Transformer leading-out bar structure and transformer
By vertically welding the tail row on the outside of the middle part of the low-voltage winding and protruding out from the high-voltage winding gap, combining copper foil and aluminum foil winding and brace insulation design, the problem of large eddy current loss of the tail row is solved, reducing the usage of copper foil and improving the heat dissipation effect, and optimizing the structure and performance of the transformer.
Patent Information
- Application Number
- CN202422056484.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-23
- Publication Date
- 2025-09-02
- Estimated Expiration
- 2034-08-23
AI Technical Summary
The tail row of the existing transformer is arranged in the main channel between the high-voltage winding and the low-voltage winding, resulting in large eddy current losses and a large amount of copper discharge.
The tail row is welded vertically on the outer surface of the middle part of the low-voltage winding, and extends out from between the first high-voltage winding and the second high-voltage winding to reduce current distribution. The upper end part and the aluminum foil are wound with copper foil and the intermediate part are wound with aluminum foil. Strings and insulated paper tubes are provided to enhance heat dissipation and insulation, and the three-phase tail row is connected through zero rows.
It reduces the loss of the tail row, reduces the usage of copper rows, improves the heat dissipation effect and insulation performance, avoids losses caused by increased eddy current and resistance, and optimizes the design and performance of the transformer.
Smart Images
Figure CN223296633U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of transformers, and more particularly to a transformer lead-out bar structure and a transformer. Background Art
[0002] The amount of copper busbar used in transformer lead bars is a parameter that needs to be considered during transformer design and manufacturing. Reducing the amount of copper busbar used can directly reduce the production cost of the transformer, and reducing the amount of copper busbar used can also reduce the load loss of the transformer.
[0003] When the low-voltage winding of an existing transformer is wound with foil, the lead-out row is usually arranged parallel to the surface of the foil. The first lead-out row welded to the foil during foil winding is the first row, and the second lead-out row is the tail row. When the transformer winding adopts a structure with the low-voltage winding inside and the high-voltage winding outside, the high-voltage winding is wound on the outside of the low-voltage winding, the first row is welded on the inside of the low-voltage winding, and the tail row is welded on the outside of the low-voltage winding. The tail row is arranged in the main channel formed between the high-voltage winding and the low-voltage winding. The leakage magnetic field in the main channel is large, resulting in relatively large eddy current loss of the tail row. Utility Model Content
[0004] In response to the shortcomings of the existing technology, the utility model provides a transformer lead-out bar structure and a transformer, which can reduce the use of copper bars and reduce the loss of the tail bar, and solve the problem that the tail bar of the existing transformer is set in the main channel between the high-voltage winding and the low-voltage winding, resulting in large eddy current losses in the tail bar.
[0005] The above technical purpose of the present utility model is achieved through the following technical solutions: a transformer lead-out bar structure, comprising: a low-voltage winding body, a high-voltage winding body and a tail bar; the low-voltage winding body comprises an upper end, a lower end and a middle part, the middle part is connected between the upper end and the lower end, and the tail bar is vertically welded to the outer surface of the middle part; the high-voltage winding body is wound outside the low-voltage winding body, the high-voltage winding body comprises a first high-voltage winding and a second high-voltage winding, the first high-voltage winding and the second high-voltage winding are arranged at intervals, and the tail bar extends from between the first high-voltage winding and the second high-voltage winding.
[0006] Optionally, the width of the metal foil at the upper end and the lower end is 60-600 mm.
[0007] Optionally, the tail row is welded to a middle position of the middle portion in the vertical direction.
[0008] Optionally, a plurality of struts are provided on the surface of the tail row, and a plurality of the struts are arranged at intervals parallel to the length direction of the tail row.
[0009] Optionally, the support bar is wrapped with an insulating paper tube.
[0010] Optionally, the upper end portion and the lower end portion are wound with copper foil, and the middle portion is wound with aluminum foil.
[0011] Optionally, a first row is welded to the inner surface of the low-voltage winding body, and the welding end of the first row is arranged parallel to the inner surface of the low-voltage winding body.
[0012] The utility model also provides a transformer, including an iron core and the above-mentioned transformer lead-out structure, the iron core including an upper iron yoke, a lower iron yoke and a plurality of winding columns arranged between the upper iron yoke and the lower iron yoke, the winding columns are arranged at intervals, and the low-voltage winding body is wound on the winding columns.
