A single-phase pole-mounted transformer

Abstract

The application relates to the technical field of transformers, and particularly discloses a single-phase pole-mounted transformer which comprises a core module and high and low voltage coils, a low voltage insulating paper tube is arranged between the low voltage coil and the core; a coil inter-insulation module is arranged between the low voltage coil and the high voltage coil, an outer coil covering insulation module is arranged on the outer side of the high voltage coil, and a coil yoke inter-insulation module is arranged between the high and low voltage coils and the yoke; through the cooperation of the multiple layers of insulation modules, the electric field distribution is obviously optimized, the main insulation breakdown voltage and the surface creepage distance are greatly improved, the insulation distance between the components is effectively reduced under the premise of ensuring the high insulation reliability, and the overall product material cost, volume and weight are reduced.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and in particular to a single-phase pole-mounted transformer. Background Technology

[0002] The core structure of a single-phase pole-mounted transformer can be referenced. Figure 1 and Figure 2 As shown, it includes an iron core module and high and low voltage coils. The iron core module includes an iron core 91 and an iron yoke 92 connected to the upper and lower ends of the iron core 91. The high and low voltage coils include a low voltage coil 93 and a high voltage coil 94 sleeved on the outside of the low voltage coil 93.

[0003] Single-phase pole-mounted transformers are particularly suitable for distributed distribution networks due to their advantages such as pole-suspended installation, compact size, low infrastructure investment, and flexible power supply (single-phase or three-unit network operation). While they can effectively reduce line losses and improve power quality in 33-46kV power grids, they place extremely high demands on the transformer's insulation performance, with relevant standards specifying lightning impulse withstand voltages as high as 200-250kV.

[0004] To meet this stringent insulation requirement, traditional design schemes often tend to simply increase the main insulation distance between the high-voltage coil and the low-voltage coil and the core. This structural design directly results in a large transformer body, high material costs, and increased overall weight, which in turn increases the suspension load on the pole.

[0005] In existing technologies, such as the main insulation structure and manufacturing method of an oil-immersed transformer disclosed in patent publication number CN103971907B, the main insulation structure is achieved by wrapping cable paper and insulating paperboard around the low-voltage coil, and then wrapping it with corrugated paper to form a soft corner ring to strengthen the end insulation. This is combined with upper and lower insulating pads, aiming to achieve structural reliability and ease of production. However, when facing higher voltage levels of 33-46kV, the limitations of the insulation design become apparent: it fails to systematically apply small oil gap insulation technology to significantly improve the insulation strength per unit distance, and it lacks the ability to optimize the electric field distribution through a combination of specific dielectric materials. Its insulation configuration has limited potential for significantly reducing the main insulation distance, thereby achieving a compact and lightweight transformer body while maintaining a high insulation level.

[0006] Therefore, existing main insulation structures, especially when applied to high-voltage scenarios, generally suffer from the problem of balancing high insulation strength with miniaturization and lightweight design. Their insulation efficiency still has room for improvement, often at the expense of product size and weight to achieve better insulation performance. This not only restricts the product's economic viability but also contradicts the stringent weight requirements of pole-mounted installations. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a single-phase pole-mounted transformer that can significantly enhance the main insulation capability, effectively reduce cost and size and weight, so as to solve the above problems.

[0008] A single-phase pole-mounted transformer includes a core module and high-voltage and low-voltage coils. The core module includes a core and yokes connected to the upper and lower ends of the core. The high-voltage and low-voltage coils include a low-voltage coil and a high-voltage coil.

[0009] A low-voltage insulating paper tube is provided between the low-voltage coil and the iron core;

[0010] An inter-coil insulation module is provided between the low-voltage coil and the high-voltage coil. The inter-coil insulation module includes a first padding paper oil gap layer, a first combined insulation layer and a first soft corner ring arranged sequentially from the inside to the outside. The first padding paper oil gap layer is provided with a plurality of first oil channels. The first combined insulation layer includes alternating layers of first insulating adhesive paper and first polyester film. The first soft corner ring is made of crepe paper and extends to cover the end of the high-voltage coil.

