Oil-immersed transformer and manufacturing method thereof

Abstract

The present invention provides an oil-immersed transformer. The oil-immersed transformer comprises a transformer body; a first oil tank having a first accommodating chamber within which the transformer body is mounted; a tap changer; and a second oil tank secured to the exterior of the first oil tank and having a second accommodating chamber separate from the first accommodating chamber. The tap changer is mounted in the second oil tank and at least partially located within the second accommodating chamber. The second oil tank is provided with a wiring opening for passing leads connected to the tap changer. A bottom support is provided at the bottom of the second oil tank to support the second oil tank. This oil-immersed transformer has improved explosion-proof performance.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of transformers, and in particular to an oil-immersed transformer and a manufacturing method thereof. Background Art

[0002] Transformers can be categorized as oil-immersed or dry-type, depending on their insulation method. Oil-immersed transformers primarily consist of an iron core, windings, an oil tank, and a tap changer. The oil tank is filled with transformer oil, and the iron core, windings, and tap changer are all housed within it. The oil provides insulation and cooling. The tap changer can be used to adjust the transformer's output voltage.

[0003] During operation, existing transformers can experience internal faults in the tapchanger, such as a short circuit, which can cause the tapchanger's oil compartment to rupture. This can cause the transformer's oil tank to rupture, leading to oil leaks and fires. Furthermore, tapchanger oil can flow into the tank, contaminating the transformer oil and damaging other components. This can lead to secondary failures, expand the scope of the fault, and make transformer faults difficult to diagnose and troubleshoot, resulting in high repair costs. Summary of the Invention

[0004] In order to solve the above problems, embodiments of the present application provide an oil-immersed transformer and a manufacturing method thereof, so as to at least partially solve the above problems.

[0005] According to a first aspect of an embodiment of the present application, there is provided an oil-immersed transformer comprising: a transformer body; a first oil tank, the first oil tank having a first accommodating chamber, the transformer body being mounted within the first accommodating chamber of the first oil tank; a tap changer; a second oil tank, the second oil tank being fixed outside the first oil tank, the second oil tank having a second accommodating chamber separated from the first accommodating chamber, the tap changer being mounted in the second oil tank and at least partially located within the second accommodating chamber, the second oil tank being provided with a wiring opening for a lead wire connected to the tap changer to pass through, and the bottom of the second oil tank being provided with a bottom support seat for supporting the second oil tank.

[0006] Optionally, the oil-immersed transformer further includes an insulating cover plate, which is disposed on the second oil tank and covers the wiring opening, and a wiring hole for the lead wire to pass through is provided on the insulating cover plate.

[0007] Optionally, the second oil tank includes a cylinder and a reinforcement portion, wherein the reinforcement portion is provided on the cylinder to enhance the strength of the cylinder and enable the cylinder to deform to absorb arc energy generated by the tap changer.

[0008] Optionally, the cylinder includes a first side wall connected to the first oil tank, the wiring opening is arranged on the first side wall, the reinforcement portion includes a plurality of first reinforcement protrusions, the plurality of first reinforcement protrusions are arranged on the wall surface of the first side wall facing the tap changer, the length direction of the first reinforcement protrusion is parallel to the first direction, the plurality of first reinforcement protrusions are arranged at intervals along the second direction, and the first direction and the second direction are perpendicular to each other.

[0009] Optionally, multiple wiring openings are provided on the first side wall, and the multiple wiring openings are spaced apart along the first direction. The reinforcement portion further includes a second reinforcement protrusion, and a second reinforcement protrusion is provided between two adjacent wiring openings. The length direction of the second reinforcement protrusion is parallel to the second direction.

[0010] Optionally, the cylinder also includes a second side wall arranged spaced apart from the first side wall in the third direction, and the reinforcement portion also includes a plurality of third reinforcement protrusions, and the plurality of third reinforcement protrusions are arranged on the wall surface of the second side wall away from the tap changer, the length direction of the third reinforcement protrusions is parallel to the first direction, and the plurality of third reinforcement protrusions are arranged at intervals along the second direction, and the third direction is perpendicular to the plane formed by the first direction and the second direction.

