An AC phase coil radial reinforcement device for improving the short circuit resistance of an oil-immersed transformer

Abstract

The utility model discloses an AC phase coil radial reinforcing device of improving oil -immersed transformer anti short -circuit capability, including AC phase coil, upper clamp support, lower clamp support, insulating bracing oil channel board, reinforcing plate, reinforced flange and reinforcing rib, the top of AC phase coil is fixedly arranged with upper clamp support, the bottom of AC phase coil is fixedly arranged with lower clamp support, the outside of AC phase coil is provided with insulating bracing oil channel board, the outside of insulating bracing oil channel board is fixedly arranged with a plurality of reinforcing plate, the upper and lower ends of reinforcing plate are provided with reinforced flange, the upper and lower ends of reinforcing plate are fixedly arranged on upper clamp support and lower clamp support, a plurality of reinforcing ribs are arranged on the reinforcing plate, can effectively improve the mechanical strength and anti short -circuit failure capacity of transformer body, solve the radial instability problem of oil -immersed transformer AC phase coil under short -circuit working condition, avoid the insulation failure caused by coil radial deformation.

Description

Technical Field

[0001] This utility model relates to the technical field of transformers, and in particular to the technical field of a radial reinforcement device for AC phase coils to improve the short-circuit withstand capability of oil-immersed transformers. Background Technology

[0002] As a core piece of equipment in the power grid, the short-circuit withstand capability of oil-immersed distribution transformers is directly related to the reliability of power supply. With the grid connection of new energy sources and the surge in load density, the short-circuit current level of the system continues to rise. The radial instability problem of the coils of traditional transformers under short-circuit impact is becoming increasingly prominent, especially the AC phase fault. Under three-phase short-circuit conditions, the AC phase coils bear 20%-30% higher radial expansion force than the B phase due to the electromagnetic force vector superposition effect, making it the weakest point in the structure. The AC phase coils of oil-immersed transformers have radial instability problems under short-circuit conditions, and the radial deformation of the coils can easily lead to insulation failure. Summary of the Invention

[0003] The purpose of this invention is to solve the problems in the prior art by proposing a radial reinforcement device for the AC phase coil of an oil-immersed transformer to improve its short-circuit withstand capability. This device can effectively improve the mechanical strength and short-circuit fault withstand capability of the transformer body, solve the problem of radial instability of the AC phase coil of an oil-immersed transformer under short-circuit conditions, and avoid insulation failure caused by radial deformation of the coil.

[0004] To achieve the above objectives, this utility model proposes a radial reinforcement device for the AC phase coil to improve the short-circuit withstand capability of an oil-immersed transformer. The device includes an AC phase coil, an upper clamping bracket, a lower clamping bracket, an insulating support oil duct plate, reinforcing plates, reinforcing folds, and reinforcing ribs. The upper clamping bracket is fixedly installed at the top of the AC phase coil, and the lower clamping bracket is fixedly installed at the bottom of the AC phase coil. An insulating support oil duct plate is installed on the outer side of the AC phase coil, and several reinforcing plates are fixedly installed on the outer side of the insulating support oil duct plate. Reinforcing folds are provided at both the upper and lower ends of the reinforcing plates, which are fixedly installed on the upper and lower clamping brackets. Several reinforcing ribs are provided on the reinforcing plates.

[0005] Preferably, the upper clamping bracket has two first long channel steels with outer openings symmetrically arranged on the front and rear sides, and the two first long channel steels are fixedly connected together by multiple connecting pillars.

[0006] Preferably, a plurality of connecting vertical rods are evenly fixedly arranged between the upper clamping bracket and the lower clamping bracket, and the upper and lower ends of the connecting vertical rods are respectively fixedly connected to the upper clamping bracket and the lower clamping bracket by locking nuts.

[0007] Preferably, the lower clamping bracket has two second long channel steels with outer openings symmetrically arranged on the front and rear sides. The bottoms of the two second long channel steels are fixedly connected together by multiple support bases. The support base is a long, rectangular, suspended base with a raised block on top. The raised block is fixedly connected to the bottom of the second long channel steel. The two ends of the support base are vertically connected with connecting holes.

[0008] Preferably, the surface of the insulating support strip oil channel plate is provided with an insulating paperboard layer, and epoxy support strips are uniformly pasted on the insulating paperboard layer, with the spacing between the epoxy support strips being less than 25mm.

[0009] Preferably, the reinforcing plate and the reinforcing fold are an integral structure, and there are multiple reinforcing plates. Adjacent reinforcing plates are welded and fixed together, and several reinforcing ribs are uniformly welded onto the reinforcing plates.

[0010] Preferably, the reinforcing plate is provided with symmetrically bent reinforcing plates at its left and right ends, and the bent reinforcing plates are provided with mounting holes at their upper and lower ends. The upper clamping bracket and the lower clamping bracket are respectively fixedly connected to the mounting holes by fixing bolts.

[0011] The beneficial effects of this utility model are as follows: This utility model combines the AC phase coil, upper clamping bracket, lower clamping bracket, insulating support bar oil duct plate, reinforcing plate, reinforced folded edge, and reinforcing rib into a single unit. Through experimental optimization, the reinforcing plate on the outside of the AC phase coil and the evenly distributed insulating support bar oil duct plate achieve directional constraint of the short-circuit electromagnetic force. While maintaining unobstructed oil channels, the device reduces the radial deformation of the AC phase coil by more than 75%, significantly improving the transformer's short-circuit withstand capability. It is suitable for oil-immersed distribution transformers of 35kV and below.