[0011] The high-voltage coil is covered with an outer ring insulation module. The outer ring insulation module includes a second pad paper oil gap layer and a second combined insulation layer arranged sequentially from the inside to the outside. The second pad paper oil gap layer is provided with a plurality of second oil channels. The second combined insulation layer includes a second insulating adhesive paper and a second polyester film arranged alternately.

[0012] An inter-coil-yoke insulation module is provided between the high-voltage and low-voltage coils and the yoke. The inter-coil-yoke insulation module includes a third padding paper oil gap layer disposed at the end of the high-voltage and low-voltage coils, a wrapping layer wrapped around the outer side and end of the high-voltage and low-voltage coils, a fourth padding paper oil gap layer disposed between the high-voltage and low-voltage coils and the yoke, an oil channel paper pad, and a first high-density paperboard inserted into the low-voltage insulating paper tube at both ends. The end of the third padding paper oil gap layer, the wrapping layer, the fourth padding paper oil gap layer, the oil channel paper pad, and the body of the first high-density paperboard are stacked sequentially along the direction from the high-voltage and low-voltage coils to the yoke. The third padding paper oil gap layer is provided with a third oil channel, and the fourth padding paper oil gap layer is provided with a fourth oil channel.

[0013] Specifically, the low-pressure insulating paper tube includes a second high-density cardboard, at least one third polyester film, and a third insulating adhesive paper stacked in sequence.

[0014] Specifically, the first padding paper oil gap layer includes a fourth insulating adhesive paper and a plurality of first paper support strips spaced apart on the fourth insulating adhesive paper, with the first oil channel formed between adjacent first paper support strips.

[0015] Specifically, the second padding paper oil gap layer includes a fifth insulating adhesive paper and a plurality of second paper support strips spaced apart on the fifth insulating adhesive paper, with the second oil channel formed between adjacent second paper support strips.

[0016] Specifically, the third padding paper oil gap layer includes a third high-density paperboard and a plurality of third paper support strips spaced apart and pasted on the third high-density paperboard, with the third oil channel formed between adjacent third paper support strips.

[0017] Specifically, the wrapping layer includes at least one sheet of cardboard.

[0018] Specifically, the fourth padding paper oil gap layer includes a fourth high-density paperboard and a plurality of fourth paper support strips spaced apart and pasted on the fourth high-density paperboard, with the fourth oil channel formed between adjacent fourth paper support strips.

[0019] Specifically, it also includes the upper clamping component and the lower clamping component fixed to the upper and lower ends of the core module, respectively.

[0020] Specifically, the total number of layers of the first insulating adhesive paper and the first polyester film in the first combined insulation layer, and the total number of layers of the second insulating adhesive paper and the second polyester film in the second combined insulation layer, are configured according to the lightning impulse withstand voltage level of the single-phase pole-mounted transformer.

[0021] Specifically, the first soft corner ring is made of multiple layers of crepe paper, and the number of layers is configured according to the lightning impulse withstand voltage level of the single-phase pole-mounted transformer.

[0022] The beneficial effects of this invention are:

[0023] The single-phase column-mounted transformer of the present invention includes a core module and high-voltage and low-voltage coils. A low-voltage insulating paper tube is disposed between the low-voltage coil and the core. An inter-coil insulation module is disposed between the low-voltage coil and the high-voltage coil, which includes a first paper-filled oil gap layer, a first combined insulation layer, and a first soft-angle ring arranged sequentially from the inside to the outside. An outer ring insulation module is wrapped around the outside of the high-voltage coil, which includes a second paper-filled oil gap layer and a second combined insulation layer arranged sequentially from the inside to the outside. An inter-coil-yoke insulation module is disposed between the high-voltage and low-voltage coils and the yoke, which includes a third paper-filled oil gap layer disposed at the end of the coil and a wrapping layer. The application includes a wrapping layer wound around the outer side and ends of the coil, a fourth padding paper oil gap layer, an oil channel paper pad plate, and a first high-density paperboard inserted into a low-voltage insulating paper tube. By setting up structures such as small oil gap insulation, alternating combinations of dielectric materials, and soft corner rings to enhance end insulation, the application significantly optimizes the electric field distribution through the synergistic effect of multi-level insulation modules, greatly improves the main insulation breakdown voltage and surface creepage distance, thereby effectively reducing the insulation distance between various components while ensuring high insulation reliability, and achieving an overall reduction in product material cost, volume, and weight. Attached Figure Description

