Dry-type transformer coil insulation structure and dry-type transformer

Abstract

The utility model discloses a dry-type transformer coil insulation structure and a dry-type transformer. The dry-type transformer coil insulation structure comprises a high-voltage coil, a low-voltage coil and an insulation pouring body, the high-voltage coil and the low-voltage coil are annular, the high-voltage coil is located on the outer side of the low-voltage coil, an insulation space is formed between the inner side wall face of the high-voltage coil and the outer side wall face of the low-voltage coil, and the insulation pouring body is arranged in the insulation space. The insulating casting body is annular, the inner side wall surface of the insulating casting body is connected with the outer side wall surface of the low-voltage coil, and the outer side wall surface of the insulating casting body is connected with the inner side wall surface of the high-voltage coil; the insulation pouring body is provided with a plurality of long-hole air channels, the long-hole air channels penetrate through the upper end face and the lower end face of the insulation pouring body, and the long-hole air channels are in an S shape. The dry-type transformer comprises the dry-type transformer coil insulation structure. The insulation distance between the high-voltage coil and the low-voltage coil is reduced, and the material cost of the dry-type transformer is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of transformers, in particular to a dry-type transformer coil insulation structure and a dry-type transformer. Background Art

[0002] The traditional dry-type transformer coil structure is: multiple thin insulating cylinders are set in the space between the high-voltage coil and the low-voltage coil, and the space between the high-voltage coil and the low-voltage coil is divided by multiple thin insulating cylinders to improve the air pressure resistance per unit distance. Figure 1 .

[0003] Using the above traditional dry-type transformer coil structure will bring the following problems:

[0004] (1) At high voltage levels (such as 35 kV and above), the insulation distance between the high-voltage coil and the low-voltage coil needs to be very large to meet the insulation standards. The materials used in the dry-type transformer will increase, and the cost of producing the dry-type transformer will become very high. At the same time, the increase in the volume of the coil structure will increase energy loss, which is not conducive to energy saving and efficiency improvement of the power grid;

[0005] (2) When the above-mentioned traditional coil structure is used on a large-capacity dry-type transformer, the increase in the volume of the coil structure will increase the capacitance of the coil structure to the ground, reduce the withstand voltage strength of the divided air duct, and reduce the insulation performance of the coil structure, which is not conducive to the safe operation of the transformer. Utility Model Content

[0006] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a dry-type transformer coil insulation structure and a dry-type transformer.

[0007] The solution of the utility model to solve the technical problem is:

[0008] A dry-type transformer coil insulation structure comprises: a high-voltage coil, a low-voltage coil and an insulating cast body, wherein the high-voltage coil and the low-voltage coil are both in an annular shape, the high-voltage coil is located on the outside of the low-voltage coil, an insulating space is formed between the inner wall surface of the high-voltage coil and the outer wall surface of the low-voltage coil, the insulating cast body is arranged in the insulating space, the insulating cast body is in an annular shape, the inner wall surface of the insulating cast body is connected to the outer wall surface of the low-voltage coil, and the outer wall surface of the insulating cast body is connected to the inner wall surface of the high-voltage coil; the insulating cast body is provided with a plurality of long-hole air ducts, the long-hole air ducts penetrate the upper and lower end surfaces of the insulating cast body, and the long-hole air ducts are S-shaped.

[0009] The utility model has at least the following beneficial effects: by providing an S-shaped long hole air duct, the heat dissipation path of the air inside the insulating space can be increased, thereby improving the heat dissipation effect, while improving the insulation strength between the high-voltage coil and the low-voltage coil and ensuring the heat dissipation effect, reducing the insulation distance between the high-voltage coil and the low-voltage coil, reducing the material cost of the dry-type transformer, and improving the transformer's voltage resistance and impact resistance.

[0010] As a further improvement of the above technical solution, the long hole air channel is provided with multiple layers, each layer of the long hole air channel has multiple long hole air channels, and the multiple long hole air channels located in the same layer surround to form an annular structure, and the annular structures formed by the long hole air channels in each layer are arranged concentrically. Such an arrangement can make the long hole air channels more evenly distributed in the insulating casting, thereby avoiding the situation of local overheating of the insulating casting and ensuring the insulation effect of the insulating casting.

[0011] As a further improvement of the above technical solution, the long hole air ducts located in two adjacent layers are staggered, so that the electric field distribution between the high voltage coil and the low voltage coil can be more discrete, and the compressive strength of the insulating casting and the long hole air duct per unit volume can be enhanced.

