficiency when using insulating oil as a cooling medium. As a result, the heat generated by the winding 3 can be cooled by the main wire section 1A of the busbar 1 using the insulating oil, thereby improving cooling.

[0022] Furthermore, since the main line section 1A, the terminal connection section 1B, and the winding connection section 1C are integrated, an increase in the connection resistance of the busbar itself can be avoided.

[0023] The application of busbar 1 is not limited to the high-voltage or low-voltage side. However, for oil-immersed transformers with a certain level of rating or higher, it may be applied only to the low-voltage side.

[0024] Furthermore, since the structure of conventional oil-filled transformers can be applied to parts not directly related to the busbar, we will omit the explanation.

[0025] Next, we will describe an example of the manufacturing process for an oil-filled transformer using busbar 1.

[0026] As the first step, the busbar 1 is processed, for example, by pressurization as shown in Figure 1, into a shape having a main wire section 1A, a terminal connection section 1B, and a winding connection section 1C.

[0027] As the second step, the busbar 1 is inserted into the winding 3, and the winding connection part 1C enables an electrical connection between the winding 3 and the busbar 1.

[0028] As the third step, the main line portion 1A of the busbar 1 is processed to create a bent or folded portion.

[0029] In the fourth step, the external lead wire 7 and the terminal connection part 1B are connected by a fastening member 6. As an example of a fastening member, screws or bolts can be used.

[0030] As the fifth step, winding 3 is installed inside the transformer casing 10.

[0031] As the sixth step, insulating oil is injected into the transformer housing 10.

[0032] By following the steps described above, an oil-filled transformer with busbars suitable for oil-filled transformers can be realized.

[0033] Please note that the manufacturing method is not limited to the order described above. This is merely an example of a manufacturing method.

[0034] Furthermore, since the conventional manufacturing methods for oil-filled transformers can be applied to parts not directly related to the busbars, we will omit the explanation.

[0035] The oil-immersed transformer of this embodiment provides an oil-immersed transformer having busbars suitable for oil-immersed transformers. [Examples]

[0036] This embodiment differs from Embodiment 1 in the shape of the busbars used in the oil-filled transformer. Otherwise, it is identical to Embodiment 1.

[0037] Figure 3A, like Figure 1A, shows the state of the metal component before processing.

[0038] Figure 3B shows the same state as in Figure 1B, where pressure or press processing has been performed to create a shape having a main wire section 1A, a terminal connection section 1B, and a winding connection section 1C.

[0039] The difference from Example 1 is that Figure 3B shows the state after the first processing.

[0040] Figure 3C shows the busbar viewed from a direction perpendicular to it after the processing shown in Figure 3B. The difference from Example 1 is that a second processing step, pressurization or press working PS, is performed on the main line section 1A.

[0041] Figure 3D is a schematic diagram of the busbar after the second machining process.

[0042] Figure 3E is a view of Figure 3D from a direction perpendicular to it. The main line section 1A has been widened as a result of the second processing being performed on it.

[0043] The shape characteristics of Figures 3D and 3E can also be described as the main line section 1A, terminal connection section 1B, and winding connection section 1C of the busbar having directions in which they widen that are perpendicular to each other.

[0044] Figure 3F is a diagram showing that, similar to Figure 1D, a hole 2 is provided in the terminal connection part 1B.

[0045] Figure 4 corresponds to Figure 2. The difference from Figure 2 is that the thickness of the main line portion 1A visible in Figure 4 is thinner than in Figure 2. This is because the busbar surface visible in Figure 3D is shown in Figure 4. Therefore, when viewed from a plane perpendicular to Figure 4 within the oil-filled transformer, the main line portion 1A of the busbar is wider, as shown in Figure 3E.

[0046] In this embodiment, because the main wire section 1A is wide, the contact area with the insulating oil can be increased, resulting in a further improvement in cooling performance.