[0011] Optionally, the cylinder also includes a third side wall, which connects the first side wall and the second side wall, and the reinforcement portion also includes a fourth reinforcement protrusion, which is arranged on the wall surface of the third side wall away from the tap changer, and the fourth reinforcement protrusion includes a main reinforcement section and a bending reinforcement section, the length direction of the main reinforcement section is parallel to the third direction, the bending reinforcement section is arranged at one end of the main reinforcement section close to the second side wall, the length direction of the bending reinforcement section is parallel to the second direction, and the bending reinforcement section abuts against the second side wall.

[0012] Optionally, a first buffer groove is provided on the bending reinforcement section, and an opening of the first buffer groove faces the second side wall.

[0013] Optionally, one end of the bent reinforcement section away from the main reinforcement section abuts against the third reinforcement protrusion, and a second buffer groove is provided on the bent reinforcement section, with an opening of the second buffer groove facing the connection position between the second side wall and the third reinforcement protrusion.

[0014] Optionally, the insulating cover comprises laminated paperboard.

[0015] According to another aspect of the present invention, a method for manufacturing an oil-immersed transformer is provided. The method is used to manufacture the above-mentioned oil-immersed transformer, and the method comprises: welding a second oil tank to the outside of a first oil tank, with the bottom surface of the bottom support base of the second oil tank flush with the bottom surface of the first oil tank; connecting a first end of a lead wire to a transformer body located in a first accommodating cavity of the first oil tank, passing the lead wire through a wiring opening of the second oil tank into the second accommodating cavity of the second oil tank, and connecting a second end of the lead wire to a tap changer.

[0016] According to the oil-immersed transformer provided in an embodiment of the present application, the second oil tank for housing the tap changer is provided independently of the first oil tank, and the transformer body is provided within the first oil tank, thereby separating the tap changer from the transformer body. This allows the second oil tank to contain the damage caused by the tap changer explosion, thus minimizing damage to the first oil tank. Furthermore, a wiring opening is provided in the second oil tank, allowing the leads connected to the tap changer to pass through the second oil tank and into the first oil tank, thereby achieving an electrical connection between the transformer body and the tap changer. A bottom support is provided at the bottom of the second oil tank, which enhances the mechanical strength of the second oil tank and supports the second oil tank to ensure that its height meets requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following drawings are only intended to illustrate and explain the present application and do not limit the scope of the present application.

[0018] Figure 1 A partially cutaway perspective structural diagram of the cooperation between a first oil tank and a second oil tank of an oil-immersed transformer according to an embodiment of the present application is shown;

[0019] Figure 2 A first cross-sectional structural schematic diagram of an oil-immersed transformer according to an embodiment of the present application is shown;

[0020] Figure 3 shows a second cross-sectional schematic diagram of an oil-immersed transformer according to an embodiment of the present application;

[0021] Figure 4 A schematic diagram of the three-dimensional structure of a second oil tank of an oil-immersed transformer according to an embodiment of the present application is shown from a first perspective;

[0022] Figure 5 A first cross-sectional perspective structural diagram of a second oil tank of an oil-immersed transformer according to an embodiment of the present application is shown;

[0023] Figure 6 A schematic diagram of the three-dimensional structure of the second oil tank of the oil-immersed transformer according to an embodiment of the present application is shown from a second perspective;

[0024] Figure 7 A schematic diagram of the three-dimensional structure of the second oil tank of the oil-immersed transformer according to an embodiment of the present application is shown in a third perspective;

[0025] Figure 8 Shown Figure 7 A partial enlarged view of point 1 in the middle;

[0026] Figure 9A schematic diagram of the three-dimensional structure of the second oil tank of the oil-immersed transformer according to an embodiment of the present application is shown in a fourth perspective;

[0027] Figure 10 A second cross-sectional perspective structural diagram of a second oil tank of an oil-immersed transformer according to an embodiment of the present application is shown;

[0028] Figure 11 A schematic diagram of the three-dimensional structure of the second oil tank of the oil-immersed transformer according to an embodiment of the present application is shown in a fifth perspective.

