Insulating paperboard assembly structure for oil tank of single-column coil single-phase autotransformer

Abstract

The invention belongs to the field of transformer manufacturing, and relates to a single-column coil single-phase autotransformer oil tank insulating paperboard assembly structure, a fixed base with an internal threaded hole is welded on the side wall of an oil tank, an insulating screw rod is screwed in the internal threaded hole of the fixed base in a threaded manner, and the end part of the insulating screw rod penetrates through a through hole I in an outer-layer insulating paperboard; the supporting strip is of a long strip structure, a kidney-shaped hole corresponding to the insulating screw rod is formed in the supporting strip, and a round wire hole is further formed in the supporting strip. The end part of the insulating screw rod penetrates through the kidney-shaped hole of the supporting strip, the end part of the insulating screw rod is screwed in the round wire hole of the supporting strip in a threaded manner, and the end part of the insulating screw rod penetrates through the through hole II in the middle-layer insulating paper board; an insulating nut is screwed on the insulating screw in a threaded mode, a third through hole corresponding to the insulating screw is formed in the inner-layer insulating paper board, the end of the insulating screw penetrates through the third through hole in the inner-layer insulating paper board, and the insulating nut is screwed on the insulating screw in a threaded mode. The supporting strip is of a transverse integrated structure, the multiple layers of insulating paper boards do not need to be disconnected, and the assembling workload is reduced.

Description

Technical Field

[0001] This invention belongs to the field of transformer manufacturing technology, specifically relating to an insulating paperboard assembly structure for a single-column coil single-phase autotransformer tank. Background Technology

[0002] Large power transformers are among the main and critical pieces of equipment in power systems. During normal operation, transformers generate leakage flux. When this leakage flux enters the oil tank, it causes eddy current losses and generates heat. To prevent leakage flux from entering the tank, magnetic shielding (silicon steel sheets) or electrical shielding (copper plates, etc.) is typically installed on the inner wall of the transformer tank to limit its path. The synergistic effect of electrical and magnetic shielding is needed to optimize the leakage flux path, reduce additional losses, and prevent localized overheating. Simultaneously, insulating paperboard is laid on the inner wall of the tank and secured with support strips. While the insulating paperboard, being a non-magnetic material, does not inherently possess the ability to conduct magnetic flux or shield leakage flux, its structural layout improves the electric field distribution and enhances insulation strength.

[0003] When a large single-phase autotransformer adopts a double-column coil structure, the assembly dimensions of the transverse insulating cardboard of the tank are relatively long. This requires double-layer longitudinal overlap after the support bars are broken, and then multi-layer transverse staggered overlap after the insulating cardboard is broken. This structure uses a large number of support bars and has a complex assembly process. With the improvement of transformer structure, when a large single-phase autotransformer adopts a single-column coil structure, the assembly dimensions of the transverse insulating cardboard of the tank are shortened. Therefore, it is necessary to develop a new assembly method for the tank insulating cardboard of large single-phase autotransformers that reduces the number of support bars and the cutting of cardboard, reduces the workload of assembly personnel, and effectively improves work efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide an assembly structure for insulating paperboard in the tank of a single-column coil single-phase autotransformer, so as to meet the technical requirements for rapid and efficient assembly of insulating paperboard when a large single-phase transformer adopts a single-column coil structure.

[0005] The technical solution adopted in this invention is: An insulating cardboard assembly structure for a single-column coil single-phase autotransformer tank is disclosed. Several strip-shaped magnetic shields are laid on the inner surface of the tank sidewall. Several fixed bases (base 1 and base 2) form a rectangular or square structure welded to the tank sidewall surrounding the strip-shaped magnetic shields. Fixed bases (base 1) at the top and bottom are horizontally arranged, while fixed bases (base 2) on the left and right sides are vertically arranged. Internal threaded holes are opened at the center of fixed bases (base 1 and base 2). Insulating screw 1 is threaded into the internal threaded hole of fixed base 1, and insulating screw 2 is threaded into the internal threaded hole of fixed base 2. Through holes (base 1 and base 2) corresponding to insulating screws (base 1 and base 2) are opened on the outer insulating cardboard, with the ends of insulating screws (base 1 and base 2) passing through the through holes (base 1). Support bars (base 1 and base 2) are elongated structures. Support bar 1 has waist holes corresponding to insulating screws (base 1), and support bar 2 has corresponding holes at both ends corresponding to insulating screws (base 2). The insulation board has a waist hole, and the support rods one and two also have corresponding circular wire holes. The ends of the insulating screws one and two pass through the waist holes of the support rods one and two, respectively. The end of the insulating screw three is threaded into the circular wire holes of the support rods one and two. The middle layer of insulating paperboard has a through hole two corresponding to the insulating screws one, two, and three. The ends of the insulating screws one, two, and three pass through the through hole two on the middle layer of insulating paperboard. The insulating nut one is threaded onto the insulating screw one, the insulating nut two is threaded onto the insulating screw two, and the insulating nut three is threaded onto the insulating screw three. The inner layer of insulating paperboard has a through hole three corresponding to the insulating screws one, two, and three. The ends of the insulating screws one, two, and three pass through the through hole three on the inner layer of insulating paperboard. The insulating nut three is threaded onto the insulating screw three.

