Oil-immersed transformer

Abstract

The oil-immersed transformer comprises an oil tank, a transformer body, a tap switch and a cover plate, the oil tank comprises a first tank body and a second tank body which are distributed in the vertical direction, the first tank body and the second tank body are communicated and jointly surround to form a containing cavity so as to contain insulating oil liquid, the first tank body is provided with an oil outlet so as to discharge the insulating oil liquid, and the second tank body is provided with an oil outlet so as to discharge the insulating oil liquid. An avoiding opening is formed in the second box body; the transformer main body is mounted in the first box body; the tap switch is mounted in the second box body and is connected with the transformer main body; the cover plate and the second box body can be connected to seal the avoiding opening; and the transformer main body and the tap switch are both soaked in the insulating oil, and when the liquid level of the insulating oil drops to the position below the tap switch and drops to the position below the avoiding opening, the cover plate is dismounted, so that the tap switch can be maintained through the avoiding opening. Therefore, the tap switch can be maintained as long as a part of oil in the oil tank accommodating cavity is discharged and the liquid level of the oil is lowered to be below the tap switch and the avoiding opening.

Description

Technical Field

[0001] This application relates to the technical field of transformers, and particularly to an oil-immersed transformer. Background Art

[0002] Transformers can be divided into dry-type transformers and oil-immersed transformers. A dry-type transformer refers to a transformer in which the iron core and windings are not immersed in insulating oil. An oil-immersed transformer mainly consists of an iron core, windings, an oil tank, an oil conservator, insulating bushings, a tap changer, and a gas relay, etc. The oil tank is welded with steel plates and is used to contain insulating oil. The main body (coil windings and iron core) of the oil-immersed transformer is installed in the oil tank and is impregnated with insulating oil. The tap changer also needs to be impregnated with insulating oil in the switch compartment. As a mechanical moving part, the tap changer often requires frequent inspection and maintenance. In traditional designs, the tap changer and the transformer body are located in the same oil tank, and the switch shaft is parallel to the coil shaft. However, when performing switch inspection and maintenance, the oil in the oil tank must be drained, and manual operation is carried out by entering the oil tank through a manhole.

[0003] In related technologies, an isolated oil tank structure is adopted, that is, an isolation layer is added to the oil tank, the transformer body and the tap changer are respectively placed on both sides of the isolation layer, and a connecting valve is provided on the isolation layer. Before performing switch maintenance, first close the connecting valves on both sides, and then only drain the oil in the switch-side oil tank. Or, a composite type switch installed outside the tank is adopted, that is, the tap changer is placed in an independent switch compartment, and the switch compartment is fixed to the side wall of the main oil tank by welding or bolting. A lead sealing plate is provided between the switch compartment and the main oil tank. When maintaining the tap changer, only the oil in the switch compartment needs to be drained.

[0004] However, since there are leads connected between the tap changer and the transformer body, the leads need to pass through the isolation layer or the side wall of the switch compartment, which not only makes the transformer structure complex, but also requires high sealing performance and insulation performance for the lead sealing plate. Summary of the Utility Model

[0005] In order to solve the above technical problems, an embodiment of this application provides an oil-immersed transformer, which can solve the above technical problems.

[0006] In a first aspect, an oil-immersed transformer includes an oil tank, a transformer body, a tap changer, and a cover plate. The oil tank includes a first box body and a second box body. The first box body and the second box body are distributed in the vertical direction. A first opening is provided at the top of the first box body, and a second opening is provided at the bottom of the second box body. The top of the first box body is connected to the bottom of the second box body, and the first opening and the second opening are communicated. The first box body and the second box body jointly enclose a receiving cavity of the oil tank for receiving insulating oil. An oil drain port is further provided on the first box body, and an avoidance opening is provided on the second box body; the transformer body is installed in the first box body; the tap changer is installed in the second box body, and the tap changer is connected to the transformer body for adjusting the output voltage of the transformer; the cover plate is detachably and sealingly connected to the second box body to close the avoidance opening; both the transformer body and the tap changer are impregnated with the insulating oil, and the insulating oil can be discharged through the oil drain port. When the liquid level of the insulating oil drops below the tap changer and below the avoidance opening, the discharge of the insulating oil is stopped, and the cover plate is removed to expose the avoidance opening, and the tap changer can be maintained through the avoidance opening.

[0007] Optionally, the axis of the tap changer is perpendicular to the vertical direction. The transformer body includes a coil winding and an iron core. The axis of the coil winding extends along the vertical direction, and the axis of the tap changer is perpendicular to the vertical direction.