[0029] Description of reference numerals:

[0030] 10. First fuel tank;

[0031] 20. Tap changer;

[0032] 30. Second fuel tank;

[0033] 31. first side wall;

[0034] 311, first reinforcement protrusion;

[0035] 312, second reinforcement protrusion;

[0036] 32. second side wall;

[0037] 321, third reinforcement protrusion;

[0038] 33. third side wall;

[0039] 331, fourth reinforcement protrusion;

[0040] 331a, main body reinforcement section;

[0041] 331b, bending reinforcement section;

[0042] 331c, first buffer groove;

[0043] 331d, second buffer groove;

[0044] 34. Internal reinforcement;

[0045] 35. Top cover;

[0046] 361, transverse reinforcement plate;

[0047] 362, longitudinal reinforcement plate;

[0048] 40. Insulation cover;

[0049] 50. Lead. DETAILED DESCRIPTION

[0050] In order to have a clearer understanding of the technical features, purposes and effects of the embodiments of the present application, the specific implementation methods of the embodiments of the present application are now described with reference to the accompanying drawings.

[0051] Reference Figures 1-11 In this embodiment, an oil-immersed transformer is provided, including a transformer body, a first oil tank 10, a tap changer 20, and a second oil tank 30. The first oil tank 10 has a first accommodating chamber, and the transformer body is mounted in the first accommodating chamber of the first oil tank 10; the second oil tank 30 is fixed to the outside of the first oil tank 10, and has a second accommodating chamber separated from the first accommodating chamber. The tap changer 20 is mounted in the second oil tank 30 and is at least partially located in the second accommodating chamber. The second oil tank 30 is provided with a wiring opening for a lead wire 50 connected to the tap changer 20 to pass through. The bottom of the second oil tank 30 is provided with a bottom support base for supporting the second oil tank 30.

[0052] The second oil tank 30 of this oil-immersed transformer, which houses the tap changer 20, is located independently of the first oil tank 10. The transformer body is housed within the first oil tank 10, thus isolating the tap changer 20 from the transformer body. This allows the second oil tank 30 to contain any damage caused by a malfunction and explosion, minimizing damage to the first oil tank 10. Furthermore, a wiring opening in the second oil tank 30 allows the lead wires 50 connected to the tap changer 20 to pass through the second oil tank 30 and into the first oil tank 10, establishing an electrical connection between the transformer body and the tap changer 20. A bottom support is provided at the bottom of the second oil tank 30 to enhance its mechanical strength and support it to a desired height.

[0053] It should be noted that Figure 1 The figure is merely a simplified illustration of the tap changer 20 and does not constitute a limitation on the structure of the tap changer 20 .

[0054] In this embodiment, transformer oil for insulation and protection is provided in the first oil tank 10 to protect the transformer body provided in the first oil tank 10. The transformer body includes but is not limited to an iron core and windings.

[0055] like Figure 1-Figure 5As shown, in this embodiment, the second oil tank 30 includes a cylindrical body and a reinforcement portion. The reinforcement portion is provided on the cylindrical body to enhance its strength and enable it to deform to absorb the arc energy generated by the tap changer 20. The reinforcement portion is provided on the cylindrical body of the second oil tank 30. The reinforcement portion does not simply increase the structural strength of the cylindrical body. Instead, the design of the reinforcement portion takes into account the cylindrical body's deformability. When an arc is generated by the tap changer 20, the cylindrical body can deform, absorbing some of the arc energy through deformation. This improves the explosion-proof performance of the second oil tank 30, achieving a balance between structural strength and deformability of the second oil tank 30, and meeting explosion-proof requirements.

[0056] In addition to the barrel and reinforcement, the second oil tank 30 also includes a top cover 35 and a bottom support base. The barrel encloses the aforementioned second accommodating chamber, which is separated from the first accommodating chamber. This prevents transformer oil in the second oil tank 30 from flowing into the first oil tank 10, thus preventing contamination of the transformer oil in the first tank 10. Even if the tap changer 20 malfunctions and explodes, the second oil tank 30 can effectively limit the scope of the explosion and fully prevent damage to the first oil tank 10. The barrel can be of any suitable structure. For example, the cross-section of the barrel can be rectangular, circular, triangular, pentagonal, hexagonal, or elliptical.

[0057] Optionally, in order to ensure the structural strength of the second oil tank 30, effectively prevent it from bursting, and protect the tap changer 20, the cylinder includes a first side wall 31 connected to the first oil tank 10, the wiring opening is provided on the first side wall 31, and the reinforcement portion includes a plurality of first reinforcement protrusions 311, which are provided on the wall surface of the first side wall 31 facing the tap changer 20, the length direction of the first reinforcement protrusions 311 is parallel to the first direction, and the plurality of first reinforcement protrusions 311 are arranged at intervals along the second direction, and the first direction and the second direction are perpendicular to each other.

