A transformer low-voltage winding structure

Abstract

This invention discloses a low-voltage winding structure and manufacturing process for a transformer, relating to the field of transformer technology. The structure includes a coil body with a through-hole for mounting the iron core at its center. The coil body is formed by alternating windings of multiple layers of foil and insulation, with copper busbars on it and axially extending air channels inside. The air channels are supported by a support bar mechanism, which includes a first and a second support bar arranged in an alternating pattern and attached to the insulation layer. The first support bar is a solid wooden I-beam structure, and the second support bar is an aluminum alloy hollow tube structure with axial heat dissipation fins on its sidewalls. The manufacturing process includes prefabricating the support bar assembly, alternately winding the foil and insulation layer, placing the support bar assembly as a whole and pressing it firmly, repeating the operation until coil forming and end treatment. Through the collaborative design of the dual support bars, both structural support strength and heat dissipation efficiency are considered, resolving the technical contradictions of a single support bar. The modular manufacturing process improves product consistency and production efficiency, effectively extending the service life of the transformer.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, specifically to a low-voltage winding structure for a transformer. Background Technology

[0002] Dry-type transformers are core equipment for power transmission and distribution in power systems, widely used in critical scenarios such as industrial production, high-rise buildings, and data centers. Their low-voltage windings, as the core component for current conversion, directly determine the transformer's operational stability and service life. The core structure of the low-voltage winding is the coil body, with a through-hole for the iron core to be installed in the center for electromagnetic conversion. The coil body is made of multiple layers of conductive foil and insulating layers wound alternately, and copper busbars on the surface serve as interfaces for current input and output. To address the Joule heat buildup during winding operation, axially extending air channels are typically provided inside the coil body. These channels are supported by a strut mechanism, allowing for heat dissipation through airflow and ensuring the winding temperature is controlled within a safe range.

[0003] Existing low-voltage winding air duct supports generally adopt a single structure and material for the support bar design, which has intractable technical defects: a single solid support bar (such as a metal I-beam or ordinary wooden support bar) can provide sufficient radial support force to prevent deformation during winding and operation, but the ventilation cross-sectional area is insufficient, the heat dissipation path is blocked, and local hot spots are easily formed, accelerating the aging of the insulation layer; solid support bars cannot simultaneously provide support and heat dissipation. At the same time, in traditional manufacturing processes, support bars are mostly inserted one by one directly during the winding process, resulting in poor positioning accuracy and low assembly efficiency. Summary of the Invention

[0004] In view of the above situation and to overcome the defects of the prior art, the purpose of the present invention is to provide a low-voltage winding structure for a transformer, so as to at least partially solve the problems mentioned in the background art.

[0005] The technical solution adopted by the present invention is as follows: a low-voltage winding structure for a transformer is proposed, including a coil body, wherein a through-type iron core mounting hole is provided in the center of the coil body, and at least one copper busbar is also provided on the coil body. The coil body is made of multiple layers of foil and insulation layer alternately wound. The characteristic is that at least one axially extending air passage is provided inside the coil body. The air passage is formed by a support bar mechanism, which includes multiple first support bars and multiple second support bars, which are arranged alternately and attached to the surface of the insulating layer to form a heat dissipation channel. The first support bar is a solid structure; The second support bar is a hollow tube structure, and heat dissipation fins are provided on the side wall of the second support bar.

[0006] Furthermore, the second support bar is connected to the outside, and the heat dissipation fins are distributed axially on the side wall of the hollow tube.

[0007] Furthermore, the second support bar has a rectangular cross-section, and its outer wall is tightly fitted with the insulation layer.

[0008] Furthermore, the second support bar is made of aluminum alloy.

[0009] Furthermore, the first support bar is made of wood and has an I-shaped cross-section.

[0010] Furthermore, the first support bar and the second support bar are arranged alternately along the airway extension direction, or are arranged in a unit cycle that includes at least one first support bar and one second support bar.

[0011] On the other hand, a manufacturing process for a transformer low-voltage winding is proposed, which is used to prepare the transformer low-voltage winding structure as described above, including the following steps: S1: Prepare the solid strip that forms the first support strip, the hollow tube with heat dissipation fins on the inner wall that forms the second support strip, the foil, and the insulating material; S2: On the insulating layer, according to the preset air passage layout, the first and second support bars are staggered and temporarily fixed to form a support bar group; S3: Using a foil winding machine, foil and insulation layer are alternately wound on the coil frame. When the winding reaches the position where the support bar group needs to be set, the support bar group is placed on the layer being wound as a whole, ensuring that each support bar is in contact with the surface of the insulation layer and maintains a predetermined distance. S4: Continue winding the subsequent foil and insulating layer, and press and fix the support bar group to form an axially extending air passage supported by the first support bar and the second support bar. S5: Repeat steps S2 to S4 until the entire coil body is wound. Finally, install the copper busbars and treat the end insulation.

