Shielding structure of transformer

Abstract

The shielding structure comprises cables, a fixing steel plate and a supporting steel plate, one side of the supporting steel plate is fixedly connected with the fixing steel plate, and the periphery of the supporting steel plate is fixedly connected with the cables in a binding mode. The cable comprises a copper stranded wire, an insulating layer, a wiring sleeve and a wiring terminal, the insulating layer is arranged outside the copper stranded wire, the butt joint of the two ends of the copper stranded wire is connected through the wiring sleeve, and the butt joint of the two ends of the copper stranded wire is connected with the wiring terminal through a wire. The power transformer has the advantages of being reasonable in structure and suitable for energy-saving power transformers. Compared with a traditional shielding rod structure, the shielding structure is better in shielding effect, light in weight and convenient to install and use, the structural size of the transformer is reduced, and materials are saved.

Description

Technical Field

[0001] The utility model belongs to the field of transformer manufacturing, and in particular relates to a shielding structure suitable for an oil-immersed energy-saving power transformer. Background Art

[0002] Since the edges of the channel steel clamps assembled in the iron core of the oil-immersed power transformer are all angular, the field strength at the corners is relatively large, and partial discharge is prone to occur. Usually, a shielding structure is installed at the channel steel clamps.

[0003] At present, the shielding structure of oil-immersed power transformers adopts shielding rods. The shielding rod structure is as follows: Figure 1-Figure 3 As shown, the shielding rod is welded with the channel steel clamp. The shielding rod is made of round steel, usually with a diameter of not less than 25mm. The two ends of the round steel are processed into arc shape, and the surface must be smooth and free of burrs. Although the material of this structure is easy to obtain, it requires a relatively high surface processing accuracy, and the smoothness is not easy to ensure. If there are burrs, it will not only fail to play the proper shielding role, but also increase the hidden dangers. The shielding rod is welded at the sharp corners of the channel steel clamp legs to play the role of shielding the sharp corners. The shielding rods at both ends of the channel steel clamp are made into L-shape, the purpose is to shield the end sharp corners of the channel steel clamp. The shielding rod must be straightened before welding. Welding requires a lot of man-hours, and the welding position must be polished.

[0004] Moreover, the shielding rod cannot be disassembled and is an integrated structure with the channel steel clamp. It is relatively heavy and must be well protected from bumps in subsequent processes, which increases the difficulty of operation and is very inconvenient to use. More importantly, the shielding rod also occupies space, resulting in an increase in insulation distance and unsatisfactory shielding effect. It is generally used in transformers with not very high voltage levels (66~110kV). Otherwise, discharge breakdown is likely to occur, and the safety and reliability of transformer operation cannot be guaranteed. Therefore, the production needs of high-voltage transformers cannot be met in product manufacturing. Summary of the invention

[0005] The utility model aims to provide a transformer shielding structure which can be separated from a channel steel clamp and is easy to install and use.

[0006] To achieve the above purpose, the utility model is implemented through the following technical solutions:

[0007] A transformer shielding structure comprises a cable, a fixed steel plate and a supporting steel plate, wherein one side of the supporting steel plate is fixedly connected with the fixed steel plate, and the surrounding areas of the supporting steel plate are bound and fixedly connected with the cable;

[0008] The cable comprises a copper stranded wire, an insulating layer, a wiring sleeve and a wiring terminal. The copper stranded wire is provided with an insulating layer outside, the two ends of the copper stranded wire are connected by a wiring sleeve, and the two ends of the copper stranded wire are connected to the wiring terminal by a wire.

[0009] The supporting steel plate is rectangular.

[0010] The supporting steel plate has rounded corners on all sides.

[0011] The supporting steel plate is provided with through holes around it.

[0012] The fixing steel plate is provided with mounting holes.

[0013] The number of the fixed steel plates is more than two.

[0014] The wiring terminal is connected to the channel steel clamp.

[0015] The insulating layer is formed by wrapping crepe paper and white cloth tape.

[0016] The diameter of the copper stranded wire is 12-20 mm.

[0017] The thickness of the supporting steel plate is 1.5-3 mm.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] A transformer shielding structure has a reasonable structure and is suitable for energy-saving power transformers. Compared with the traditional shielding rod structure, the shielding structure has better shielding effect, light weight, convenient installation and use, reduces the size of the transformer structure, and saves materials. The shielding structure can be installed with bolts and can be installed in the final assembly process of the transformer to avoid collision damage to the shielding structure. The use of the shielding structure can completely shield the sharp corners on the channel steel clamp, which is equivalent to a flat electrode. The field strength is much more uniform than that of a round rod electrode, and it is more effective in reducing the discharge voltage and reducing the insulation distance with other charged fixed electrodes, thereby reducing the size of the oil tank and saving insulating oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the front view of the power transformer core assembly.

[0021] Figure 2 It is a top view of the power transformer core assembly.

[0022] Figure 3 It is a side view of the power transformer core assembly.

[0023] Figure 4 It is a side view of the installation position of the shielding structure.

[0024] Figure 5 This is the main view of the installation position of the shielding structure.

