A body structure for a 35kV double-split transformer with low-voltage layer and high-voltage disc design.

Abstract

This utility model belongs to the technical field of transformer body structure, and provides a body structure for a 35kV double-split transformer with low-voltage layer and high-voltage disc type. It includes a low-voltage coil, a high-voltage coil, and a core column. The low-voltage coil and high-voltage coil are mounted on the outside of the core column. The low-voltage coil includes an upper low-voltage coil, a lower low-voltage coil, and end rings. The end rings include a first end ring, a second end ring, and a third end ring. Both the upper and lower low-voltage coils are layered coils, each composed of a copper foil layer, a first insulating material, a shielding layer, and a first support bar. The top end of the upper low-voltage coil is fixedly connected to the first end ring, and the bottom end of the upper low-voltage coil is connected to the top end of the lower low-voltage coil through the second end ring. The bottom end of the lower low-voltage coil is fixedly connected to the third end ring. This utility model ensures the safety and reliability of the high-voltage coil's interlayer insulation withstand voltage and overvoltage protection during operation, and also solves the problem of excessive local temperature rise in the low-voltage coil, ensuring the normal operation of the transformer.

Description

Technical Field

[0001] This utility model belongs to the technical field of transformer body structure, specifically, it relates to a body structure for a 35kV double-split transformer with low-voltage layer and high-voltage disc. Background Technology

[0002] With the global energy transition, the demand for containerized structures in new energy transformer substations is gradually becoming mainstream. As a crucial component of containerized substations, the 35kV large-capacity oil-immersed double-split transformer's coil structure directly affects the transformer's operational quality and the overall project cost.

[0003] The current standard structure for double-split transformers in the industry is as follows: the high-voltage and low-voltage coils are located on the outer side of the core column, with the low-voltage coil inside the high-voltage coil. The low-voltage coil is a copper foil winding structure; the high-voltage coil is a two-layer winding structure, directly wound on the low-voltage coil as a single integral unit. However, this structure results in excessively high interlayer electric field strength, which can easily lead to partial discharge, especially under overvoltage conditions, posing a significant insulation risk. In addition, the excessive tension of the single-layer copper foil winding makes winding difficult, and the insufficient heat dissipation channel design can lead to excessively high local temperature rise, which can easily cause insulation aging. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a 35kV double-split transformer body structure with a low-voltage layer and a high-voltage disc coil. By combining the winding method of low-voltage layer coil and high-voltage disc coil, it not only ensures the safety and reliability of the high-voltage coil interlayer insulation withstand voltage and overvoltage during operation, but also solves the problem of excessive local temperature rise in the low-voltage coil, ensuring the normal operation of the transformer.

[0005] The present invention adopts the following technical solution.

[0006] A 35kV double-split transformer body structure with low-voltage layer and high-voltage disc configuration includes a low-voltage coil, a high-voltage coil, and an iron core column. The low-voltage coil and high-voltage coil are mounted on the outside of the iron core column. The low-voltage coil includes an upper low-voltage coil, a lower low-voltage coil, and end rings. The end rings include a first end ring, a second end ring, and a third end ring. Both the upper and lower low-voltage coils are layered coils, each composed of a copper foil layer, a first insulating material, a shielding layer, and a first support bar. The top end of the upper low-voltage coil is fixedly connected to the first end ring, and the bottom end of the upper low-voltage coil is connected to the top end of the lower low-voltage coil through a second end ring. The bottom end of the lower low-voltage coil is fixedly connected to the third end ring. The first insulating material includes DMD insulating paper and insulating paperboard, with the DMD insulating paper, copper foil layer, first support bar, shielding layer, and insulating paperboard connected sequentially from the inside out.

[0007] The high-voltage coil includes an upper high-voltage coil and a lower high-voltage coil. Both the upper and lower high-voltage coils are disc-shaped coils. Both the upper and lower high-voltage coils are composed of a winding structure and a second insulating material. The second insulating material includes a T4 cardboard tube and a second support bar. The T4 cardboard tube, the second support bar, and the winding structure are connected sequentially from the inside to the outside.

[0008] Furthermore, the low-voltage coil also includes an outlet structure, which includes an upper outlet and a lower outlet. The upper outlet and the lower outlet are respectively welded to the copper foil layer of the upper low-voltage coil and the lower low-voltage coil to realize a double-split circuit.