[0024] Figure 1 A schematic diagram of the structure of a single-phase pole-mounted transformer in the prior art. Figure 1 ;

[0025] Figure 2 A schematic diagram of the structure of a single-phase pole-mounted transformer in the prior art. Figure 2 ;

[0026] Figure 3 This is a front view of the single-phase pole-mounted transformer of this application;

[0027] Figure 4 This is a structural schematic diagram of the iron core, high and low voltage coils, low voltage insulating paper tube, coil insulation module and outer ring covering insulation module of this application;

[0028] Figure 5 This is a schematic diagram of the structure of the low-voltage insulating paper tube of this application;

[0029] Figure 6 This is a schematic diagram of the structure of the first padding paper oil gap layer in this application;

[0030] Figure 7 This is a schematic diagram of the structure of the first composite insulating layer of this application;

[0031] Figure 8 This is a schematic diagram of the structure of the first soft corner ring of this application;

[0032] Figure 9 This is a schematic diagram of the structure of the second padding paper oil gap layer in this application;

[0033] Figure 10 This is a schematic diagram of the structure of the second composite insulating layer of this application;

[0034] Figure 11 This is a cross-sectional view of the single-phase pole-mounted transformer of this application;

[0035] Figure 12 This is a schematic diagram of the structure of the third pad paper oil gap layer in this application;

[0036] Figure 13 This is a schematic diagram of the structure of the wrapping layer in this application;

[0037] Figure 14 This is a schematic diagram of the structure of the fourth padding paper oil gap layer in this application;

[0038] Figure 15 This is a schematic diagram of the oil passage paper gasket of this application;

[0039] Figure 16 This is a schematic diagram of the structure of the first high-density paperboard of this application.

[0040] The attached figures are labeled as follows: core module 10, high and low voltage coils 20, core 11, yoke 12, low voltage coil 21, high voltage coil 22, low voltage insulating paper tube 30, coil-to-coil insulation module 40, first padding paper oil gap layer 41, first combined insulation layer 42, first soft angle ring 43, crepe paper 431, first oil channel 401, first insulating adhesive paper 421, first polyester film 422, outer ring covering insulation module 50, second padding paper oil gap layer 51, second combined insulation layer 52, second oil channel 501, second insulating adhesive paper 521, second polyester film 522, coil-to-yoke interlayer. Insulating module 60, third padding paper oil gap layer 61, wrapping layer 62, fourth padding paper oil gap layer 63, oil channel paper pad 64, first high-density paperboard 65, third oil channel 601, fourth oil channel 602, second high-density paperboard 31, third polyester film 32, third insulating adhesive paper 33, fourth insulating adhesive paper 411, first paper support strip 412, fifth insulating adhesive paper 511, second paper support strip 512, third high-density paperboard 611, third paper support strip 612, paperboard 621, fourth high-density paperboard 631, fourth paper support strip 632, clamping part on the body 70, clamping part on the lower body 80. Detailed Implementation

[0041] This invention provides a single-phase pole-mounted transformer. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0042] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0043] Please refer to Figure 3-16 As shown, this embodiment discloses a single-phase pole-mounted transformer, including a core module 10 and high and low voltage coils 20. The core module 10 includes a core 11 and yokes 12 connected to the upper and lower ends of the core 11. The high and low voltage coils 20 include a low voltage coil 21 and a high voltage coil 22. A low voltage insulating paper tube 30 is provided between the low voltage coil 21 and the core 11 to separate the low voltage coil 21 from the core 11, so that the two are electrically insulated.