[0012] As a further improvement of the above technical solution, the straight line between the two end openings of each long hole air channel is a reference line, and the reference line extends in the up-down direction. Such a setting is conducive to opening an S-shaped long hole air channel on the insulating casting body, the production process is simpler, and the long hole air channels between different layers can be prevented from interfering with each other.

[0013] As a further improvement of the above technical solution, each of the long hole air ducts is provided with two curved structures, and the two curved structures of the same long hole air duct are arranged up and down and protrude toward opposite sides respectively, and the distance that the curved structure protrudes from the reference line is less than or equal to 12 mm. Such an arrangement can ensure the processability of the long hole air duct during demolding, and is more convenient for production.

[0014] As a further improvement of the above technical solution, the aperture of each of the long hole air channels is the same. Such an arrangement can ensure that the heat dissipation performance of each of the long hole air channels is consistent, and can be more conducive to the production of the insulating casting body.

[0015] As a further improvement of the above technical solution, the aperture of each of the long hole air ducts is less than or equal to 20 mm. Such an arrangement can avoid the overall size of the entire dry-type transformer coil insulation structure and the dry-type transformer using the structure being too large, thereby reducing the material cost of production.

[0016] As a further improvement of the above technical solution, there is a casting entity between two adjacent long hole air channels, the thickness of the casting entity between two adjacent long hole air channels on the same layer is greater than or equal to 5 mm and less than or equal to 10 mm, and the thickness of the casting entity between two adjacent layers of the annular structure is greater than or equal to 5 mm and less than or equal to 10 mm. The casting entity is designed within the above thickness range, and the obtained insulating casting body has a more uniform electric field distribution during use, thereby improving the electrical insulation performance of the overall dry-type transformer coil insulation structure.

[0017] As a further improvement of the above technical solution, the insulating casting body is made of epoxy resin material. Epoxy resin material has good electrical insulation and chemical corrosion resistance, can be stored for a relatively long time, and has small curing shrinkage, so the insulating casting body made has relatively high dimensional stability.

[0018] A dry-type transformer, comprising the dry-type transformer coil insulation structure described in any one of the above technical solutions. Since the dry-type transformer includes the dry-type transformer coil insulation structure of the above technical solution, the insulation space between the high-voltage coil and the low-voltage coil is finely divided by the insulating casting body with an S-shaped long hole air channel, and the air in the long hole air channel has a high pressure resistance, which can reduce the insulation distance between the high-voltage coil and the low-voltage coil, thereby reducing the volume of the entire dry-type transformer, reducing production materials, reducing production costs, and reducing energy loss, which is beneficial to energy saving and efficiency improvement of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following is a brief description of the drawings required for the description of the embodiments. Obviously, the drawings described are only part of the embodiments of the present utility model, not all of the embodiments, and those skilled in the art can also obtain other design solutions and drawings based on these drawings without creative work.

[0020] Figure 1 It is a schematic diagram of the structure of the traditional dry-type transformer coil structure;

[0021] Figure 2 It is a schematic diagram of the overall structure of the dry-type transformer coil insulation structure of the embodiment of the utility model;

[0022] Figure 3 It is a schematic diagram of the internal structure of the insulating cast body of an embodiment of the utility model.

[0023] Figure numerals: 100, low-voltage coil; 200, high-voltage coil; 300, iron core; 400, insulating cast body; 410, long-hole air duct; 411, reference line; 420, cast entity. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0025] In the description of the present invention, descriptions of orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0026] In the description of the present utility model, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0027] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0028] Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, other embodiments obtained by technicians in this field without creative work are all within the scope of protection of the utility model. The various technical features in the utility model can be combined interchangeably without conflicting with each other.