[0008] Optionally, the first box body includes a first bottom plate, a first side plate, and a first top plate. The first side plate surrounds the first bottom plate and is connected to the edge of the first bottom plate. The first top plate is connected to the top end of the first side plate. Among them, the first opening is located on the first top plate; alternatively, the first top plate and the first side plate enclose the first opening; among them, the second box body includes a second top plate and a second side plate. The second side plate surrounds the second top plate and is connected to the edge of the second top plate. The second side plate encloses the second opening, and the second side plate is connected to the first box body to communicate the first opening and the second opening.

[0009] Optionally, the avoidance opening is located on the second side plate of the second box body.

[0010] Optionally, the second side plate of the second box body is connected to the first top plate of the first box body.

[0011] Optionally, the cross-sectional shape of the second box body is the same as the shape of the first opening, and the cross-sectional dimension of the second box body is the same as the inner diameter dimension of the first opening.

[0012] Optionally, the oil-immersed transformer further includes a connecting member, and the tap changer is connected to the second top plate through the connecting member, and / or the tap changer is connected to the second side plate through the connecting member.

[0013] Optionally, the oil-immersed transformer further includes a lead wire. The tap changer includes a second terminal. Wherein, the transformer body includes a first terminal. One end of the lead wire is connected to the first terminal, and the other end is connected to the second terminal. Wherein, the second terminal is located on the lower side of the tap changer and faces the transformer body. Wherein, the second terminal corresponds to the avoidance opening so that the operation of connecting the lead wire and the second terminal can be performed through the avoidance opening.

[0014] Optionally, the oil-immersed transformer further includes a bracket located in the accommodating cavity, and the lead wire is installed on the bracket.

[0015] Optionally, the oil-immersed transformer further includes a liquid level indicating device for indicating the liquid level of the insulating oil in the fuel tank.

[0016] With the oil-immersed transformer provided by the present application, since the tap changer is located above the transformer body and both are in the same accommodating cavity, therefore, there is not only enough space for arranging the lead wire connected between the tap changer and the transformer body, and there is no need to use a lead wire sealing plate, which is beneficial to simplifying the transformer structure. Moreover, only a part of the oil in the fuel tank accommodating cavity needs to be drained so that the liquid level of the oil drops to a liquid level at which the tap changer can be completely exposed, and then the tap changer can be maintained. There is no need to drain all the oil, which can reduce the oil draining time and reduce the waste of oil. Description of the Drawings

[0017] Figure 1 is a schematic structural diagram of an oil-immersed transformer provided by an embodiment of the present application;

[0018] Figure 2 is based on Figure 1 left view;

[0019] Figure 3 is a schematic structural diagram of another oil-immersed transformer provided by an embodiment of the present application;

[0020] Figure 4 is a schematic structural diagram of still another oil-immersed transformer provided by an embodiment of the present application;

[0021] Figure 5 is a top view of a first box body provided by an embodiment of the present application;

[0022] Figure 6It is a top view of another first box body provided by an embodiment of the present application;

[0023] Figure 7 It is a top view of the third first box body provided by an embodiment of the present application;

[0024] Figure 8 It is a top view of the fourth first box body provided by an embodiment of the present application.

[0025] Reference numerals:

[0026] 10 - fuel tank, 11 - first box body, 111 - first opening, 112 - first top plate,

[0027] 12 - second box body, 121 - second opening, 122 - second top plate; 123 - avoidance opening,

[0028] 13 - oil drain port, 14 - oil inlet port;

[0029] 20 - transformer main body, 21 - first terminal, 30 - tap changer, 31 - second terminal,

[0030] 40 - lead wire, 50 - bracket, 60 - connecting piece, X - up - down direction. Detailed implementation manners

[0031] To make the objectives, technical solutions and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the drawings.