[0058] like Figure 1 As shown, the first direction may be the height direction of the second fuel tank 30 (ie Figure 1 The second direction may be the length direction of the second oil tank 30 (ie the Z direction shown in FIG. Figure 1 In addition to the first and second directions, there may also be a third direction (i.e. Figure 1 The third direction is perpendicular to the plane formed by the first direction and the second direction.

[0059] In this embodiment, the first side wall 31 can be made of a steel plate or other plate material that meets the required mechanical strength. Since the first side wall 31 needs to be connected to the first fuel tank 10, thereby mounting the second fuel tank 30 thereon, to facilitate installation and reduce processing difficulty, a first reinforcing protrusion 311 is provided on the surface of the first side wall 31 facing the tap changer 20 (i.e., the inner surface of the first side wall 31). This allows the surface of the first side wall 31 facing away from the tap changer 20 to be flat, making it easier to connect to the first fuel tank 10 and more convenient to process and operate.

[0060] The first side wall 31 can be connected to the first oil tank 10 by welding or the like, and can also be connected and fixed by fasteners, which is not limited in this embodiment.

[0061] like Figure 1 and Figure 5 As shown, in order to fully improve the mechanical strength of the first side wall 31 and enhance its anti-burst ability, the length direction of the first reinforcing protrusion 311 on the first side wall 31 is parallel to the first direction. In other words, the first reinforcing protrusion 311 extends along the first direction; in addition, there are multiple first reinforcing protrusions 311 on the first side wall 31, and they are arranged in sequence at intervals along the second direction. This can enhance the mechanical strength of the first side wall 31 in the first direction and the second direction, and reduce the risk of breakage when subjected to external force.

[0062] Optionally, to meet wiring requirements, the first side wall 31 is provided with multiple wiring openings spaced apart along the first direction. The reinforcement portion further includes a second reinforcing protrusion 312, with a second reinforcing protrusion 312 disposed between two adjacent wiring openings. The length of the second reinforcing protrusion 312 is parallel to the second direction. The provision of the second reinforcing protrusion 312 effectively avoids the adverse effects of the wiring openings on the mechanical strength of the first side wall 31, thereby enhancing the mechanical strength and explosion-proof capability of the first side wall 31.

[0063] To reduce the weight of the second fuel tank 30, the first reinforcement protrusion 311 and the second reinforcement protrusion 312 can be hollow profiles provided on the first side wall 31. For example, these profiles can have a rectangular, T-shaped, U-shaped, or trapezoidal cross-section. Since the profiles are hollow, they can reduce weight while maintaining structural strength.

[0064] Of course, in other embodiments, the first reinforcement protrusion 311 and the second reinforcement protrusion 312 may be other appropriate structures, such as plates or bumps.

[0065] In this embodiment, since the first sidewall 31 of the second oil tank 30 is made of steel, and to electrically connect the tap changer 20 to the transformer body, the lead wire 50 must pass through the first sidewalls 31 of the first and second oil tanks 10 and 30. To prevent the danger of discharge from the lead wire 50 (also referred to as a current guide wire), the oil-immersed transformer also includes an insulating cover plate 40. The insulating cover plate 40 is disposed on the second oil tank 30 and covers the wiring opening. The insulating cover plate 40 is provided with a wiring hole for the lead wire 50 to pass through. The insulating cover plate 40 not only seals the wiring opening, but also provides insulation, preventing accidental discharge of the lead wire 50 and improving safety. In this way, the insulating cover plate 40 provides insulation between the lead wire 50 and the first sidewall 31.

[0066] It should be noted that in Figure 4 and Figure 5 The wiring holes on the insulating cover plate 40 are omitted.

[0067] To ensure insulation and mechanical strength, the insulating cover 40 comprises laminated paperboard. Laminated paperboard not only has good structural strength and insulation, meeting the insulation, sealing and protection requirements of the second fuel tank 30, but also has low cost and is very easy to produce and process.

[0068] like Figure 6 As shown, the cylinder also includes a second side wall 32 spaced apart from the first side wall 31 in the third direction. The reinforcement portion also includes a plurality of third reinforcement protrusions 321 disposed on the surface of the second side wall 32 facing away from the tap changer 20. The length of the third reinforcement protrusions 321 is parallel to the first direction. The plurality of third reinforcement protrusions 321 are spaced apart along the second direction, which is perpendicular to the plane formed by the first and second directions. Providing the third reinforcement protrusions 321 on the surface of the second side wall 32 facing away from the tap changer 20 (i.e., the outer surface of the second side wall 32) enhances the mechanical strength and burst resistance of the second side wall 32.