[0012] Beneficial effects: By integrating axial air channels and a dual-support bar synergistic heat dissipation structure between the insulation layers, the winding's heat conduction efficiency and mechanical stability are significantly improved. The staggered arrangement of the first and second support bars provides both stable support and a stable heat dissipation channel. The design of solid and hollow support bars balances structural strength and heat dissipation efficiency without increasing the winding weight, effectively extending the transformer's service life.

[0013] By prefabricating the support strips and using a modular winding method, human error was reduced, the consistency of the coil structure was significantly improved, and production efficiency and finished product qualification rate were increased. Attached Figure Description Figure 1This is a schematic diagram of a transformer low-voltage winding structure according to an embodiment of the present invention; Figure 2 This is a top view schematic diagram of a transformer low-voltage winding structure according to an embodiment of the present invention; Figure 3 for Figure 2 Schematic diagram of the AA section along the middle edge; Figure 4 for Figure 3 Enlarged view of point B in the middle; Figure 5 for Figure 1 Schematic diagram of the first strut cross section; Figure 6 for Figure 1 Schematic diagram of the cross-section of the second support bar.

[0014] The components include: 1. coil body; 2. first support bar; 3. second support bar; 4. copper busbar; 5. iron core mounting hole; 6. air passage; 7. insulation layer; 8. foil material; and 9. heat dissipation fins.

[0015] The accompanying drawings are provided to further understand the embodiments and form part of the specification. They are used together with the embodiments for explanation and do not constitute a limitation on the embodiments. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection.

[0017] In the description of the embodiments, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments 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 limitations on the embodiments.

[0018] The first aspect of this invention provides a transformer low-voltage winding structure, such as... Figures 1-4 As shown, the low-voltage winding structure includes a coil body 1, which is cylindrical in shape. It is formed by alternating layers of conductive foil 8 (such as copper foil or aluminum foil) and insulating material 7 through a foil winding machine.

[0019] A core mounting hole 5 is provided at the center of the coil body 1. The hole passes through both ends of the coil body 1 in the axial direction and is used to nest and install the core to realize the electromagnetic conversion function of the transformer.

[0020] At least one copper busbar 4 is provided on the coil body 1. These copper busbars 4 extend axially and are connected to the wire foil 8, forming the key path for current input and output.

[0021] Specifically, the coil body 1 has at least one axially extending air passage 6 inside, the sidewalls of which are all surrounded by an insulating layer 7, and axially penetrate the coil body 1 to improve heat dissipation efficiency and reduce operating temperature rise.

[0022] Specifically, the air passage 6 is formed by a support bar mechanism supporting the gap between two adjacent insulating layers 7, and its cross-section is adapted to the cross-sectional profile of the coil body 1 to ensure that the airflow flows axially.

[0023] The support mechanism includes multiple first support bars 2 and second support bars 3, which are arranged alternately and attached to the surface of the insulation layer 7 to form a stable heat dissipation channel. This heat dissipation channel is crucial for the normal operation of the transformer, as it can dissipate the heat generated during the operation of the transformer in a timely manner and prevent heat accumulation from affecting the transformer performance.

[0024] It should be noted that the lengths of both the first support bar 2 and the second support bar 3 are consistent with the axial length of the coil body 1, and their ends are flush with the upper and lower end faces of the coil body 1. The first support bar 2 adopts a solid structure, which provides good mechanical support strength; the second support bar 3 adopts a hollow tube structure. Furthermore, the sidewalls of the second support bar 3 are equipped with heat dissipation fins 9, which further increase the heat dissipation area and can more effectively dissipate heat, thereby improving the heat dissipation efficiency of the entire transformer low-voltage winding structure. The beneficial effects of this embodiment are as follows: By integrating the axial air passage 6 and the double support bar synergistic heat dissipation structure between the insulation layers 7, the heat conduction efficiency and mechanical stability of the winding are significantly improved. The staggered arrangement of the first support bar 2 and the second support bar 3 provides both stable support and forms a stable heat dissipation channel. The design of solid and hollow support bars balances structural strength and heat dissipation efficiency without increasing the weight of the winding, effectively extending the service life of the transformer.