[0009] Furthermore, the high-voltage coil also includes connecting terminals, which include a high-voltage upper coil start end, a high-voltage upper coil end, a high-voltage upper coil tap end, a high-voltage lower coil start end, a high-voltage lower coil end, and a high-voltage lower coil tap end. The high-voltage upper coil start end is located at the beginning of the high-voltage upper coil, the high-voltage upper coil end is located at the end of the high-voltage upper coil, and the high-voltage upper coil tap end is led out from the middle section of the high-voltage upper coil. The high-voltage lower coil start end is located at the beginning of the high-voltage lower coil, the high-voltage lower coil end is located at the end of the high-voltage lower coil, and the high-voltage lower coil tap end is led out from the middle section of the high-voltage lower coil.

[0010] Furthermore, the high-voltage upper coil includes two winding sections, and the high-voltage lower coil includes two winding sections, with the four winding sections integrally wound; each winding section is formed by winding copper wire into an independent coil, and each winding section is isolated and insulated by spacers.

[0011] Furthermore, the thickness of the T4 cardboard tube is 4.0 mm, and the inner diameter of the T4 cardboard tube is 4 mm smaller than the outer diameter of the low-voltage coil.

[0012] Furthermore, the number of the second support bars is 12, which are evenly distributed along the T4 cardboard tube to serve as longitudinal supports for the winding structure.

[0013] Furthermore, the high-voltage coil also includes a corner ring, with the top end of the upper high-voltage coil and the bottom end of the lower high-voltage coil fixedly connected to the corner ring.

[0014] Furthermore, the shielding layer is a 0.3mm copper foil shielding layer, the width of which is greater than the width of the copper foil layer.

[0015] Furthermore, the insulation distance between the high-voltage coil and the main channel of the low-voltage coil is greater than 20mm.

[0016] The beneficial effects of this utility model are as follows, compared with the prior art:

[0017] 1. The high-voltage coil of this utility model is formed by integral winding of four sections. The winding method adopts the pancake coil winding method. The voltage between coil sections is reduced from 35 / 2kV to 35 / 4kV. The reduction of the potential difference between layers can reduce the electric field strength, and solve the problems of insulation withstand voltage between layers and overvoltage during operation of high-voltage coil. The pancake coil has advantages over layer winding in terms of resistance, inductance and short-circuit current withstand.

[0018] 2. The low-voltage coil of this utility model is wound separately with double-layer copper foil, which effectively reduces the problem of difficult coil winding caused by excessive tension of single-layer copper foil. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the body structure of a 35kV double-split transformer with a low-voltage layer and a high-voltage disc shape, provided by this utility model.

[0020] In the diagram: 1-Low-voltage upper coil, 2-Copper foil layer, 3-DMD insulating paper, 4-Insulating cardboard, 5-Shielding layer, 6-First support bar, 7-Low-voltage lower coil, 8-First end coil, 9-Second end coil, 10-Third end coil, 11-Upper outlet, 12-Lower outlet, 13-High-voltage upper coil, 14-T4 cardboard tube, 15-Second support bar, 16-High-voltage lower coil, 17-Corner ring, 18-High-voltage upper coil start, 19-High-voltage upper coil end, 20-High-voltage upper coil tap, 21-High-voltage lower coil start, 22-High-voltage lower coil end, 23-High-voltage lower coil tap, 24-Padded block. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. The embodiments described in this application are merely some embodiments of this utility model, and not all embodiments. Based on the spirit of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0022] like Figure 1 As shown, a 35kV double-split transformer body structure of low-voltage layer type and high-voltage disc type includes a low-voltage coil, a high-voltage coil and an iron core column, with the low-voltage coil and the high-voltage coil mounted on the outside of the iron core column.

[0023] The low-voltage coil includes a low-voltage upper coil 1, a low-voltage lower coil 7, end coils, and an outlet structure. Both the low-voltage upper coil 1 and the low-voltage lower coil 7 are layered coils, consisting of a copper foil layer 2, a first insulating material, a shielding layer 5, and a first support bar 6. The end coils include a first end coil 8, a second end coil 9, and a third end coil 10. The top end of the low-voltage upper coil 1 is fixedly connected to the first end coil 8, the bottom end of the low-voltage upper coil 1 is connected to the top end of the low-voltage lower coil 7 through the second end coil 9, and the bottom end of the low-voltage lower coil 7 is fixedly connected to the third end coil 10.