[0044] like Figure 4As shown, an inter-coil insulation module 40 is provided between the low-voltage coil 21 and the high-voltage coil 22. The inter-coil insulation module 40 includes a first paper gap layer 41, a first combined insulation layer 42 and a first soft corner ring 43 arranged sequentially from the inside to the outside.

[0045] like Figure 3 , Figure 4 and Figure 10 As shown, the outer side of the high-voltage coil 22 is covered by an outer ring insulation module 50. The outer ring insulation module 50 includes a second paper oil gap layer 51 and a second combined insulation layer 52 arranged sequentially from the inside to the outside. The second paper oil gap layer 51 is provided with multiple second oil channels 501 to form small oil gap insulation.

[0046] like Figure 3 As shown, the single-phase pole-mounted transformer of this application also includes a body clamp 70 and a lower body clamp 80, which are respectively fixed to the upper and lower ends of the core module 10. The body clamp 70 and the lower body clamp 80 provide a stable mechanical fixation for the entire transformer body, ensuring the integrity and stability of the transformer body structure during transportation and operation, and are the basis for the reliable functioning of the insulation structure.

[0047] like Figure 3 , Figure 11 , Figure 15 and Figure 16 As shown, a coil-yoke inter-insulation module 60 is provided between the high-voltage and low-voltage coils 20 and the yoke 12. The coil-yoke inter-insulation module 60 includes a third padding paper oil gap layer 61 disposed at the end of the high-voltage and low-voltage coils 20, a wrapping layer 62 wrapped around the outer side and end of the high-voltage and low-voltage coils 20, a fourth padding paper oil gap layer 63 disposed between the high-voltage and low-voltage coils 20 and the yoke 12, an oil channel paper pad plate 64, and a first high-density paperboard 65 inserted into the low-voltage insulating paper tube 30 at both ends. The ends of the third padding paper oil gap layer 61 and the wrapping layer 62, the fourth padding paper oil gap layer 63, the oil channel paper pad plate 64, and the body of the first high-density paperboard 65 are stacked sequentially along the direction from the high-voltage and low-voltage coils 20 to the yoke 12. The third padding paper oil gap layer 61 is provided with a third oil channel 601, and the fourth padding paper oil gap layer 63 is provided with a fourth oil channel 602. The use of a multi-layer insulation structure with guiding oil channels can increase the breakdown voltage and creepage distance between the end of the high-voltage coil 22 and the iron core yoke 12.

[0048] In summary, the single-phase pole-mounted transformer of this application has more reliable electrical insulation performance compared with the traditional design, and can effectively reduce the insulation distance between various components, thereby reducing the amount of materials used and reducing the product size and weight.

[0049] like Figure 5As shown, the low-voltage insulating paper tube 30 includes a second high-density paperboard 31, at least one third polyester film 32, and a third insulating adhesive paper 33 stacked sequentially. This composite laminate structure forms the basic insulation barrier between the low-voltage coil 21 and the iron core 11. The second high-density paperboard 31 provides stable mechanical support and primary insulation, while the combination of the third polyester film 32 and the third insulating adhesive paper 33 enhances the initial insulation strength and improves the electric field distribution.

[0050] like Figure 6 As shown, the first padding paper oil gap layer 41 includes a fourth insulating adhesive paper 411 and multiple first paper support strips 412 spaced apart and pasted on the fourth insulating adhesive paper 411. A first oil channel 401 is formed between adjacent first paper support strips 412. Specifically, the gap size (i.e., the oil gap size) of the first oil channel 401 is L1, where L1 is 22-25mm; the width of the first paper support strip 412 is D1, where D1 is 6mm; and the thickness of the first paper support strip 412 is H1, where H1 is 3mm. Utilizing the principle of small oil gap insulation, multiple regular first oil channels 401 are formed through the first paper support strips 412, refining the oil gap segmentation and thus significantly improving the electrical resistance of the oil gap.