[0069] The second sidewall 32 may be made of a steel plate or other sheet material that meets the required mechanical strength. The third reinforcing protrusion 321 may be a hollow profile with a rectangular, trapezoidal, U-shaped, T-shaped cross-section, etc. The cross-sectional shapes of the first reinforcing protrusion 311, the second reinforcing protrusion 312, and the third reinforcing protrusion 321 may be the same or different.

[0070] In this embodiment, the cylinder further includes a third side wall 33, which connects the first side wall 31 and the second side wall 32. The reinforcement portion further includes a fourth reinforcement protrusion 331, which is provided on the wall surface of the third side wall 33 away from the tap changer 20. Figure 6-Figure 8As shown, to enclose the second accommodating cavity, two third side walls 33 are provided, one corresponding to each other at the ends of the first side wall 31 in the second direction. Thus, the first side wall 31, the second side wall 32, and the two third side walls 33 form a cylindrical body with a rectangular cross-section. Of course, in other embodiments, the cross-sectional shape of the cylindrical body can also be circular, trapezoidal, or other appropriate shapes, and this embodiment is not limited thereto. The advantage of a cylindrical body with a rectangular cross-section is that it is easy to process and transport, which can reduce production costs.

[0071] like Figure 8 As shown, the fourth reinforcement protrusion 331 includes a main reinforcement section 331a and a bent reinforcement section 331b. The length of the main reinforcement section 331a is parallel to the third direction, and the bent reinforcement section 331b is provided at an end of the main reinforcement section 331a close to the second side wall 32. The length of the bent reinforcement section 331b is parallel to the second direction, and the bent reinforcement section 331b abuts against the second side wall 32. The provision of the fourth reinforcement protrusion 331 can enhance the mechanical strength and burst resistance of the third side wall 33, and can also enhance the strength of the connection between the third side wall 33 and the second side wall 32, effectively avoiding stress concentration at the connection between the second and third side walls 32 and 33.

[0072] Specifically, the main reinforcement section 331a of the fourth reinforcement protrusion 331 is primarily used to enhance the mechanical strength of the third side wall 33. Because the bent reinforcement section 331b and the main reinforcement section 331a are integrally formed and mounted on the second side wall 32, the bent reinforcement section 331b enhances the mechanical strength of the second side wall 32. Furthermore, the bent reinforcement section 331b and the main reinforcement section 331a cooperate to reinforce the connection between the second side wall 32 and the third side wall 33.

[0073] Optionally, a first buffer groove 331c is provided on the bent reinforcement section 331b, and the opening of the first buffer groove 331c faces the second side wall 32. For example, the opening of the first buffer groove 331c faces the connection position of the second side wall 32 and the third side wall 33. By providing the first buffer groove 331c at this position, it is possible to avoid rigid constraint at the connection position of the second side wall 32 and the third side wall 33, thereby avoiding stress concentration. In addition, it is possible to prevent the fourth reinforcement protrusion 331 from excessively constraining the connection position of the second side wall 32 and the third side wall 33, thereby suppressing deformation of the second fuel tank 30, thereby preventing local stress concentration at the connection position of the second side wall 32 and the third side wall 33.

[0074] In this embodiment, the first buffer groove 331 c may be a U-shaped groove.

[0075] Optionally, one end of the bent reinforcement section 331b, which is away from the main reinforcement section 331a, abuts against the third reinforcement protrusion 321. A second buffer groove 331d is provided on the bent reinforcement section 331b, with the opening of the second buffer groove 331d facing the connection between the second side wall 32 and the third reinforcement protrusion 321. By providing the second buffer groove 331d, with its opening facing the connection between the third reinforcement protrusion 321 and the second side wall 32, stress concentration at the connection between the third reinforcement protrusion 321 and the second side wall 32 can be avoided, thereby improving reliability.

[0076] like Figure 8 As shown, the second buffer groove 331d may be a V-shaped groove.

[0077] Optionally, in order to further enhance the mechanical strength of the third side wall 33, a fifth reinforcing protrusion may be provided on the third side wall 33, and the length direction of the fifth reinforcing protrusion is parallel to the first direction. In this way, the fourth reinforcing protrusion 331 and the fifth reinforcing protrusion cooperate with each other to increase the mechanical strength of the third side wall 33, thereby improving the explosion-proof capability of the second oil tank 30.