[0029] Reference Figure 1The traditional dry-type transformer coil structure is: a plurality of thin insulating cylinders 500 are arranged in the space between the low-voltage coil 100 and the high-voltage coil 200, and the plurality of thin insulating cylinders 500 are arranged concentrically between the low-voltage coil 100 and the high-voltage coil 200, and the insulating space between the low-voltage coil 100 and the high-voltage coil 200 is divided by the plurality of thin insulating cylinders 500 to improve the air withstand voltage strength per unit distance. However, at high voltage levels (such as 35kV and above), the insulation distance between the high-voltage coil 200 and the low-voltage coil 100 needs to be very large to meet the insulation standard, and the materials used in the manufactured dry-type transformer will increase, and the cost of producing the dry-type transformer will become very high. At the same time, the increase in the volume of the dry-type transformer coil structure will increase energy loss, which is not conducive to energy saving and efficiency improvement of the power grid. When the above-mentioned traditional dry-type transformer coil structure is used on a large-capacity dry-type transformer, the dry-type transformer coil structure capacitance to ground will increase due to the increase in the volume of the dry-type transformer coil structure, the withstand voltage strength of the divided insulation space will decrease, and the insulation performance of the dry-type transformer coil structure will decrease, which is not conducive to the safe operation of the dry-type transformer.

[0030] To solve the above problems, refer to Figure 2 and Figure 3 In the first aspect, the embodiment of the utility model proposes a dry-type transformer coil insulation structure, which is applied to a dry-type transformer, and includes a low-voltage coil 100 and a high-voltage coil 200. An insulating cast body 400 is arranged between the low-voltage coil 100 and the high-voltage coil 200. The insulating cast body 400 can achieve a good insulation effect between the low-voltage coil 100 and the high-voltage coil 200 to ensure the safe operation of the transformer. It can also greatly shorten the insulation distance between the low-voltage coil 100 and the high-voltage coil 200, reduce the materials used in making the dry-type transformer, reduce the production cost of the dry-type transformer, and can reduce the volume of the entire dry-type transformer coil insulation structure, reduce energy loss, and be beneficial to energy saving and efficiency improvement of the dry-type transformer.

[0031] In this embodiment, the low-voltage coil 100 and the high-voltage coil 200 are both ring-shaped. Specifically, the low-voltage coil 100 is arranged on the inner side of the high-voltage coil 200, and an insulating space is formed between the outer wall of the low-voltage coil 100 and the inner wall of the high-voltage coil 200, and the insulating cast body 400 is arranged in the insulating space.

[0032] The insulating space formed by the low-voltage coil 100 and the high-voltage coil 200 is annular, and the insulating cast body 400 is arranged in the insulating space by casting. The insulating cast body 400 is also annular, and the outer wall of the low-voltage coil 100 is connected to the inner wall of the insulating cast body 400, and the inner wall of the high-voltage coil 200 is connected to the outer wall of the insulating cast body 400.

[0033] It is worth noting that, in the present embodiment, the insulating casting body 400 is provided with a plurality of long hole air channels 410 , and each long hole air channel 410 penetrates the upper end surface and the lower end surface of the insulating casting body 400 , and the long hole air channel 410 is S-shaped.

[0034] It can be understood that the long hole air duct 410 of this embodiment is not a straight air duct structure from top to bottom, but an “S”-shaped curved air duct along the height direction of the high-voltage coil 200 and the low-voltage coil 100.

[0035] Such a configuration can increase the heat dissipation path of the air inside the insulating space, thereby improving the heat dissipation effect. While increasing the insulation strength between the high-voltage coil 200 and the low-voltage coil 100, it can reduce the insulation distance between the high-voltage coil 200 and the low-voltage coil 100, reduce the material cost of the dry-type transformer, and improve the transformer's voltage and impact resistance.

[0036] In some embodiments, the long hole air duct 410 is provided with multiple layers, each layer of the long hole air duct 410 has multiple long hole air ducts 410, and the long hole air ducts 410 located in the same layer are surrounded together to form an annular structure, and the annular structures formed by each layer of the long hole air duct 410 are concentrically arranged.

[0037] It can be understood that the diameter of each annular structure is different, and the multiple annular structures are arranged in sequence from the inside to the outside, with the annular structure with the smallest diameter located at the innermost side and the annular structure with the largest diameter located at the outermost side.

[0038] Such a configuration can make the long hole air channel 410 more evenly distributed in the insulating casting body 400, thereby avoiding local overheating of the insulating casting body 400 and ensuring the insulating effect of the insulating casting body 400.

[0039] In this embodiment, the long hole air channels 410 located in two adjacent layers are staggered. Specifically, the center of two adjacent long hole air channels 410 located in the outer layer is connected to form a straight line, and the midpoint of the straight line is located on the extension line formed by connecting the center of a long hole air channel 410 in the inner layer and the center of the annular structure. Figure 2 .