[0051] This application provides a plurality of first oil channels 401 in the first pad paper oil gap layer 41, which adopts a small oil gap structure and utilizes the characteristic that the electrical conductivity of the oil gap increases as the size decreases, thereby effectively improving the insulation strength.

[0052] like Figure 7 As shown, the first combined insulation layer 42 includes alternating layers of first insulating adhesive paper 421 and first polyester film 422. By alternating the placement of two insulating materials with different dielectric constants, the electric field distribution is made more uniform, greatly enhancing the breakdown voltage of the main insulation between the high-voltage and low-voltage coils 21 and 22. For example, in a single-phase pole-mounted transformer product with a lightning impulse withstand voltage of 200kV, the first combined insulation layer 42 is made by alternating placement of 13 sheets of first insulating adhesive paper 421 with a thickness of 0.08mm and 13 sheets of first polyester film 422 with a thickness of 0.05mm; in a single-phase pole-mounted transformer product with a lightning impulse withstand voltage of 250kV, the first combined insulation layer 42 is made by alternating placement of 16 sheets of first insulating adhesive paper 421 with a thickness of 0.08mm and 16 sheets of first polyester film 422 with a thickness of 0.05mm.

[0053] like Figure 8As shown, the first soft angle ring 43 is made of crepe paper 431 and extends to cover the end of the high-voltage coil 22. It can block the discharge path of high voltage to low voltage and high voltage to yoke 12, causing the electric field line to bend to increase the creepage distance along the surface and effectively enhance the end insulation. For example, in a single-phase pole-mounted transformer product with a lightning impulse withstand voltage of 200kV, the first soft angle ring 43 is made of 13 sheets of crepe paper 431 with a thickness of 0.05mm; in a single-phase pole-mounted transformer product with a lightning impulse withstand voltage of 250kV, the first soft angle ring 43 is made of 16 sheets of crepe paper 431 with a thickness of 0.05mm.

[0054] like Figure 9 As shown, the second padding paper oil gap layer 51 includes a fifth insulating adhesive paper 511 and multiple second paper support strips 512 spaced apart and pasted on the fifth insulating adhesive paper 511. Second oil channels 501 are formed between adjacent second paper support strips 512. Specifically, the gap size (i.e., oil gap size) of the second oil channels 501 is L2, which is 22-25 mm; the width of the second paper support strip 512 is D2, which is 6 mm; and the thickness of the second paper support strip 512 is H2, which is 3 mm. Based on the principle of small oil gaps, uniformly distributed second oil channels 501 are formed on the outside of the high-voltage coil 22, effectively enhancing the insulation strength between the high-voltage coil 22 and the external environment (such as another high-voltage coil or the tank wall), creating conditions for reducing the tank size.

[0055] like Figure 10 As shown, the second combined insulation layer 52 includes alternating layers of second insulating adhesive paper 521 and second polyester film 522. This structure greatly enhances the high-voltage insulation level, reducing the insulation distance between the two sets of high-voltage coils 22 and between the high-voltage coil 22 and the tank wall, thereby helping to reduce the tank size. For example, in a single-phase pole-mounted transformer with a lightning impulse withstand voltage of 200kV, the second combined insulation layer 52 is made by alternating layers of 6 sheets of 0.08mm thick second insulating adhesive paper 521 and 6 sheets of 0.05mm thick second polyester film 522; in a single-phase pole-mounted transformer with a lightning impulse withstand voltage of 250kV, the second combined insulation layer 52 is made by alternating layers of 10 sheets of 0.08mm thick second insulating adhesive paper 521 and 10 sheets of 0.05mm thick second polyester film 522.

[0056] like Figure 12As shown, the third padding paper oil gap layer 61 includes a third high-density paperboard 611 and multiple third paper support strips 612 spaced apart and pasted on the third high-density paperboard 611, with a third oil channel 601 formed between adjacent third paper support strips 612. Specifically, the gap size (i.e., oil gap size) of the third oil channel 601 is L3, where L3 is 10-15mm; the width of the third paper support strip 612 is D3, where D3 is 15-20mm; and the thickness of the third paper support strip 612 is H3, where H3 is 4mm. This structure constructs a guiding oil channel at the ends of the high and low voltage coils 20, which not only increases the insulation distance but also facilitates heat dissipation and the flow of insulating oil, further improving the reliability of the end insulation.