[0078] like Figure 10 As shown, optionally, in order to further enhance the mechanical strength at the connection position between the second side wall 32 and the third side wall 33, an internal reinforcing rib 34 is connected between the second side wall 32 and the third side wall 33, and the first end of the internal reinforcing rib 34 is connected to the second side wall 32, and the second end of the internal reinforcing rib 34 is connected to the third side wall 33.

[0079] In this embodiment, the internal reinforcing ribs 34 can be formed from a steel plate and connected between the second side wall 32 and the third side wall 33 to enhance mechanical strength at the junction. To ensure mechanical strength and reduce production costs and the weight of the second fuel tank 30, multiple internal reinforcing ribs 34 are provided, spaced sequentially along the first height direction.

[0080] Optionally, to optimize the uniformity of force applied to the side walls of the second oil tank 30 and minimize damage in the event of a rupture of the tap changer 20, the oil-immersed transformer further includes a top cover 35 connected to the first end of the cylinder in the first direction, and the tap changer 20 is connected to the top cover 35. Connecting the tap changer 20 to the top cover 35 secures the tap changer 20 and provides spacing between the tap changer 20 and the first side wall 31, the second side wall 32, and the third side wall 33, thereby preventing the tap changer 20 from being too close to any of the side walls, thereby causing excessive damage to the side walls.

[0081] In addition, the top cover 35 of the second fuel tank 30 is independent of the top cover of the first fuel tank 10. In this way, when an explosion or the like occurs, even if the top cover 35 of the second fuel tank 30 is damaged, it will not affect the top cover of the first fuel tank 10. During maintenance, it is only necessary to remove the top cover 35 of the second fuel tank 30 without affecting the top cover of the first fuel tank 10, thereby making maintenance more convenient.

[0082] In this embodiment, the bottom support seat of the second oil tank 30 includes a bottom plate, a transverse reinforcing plate 361, a longitudinal reinforcing plate 362 and an auxiliary support plate. The bottom plate is arranged at one end of the third side wall 33 and the second side wall 32 away from the top cover 35 to close the second end of the cylinder in the first direction. A plurality of transverse reinforcing plates 361 arranged in sequence along the third direction are provided on the bottom plate, and the length direction of the transverse reinforcing plates 361 is parallel to the second direction. In addition, a plurality of longitudinal reinforcing plates 362 arranged in sequence along the second direction are also provided on the bottom plate, and the length direction of the longitudinal reinforcing plates 362 is parallel to the third direction. By providing the transverse reinforcing plates 361 and the longitudinal reinforcing plates 362, on the one hand, the mechanical strength of the bottom plate is increased, and on the other hand, the height of the cylinder is increased so that it can better cooperate with the first oil tank 10.

[0083] In this embodiment, the auxiliary support plate is disposed on the outer wall surfaces of the third side wall 33 and the second side wall 32. The transverse reinforcement plate 361 has a first extending portion that protrudes from the outer wall surface of the third side wall 33 in the second direction. A first vertical reinforcement portion extending along the first direction is disposed on the first extending portion. The first vertical reinforcement portion abuts against the auxiliary support plate, thereby enhancing the mechanical strength of the connection between the third side wall 33 and the bottom plate.

[0084] Similarly, the longitudinal reinforcement plate 362 has a second extension portion protruding from the outer wall surface of the second side wall 32 in the third direction, and a second vertical reinforcement portion extending along the first direction is provided on the second extension portion. The second vertical reinforcement portion is pressed against the auxiliary support plate, thereby enhancing the mechanical strength of the connection position between the second side wall 32 and the bottom plate.

[0085] Optionally, in order to reduce the overall weight, a plurality of weight-reducing holes are provided on both the transverse reinforcing plate 361 and the longitudinal reinforcing plate 362 .