[0040] Such an arrangement can make the electric field distribution between the high-voltage coil 200 and the low-voltage coil 100 more discrete, and enhance the compressive strength of the insulating casting 400 and the compressive strength of the long-hole air duct 410 per unit volume.

[0041] In this embodiment, the straight line between the two end openings of each long hole air duct 410 is used as the reference line 411 of the long hole air duct 410, and the reference line 411 extends in the up and down direction, that is, the upper end opening and the lower end opening of the long hole air duct 410 are on the same vertical line.

[0042] Such a configuration is conducive to opening an S-shaped long hole air channel 410 on the insulating casting body 400, simplifies the production process, and can avoid mutual interference between the long hole air channels 410 between different layers.

[0043] It can be understood that each long hole air channel 410 is provided with two curved structures, and the two curved structures on the same long hole air channel 410 are arranged up and down, and the two curved structures on the same long hole air channel 410 are respectively protruded toward opposite sides, that is, forming the above-mentioned S shape. In this embodiment, in order to avoid mutual interference between two adjacent layers of two long hole air channels 410, the curved structures of each long hole air channel 410 are all protruded along the radial direction of the annular structure.

[0044] In this embodiment, the distance that the curved structure protrudes from the reference line 411 is less than or equal to 12 mm. This arrangement can ensure the processability of the long hole air duct 410 during demolding, making it easier to produce.

[0045] It is understandable that the above-mentioned reference line 411 is not an objectively existing line, but is only an auxiliary line for facilitating the production and manufacturing design. It is not reflected in the entity of the dry-type transformer coil insulation structure, but can be reflected in the design drawing when designing the mold corresponding to the insulation casting body 400. Figure 3 The dotted line in FIG. 4 is an example of a reference line 411 of a single long hole air channel 410 , and each long hole air channel 410 has a corresponding reference line 411 during design.

[0046] In this embodiment, the aperture of each long hole air channel 410 is the same. This arrangement can ensure that the heat dissipation performance of each long hole air channel 410 is consistent, and can be more conducive to the production of the insulating casting body 400.

[0047] It is understandable that the apertures at various positions of the same long hole air channel 410 are the same, so as to avoid uneven heat dissipation caused by different heat dissipation performances at different positions in the same long hole air channel 410 .

[0048] In this embodiment, the aperture of each long hole air channel 410 is ≤ 20 mm. It is understandable that the aperture of the long hole air channel 410 exceeding 20 mm will not enhance the heat dissipation effect of the insulating casting 400, but will increase the overall size of the entire dry-type transformer coil insulation structure and the dry-type transformer, and increase the material cost of production.

[0049] In this embodiment, there is a cast entity 420 between two adjacent long-hole air ducts 410, which are located in the same layer. The thickness of the cast entity 420 between the two adjacent long-hole air ducts 410 is in the range of ≥5 mm and ≤10 mm, and the thickness of the cast entity 420 between two adjacent layers of annular structures is in the range of ≥5 mm and ≤10 mm.

[0050] The thickness range of the casting entity 420 is obtained after testing and analysis. By designing the casting entity 420 within the above thickness range, the obtained insulating casting body 400 has a more uniform electric field distribution during use, thereby improving the overall electrical insulation performance of the dry-type transformer coil insulation structure.

[0051] In this embodiment, the aperture of the long hole air channel 410 satisfies the condition of being less than or equal to 20 mm. At the same time, in the same layer, the thickness of the cast entity 420 between two adjacent long hole air channels 410 satisfies the thickness range condition of ≥5 mm and ≤10 mm, and the thickness of the cast entity 420 between two adjacent layers of annular structures satisfies the thickness range condition of ≥5 mm and ≤10 mm. At this time, the size of the long hole air channel 410 and the thickness of the cast entity 420 are in a relatively reasonable proportion state. When the dry-type transformer coil insulation structure of this embodiment is used, the electric field distribution is more uniform and reasonable, and has better electrical insulation performance.

[0052] In this embodiment, the insulating casting body 400 is formed by casting an epoxy resin material, and is an epoxy resin material part. The epoxy resin material has good electrical insulation and chemical corrosion resistance, and can be stored for a relatively long time. In addition, the epoxy resin material has a small curing shrinkage, so the insulating casting body 400 has a relatively high dimensional stability.

[0053] In addition, this embodiment adopts a production process of casting the low-voltage coil 100, the high-voltage coil 200 and the insulating casting body 400 together, which can reduce the use of molds and reduce labor costs.