[0047] Furthermore, Figure 4 shows that the main line portion 1A of the busbar is bent at a thin surface. Therefore, it is possible to facilitate the bending or folding process of the main line portion 1A.

[0048] Furthermore, the main wire portion 1A will be thinner than in Example 1 at the bent or folded surface. Therefore, to prevent breakage of the main wire portion 1A, it is desirable that the busbar 1 be made of a material with high toughness. From this point of view as well, aluminum is suitable for the busbar 1.

[0049] In this embodiment, in addition to the effects of Example 1, an improvement in cooling performance is achieved. [Examples]

[0050] This embodiment is identical to Embodiment 2, except for a slight modification to the busbar structure.

[0051] Figure 5A corresponds to Figure 3C. In this embodiment, during the second processing, the position where pressure or pressing is applied to the main wire section 1A is located away from the terminal connection section 1B and the winding connection section 1C.

[0052] Figure 5B corresponds to Figure 3D. After pressurization or pressing, the unprocessed portion 1D exists between the main wire portion 1A, the terminal connection portion 1B, and the winding connection portion 1C.

[0053] Figure 5C corresponds to Figure 3E.

[0054] In this embodiment, by providing an unprocessed portion 1D, the application of processing stress twice to the same region between the main wire portion 1A and the terminal connection portion 1B, and between the main wire portion 1A and the winding connection portion 1C is avoided. This prevents busbar breakage due to processing and realizes a highly productive busbar structure.

[0055] Each of the embodiments described above can be used individually or in combination.

[0056] Furthermore, insofar as the above-described technical concept is applied, variations and equivalents are also included within the scope of the description in this specification.

[0057] Furthermore, an example of the present invention described using the above embodiments can also be expressed as follows.

[0058] <Part 1> An oil-filled transformer having a housing, insulating oil provided in the housing, and windings arranged in the insulating oil, It has a busbar connected to the winding and for electrically connecting the winding to the outside of the housing via an external connection wire, The busbar has a winding connection portion that connects to the winding, a terminal connection portion that connects to the external connection wire, and a main wire portion between the winding connection portion and the terminal connection portion. An oil-immersed transformer in which, when viewed from one direction, the busbar is wide at the winding connection section and the terminal connection section, and thin at the main line section. <Part 2> The busbar is an oil-filled transformer according to <Part 1> having a bent or folded portion in the main line portion. <Part 3> The oil-filled transformer described in <Part 2>, wherein the bent portion or folded portion is located in the insulating oil. <Part 4> The oil-immersed transformer described in <Part 3>, wherein the busbar has a hole in the terminal connection portion and is connected to the external connection wire by a fastening member through the hole. <Part 5> The aforementioned fastening member is a screw or a bolt in the oil-filled transformer described in <Part 4>. <Part 6> The oil-immersed transformer described in <Part 1>, wherein the busbar is configured to be thin in thickness at the winding connection portion and the terminal connection portion in a direction perpendicular to the aforementioned one direction, and wide at the main line portion. <Part 7> The oil-immersed transformer described in <Part 1>, wherein the direction in which the busbar widens is perpendicular to the winding connection portion and the terminal connection portion and the main line portion. <Part 8> The oil-immersed transformer according to <6>, wherein the busbar has regions between the winding connection portion and the main wire portion, and between the terminal connection portion and the main wire portion, that have different thicknesses and widths from the winding connection portion, the terminal connection portion, and the main wire portion. <Part 9> The oil-immersed transformer according to <7>, wherein the busbar has regions between the winding connection portion and the main line portion, and between the terminal connection portion and the main line portion, with regions having different thickness and width from the winding connection portion, the terminal connection, and the main line portion. <Part 10> An oil-filled transformer as described in any one of paragraphs 1 through 9, wherein the busbar is made of aluminum. <Part 11> The oil-immersed transformer described in <Part 10>, wherein the aforementioned busbar is used on the low-voltage side. <Part 12> A first step involves connecting a busbar, which has a wide terminal connection portion and a winding connection portion when viewed from one direction, and a main wire portion between the terminal connection portion and the winding connection portion, to a winding. A second step of forming a bent or folded portion on the main line portion of the busbar, A third step involves installing the windings into the transformer housing, A method for manufacturing an oil-filled transformer, comprising a fourth step of injecting insulating oil into the transformer housing. <Part 13> A method for manufacturing an oil-filled transformer according to <12>, wherein the insulating oil is injected up to the area above the bent portion or folded portion. <Part 14> The method for manufacturing an oil-filled transformer according to <13>, wherein the terminal connection portion has a hole, and a step is to connect the terminal connection portion and an external connection wire at the hole using a fastening member. <Part 15> A method for manufacturing an oil-filled transformer as described in <No. 14>, wherein the busbar is made of aluminum. [Explanation of Symbols]