[0024] The first insulating material includes DMD insulating paper 3 and insulating paperboard 4. The output structure includes upper output 11 and lower output 12. The copper foil layer 2 is wound separately to form two independent coils. The upper output 11 and lower output 12 are welded to the copper foil of the low-voltage upper coil 1 and the low-voltage lower coil 7 to realize a double split circuit.

[0025] The DMD insulating paper 3, copper foil layer 2, first support strip 6, shielding layer 5, and insulating paperboard 4 are connected sequentially from the inside out. Specifically, the low-voltage coil is first insulated with several layers of DMD insulating paper 3, then the upper and lower copper foil layers 2 are wound. For the external insulation of the low-voltage coil, the first support strip 6 is wound first, followed by the shielding layer 5 structure, and finally the insulating paperboard 4 is wound. The shielding layer 5 is a 0.3mm copper foil shielding layer, and its width is greater than the width of the copper foil layer 2.

[0026] The high-voltage coil includes an upper high-voltage coil 13, a lower high-voltage coil 16, a corner ring 17, and connecting terminals. Both the upper high-voltage coil 13 and the lower high-voltage coil 16 are pancake coils. Both the upper high-voltage coil 13 and the lower high-voltage coil 16 include winding structures and a second insulating material. The four winding segments are wound as a single unit using a pancake coil winding method. The inter-segment voltage is reduced from 35 / 2kV to 35 / 4kV, and the reduced interlayer potential difference lowers the electric field strength. The second insulating material includes a T4 cardboard tube 14 and a second support bar 15. The connecting terminals include the upper high-voltage coil start 18, the upper high-voltage coil end 19, the upper high-voltage coil tap 20, the lower high-voltage coil start 21, the lower high-voltage coil end 22, and the lower high-voltage coil tap 23. The T4 cardboard tube 14, the second support bar 15, and the winding structure are connected sequentially from the inside out.

[0027] Specifically, the thickness of the T4 cardboard tube 14 is 4.0 mm, and the inner diameter of the T4 cardboard tube 14 needs to be 4 mm smaller than the outer diameter of the low-voltage coil; there are 12 second support bars 15, which are evenly distributed along the T4 cardboard tube 14 to serve as longitudinal support for the winding; the winding structure includes 4 windings, the high-voltage upper coil 13 includes 2 windings, and the high-voltage lower coil 16 includes 2 windings. Each winding is formed by winding copper wire into an independent coil, and each winding is isolated and insulated by a spacer 24; after the winding is completed, the high-voltage coil is bound and fixed with white cloth tape. The top of the high-voltage upper coil 13 and the bottom of the high-voltage lower coil 16 are connected to the corner ring 17 to protect the coil insulation and increase the creepage distance.

[0028] The high-voltage upper coil start 18 is located at the beginning of the high-voltage upper coil 13, and the high-voltage upper coil end 19 is located at the end of the high-voltage upper coil 13. The high-voltage upper coil tap 20 is led out from the middle section of the high-voltage upper coil 13. The high-voltage lower coil start 21 is located at the beginning of the high-voltage lower coil 16, and the high-voltage lower coil end 22 is located at the end of the high-voltage lower coil 16. The high-voltage lower coil tap 23 is led out from the middle section of the high-voltage lower coil 16. The insulation distance between the main channels of the high-voltage coil and the low-voltage coil is greater than 20mm.

[0029] The 35kV double-split transformer body structure provided by this utility model is fixed by being mounted on the core column. Because the low-voltage coil is a separate structure and the high-voltage coil is an integrated structure, it is not possible to individually mount each winding coil on the core column. On the winding assembly platform, the low-voltage lower coil 7, balance pads, yoke guards, etc., of the transformer body structure are first assembled. Then, the high-voltage coil is mounted on its outside. Next, the second end coil 9 between the low-voltage upper coil 1 and the low-voltage lower coil 7 is installed. Then, the low-voltage upper coil 3, upper pressure plate, and other components are mounted. Finally, the high and low voltage coils are assembled into a core-single-column winding transformer body, which is then mounted as a whole on the core column.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the protection scope of the claims of this utility model.