[0025] Figure 6 This is a top view of the installation location of the shielding structure.

[0026] Figure 7 It is the front view of the shielding structure.

[0027] Figure 8 is a side view of the shielding structure.

[0028] Fig. 9 is a top view of the shielding structure.

[0029] Fig.10 It is the main view of the connection between the supporting steel plate and the fixed steel plate.

[0030] Fig.11 It is a side view of the connection between the supporting steel plate and the fixed steel plate.

[0031] Fig.12 It is a schematic diagram of the cables tied and fixed around the supporting steel plate.

[0032] In the figure: 1-shielding structure 2-supporting steel plate 3-fixing steel plate 4-cable 5-copper stranded wire 6-wiring sleeve 7-wiring terminal 8-insulating layer 9-fixing bolt 10-channel steel clamp 11-shielding rod 12-through hole 13-white cloth tape. DETAILED DESCRIPTION

[0033] The present invention is described in detail below in conjunction with the accompanying drawings of the specification, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0034] See Figure 4-Figure 12 A shielding structure 1 of a transformer includes a cable 4, a fixed steel plate 3, and a supporting steel plate 2. A fixed steel plate 3 is welded on one side of the supporting steel plate 2 to fix the shielding structure 1. There are more than two fixed steel plates 3, and through holes 12 (installation holes) are opened on the fixed steel plates 3. Threaded holes are opened at corresponding positions on the channel steel clamp 10. The fixed steel plates 3 and the channel steel clamp 10 are connected by fixing bolts 9. The supporting steel plate 2 is tied and fixed with a cable 4 around it. In order to protect the shielding structure 1 from being bumped, the shielding structure 1 with a detachable structure is not installed first, and can be installed in the final assembly process of the transformer.

[0035] The cable 4 includes a copper stranded wire 5, an insulating layer 8, a wiring sleeve 6, and a terminal 7. The copper stranded wire 5 is coated with an insulating layer 8. The two ends of the copper stranded wire 5 are connected by a wiring sleeve 6, and the two ends of the copper stranded wire 5 are connected by a wire. The terminal 7 is connected to the channel steel clamp 10 and is reliably grounded. The diameter of the copper stranded wire 5 is 12 to 20 mm, preferably 16 mm. The insulating layer 8 is wrapped with crepe paper and white cloth tape, and the wrapping thickness is determined according to the voltage level and insulation distance.

[0036] In addition, the support steel plate 2 can be rectangular with a thickness of 1.5 to 3 mm, preferably 2 mm. The support steel plate 2 is provided with circular through holes 12 on all sides. The support steel plate 2 is polished smooth, and all chamfers, circular through holes 12, welding, etc. must be free of burrs to ensure that all positions of the support steel plate are smooth and free of burrs. The support steel plate 2 is rounded on all sides.

[0037] The support steel plate 2 and the cable 4 are bound with a white cloth tape 13 , and the through hole 12 is used to bind and fix the cable 4 . The white cloth tape 13 is spirally wrapped and bound through the through hole 12 , and after binding, the cable 4 completely covers the edge of the support steel plate 2 and the through hole 12 .

[0038] Each transformer is generally equipped with three shielding structures 1. The use of the shielding structure 1 can completely shield the sharp corners on the channel steel clamp 10, which is equivalent to a flat electrode. The field strength is much more uniform than that of a round rod electrode, and it is more effective in reducing the discharge voltage and shortening the insulation distance with other charged fixed electrodes, thereby reducing the size of the oil tank and saving insulating oil, steel and other materials.

Claims

1. A shielding structure of a transformer, It is characterized in that It includes cables, fixed steel plates and supporting steel plates. One side of the supporting steel plate is fixedly connected with the fixed steel plate, and the supporting steel plate is tied and fixedly connected with cables around it. The cable comprises a copper stranded wire, an insulating layer, a wiring sleeve and a wiring terminal. The copper stranded wire is provided with an insulating layer outside, the two ends of the copper stranded wire are connected by a wiring sleeve, and the two ends of the copper stranded wire are connected to the wiring terminal by a wire.

2. A transformer shielding structure according to claim 1, It is characterized in that The supporting steel plate is rectangular.

3. The shielding structure of a transformer according to claim 2, It is characterized in that The supporting steel plate has rounded corners on all sides.

4. The shielding structure of a transformer according to claim 1, It is characterized in that The supporting steel plate is provided with through holes around it.

5. The shielding structure of a transformer according to claim 1, It is characterized in that The fixing steel plate is provided with mounting holes.

6. The shielding structure of a transformer according to claim 1, It is characterized in that The number of the fixed steel plates is more than two.

7. The shielding structure of a transformer according to claim 1, It is characterized in that The wiring terminal is connected to the channel steel clamp.

8. The shielding structure of a transformer according to claim 1, It is characterized in that The insulating layer is formed by wrapping crepe paper and white cloth tape.

9. The shielding structure of a transformer according to claim 1, It is characterized in that The diameter of the copper stranded wire is 12-20 mm.

10. The shielding structure of a transformer according to claim 1, It is characterized in that The thickness of the supporting steel plate is 1.5-3 mm.

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