[0013] Optionally, the transformer also includes a zero bar, and three windings are provided. The three windings are respectively wound with the low-voltage winding body of phase A, the low-voltage winding body of phase B and the low-voltage winding body of phase C. The middle part of the low-voltage winding body of phase A, the middle part of the low-voltage winding body of phase B and the middle part of the low-voltage winding body of phase C are respectively vertically welded with the tail bar of phase A, the tail bar of phase B and the tail bar of phase C. The tail bar of phase A, the tail bar of phase B and the tail bar of phase C are connected through the zero bar.
[0014] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:
[0015] By vertically welding the tail bus to the outer surface of the middle part, and extending the tail bus from the gap between the first high-voltage winding and the second high-voltage winding, the current distribution on the tail bus can be reduced, the heat generated on the tail bus can be reduced, the increase in resistance caused by overheating of the tail bus can be avoided, and the loss caused by the increase in the AC resistance of the conductor can be reduced. The tail bus is welded vertically to the outer surface of the low-voltage winding body, replacing the existing welding method of the tail bus parallel to the surface of the low-voltage winding body. The amount of copper bus used for the tail bus is only the length extending from the surface of the low-voltage winding body to the outside of the high-voltage winding body, which can reduce the amount of copper bus used. A main channel is formed between the outer surface of the low-voltage winding body and the inner surface of the high-voltage winding body. The volume of the tail bus in the main channel is only the part of the tail bus welded to the low-voltage winding body. The eddy current loss of the tail bus affected by the leakage magnetic field in the main channel is small, reducing the loss of the tail bus. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a schematic structural diagram of a transformer lead-out bar structure according to an embodiment of the present utility model;
[0017] Figure 2 This is a schematic structural diagram of a transformer lead-out structure according to an embodiment of the present invention (excluding the high-voltage winding body);
[0018] Figure 3This is a front view of the low-voltage winding body and tail bar of the transformer lead-out bar structure according to one embodiment of the present invention;
[0019] Figure 4 for Figure 3 A partial enlarged view of point A in the middle;
[0020] Figure 5 This is a schematic structural diagram of a transformer according to an embodiment of the present invention.
[0021] Explanation of the accompanying reference numerals: 1. Low-voltage winding body; 101. Upper end; 102. Lower end; 103. Middle part; 2. High-voltage winding body; 201. First high-voltage winding; 202. Second high-voltage winding; 3. Tail row; 4. Support bar; 5. Insulating paper tube; 6. First row; 7. Iron core; 701. Upper iron yoke; 702. Lower iron yoke; 703. Winding column; 8. Zero row. DETAILED DESCRIPTION
[0022] The following describes the implementation of the present invention through specific embodiments. People familiar with this technology can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.
[0023] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content. The specific structure can be described with reference to the drawings of the patent application.
[0024] In order to solve the above technical problems, the utility model discloses a transformer lead-out structure, such as Figure 1 and 2As shown, it includes: a low-voltage winding body 1, a high-voltage winding body 2 and a tail bar 3; the low-voltage winding body 1 includes an upper end 101, a lower end 102 and a middle part 103, the middle part 103 is connected between the upper end 101 and the lower end 102, and the tail bar 3 is vertically welded to the outer surface of the middle part 103; the high-voltage winding body 2 is wound outside the low-voltage winding body 1, and the high-voltage winding body 2 includes a first high-voltage winding 201 and a second high-voltage winding 202, the first high-voltage winding 201 and the second high-voltage winding 202 are arranged at intervals, and the tail bar 3 extends from between the first high-voltage winding 201 and the second high-voltage winding 202.
[0025] Due to the skin effect, current tends to concentrate at the ends of the winding, namely the upper end 101 and the lower end 102. After the low-voltage winding foil is wound, the tail bar 3 is welded perpendicularly to the outer surface of the middle portion 103 before the high-voltage winding is wound. The tail bar 3 extends from the gap between the first high-voltage winding 201 and the second high-voltage winding 202. This reduces the current distribution on the tail bar 3 and reduces losses caused by the increased AC resistance of the conductor. The tail bar 3 is welded perpendicularly to the outer surface of the low-voltage winding body 1, replacing the existing method of welding the tail bar parallel to the surface of the low-voltage winding body 1. In this lead-out bar structure, the copper used for the tail bar 3 is only the length extending from the surface of the low-voltage winding body 1 to the outside of the high-voltage winding body 2, which can reduce the amount of copper used. The main channel is formed between the outer surface of the low-voltage winding body 1 and the inner surface of the high-voltage winding body 2. The volume of the tail bar 3 in this main channel is only the portion where the tail bar 3 is welded to the low-voltage winding body 1. Therefore, the eddy current loss of the tail bar 3 affected by leakage magnetic flux in the main channel is relatively small, reducing tail bar losses.