[0032] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0033] Refer to Figures 1 to 4, the oil-immersed transformer provided by the present application includes an oil tank 10, a transformer main body 20, a tap changer 30, and a cover plate. The oil tank 10 includes a first box body 11 and a second box body 12. The first box body 11 and the second box body 12 are distributed in the vertical direction. A first opening 111 is provided at the top of the first box body 11, and a second opening 121 is provided at the bottom of the second box body 12. The top of the first box body 11 is connected to the bottom of the second box body 12, and the first opening 111 and the second opening 121 are communicated. The first box body 11 and the second box body 12 jointly enclose an accommodation cavity of the oil tank 10 for accommodating insulating oil. An oil drain port 13 is further provided on the first box body 11, and an avoidance port 123 is provided on the second box body; the transformer main body 20 is installed in the first box body 11; the tap changer 30 is installed in the second box body 12, and the tap changer 30 is connected to the transformer main body 20 for adjusting the output voltage of the transformer; the cover plate is detachably and sealingly connected to the second box body 12 to close the avoidance port 123. Both the transformer main body 20 and the tap changer 30 are impregnated with insulating oil, and the insulating oil can be discharged through the oil drain port 13. When the liquid level of the insulating oil drops below the tap changer 30 and below the avoidance port 123, the discharge of the insulating oil is stopped, and the cover plate is removed to expose the avoidance port 123, and the tap changer 30 can be maintained through the avoidance port.

[0034] Based on the above technical solution, since the first box body 11 and the second box body 12 are distributed in the vertical direction X, the tap opening 30 and the transformer main body 20 are distributed in the vertical direction X, and the tap changer 30 is located above the transformer main body 20. Then, when maintenance is required for the in-use transformer, after power-off, only the insulating oil needs to be discharged from the oil drain port 13 to lower the liquid level of the oil until the liquid level is below the tap changer 30 and below the avoidance port 123. At this time, the tap changer 30 and the oil drain port 13 are no longer impregnated with insulating oil, and it is allowed to stop discharging the insulating oil and to remove the cover plate to expose the avoidance port 123. In this way, the maintenance worker can maintain the tap changer 30 through the avoidance port 123. Obviously, it is not necessary to empty all the insulating oil in the accommodation cavity. At most, the insulating oil in the second box body 12 is emptied, and the tap changer 30 can be maintained through the avoidance port 123. In this way, the oil discharge amount and the oil discharge time can be reduced, and the waste of insulating oil can be reduced. Moreover, the tap changer 30 and the transformer main body 20 need to be connected by a lead wire 40. Since the tap changer 30 and the transformer main body 20 are spaced apart in the vertical direction X in the same accommodation cavity, there is enough space in the accommodation cavity for arranging the lead wire 40, and there is no need to use the sealing plate mentioned in the background art, which can simplify the structure of the transformer.

[0035] It should be clear here that draining the insulating oil is a step in the maintenance procedure for the tap-changer. Before draining the insulating oil, the transformer needs to be powered off. Among them, when the cover plate closes the avoidance opening 123, it is necessary to achieve the effect of preventing the insulating oil from leaking out of the avoidance opening 123. Therefore, a good sealing and leak-proof structure needs to be provided between the cover plate and the second box body, which is a well-known technical means in the art and will not be elaborated here. Only the avoidance opening 123 is shown in the drawings of this application, and the cover plate is not shown. The up and down directions in this article can be understood as being consistent with the direction of gravity. In the actual use of the oil-immersed transformer, the second box body 12 is located above the first box body 11, and the tap-changer 30 is located above the transformer main body 20.

[0036] In one example, the tap-changer 30 and the transformer main body 20 are spaced apart in the up and down directions, and the spacing distance between the two can be set according to the actual situation.

[0037] In a possible embodiment, referring to Figure 2 , the axis of the tap-changer 30 is perpendicular to the up and down directions. The transformer main body 20 includes a coil winding and an iron core, and the axis of the coil winding can extend along the up and down direction X. Through this setting, the space between the transformer main body 20 and the top of the fuel tank 10 can be fully utilized, and the tap-changer 30 can be arranged in this space, which is beneficial to reducing the volume of the fuel tank 10. In one example, the axis of the tap-changer 30 is parallel to the horizontal direction. Among them, the tap-changer 30 is a device well-known to those skilled in the art. The tap-changer 30 can generally have a long cylindrical contour, and generally the axis of the long cylinder is regarded as the axis of the tap-changer 30. If the axis of the tap-changer 30 is made to be consistent with the up and down directions, then the size of the tap-changer 30 in the up and down directions plus the size of the transformer main body 20 in the up and down directions will result in an overly high overall height of the transformer. If the axis of the tap-changer 30 is made perpendicular to the up and down directions, then the size of the tap-changer 30 in the up and down directions is smaller, which can reduce the overall height of the transformer main body 20. At the same time, the width of the transformer main body 20 is generally larger and greater than the axial length of the tap-changer 30. Therefore, the width space of the transformer main body 20 can be fully utilized.