[0059] 1: Bus bar 1A: Main line section 1B: Terminal connection section 1C: Winding connection 1D: Unprocessed part 2: Hole 3: Winding 5: Oil level 6: Fastening members 7: External lead wire 10: Transformer enclosure PS: Pressurized

Claims

1. An oil-filled transformer having a housing, insulating oil provided in the housing, and windings arranged in the insulating oil, It has a busbar connected to the winding and for electrically connecting the winding to the outside of the housing via an external connection wire, The busbar has a winding connection portion that connects to the winding, a terminal connection portion that connects to the external connection wire, and a main wire portion between the winding connection portion and the terminal connection portion. An oil-immersed transformer in which, when viewed from one direction, the busbar is wide at the winding connection section and the terminal connection section, and thin at the main line section.

2. The oil-filled transformer according to claim 1, wherein the busbar has a bent portion or a folded portion in the main line portion.

3. The oil-filled transformer according to claim 2, wherein the bent portion or folded portion is located in the insulating oil.

4. The oil-immersed transformer according to claim 3, wherein the busbar has a hole in the terminal connection portion and is connected to the external connection wire by a fastening member through the hole.

5. The oil-filled transformer according to claim 4, wherein the fastening member is a screw or a bolt.

6. The oil-immersed transformer according to claim 1, wherein the busbar is configured to be thin in the winding connection portion and the terminal connection portion in a direction perpendicular to the aforementioned one direction, and wide in the main line portion.

7. The oil-immersed transformer according to claim 1, wherein the busbar has a winding connection portion, a terminal connection portion, and a main wire portion, and the direction in which it widens is perpendicular to each other.

8. The oil-immersed transformer according to claim 6, wherein the busbar has regions between the winding connection portion and the main line portion, and between the terminal connection portion and the main line portion, that have different thicknesses and widths from the winding connection portion, the terminal connection portion, and the main line portion.

9. The oil-immersed transformer according to claim 7, wherein the busbar has regions between the winding connection portion and the main line portion, and between the terminal connection portion and the main line portion, that have different thickness and width from the winding connection portion, the terminal connection, and the main line portion.

10. An oil-filled transformer according to any one of claims 1 to 9, wherein the busbar is made of aluminum.

11. The oil-filled transformer according to claim 10, wherein the busbar is used on the low-voltage side.

12. A first step involves connecting a busbar, which has a wide terminal connection portion and a winding connection portion when viewed from one direction, and a main wire portion between the terminal connection portion and the winding connection portion, to a winding. A second step of forming a bent or folded portion on the main line portion of the busbar, A third step involves installing the windings into the transformer housing, A method for manufacturing an oil-filled transformer, comprising a fourth step of injecting insulating oil into the transformer housing.

13. The method for manufacturing an oil-filled transformer according to claim 12, wherein the insulating oil is injected up to the area above the bent portion or folded portion.

14. The method for manufacturing an oil-filled transformer according to claim 13, wherein the terminal connection portion has a hole, and the process involves connecting the terminal connection portion and an external connection wire through the hole using a fastening member.

15. The method for manufacturing an oil-filled transformer according to claim 14, wherein the busbar is made of aluminum.

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