[0026] The transformer lead-out bar structure can reduce the use of copper bars and reduce the loss of the tail bar 3, solving the problem that the tail bar of the existing transformer is set in the main channel between the low-voltage winding body 1 and the high-voltage winding body 2, resulting in large eddy current losses in the tail bar 3.
[0027] Further, such as Figure 2 As shown, in one embodiment of the present invention, the width of the metal foil at the upper end portion 101 and the lower end portion 102 is 60-600 mm.
[0028] The width of the metal foil at the upper end 101 and the lower end 102 is 60-600mm. This width range is the interval where the current distribution density in the low-voltage winding body 1 is relatively high. The tail bar 3 is avoided from being welded at the upper end 101 and the lower end 102, which can avoid excessive current concentration on the tail bar 3 or the welding point between the tail bar 3 and the low-voltage winding body 1, and avoid local current concentration in the winding, resulting in excessive winding loss, high temperature rise, and affecting transformer performance.
[0029] Further, such as Figure 2 and 3As shown, in one embodiment of the present invention, the tail row 3 is welded to the middle position of the middle portion 103 in the vertical direction.
[0030] The tail bus 3 is welded at the middle position of the middle portion 103 in the vertical direction. The tail bus 3 is least affected by the skin effect and the eddy current loss of the tail bus 3 caused by magnetic leakage is smallest.
[0031] Further, such as Figure 3 and 4 As shown, in one embodiment of the present invention, a plurality of struts 4 are provided on the surface of the tail row 3 , and the plurality of struts 4 are arranged at intervals parallel to the length direction of the tail row 3 .
[0032] The cavity formed between two adjacent struts 4 can be used as an oil channel or air channel, so that the heat exchange between the insulating oil or air and the tail bus 3 is more complete, which can effectively conduct and dissipate the heat generated by the tail bus 3, improve the heat dissipation effect of the transformer, extend the service life of the transformer, and ensure the safe and stable operation of the power system.
[0033] Further, such as Figure 4 As shown, in one embodiment of the present invention, the support bar 4 is wrapped with an insulating paper tube 5.
[0034] There needs to be sufficient insulation distance between the high-voltage winding body 2 and the tail bar 3 to prevent the occurrence of arcing or flashover. The insulating paper tube 5 is wrapped around the support bar 4 to increase the insulation distance between the tail bar 3 and the high-voltage winding body 2, reduce the risk of partial discharge, and improve the safety performance of the transformer.
[0035] Further, such as Figure 2 As shown, in one embodiment of the present invention, the upper end portion 101 and the lower end portion 102 are wound with copper foil, and the middle portion 103 is wound with aluminum foil.
[0036] Aluminum and copper foil are commonly used materials for transformer foil windings. Copper foil has lower resistance than aluminum foil, so windings made solely of copper foil offer better performance than those made with aluminum foil. However, copper foil alone is more expensive to manufacture. Due to the skin effect, current tends to concentrate at the upper and lower ends 101 and 102. Therefore, using copper foil for windings at these ends can reduce heat generation, improving transformer performance while limiting manufacturing costs.
[0037] Further, such as Figure 1 and 5 As shown, in one embodiment of the present invention, a first row 6 is welded to the inner surface of the low-voltage winding body 1 , and the welding end of the first row 6 is arranged parallel to the inner surface of the low-voltage winding body 1 .
[0038] The first row 6 marks the starting point of the low-voltage winding body 1, while the last row 3 marks the end of the low-voltage winding body 1. The connection between the first row 6 and the last row 3 forms a closed circuit, allowing current to flow through the low-voltage winding body 1. Distinguishing the first row 6 from the last row 3 helps identify the polarity of the low-voltage winding body 1. In the event of a transformer fault, technicians can quickly locate the fault, facilitating repair and replacement.
[0039] This embodiment also provides a transformer, such as Figure 5 As shown, the transformer includes an iron core 7 and a lead-out bar structure. The iron core 7 includes an upper iron yoke 701, a lower iron yoke 702, and a plurality of winding columns 703 arranged between the upper iron yoke 701 and the lower iron yoke 702. The winding columns 703 are arranged at intervals, and the low-voltage winding body 1 is wound on the winding columns 703.