[0038] In a possible implementation manner, referring to Figure 1 and Figure 3, the first box body 11 includes a first bottom plate, a first side plate, and a first top plate 112. The first side plate surrounds the first bottom plate and is connected to the edge of the first bottom plate. The first top plate 112 is connected to the top end of the first side plate. The first opening 111 is located on the first top plate 112. The second box body 12 includes a second top plate 122 and second side plates. The second side plates surround the second top plate and are connected to the edge of the second top plate 122. The second side plates enclose a second opening 121. The second side plates are connected to the first box body 11 so that the first opening 111 and the second opening 121 are communicated.

[0039] Alternatively, in another possible implementation, the first top plate 112 and the first side plate enclose the first opening 111.

[0040] Regarding the first opening 111 being located on the first top plate 112, reference can be made to Figure 5 the schematic diagram, that is, the first opening 111 is formed in the middle part of the first top plate 112. Or, reference can be made to Figure 6 the schematic diagram, that is, the first opening 111 is formed in the edge part of the first top plate 112.

[0041] Regarding the first top plate 112 and the first side plate enclosing the first opening 111, reference can be made to Figure 7 the schematic diagram, or reference can be made to Figure 8 the schematic diagram. Among them, in Figures 5 to 8 the first top plate 112 is shaded to facilitate distinguishing the first top plate 112 from the first opening 111.

[0042] Among them, the second side plate of the second box body 12 can be connected to the first top plate 112 or to the top of the first side plate, so that the first opening 111 and the second opening 121 are communicated. Taking Figure 5 the first opening 111 shown as an example, the second side plate of the second box body 12 only needs to be connected to the first top plate 112.

[0043] In a possible embodiment, the avoidance opening 123 can be located on the second side plate of the second box body 12. In this way, the avoidance opening 123 is substantially corresponding to the tap-changer 30 in the up-down direction X, which facilitates maintaining the tap-changer 30 through the avoidance opening 123 and facilitating connecting the lead wire to the tap-changer 30 through the avoidance opening 123.

[0044] In a possible embodiment, the cross-sectional shape of the second box body 12 is the same as the shape of the first opening 111, and the cross-sectional dimension of the second box body 12 is the same as the inner diameter dimension of the first opening 111. Thus, when the first opening 11 is formed on the first top plate or surrounded by the first top plate and the first side plate, the inner diameter dimension of the first opening 11 must be smaller than the cross-sectional dimension of the first box body 11, so that the area of the first opening 111 on the first box body 11 is smaller than the cross-sectional area of the first box body 11, and further the cross-sectional area of the second box body 12 is smaller than the cross-sectional area of the first box body 11. Since the axial length of the tap changer 30 is generally smaller than the width dimension of the transformer body 20, even if the cross-sectional area of the second box body 12 is small, the tap changer 30 can be accommodated. Further, the volume of the second box body 12 can be made smaller than the volume of the first box body 11, so that the capacity of the insulating oil in the second box body 11 can be reduced, the insulating oil to be discharged can be further reduced, and the oil discharge time can be reduced. In one example, the axis of the tap changer 30 is perpendicular to the up-and-down direction, that is, the tap changer is horizontally placed above the transformer body 20, which can make full use of the horizontal dimension of the first box body 11 and reduce the up-and-down dimension of the second box body 12. As long as it is ensured that the second box body 12 can accommodate the tap changer 30, the effect of making the volume of the second box body 12 as small as possible can be achieved. It should be clear here that the horizontal dimension direction and the cross-section of the first box body 11 are both perpendicular to the up-and-down direction X.

[0045] Of course, referring to Figure 4 , the first side plate of the first box body 11 and the second side plate of the second box body 12 can be directly connected to each other, and the shapes and sizes of the first opening 111 and the second opening 121 are the same. It can be understood that the first box body 11 may also have no first top plate, the first opening 111 is surrounded by the first side plate, the second opening 121 is surrounded by the second side plate, and the oil tank 10 is in an overall cuboid shape. Or, it can also be regarded that the first box body 11 is a cylindrical structure without a top plate but with a bottom plate, the second box body 12 is a cylindrical structure without a bottom plate but with a top plate, and the first opening 111 of the first box body 11 and the second opening 121 of the second box body 12 are butt-connected and communicated.

[0046] Regarding the installation method of the tap changer 30, referring to Figure 2 , the oil-immersed transformer further includes a connecting member 60. The tap changer 30 is connected to the second top plate through the connecting member 60, and / or the tap changer 30 is connected to the second side plate through the connecting member 60. Thus, when the tap changer 30 is located in the second box body 12, both ends of the tap changer 30 can be respectively connected to the two opposite second side plates through the connecting member 60. Or, the tap changer 30 can be connected to the second top plate through the connecting member 60.