[0057] like Figure 13 As shown, the wrapping layer 62 includes at least one piece of cardboard 621. The cardboard 621 and the wrapping layer 62 form an integral cover over the outer surface and ends of the high and low voltage coils 20, effectively increasing the surface creepage distance and providing physical protection, thus enhancing the insulation capability of the yoke 12.

[0058] like Figure 14 As shown, the fourth oil gap layer 63 includes a fourth high-density paperboard 631 and multiple fourth paper support strips 632 spaced apart and pasted on the fourth high-density paperboard 631, with a fourth oil channel 602 formed between adjacent fourth paper support strips 632. Specifically, the gap size (i.e., oil gap size) of the fourth oil channel 602 is L4, where L4 is 10-15mm; the width of the fourth paper support strip 632 is D4, where D4 is 15-20mm; and the thickness of the fourth paper support strip 632 is H4, where H4 is 4mm. This layer, in conjunction with the oil channel paper pad 64, forms another small oil gap insulation barrier between the high and low voltage coils 20 and the yoke 12, synergistically increasing the breakdown voltage and creepage distance.

[0059] It should be noted that the total number of layers of the first insulating adhesive paper 421 and the first polyester film 422 in the first combined insulation layer 42, and the total number of layers of the second insulating adhesive paper 521 and the second polyester film 522 in the second combined insulation layer 52, are configured according to the lightning impulse withstand voltage level of the single-phase pole-mounted transformer. This configurability reflects the design flexibility. By adjusting the combination of the number of layers of the first insulating adhesive paper 421 and the first polyester film 422 (and the second insulating adhesive paper 521 and the second polyester film 522) with different dielectric constants, the electric field distribution can be optimized in a targeted manner to meet the stringent requirements of different lightning impulse withstand voltage levels such as 200kV or 250kV.

[0060] It should be noted that the first soft angle ring 43 is made of multiple layers of crepe paper 431, and the number of layers is configured according to the lightning impulse withstand voltage level of the single-phase pole-mounted transformer. The number of layers of the first soft angle ring 43 made of crepe paper 431 is adjustable, which ensures that the discharge creepage path that may occur from the end of the high-voltage coil 22 to the low-voltage coil 21 or the yoke 12 can be effectively blocked, and it can adapt to different insulation level requirements and enhance the reliability of the end insulation.

[0061] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of the present invention.