[0006] Preferably, an insulating nut is screwed onto the insulating screw one inside the inner layer of insulating paperboard, and an insulating nut two is screwed onto the insulating screw two inside the inner layer of insulating paperboard.

[0007] The beneficial effects of this invention are: This invention uses a fixed base, support bars, insulating screws, and insulating nuts to fix three layers of insulating paperboard inside a strip magnetic shield. The support bars adopt a transverse integrated structure, and only four support bars are used to achieve the fixed installation of three layers of insulating paperboard. This changes the previous double-layer longitudinal overlapping structure after the support bars were broken. The three layers of insulating paperboard also do not need to be broken and interlaced laterally. Instead, they are assembled directly using whole sheets of insulating paperboard. This reduces the number of support bars and insulating paperboard to be cut and assembled, reduces the assembly workload of assembly personnel, and effectively improves work efficiency. Attached Figure Description

[0008] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is an exploded view of the insulating paperboard assembly structure according to an embodiment of the present invention; Figure 2 This is a front view of the support bar according to an embodiment of the present invention. Figure 2 Part (a) in the diagram is the front view of support bar one. Figure 2 Part (b) is the front view of support bar two; Figure 3 This is a cross-sectional view of the assembly structure of the second support strip and the insulating paperboard according to an embodiment of the present invention; Figure 4 This is a top view of the assembly structure of the insulating paperboard according to an embodiment of the present invention; Among them, 1-support bar one, 2-support bar two, 3-inner insulating paperboard, 4-middle insulating paperboard, 5-outer insulating paperboard, 6-strip magnetic shield, 7-fixed base one, 8-tank side wall, 9-fixed base two, 10-waist hole, 11-round wire hole, 12-insulating screw one, 13-insulating screw two, 14-insulating nut one, 15-insulating nut two, 16-insulating screw three, 17-insulating nut three. Detailed Implementation

[0009] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0010] In this embodiment of the invention, the center of the fuel tank is used as a reference point. The position near the center of the fuel tank (i.e., away from the side wall 8 of the fuel tank) is called the inner layer, inner side, or inner end, and the position away from the center of the fuel tank (i.e., near the side wall 8 of the fuel tank) is called the outer layer, outer side, or outer end.

[0011] like Figure 1-4 As shown, the single-column coil single-phase autotransformer tank insulating paperboard assembly structure provided by this embodiment of the invention includes a support bar 1, a support bar 2, a fixed base 7, a fixed base 9, an insulating screw 12, an insulating nut 14, an insulating screw 13, and an insulating nut 2 (15). In the design of a single-phase autotransformer, several vertically evenly arranged strip magnetic shields 6 are fixedly installed on the inner surface of the tank side wall 8. In order to work synergistically with the strip magnetic shields 6 and further isolate leakage magnetic flux from entering the tank, insulating paperboard needs to be laid inside the strip magnetic shields 6. For large single-phase autotransformers using a single-column coil structure, this embodiment of the invention provides an innovative insulating paperboard assembly structure to accommodate the assembly of the insulating paperboard.

[0012] Along the periphery of the strip magnetic shield 6, several fixed bases 1 7 and fixed base 2 9 are welded onto the side wall 8 of the oil tank. Internal threaded holes are formed at the center of each fixed base 1 7 and fixed base 2 9. Specifically, four horizontally arranged fixed bases 1 7 are welded to the top and bottom ends of the strip magnetic shield 6, and two vertically arranged fixed bases 2 9 are welded to the left and right sides of the strip magnetic shield 6, with the two fixed bases 2 9 arranged vertically to the fixed bases 1 7 on the outer sides of the top and bottom ends. This embodiment of the invention employs a three-layer insulating paperboard structure in synergy with the strip magnetic shield 6 to optimize the leakage magnetic flux path, reduce eddy current losses within the oil tank, and prevent localized overheating. The three-layer insulating paperboard structure specifically includes: an inner insulating paperboard 3, a middle insulating paperboard 4, and an outer insulating paperboard 5.