[0086] The oil-immersed transformer of this embodiment utilizes a second oil tank 30, independent of the first oil tank 10, to house the tap changer 20. This solves the existing problem of placing the tap changer in the first oil tank, where a rupture of the tap changer 20 can damage the first oil tank, potentially leading to oil leaks and fires. It also prevents oil from the oil chamber of the tap changer 20 from leaking into the first oil tank 10 and causing oil contamination that could spread to the transformer body, effectively preventing secondary accidents and widening the scope of the fault, thereby addressing the difficulties in subsequent fault diagnosis and high repair costs. Furthermore, this approach eliminates the need for structural reinforcement of the first oil tank, thus addressing the high construction cost associated with the previous approach of performing simulation analysis on the first oil tank to determine its structural strength under short-circuit conditions and then reinforcing any weak structures. It also avoids the problem of the first oil tank being too deformed due to its excessive structural strength, which could lead to insufficient deformation and stress concentration in the first oil tank if the tap changer 20 short-circuits and generates a significant arc.

[0087] According to another aspect of the present invention, a method for manufacturing an oil-immersed transformer is provided. The method is used to manufacture the above-mentioned oil-immersed transformer, and the method includes welding a second oil tank to the outside of a first oil tank, with the bottom surface of the bottom support of the second oil tank flush with the bottom surface of the first oil tank; connecting a first end of a lead wire 50 to a transformer body located in a first accommodating cavity of the first oil tank 10; passing the lead wire 50 through a wiring opening of the second oil tank 30 into the second accommodating cavity of the second oil tank 30; and connecting a second end of the lead wire 50 to a tap changer 20.

[0088] The oil-immersed transformer produced by this manufacturing method includes a second oil tank 30, which is independent of the first oil tank 10. The second oil tank 30 is used to install the tap changer 20, separating the tap changer 20 from the transformer body to prevent damage to the transformer body if the tap changer 20 explodes. Furthermore, the second oil tank 30 can effectively control the damage range of the tap changer 20 in the event of an explosion, making maintenance more convenient. The second oil tank 30 is fixed to the outside of the first oil tank 10 by welding, ensuring stable and reliable installation of the second oil tank 30. Furthermore, the lead wire 50 passes through the second oil tank through a wiring opening, allowing the lead wire 50 to connect the tap changer 20 and the transformer body, thereby achieving an electrical connection between the two. This manufacturing method can quickly produce a highly reliable oil-immersed transformer.

[0089] According to the embodiments of the present application, the aforementioned oil-immersed transformer has the following beneficial effects:

[0090] The tap changer is placed in a separate second tank, separated from the first tank by laminated cardboard. This ensures insulation and protection, and isolates the tap changer from the transformer oil in the first tank, preventing contamination. The laminated cardboard has sufficient mechanical strength to prevent the second tank from rupturing in the event of an explosion inside the tap changer, thus preventing oil spillage.

[0091] The second oil tank limits the damage range of the tap changer explosion, isolates the pollution, and avoids the spread of the accident. Since the fault is controlled within a certain range, it also makes fault diagnosis more convenient and can reduce maintenance costs.

[0092] The second fuel tank is reinforced by the first reinforcement protrusion, the second reinforcement protrusion, the third reinforcement protrusion, the fourth reinforcement protrusion, etc., so that the second fuel tank has high structural strength, good explosion-proof capability, and high structural reliability.

[0093] Finite element simulation analysis of the second fuel tank determined that in the event of a tap changer explosion, the maximum stress on the second tank occurred at the top cover, effectively preventing the tank from rupturing and damaging. The top cover and tap changer are easily replaced and repaired. Furthermore, the maximum overall deformation of the second tank occurred in the middle of the second sidewall, but the deformation was insufficient to cause fracture, thus ensuring safety. Furthermore, the maximum deformation of the laminated paperboard occurred near the tap changer, and the deformation was minimal, preventing fracture. This confirmed that the laminated paperboard possessed sufficient mechanical strength to meet protection requirements.

[0094] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0095] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes, modifications, and combinations made by any person skilled in the art without departing from the concept and principle of the present invention should fall within the scope of protection of the present invention.

Claims

1. An oil-immersed transformer, characterized in that: include: Transformer body; A first oil tank (10), the first oil tank (10) having a first accommodating cavity, the transformer body being installed in the first accommodating cavity of the first oil tank (10); Tap changer (20); a second oil tank (30), the second oil tank (30) being fixed outside the first oil tank (10), the second oil tank (30) having a second accommodating cavity separated from the first accommodating cavity, the tap changer (20) being installed in the second oil tank (30) and at least partially located in the second accommodating cavity, the second oil tank (30) being provided with a wiring opening for a lead wire (50) connected to the tap changer (20) to pass through, and a bottom support base for supporting the second oil tank (30) being provided at the bottom of the second oil tank (30), The second oil tank (30) comprises a cylinder and a reinforcement portion, wherein the reinforcement portion is provided on the cylinder to enhance the strength of the cylinder and enable the cylinder to deform to absorb arc energy generated by the tap changer (20). The reinforcement portion comprises a fourth reinforcement protrusion (331), the fourth reinforcement protrusion (331) comprises a main reinforcement section (331a) and a bending reinforcement section (331b), a first buffer groove (331c) is provided on the bending reinforcement section (331b), and the opening of the first buffer groove (331c) faces the side wall of the cylinder.