Claims

1. A core structure for a 35kV double-split transformer with a low-voltage layer and a high-voltage disc shape, comprising a low-voltage coil, a high-voltage coil, and a core column, characterized in that: The low-voltage coil and the high-voltage coil are mounted on the outside of the iron core column. The low-voltage coil includes a low-voltage upper coil (1), a low-voltage lower coil (7) and end rings. The end rings include a first end ring (8), a second end ring (9) and a third end ring (10). Both the low-voltage upper coil (1) and the low-voltage lower coil (7) are layered coils and are composed of a copper foil layer (2), a first insulating material, a shielding layer (5) and a first support bar (6). The top of the low-voltage upper coil (1) is fixedly connected to the first end ring (8), the bottom of the low-voltage upper coil (1) is connected to the top of the low-voltage lower coil (7) through the second end ring (9), and the bottom of the low-voltage lower coil (7) is fixedly connected to the third end ring (10). The first insulating material includes DMD insulating paper (3) and insulating paperboard (4). The DMD insulating paper (3), the copper foil layer (2), the first support bar (6), the shielding layer (5) and the insulating paperboard (4) are connected sequentially from the inside to the outside. The high-voltage coil includes a high-voltage upper coil (13) and a high-voltage lower coil (16). Both the high-voltage upper coil (13) and the high-voltage lower coil (16) are pancake coils. Both the high-voltage upper coil (13) and the high-voltage lower coil (16) are composed of winding structures and a second insulating material. The second insulating material includes a T4 cardboard tube (14) and a second support bar (15). The T4 cardboard tube (14), the second support bar (15), and the winding structure are connected sequentially from the inside to the outside.

2. The transformer body structure for a 35kV double-split transformer of low-voltage layer type and high-voltage disc type according to claim 1, characterized in that: The low-voltage coil also includes an outlet structure, which includes an upper outlet (11) and a lower outlet (12). The upper outlet (11) and the lower outlet (12) are respectively welded to the copper foil layer (2) of the upper low-voltage coil (1) and the lower low-voltage coil (7) to realize a double-split circuit.

3. The transformer body structure for a 35kV double-split transformer of low-voltage layer type and high-voltage disc type according to claim 1, characterized in that: The high-voltage coil also includes connection terminals, which include the high-voltage upper coil start (18), the high-voltage upper coil end (19), the high-voltage upper coil tap (20), the high-voltage lower coil start (21), the high-voltage lower coil end (22), and the high-voltage lower coil tap (23). The high-voltage upper coil start (18) is located at the beginning of the high-voltage upper coil (13), the high-voltage upper coil end (19) is located at the end of the high-voltage upper coil (13), and the high-voltage upper coil tap (20) is led out from the middle section of the high-voltage upper coil (13). The high-voltage lower coil start (21) is located at the beginning of the high-voltage lower coil (16), the high-voltage lower coil end (22) is located at the end of the high-voltage lower coil (16), and the high-voltage lower coil tap (23) is led out from the middle section of the high-voltage lower coil (16).

4. The transformer body structure for a 35kV double-split transformer of low-voltage layer type and high-voltage disc type according to claim 1, characterized in that: The high-voltage upper coil (13) includes two windings, and the high-voltage lower coil (16) includes two windings. The four windings are wound as a whole. Each winding is made of copper wire to form an independent coil, and each winding is isolated and insulated by a pad (24).

5. The transformer body structure for a 35kV double-split transformer of low-voltage layer type and high-voltage disc type according to claim 1, characterized in that: The thickness of the T4 cardboard tube (14) is 4.0 mm, and the inner diameter of the T4 cardboard tube (14) is 4 mm smaller than the outer diameter of the low voltage coil.

6. The transformer body structure for a 35kV double-split transformer of low-voltage layer type and high-voltage disc type according to claim 5, characterized in that: The number of the second support bars (15) is 12, which are evenly distributed along the T4 cardboard tube (14) to serve as longitudinal support for the winding structure.

7. The transformer body structure for a 35kV double-split transformer of low-voltage layer type and high-voltage disc type according to claim 1, characterized in that: The high-voltage coil also includes a corner ring (17), and the top end of the high-voltage upper coil (13) and the bottom end of the high-voltage lower coil (16) are fixedly connected to the corner ring (17).

8. The transformer body structure for a 35kV double-split transformer of low-voltage layer type and high-voltage disc type according to claim 1, characterized in that: The shielding layer (5) is a 0.3mm copper foil shielding layer, and its width is greater than that of the copper foil layer (2).

9. The transformer body structure for a 35kV double-split transformer of low-voltage layer type and high-voltage disc type according to claim 1, characterized in that: The insulation distance between the high-voltage coil and the main channel of the low-voltage coil is greater than 20mm.

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