[0013] To securely install the three-layer insulating cardboard structure, a long strip support is designed, consisting of one support strip 1 at each of the top and bottom ends of the strip magnetic shield 6, and two support strips 2 located between the two support strips 1. Waist holes 10 are provided at both ends of support strips 1 and 2, and two waist holes 10 are provided at a certain distance in the middle of support strip 1. The positions of the four waist holes 10 on support strip 1 correspond to the positions of four horizontally arranged fixing bases 7, and the positions of the two waist holes 10 at both ends of support strip 2 correspond to the positions of two horizontally arranged fixing bases 9. Four circular wire holes 11 are provided on support strips 1 and 2, with the positions of the circular wire holes 11 on support strip 1 and 2 corresponding to those on support strip 2.

[0014] The outer ends of eight insulating screws 12 are screwed into the fixing base 7, and the outer ends of four insulating screws 13 are screwed into the internal threaded holes of the fixing base 9. The insulating screws 12 and 13 are fixedly installed onto the side wall 8 of the oil tank through the fixing base 7 and the fixing base 9, respectively. The outer insulating cardboard 5 has twelve through holes corresponding to the insulating screws 12 and 13. The inner ends of the insulating screws 12 and 13 pass through the through holes on the outer insulating cardboard 5, and the outer insulating cardboard 5 is fixedly installed onto the inner side of the strip magnetic shield 6 through the insulating screws 12 and 13. Support strip 1, support strip 2, support strip 2, and support strip 1 are fixedly installed sequentially from top to bottom on the inner side of the outer insulating cardboard 5. The inner ends of insulating screw 12 and insulating screw 23 pass through the waist hole 10 of support strip 1 and the waist hole 10 of support strip 2, respectively. Support strip 1 and support strip 2 are fixedly installed on the inner side of the outer insulating cardboard 5 by insulating screw 12 and insulating screw 23.

[0015] The outer ends of sixteen insulating screws 16 are screwed into the round wire holes 11 on support bars 1 and 2, respectively, and the insulating screws 16 are fixedly installed on the inner side of support bars 1 and 2 through the round wire holes 11. The middle layer insulating paperboard 4 is fixedly installed on the inner side of support bars 1 and 2. The middle layer insulating paperboard 4 has twenty-eight through holes 2 corresponding to insulating screws 12, 13, and 16. The inner ends of insulating screws 12, 13, and 16 pass through the through holes 2 on the middle layer insulating paperboard 4, and the middle layer insulating paperboard 4 is fixedly installed on the inner side of outer support bars 1 and 2.

[0016] An insulating nut 14 is threaded onto the insulating screw 12 on the inner side of the middle insulating paperboard 4. An insulating nut 2 (15) is threaded onto the insulating screw 2 (13) on the inner side of the middle insulating paperboard 4. An insulating nut 3 (17) is threaded onto the insulating screw 3 (16) on the inner side of the middle insulating paperboard 4. The middle insulating paperboard 4 is reliably fixed by the insulating nut 14, the insulating nut 2 (15) and the insulating nut 3 (17).

[0017] Inner insulating paperboard 3 is fixedly installed inside insulating nuts 14, 2 (15) and 3 17. Twenty-eight through holes 3 corresponding to insulating screws 12, 2 13 and 3 16 are opened on the inner insulating paperboard 3. The inner ends of insulating screws 12, 2 13 and 3 16 pass through the through holes 3 on the inner insulating paperboard 3, and the inner insulating paperboard 3 is fixedly installed on insulating screws 12, 2 13 and 3 16. Insulating nuts 3 17 are threadedly connected to insulating screws 3 16 inside the inner insulating paperboard 3, and the inner insulating paperboard 3 is further reliably fixed by insulating nuts 3 17.

[0018] In this embodiment of the invention, a three-layer insulating paperboard structure with reliable connection is formed on the inner side of the strip magnetic shield 6 by setting support bar 1 and support bar 2 between the inner insulating paperboard 3 and the middle insulating paperboard 4, and by using insulating screw 12 in cooperation with insulating nut 14, insulating screw 23 in cooperation with insulating nut 2 (15), and insulating screw 3 16 in cooperation with insulating nut 3 17.