[0040] The transformer's use of this lead-out bar structure reduces copper busbar usage, and transformer losses are not increased by changing the lead-out bar structure. Each winding column 703 of the core 7 is wound around a corresponding winding, and the bottoms are connected by an iron yoke to form a closed magnetic circuit, ensuring the complete flow of magnetic lines of force.
[0041] Further, such as Figure 5 As shown, in one embodiment of the present invention, the transformer also includes a zero row 8, and three windings 703 are provided. The three windings 703 are respectively wound with the low-voltage winding body 1 of phase A, the low-voltage winding body 1 of phase B and the low-voltage winding body 1 of phase C. The middle part 103 of the low-voltage winding body 1 of phase A, the middle part 103 of the low-voltage winding body 1 of phase B and the middle part 103 of the low-voltage winding body 1 of phase C are respectively vertically welded with the tail bar 3 of phase A, the tail bar 3 of phase B and the tail bar 3 of phase C. The tail bar 3 of phase A, the tail bar 3 of phase B and the tail bar 3 of phase C are connected through the zero row 8.
[0042] The tail bus 3 of phases A, B, and C is connected via the neutral bus 8, balancing the three-phase resistance. Since the tail bus 3 is welded to the middle portion 103, the neutral bus 8 is also located in the middle of the transformer, reducing the number of lead busses concentrated at both ends of the transformer. If the lead busses are concentrated at the top of the transformer, the temperature rise above the transformer is greater, and the temperature rise will increase the resistance of the lead busses, resulting in increased lead bus losses. If the lead busses are concentrated at the bottom of the transformer, the transformer bottom will occupy a larger space, making it difficult to optimize the volume of the transformer housing. The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by persons of ordinary skill in the art without departing from the spirit and technical principles disclosed in the present invention shall be covered by the claims of the present invention.
Claims
1. A transformer lead bar structure, characterized in that: include: Low voltage winding body, high voltage winding body and tail bar; The low-voltage winding body includes an upper end, a lower end, and a middle portion, wherein the middle portion is connected between the upper end and the lower end, and the tail bar is vertically welded to the outer surface of the middle portion; The high-voltage winding body is wound outside the low-voltage winding body, and the high-voltage winding body includes a first high-voltage winding and a second high-voltage winding. The first high-voltage winding and the second high-voltage winding are arranged at intervals, and the tail row extends from between the first high-voltage winding and the second high-voltage winding.
2. A transformer lead bar structure according to claim 1, characterized in that: The width of the metal foil at the upper end and the lower end is 60-600 mm.
3. A transformer lead bar structure according to claim 2, characterized in that: The tail row is welded to the middle position of the middle portion in the vertical direction.
4. The transformer lead bar structure according to claim 1, characterized in that: A plurality of struts are arranged on the surface of the tail row, and a plurality of the struts are arranged at intervals parallel to the length direction of the tail row.
5. The transformer lead bar structure according to claim 4, characterized in that: The support bar is wrapped with an insulating paper tube.
6. The transformer lead bar structure according to claim 1, characterized in that: The upper end portion and the lower end portion are wound with copper foil, and the middle portion is wound with aluminum foil.
7. The transformer lead bar structure according to claim 1, characterized in that: A first row is welded to the inner surface of the low-voltage winding body, and the welding end of the first row is arranged parallel to the inner surface of the low-voltage winding body.
8. A transformer, characterized in that: It comprises an iron core and a transformer lead bar structure as described in any one of claims 1 to 7, wherein the iron core comprises an upper iron yoke, a lower iron yoke and a plurality of winding poles arranged between the upper iron yoke and the lower iron yoke, the winding poles are arranged at intervals, and the low-voltage winding body is wound on the winding poles.
9. The transformer according to claim 8, characterized in that The transformer also includes a zero bar, and there are three windings. The three windings are respectively wound with the low-voltage winding body of phase A, the low-voltage winding body of phase B and the low-voltage winding body of phase C. The middle part of the low-voltage winding body of phase A, the middle part of the low-voltage winding body of phase B and the middle part of the low-voltage winding body of phase C are respectively vertically welded with the tail bar of phase A, the tail bar of phase B and the tail bar of phase C. The tail bar of phase A, the tail bar of phase B and the tail bar of phase C are connected through the zero bar.