[0054] Moreover, since the structure of the epoxy resin material contains polar groups such as hydroxyl and epoxy groups, a large adsorption force is generated between the epoxy resin molecules and the surface of adjacent objects. Therefore, in thermosetting resins, the bonding force is relatively high, and the bonding force between the insulating casting body 400 and the low-voltage coil 100 and the high-voltage coil 200 on the adjacent two sides is strong, so as to ensure the structural stability of the entire dry-type transformer coil insulation structure.

[0055] On the other hand, an embodiment of the present utility model further proposes a dry-type transformer, comprising the dry-type transformer coil insulation structure proposed in any one of the embodiments of the first aspect above.

[0056] It can be understood that the dry-type transformer further includes a structure of an iron core 300 , which is disposed in the middle of the dry-type transformer coil insulation structure and is located in the inner ring of the low-voltage coil 100 .

[0057] It can be understood that since the dry-type transformer includes the dry-type transformer coil insulation structure in the above-mentioned embodiment, the insulation space between the high-voltage coil 200 and the low-voltage coil 100 is finely divided by the epoxy resin insulation casting body 400 having the S-shaped long hole air duct 410, and the air in the long hole air duct 410 has a high pressure resistance, which can reduce the insulation distance between the high-voltage coil 200 and the low-voltage coil 100, thereby reducing the volume of the entire dry-type transformer, reducing production materials, reducing production costs, and reducing energy loss, which is beneficial to energy saving and efficiency improvement of the power grid.

[0058] The preferred implementation modes of the present invention are specifically described above, but the present invention is not limited to the described embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention, and these equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A dry-type transformer coil insulation structure, characterized in that: It includes a high-voltage coil, a low-voltage coil and an insulating cast body, the high-voltage coil and the low-voltage coil are both in an annular shape, the high-voltage coil is located on the outside of the low-voltage coil, an insulating space is formed between the inner wall of the high-voltage coil and the outer wall of the low-voltage coil, the insulating cast body is arranged in the insulating space, the insulating cast body is in an annular shape, the inner wall of the insulating cast body is connected to the outer wall of the low-voltage coil, and the outer wall of the insulating cast body is connected to the inner wall of the high-voltage coil; the insulating cast body is provided with a plurality of long-hole air ducts, the long-hole air ducts pass through the upper and lower end surfaces of the insulating cast body, and the long-hole air ducts are S-shaped.

2. The dry-type transformer coil insulation structure according to claim 1, characterized in that: The long hole air duct is provided with multiple layers, each layer of the long hole air duct has multiple long hole air ducts respectively, and the multiple long hole air ducts located in the same layer are surrounded to form an annular structure, and the annular structures formed by the long hole air ducts in each layer are concentrically arranged.

3. The dry-type transformer coil insulation structure according to claim 2, characterized in that: The long hole air ducts located on two adjacent layers are staggered.

4. The dry-type transformer coil insulation structure according to claim 1, characterized in that: A straight line between the openings at both ends of each of the long hole air channels is a reference line, and the reference line extends in the up-down direction.

5. The dry-type transformer coil insulation structure according to claim 4, characterized in that: Each of the long hole air ducts is provided with two curved arc structures. The two curved arc structures of the same long hole air duct are arranged up and down and protrude toward opposite sides respectively. The protrusion distance of the curved arc structure from the reference line is less than or equal to 12 mm.

6. The dry-type transformer coil insulation structure according to claim 1, characterized in that: The aperture of each of the long hole air channels is the same.

7. The dry-type transformer coil insulation structure according to claim 1, characterized in that: The aperture of each of the long hole air channels is less than or equal to 20 mm.

8. The dry-type transformer coil insulation structure according to claim 2, characterized in that: There is a cast entity between two adjacent long-hole air ducts. The thickness of the cast entity between two adjacent long-hole air ducts on the same layer is greater than or equal to 5 mm and less than or equal to 10 mm. The thickness of the cast entity between two adjacent layers of the annular structures is greater than or equal to 5 mm and less than or equal to 10 mm.

9. The dry-type transformer coil insulation structure according to claim 1, characterized in that: The insulating casting body is made of epoxy resin material.

10. A dry-type transformer, characterized in that: The dry-type transformer coil insulation structure comprises the dry-type transformer coil insulation structure as claimed in any one of claims 1 to 9.

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