[0019] Because the inner surface of the side wall 8 of the oil tank is covered with several vertical strip magnetic shields 6, the fixed base 1 7 and the fixed base 2 9 cannot be welded to the middle part of the side wall 8 where the strip magnetic shields 6 are laid. However, in this embodiment of the invention, the fixed base 1 7 and the fixed base 2 9 are welded to the outer periphery of the strip magnetic shields 6, and the insulating screw 1 12 and the insulating screw 2 13 are installed on the fixed base. The support bar 1 1 and the support bar 2 2 are installed on the insulating screw 1 1 and the support bar 2 2. The insulating screw bar 3 16 is installed on the support bar 1 1 and the support bar 2 2. At the same time, the insulating nut 1 14, the insulating nut 2 (15) and the insulating nut 3 17 are used to achieve a reliable assembly of the three layers of insulating paperboard: the inner insulating paperboard 3, the middle insulating paperboard 4 and the outer insulating paperboard 5.

[0020] In the aforementioned insulating paperboard assembly structure, both support strip 1 and support strip 2 adopt a transversely integrated structure, changing the previous structure of double-layer longitudinal overlap after the support strips were broken. Similarly, the three layers of insulating paperboard do not need to be broken and transversely overlapped; instead, they are assembled directly using whole sheets of insulating paperboard. This tank insulating paperboard assembly structure, suitable for the single-column coil structure of large single-phase autotransformers, greatly reduces the number of support strips used, while also reducing the workload of cutting and overlapping support strips and insulating paperboard, and improving the work efficiency of assembly personnel.

[0021] In the embodiments of the present invention, all technical features not described in detail are existing technologies or conventional technical means, and will not be repeated here.

[0022] Finally, it should be noted that the above embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit them. The scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention.

Claims

1. A single-column coil single-phase autotransformer tank insulating paperboard assembly structure, wherein several strip magnetic shields (6) are laid on the inner surface of the tank sidewall (8), characterized in that, Several fixed bases 1 (7) and fixed bases 2 (9) are welded to the side wall (8) of the oil tank on the outer periphery of the strip magnetic shield (6) to form a rectangular or square structure. The fixed bases 1 (7) at the top and bottom are arranged horizontally, and the fixed bases 2 (9) on the left and right sides are arranged vertically. The fixed bases 1 (7) and fixed bases 2 (9) have internal threaded holes at their center. The insulating screw 1 (12) is threaded into the internal threaded hole of the fixed base 1 (7), and the insulating screw 2 (13) is threaded into the internal threaded hole of the fixed base 2 (9). The outer insulating cardboard (5) has openings Through hole one corresponding to insulating screw one (12) and insulating screw two (13), the ends of insulating screw one (12) and insulating screw two (13) pass through through hole one on the outer insulating cardboard (5); support bar one (1) and support bar two (2) are long strip structures, support bar one (1) has waist hole (10) corresponding to insulating screw one (12) on it, support bar two (2) has waist hole (10) corresponding to insulating screw two (13) at both ends, and support bar one (1) and support bar two (2) also have corresponding circular wire holes (11); insulating screw one (12) and The ends of insulating screw 2 (13) pass through the waist hole (10) of support bar 1 (1) and the waist hole (10) of support bar 2 (2) respectively. The ends of insulating screw 3 (16) are threaded into the round wire holes (11) of support bar 1 (1) and support bar 2 (2). Through holes 2 corresponding to insulating screw 1 (12), insulating screw 2 (13) and insulating screw 3 (16) are opened on the middle layer insulating paperboard (4). The ends of insulating screw 1 (12), insulating screw 2 (13) and insulating screw 3 (16) pass through the through holes 2 on the middle layer insulating paperboard (4) respectively. 2) Thread the first insulating nut (14) onto the upper thread, thread the second insulating nut (15) onto the second insulating screw (13), and thread the third insulating nut (17) onto the third insulating screw (16); the inner insulating paperboard (3) has a through hole three corresponding to the first insulating screw (12), the second insulating screw (13) and the third insulating screw (16), the ends of the first insulating screw (12), the second insulating screw (13) and the third insulating screw (16) pass through the through hole three on the inner insulating paperboard (3), and thread the third insulating nut (17) onto the third insulating screw (16).

2. The single-column coil single-phase autotransformer tank insulating paperboard assembly structure according to claim 1, characterized in that, An insulating nut (14) is screwed onto the insulating screw (12) inside the inner insulating paperboard (3), and an insulating nut (15) is screwed onto the insulating screw (13) inside the inner insulating paperboard (3).

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