[0025] Furthermore, in some embodiments, the hollow tube of the second support bar 3 is an integral extrusion molding structure, with both ends connected to the external environment, forming an axial ventilation channel inside the coil body 1, constituting a through-type air cooling path, effectively guiding airflow through the entire coil body 1, and effectively improving heat dissipation uniformity and response speed.

[0026] Meanwhile, the heat dissipation fins 9 are distributed orderly along the axial direction on the side wall of the hollow tube. This distribution maximizes the heat dissipation function of the heat dissipation fins 9. The axial distribution of the heat dissipation fins 9 increases airflow, allowing heat to be dissipated more efficiently, further improving the heat dissipation performance of the transformer's low-voltage winding structure, and ensuring the stability and reliability of the entire transformer system. Furthermore, in some embodiments, the second support bar 3 has a rectangular cross-section, and its two opposite side outer walls are tightly fitted with the insulating layer 7. The heat dissipation fins 9 are distributed on the other two sides and are arranged axially to enhance air circulation.

[0027] It should be noted that the second support bar 3 can be reliably fixed on the two sides that are in contact with the insulation layer 7 by means of adhesive, so as to ensure the firmness of the connection and the reliability of long-term operation.

[0028] The rectangular cross-section maximizes the contact area between the second support bar 3 and the insulation layer 7, improving support stability and enhancing the overall structural integrity.

[0029] Furthermore, the second support bar 3 is made of aluminum alloy. After being extruded, it is further processed to produce heat dissipation fins 9. Its surface is anodized to enhance corrosion resistance. While ensuring the structural strength of the second support bar 3, it also improves its surface hardness and oxidation resistance, thereby increasing the service life of the transformer. Aluminum alloy was chosen because of its high strength and light weight. While ensuring sufficient support strength, it can significantly reduce the weight of the support bar mechanism and even the entire winding, which is beneficial to the lightweight design of the transformer. In addition, aluminum alloy has good corrosion resistance and long service life, making it suitable for stable operation in the long-term operating environment of the transformer.

[0030] Furthermore, in some embodiments, the first support strip 2 is made of wood and has an I-shaped cross-section.

[0031] Before winding, the wooden support strips need to be impregnated to give them excellent electrical insulation properties, moisture resistance, and a certain mechanical strength.

[0032] The I-shaped structure of the first support bar 2 makes it more tightly connected to the insulation layer 7, enhancing the structural stability of the overall coil body 1.

[0033] Furthermore, in some embodiments, the first support bar 2 and the second support bar 3 are arranged in two ways: First, the support bars are arranged alternately along the direction of air passage 6, that is, the first support bar 2 and the second support bar 3 are arranged alternately to form a stable support network; the spacing between adjacent support bars is optimized to ensure that the axial force of the winding is evenly distributed, avoid local stress concentration, and at the same time ensure that the support force and ventilation passage are evenly distributed.

[0034] Secondly, the units are arranged in a periodic repeating pattern, each containing at least one first support bar 2 and one second support bar 3. That is, each unit includes one first support bar 2 and two or more second support bars 3, forming a modular support unit; the units are arranged repeatedly along the air duct 6, which increases the support density and ensures the continuity of the heat dissipation air duct.

[0035] These two arrangements can be flexibly selected according to the transformer's heat dissipation and support strength requirements, adapting to different power levels and operating conditions. The alternating arrangement ensures a uniform distribution of support points and heat dissipation channels, balancing overall support stability and heat dissipation uniformity; the unit-periodic arrangement enhances heat dissipation by increasing the number of second support bars 3, while retaining key support points. This arrangement's flexibility improves the product's versatility.

[0036] A second aspect of the present invention provides a process for manufacturing a low-voltage winding of a transformer, used to prepare the above-mentioned low-voltage winding structure of the transformer, comprising the following steps: S1: Material Preparation Prepare a solid strip that forms the first support strip 2, a hollow tube with inner wall heat dissipation fins 9 that forms the second support strip 3, foil 8, and insulating material; For the first support bar 2, according to the drawing requirements, the first support bar 2 is cut to the required length, and the end face is chamfered and the surface is polished to remove burrs. The support bar is then impregnated and dried for later use. After processing, the second support bar 3 is made to match the length of the first support bar 2.

[0037] S2: Preparation of the support assembly On a flat workbench, lay an insulating layer 7. According to the arrangement pattern and spacing of the support bars on the design drawings, arrange the first support bar 2 and the second support bar 3 alternately or in units at a predetermined spacing and fix them on the insulating layer 7 to form a support bar group. The distribution of the support bar group can be arranged according to the two distribution methods mentioned above to ensure that the relative positions of the first support bar 2 and the second support bar 3 meet the preset requirements.