2. The oil-immersed transformer according to claim 1, characterized in that: The oil-immersed transformer further comprises an insulating cover plate (40), the insulating cover plate (40) being arranged on the second oil tank (30) and covering the wiring opening, and a wiring hole for the lead wire (50) to pass through being arranged on the insulating cover plate (40).

3. The oil-immersed transformer according to claim 1, characterized in that: The cylinder comprises a first side wall (31) connected to the first oil tank (10), the wiring opening is arranged on the first side wall (31), the reinforcement portion comprises a plurality of first reinforcement protrusions (311), the plurality of first reinforcement protrusions (311) are arranged on a wall surface of the first side wall (31) facing the tap changer (20), the length direction of the first reinforcement protrusions (311) is parallel to the first direction, the plurality of first reinforcement protrusions (311) are arranged at intervals along a second direction, and the first direction and the second direction are perpendicular to each other.

4. The oil-immersed transformer according to claim 3, characterized in that: A plurality of wiring openings are provided on the first side wall (31), and the plurality of wiring openings are spaced apart along the first direction. The reinforcement portion further comprises a second reinforcement protrusion (312), and the second reinforcement protrusion (312) is provided between two adjacent wiring openings. The length direction of the second reinforcement protrusion (312) is parallel to the second direction.

5. The oil-immersed transformer according to claim 4, characterized in that: The cylinder further includes a second side wall (32) spaced apart from the first side wall (31) in a third direction, and the reinforcement portion further includes a plurality of third reinforcement protrusions (321), the plurality of third reinforcement protrusions (321) being arranged on a wall surface of the second side wall (32) away from the tap changer (20), the length direction of the third reinforcement protrusions (321) being parallel to the first direction, the plurality of third reinforcement protrusions (321) being spaced apart along the second direction, and the third direction being perpendicular to a plane formed by the first direction and the second direction.

6. The oil-immersed transformer according to claim 5, characterized in that: The cylinder further includes a third side wall (33), the third side wall (33) connecting the first side wall (31) and the second side wall (32), the fourth reinforcement protrusion (331) being arranged on a wall surface of the third side wall (33) away from the tap changer (20), the length direction of the main body reinforcement section (331a) being parallel to the third direction, the bending reinforcement section (331b) being arranged at one end of the main body reinforcement section (331a) close to the second side wall (32), the length direction of the bending reinforcement section (331b) being parallel to the second direction, and the bending reinforcement section (331b) being in contact with the second side wall (32).

7. The oil-immersed transformer according to claim 6, characterized in that: The opening of the first buffer groove (331c) faces the second side wall (32).

8. The oil-immersed transformer according to claim 7, characterized in that: One end of the bent reinforcement section (331b) away from the main body reinforcement section (331a) abuts against the third reinforcement protrusion (321), and a second buffer groove (331d) is provided on the bent reinforcement section (331b), with the opening of the second buffer groove (331d) facing the connection position between the second side wall (32) and the third reinforcement protrusion (321).

9. The oil-immersed transformer according to claim 2, characterized in that: The insulating cover plate (40) comprises laminated paperboard.

10. A method for manufacturing an oil-immersed transformer, characterized in that: The manufacturing method is used to manufacture the oil-immersed transformer according to any one of claims 1 to 9, and the manufacturing method comprises: Welding the second fuel tank to the outside of the first fuel tank, with the bottom surface of the bottom support of the second fuel tank flush with the bottom surface of the first fuel tank; The first end of the lead wire (50) is connected to the transformer body located in the first accommodating cavity of the first oil tank (10), and the lead wire (50) is passed through the wiring opening of the second oil tank (30) into the second accommodating cavity of the second oil tank (30), and the second end of the lead wire (50) is connected to the tap changer (20).

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