Claims

1. A single-phase pole-mounted transformer, comprising a core module (10) and high-voltage and low-voltage coils (20), wherein the core module (10) comprises a core (11) and yokes (12) connected to the upper and lower ends of the core (11), and the high-voltage and low-voltage coils (20) comprise a low-voltage coil (21) and a high-voltage coil (22), characterized in that: A low-voltage insulating paper tube (30) is provided between the low-voltage coil (21) and the iron core (11). An inter-coil insulation module (40) is provided between the low-voltage coil (21) and the high-voltage coil (22). The inter-coil insulation module (40) includes a first padding paper oil gap layer (41), a first combined insulation layer (42), and a first soft corner ring (43) arranged sequentially from the inside to the outside. The first padding paper oil gap layer (41) is provided with a plurality of first oil channels (401). The first combined insulation layer (42) includes 16 sheets of first insulating adhesive paper (421) with a thickness of 0.08 mm and 16 sheets of first polyester film (422) with a thickness of 0.05 mm, which are alternately stacked. The first soft corner ring (43) is made of 16 sheets of crepe paper (431) with a thickness of 0.05 mm and extends to cover the end of the high-voltage coil (22). The high-voltage coil (22) is covered with an outer ring insulation module (50). The outer ring insulation module (50) includes a second pad paper oil gap layer (51) and a second combined insulation layer (52) arranged sequentially from the inside to the outside. The second pad paper oil gap layer (51) is provided with a plurality of second oil channels (501). The second combined insulation layer (52) includes 10 sheets of second insulating adhesive paper (521) with a thickness of 0.08 mm and 10 sheets of second polyester film (522) with a thickness of 0.05 mm, which are alternately stacked. An inter-coil-yoke insulation module (60) is provided between the high-voltage and low-voltage coils (20) and the yoke (12). The inter-coil-yoke insulation module (60) includes a third padding paper oil gap layer (61) provided at the end of the high-voltage and low-voltage coils (20), a wrapping layer (62) wrapped around the outer side and end of the high-voltage and low-voltage coils (20), a fourth padding paper oil gap layer (63) provided between the high-voltage and low-voltage coils (20) and the yoke (12), an oil channel paper pad plate (64), and a first high-density paperboard (65) inserted into the low-voltage insulating paper tube (30) at both ends. The third padding paper oil gap layer (61) is provided with a third oil channel (601), and the fourth padding paper oil gap layer (63) is provided with a fourth oil channel (602). The low-pressure insulating paper tube (30) includes a second high-density paperboard (31), at least one third polyester film (32), and a third insulating adhesive paper (33) stacked in sequence. The first padding paper oil gap layer (41) includes a fourth insulating adhesive paper (411) and a plurality of first paper support strips (412) spaced apart on the fourth insulating adhesive paper (411). The first oil channel (401) is formed between adjacent first paper support strips (412). The gap size of the first oil channel (401) is L1, and L1 is 22-25mm. The width of the first paper support strip (412) is D1, and D1 is 6mm. The thickness of the first paper support strip (412) is H1, and H1 is 3mm. The second padding paper oil gap layer (51) includes a fifth insulating adhesive paper (511) and a plurality of second paper support strips (512) spaced apart on the fifth insulating adhesive paper (511). A second oil channel (501) is formed between adjacent second paper support strips (512). The gap size of the second oil channel (501) is L2, and L2 is 22-25mm. The width of the second paper support strip (512) is D2, and D2 is 6mm. The thickness of the second paper support strip (512) is H2, and H2 is 3mm. The third padding paper oil gap layer (61) includes a third high-density paperboard (611) and a plurality of third paper support strips (612) spaced apart and pasted on the third high-density paperboard (611). The third oil channel (601) is formed between adjacent third paper support strips (612). The gap size of the third oil channel (601) is L3, and L3 is 10-15mm. The width of the third paper support strip (612) is D3, and D3 is 15-20mm. The thickness of the third paper support strip (612) is H3, and H3 is 4mm. The wrapping layer (62) includes at least one sheet of cardboard (621). The fourth paper pad oil gap layer (63) includes a fourth high-density paperboard (631) and a plurality of fourth paper support strips (632) spaced apart and pasted on the fourth high-density paperboard (631). The fourth oil channel (602) is formed between adjacent fourth paper support strips (632). The gap size of the fourth oil channel (602) is L4, and L4 is 10-15mm. The width of the fourth paper support strip (632) is D4, and D4 is 15-20mm. The thickness of the fourth paper support strip (632) is H4, and H4 is 4mm.

2. The single-phase pole-mounted transformer according to claim 1, characterized in that, It also includes a body clamp (70) and a body lower clamp (80) that are respectively fixed to the upper and lower ends of the core module (10).

3. The single-phase pole-mounted transformer according to claim 1, characterized in that, The total number of layers of the first insulating adhesive paper (421) and the first polyester film (422) in the first combined insulating layer (42), and the total number of layers of the second insulating adhesive paper (521) and the second polyester film (522) in the second combined insulating layer (52) are configured according to the lightning impulse withstand voltage level of the single-phase pole-mounted transformer.

4. The single-phase pole-mounted transformer according to claim 1, characterized in that, The first soft corner ring (43) is made of multiple layers of crepe paper (431) stacked together, and the number of layers is configured according to the lightning impulse withstand voltage level of the single-phase pole-mounted transformer.

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