[0038] S3: Winding Start the foil winding machine and alternately wind the foil 8 and the insulation layer 7. When the winding reaches the position where a certain air channel 6 needs to be set, place the pre-made support strip group as a whole on the layer being wound, so that it wraps around and adheres to the surface of the already wound coil. Adjust it to make its axial alignment flat, and ensure that the edge of the foil 8 is flush with the end face of the support strip. Special care must be taken during placement to ensure that each support bar fits tightly against the surface of the insulation layer 7 and that the predetermined spacing is strictly maintained. This is to ensure that the formation of the air passage 6 meets the design requirements.

[0039] S4: Fixing and Shaping After the support bar assembly is placed, the subsequent winding of the foil 8 and insulating layer 7 continues. As the winding progresses, the support bar assembly is gradually pressed and fixed. In this way, an axially extending air passage 6 is finally formed, supported by the first support bar 2 and the second support bar 3.

[0040] S5: Repeat steps S2 to S4, continuously winding and setting up the support bar group until the entire winding of the coil body 1 is completed. After the winding is completed, finally install the copper busbar 4 and insulate the ends to ensure the safety and stability of the entire transformer low-voltage winding. This manufacturing process reduces human error and significantly improves the consistency of the coil structure by prefabricating the support bar assemblies and using a modular winding method, while also increasing production efficiency and the yield rate of finished products. Furthermore, the spacing and arrangement precision of the support bars are controllable, and the overall modular installation effectively avoids deformation of the air passages caused by misalignment of individual support bars during winding.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0042] The embodiments have been described above, and such description is not restrictive. The figures shown are only one embodiment, and the actual structure is not limited to this. In short, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the inventive spirit, such design should fall within the scope of protection.

Claims

1. A low-voltage winding structure for a transformer, comprising a coil body (1), wherein the coil body (1) has a through-hole (5) for mounting a core at its center, and at least one copper busbar (4) is also provided on the coil body (1), wherein the coil body (1) is formed by alternating winding of multiple layers of foil (8) and insulating layers (7), characterized in that, The coil body (1) has at least one axially extending air passage (6) inside. The air passage (6) is formed by a support bar mechanism, which includes multiple first support bars (2) and multiple second support bars (3), which are arranged alternately and attached to the surface of the insulating layer (7) to form a heat dissipation channel; The first support bar (2) is a solid structure; The second support bar (3) is a hollow tube structure, and the side wall of the second support bar (3) is provided with heat dissipation fins (9).

2. The transformer low-voltage winding structure according to claim 1, characterized in that, The second support bar (3) is connected to the outside, and the heat dissipation fins (9) are distributed axially on the side wall of the hollow tube.

3. The transformer low-voltage winding structure according to claim 1, characterized in that, The cross-section of the second support bar (3) is rectangular, and the outer wall of the second support bar (3) is tightly attached to the insulating layer (7).

4. The transformer low-voltage winding structure according to claim 1, characterized in that, The second support bar (3) is made of aluminum alloy.

5. The transformer low-voltage winding structure according to claim 1, characterized in that, The first support bar (2) is made of wood and has an I-shaped cross section.

6. The transformer low-voltage winding structure according to claim 1, characterized in that, The first support bar (2) and the second support bar (3) are arranged alternately along the direction of the airway (6), or are arranged in a unit cycle that includes at least one first support bar (2) and one second support bar (3).

7. A process for manufacturing a low-voltage winding of a transformer, used to manufacture the low-voltage winding structure of a transformer as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1: Prepare a solid strip that forms the first support bar (2), a hollow tube with heat dissipation fins (9) on the inner wall that forms the second support bar (3), foil (8) and insulating material; S2: On the insulating layer (7), according to the preset air passage (6) layout, the first support bar (2) and the second support bar (3) are staggered and temporarily fixed to form a support bar group; S3: Using a foil winding machine, the foil (8) and the insulation layer (7) are alternately wound on the coil frame. When the winding reaches the position where the support bar group needs to be set, the support bar group is placed on the layer being wound as a whole to ensure that each support bar is in contact with the surface of the insulation layer (7) and maintains a predetermined distance. S4: Continue to wind the subsequent foil (8) and insulation layer (7), press and fix the support bar group to form an axially extending air passage (6) supported by the first support bar (2) and the second support bar (3). S5: Repeat steps S2 to S4 until the entire winding of the coil body (1) is completed, and finally install the copper busbar (4) and process the end insulation.

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