[0047] In a possible implementation manner, referring toFigure 1 The tap changer 30 includes a second terminal 31, and the transformer main body 20 includes a first terminal 21. One end of the lead wire 40 is connected to the first terminal 21, and the other end is connected to the second terminal 31. The second terminal 31 is located on the lower side of the tap changer 30 and faces the transformer main body 20. The second terminal 31 corresponds to the avoidance opening 123 so that the operation of connecting the lead wire 40 and the second terminal 31 can be carried out through the avoidance opening 123. In this way, maintenance personnel can enter the accommodation cavity through the avoidance opening 123, and then connect the lead wire 40 and the second terminal 31. Moreover, the distance between the second terminal 31 of the tap changer 30 and the transformer main body 20 is small, which can reduce the length of the lead wire 40, thereby reducing the self-weight of the lead wire 40 and reducing the probability of loosening at the connection between the lead wire 40 and the second terminal 31.

[0048] In a possible embodiment, referring to Figure 1 the oil-immersed transformer further includes a bracket 50 located in the accommodation cavity, and the lead wire 40 is installed on the bracket 50 to be supported by the bracket 50. By supporting the lead wire 40 with the bracket 50, the pulling force of the self-weight of the lead wire 40 on the second terminal can be reduced, making the connection between the lead wire 40 and the second terminal firm.

[0049] Furthermore, the distance between the lower edge of the first opening 111 and the first bottom plate of the first box body 11 can be less than the distance between the second terminal 31 and the first bottom plate of the first box body 11. In other words, in the up-down direction X, the lower side edge of the first opening 111 is lower in height in the up-down direction than the second terminal in the up-down direction. In this way, the lead wire 40 can be conveniently connected to the second terminal through the avoidance opening 123.

[0050] In order to facilitate monitoring the liquid level change of the insulating oil, the oil-immersed transformer provided in this application may further include a liquid level indicating device, which can be used to indicate the liquid level of the insulating oil in the accommodation cavity. In this way, it is convenient to timely detect the liquid level change of the insulating oil, timely stop draining the oil, and timely open the avoidance opening 123, improving the maintenance efficiency.

[0051] Among them, the liquid level indicating device can be a liquid level gauge or an observation window installed on the side wall of the fuel tank. The current liquid level can be directly seen through the observation window. The observation window can be located on the first side plate, or on the second side plate, or a part of the observation window is located on the first side plate and the other part is located on the second side plate.

[0052] Of course, referring to Figure 1 an oil inlet 14 can also be provided on the fuel tank 10 to add insulating oil into the fuel tank 10 through the oil inlet 14 after the maintenance of the tap changer 30 is completed. The oil inlet 14 can be located on the second top plate of the second box body 12.

[0053] During the maintenance process of the tap changer 30, first, open the oil drain port 13. When the liquid level of the insulating oil is lower than the avoidance port 123 and lower than the tap changer 30, the second terminal 31 of the tap changer 30 is exposed. At this time, the oil drain port 13 can be closed to stop draining oil. Then, the cover plate can be removed to expose the avoidance port 123. Then, the maintenance worker can perform maintenance operations on the tap changer 30 through the avoidance port 123. For example, solve the problem of loose connection between the lead wire 40 and the second terminal 31. During this maintenance process, the transformer main body 20 can still be immersed in the insulating oil. When the maintenance is completed, the avoidance port 123 can be closed first through the cover plate, and then the oil inlet port 14 can be opened to fill the accommodating cavity with insulating oil through the oil inlet port 14. When it is observed through the liquid level indicating device that the insulating oil reaches the appropriate liquid level and the tap changer 30 is immersed in the insulating oil, stop filling the accommodating cavity with insulating oil and close the oil inlet port 14. Among them, the dimensions of the second box body 12 in the up-down direction X, the dimensions of the first box body 11 in the up-down direction X, and the position of the avoidance port 123 in the up-down direction X can be appropriately designed so that after draining oil through the oil drain port 13 to expose the tap changer 30, the liquid level of the insulating oil is both lower than the lower side edge of the avoidance port 123 and higher than the transformer main body 20. Or, after draining oil through the oil drain port 13 to expose the tap changer 30, the liquid level of the insulating oil is still located in the second box body 12 but is lower than the lower side edge of the avoidance port 123.

[0054] It should be noted that according to the needs of implementation, each component / step described in the embodiments of the present invention can be split into more components / steps, or two or more components / steps or partial operations of components / steps can be combined into new components / steps to achieve the purpose of the embodiments of the present invention.

[0055] The above embodiments are only used to illustrate the embodiments of the present invention, rather than to limit the embodiments of the present invention. Those of ordinary skill in the relevant technical fields can also make various changes and modifications without departing from the spirit and scope of the embodiments of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the embodiments of the present invention. The patent protection scope of the embodiments of the present invention shall be defined by the claims.

Claims

1. An oil-immersed transformer, characterized in that, Comprising: An oil tank (10), including a first box body (11) and a second box body (12), the first box body (11) and the second box body (12) are distributed along the up-down direction, a first opening (111) is provided at the top of the first box body (11), a second opening (121) is provided at the bottom of the second box body (12), the top of the first box body (11) and the bottom of the second box body (12) are connected, and the first opening (111) and the second opening (121) are communicated. The first box body (11) and the second box body (12) jointly enclose a receiving cavity of the oil tank (10) for receiving insulating oil. A drain port (13) is further provided on the first box body (11), and an avoidance port (123) is provided on the second box body; A transformer main body (20), installed in the first box body (11); A tap changer (30), installed in the second box body (12), the tap changer (30) is connected to the transformer main body for adjusting the output voltage of the transformer; A cover plate, which is detachably and sealingly connected to the second box body (12) to close the avoidance port (123); Both the transformer main body (20) and the tap changer (30) are impregnated with the insulating oil, and the insulating oil can be discharged through the drain port (13). When the liquid level of the insulating oil drops to be below the tap changer (30) and also below the avoidance port (123), the discharge of the insulating oil is stopped, and the cover plate is removed to expose the avoidance port (123), and the tap changer (30) can be maintained through the avoidance port (123).

2. The oil-immersed transformer according to claim 1, characterized in that, The transformer main body (20) includes a coil winding and an iron core, the axial direction of the coil winding extends along the up-down direction, and the axial direction of the tap changer (30) is perpendicular to the up-down direction.

3. The oil-immersed transformer according to claim 1, characterized in that, The first box body (11) includes a first bottom plate, a first side plate and a first top plate (112), the first side plate surrounds the first bottom plate and is connected to the edge of the first bottom plate, and the first top plate (112) is connected to the top end of the first side plate. Wherein, the first opening (111) is located on the first top plate (112), or the first top plate (112) and the first side plate enclose to form the first opening (111); Wherein, the second box body (12) includes a second top plate (122) and a second side plate, the second side plate surrounds the second top plate and is connected to the edge of the second top plate (122), the second side plate encloses to form the second opening (121), and the second side plate is connected to the first box body (11) to communicate the first opening (111) and the second opening (121).

4. The oil-immersed transformer according to claim 3, wherein, The avoidance port (123) is located on the second side plate of the second box body (12).

5. The oil-immersed transformer according to claim 3, wherein, The second side plate of the second box body (12) is connected to the first top plate (112) of the first box body (11).

6. The oil-immersed transformer according to claim 1, wherein, The cross-sectional shape of the second box body (12) is the same as the shape of the first opening (111), and the cross-sectional dimension of the second box body (12) is the same as the inner diameter dimension of the first opening (111).

7. The oil-immersed transformer according to claim 3, characterized in that, The oil-immersed transformer further includes a connecting member (60), and the tap-changer (30) is connected to the second top plate through the connecting member (60), and / or the tap-changer (30) is connected to the second side plate through the connecting member (60).

8. The oil-immersed transformer according to claim 1, characterized in that, The oil-immersed transformer further includes a lead wire (40), and the tap-changer (30) includes a second terminal (31). Wherein, the transformer main body (20) includes a first terminal (21), one end of the lead wire (40) is connected to the first terminal (21), and the other end is connected to the second terminal (31). Wherein, the second terminal (31) is located on the lower side of the tap-changer (30) and faces the transformer main body (20). Wherein, the second terminal (31) corresponds to the avoidance opening (123) so as to be able to operate to connect the lead wire (40) and the second terminal (31) together through the avoidance opening (123).

9. The oil-immersed transformer according to claim 8, wherein, The oil-immersed transformer further includes a bracket (50) located in the accommodation cavity, and the lead wire (40) is mounted on the bracket (50).

10. The oil-immersed transformer according to claim 1, characterized in that, The oil-immersed transformer further includes a liquid level indicating device for indicating the liquid level of the insulating oil in the fuel tank.

Images