[0012] The features and advantages of this utility model will be described in detail through embodiments and accompanying drawings. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the main structure of a radial reinforcement device for AC phase coils to improve the short-circuit withstand capability of an oil-immersed transformer according to this utility model.

[0014] Figure 2 This is a schematic diagram of the insulating support bar oil passage plate structure of the radial reinforcement device for AC phase coils to improve the short-circuit withstand capability of oil-immersed transformers according to this utility model.

[0015] Figure 3 This is a schematic diagram of the reinforcing plate structure of the insulating support strip oil channel plate of this utility model.

[0016] In the diagram: 1-AC phase coil, 2-upper clamp bracket, 3-lower clamp bracket, 4-insulating support bar oil channel plate, 5-reinforcing plate, 6-reinforced folded edge, 7-reinforcing rib, 8-first long channel steel, 9-connecting vertical rod, 10-second long channel steel, 11-overhead base. Detailed Implementation

[0017] See Figure 1 , Figure 2 and Figure 3 This utility model discloses a radial reinforcement device for AC phase coils to improve the short-circuit withstand capability of oil-immersed transformers. It includes an AC phase coil 1, an upper clamping bracket 2, a lower clamping bracket 3, an insulating support oil duct plate 4, reinforcing plates 5, reinforced folded edges 6, and reinforcing ribs 7. The upper clamping bracket 2 is fixedly installed at the top of the AC phase coil 1, and the lower clamping bracket 3 is fixedly installed at the bottom of the AC phase coil 1. An insulating support oil duct plate 4 is installed on the outer side of the AC phase coil 1, and several reinforcing plates 5 are fixedly installed on the outer side of the insulating support oil duct plate 4. The reinforcing plate 5 has reinforcing folded edges 6 at both ends. The upper and lower ends of the reinforcing plate 5 are fixedly mounted on the upper clamping bracket 2 and the lower clamping bracket 3. The reinforcing plate 5 has several reinforcing ribs 7. Two first long channel steels 8 with outer openings are symmetrically arranged on the front and rear sides of the upper clamping bracket 2. The two first long channel steels 8 are fixedly connected together by multiple connecting supports. Several connecting vertical rods 9 are evenly fixed between the upper clamping bracket 2 and the lower clamping bracket 3. The upper and lower ends of the connecting vertical rods 9 are secured with locking nuts. The upper clamping bracket 2 and the lower clamping bracket 3 are fixedly connected. Two second long channel steels 10 with outer openings are symmetrically arranged on the front and rear sides of the lower clamping bracket 3. The bottoms of the two second long channel steels 10 are fixedly connected together by multiple support bases 11. Each support base 11 is a long, raised base with a raised block on top. The raised block is fixedly connected to the bottom of the second long channel steel 10. Vertical connecting holes are provided at both ends of the support base 11. The surface of the insulating support strip oil channel plate 4 is covered with an insulating cardboard layer. Epoxy support strips are evenly pasted on the insulating cardboard layer, with a spacing of less than 25mm between the epoxy support strips. The reinforcing plate 5 and the reinforcing folded edge 6 are an integral structure. There are multiple reinforcing plates 5, and adjacent reinforcing plates 5 are welded and fixed together. Several reinforcing ribs 7 are evenly welded on the reinforcing plate 5. Bending reinforcing plates are symmetrically arranged at the left and right ends of the reinforcing plate 5. Mounting holes are provided at the upper and lower ends of the bending reinforcing plates. The upper clamping bracket 2 and the lower clamping bracket 3 are fixedly connected to the mounting holes by fixing bolts.

[0018] This invention combines an AC phase coil 1, an upper clamping bracket 2, a lower clamping bracket 3, an insulating support bar oil duct plate 4, a reinforcing plate 5, a reinforced folded edge 6, and a reinforcing rib 7. Through experimental optimization, the reinforcing plate 5 on the outer side of the AC phase coil 1 and the evenly distributed insulating support bar oil duct plate 4 achieve directional constraint of the short-circuit electromagnetic force. While maintaining unobstructed oil passages, the device reduces the radial deformation of the AC phase coil 1 by more than 75%, significantly improving the transformer's short-circuit withstand capability. It is suitable for oil-immersed distribution transformers of 35kV and below.

[0019] The above embodiments are illustrative of the present invention and are not intended to limit the present invention. Any simple modifications to the present invention are within the protection scope of the present invention.

Claims

1. A radial reinforcement device for AC phase coils to improve the short-circuit withstand capability of oil-immersed transformers, characterized in that: The device includes an AC phase coil (1), an upper clamping bracket (2), a lower clamping bracket (3), an insulating support oil channel plate (4), a reinforcing plate (5), a reinforcing fold (6), and a reinforcing rib (7). The upper clamping bracket (2) is fixedly installed at the top of the AC phase coil (1), and the lower clamping bracket (3) is fixedly installed at the bottom of the AC phase coil (1). An insulating support oil channel plate (4) is installed on the outside of the AC phase coil (1). Several reinforcing plates (5) are fixedly installed on the outside of the insulating support oil channel plate (4). Reinforcing folds (6) are installed at the upper and lower ends of the reinforcing plates (5). The upper and lower ends of the reinforcing plates (5) are fixedly installed on the upper clamping bracket (2) and the lower clamping bracket (3). Several reinforcing ribs (7) are installed on the reinforcing plates (5).

2. The radial reinforcement device for AC phase coils to improve the short-circuit withstand capability of an oil-immersed transformer as described in claim 1, characterized in that: The upper clamping bracket (2) has two first long channel steels (8) with outer openings symmetrically arranged on the front and rear sides. The two first long channel steels (8) are fixedly connected together by multiple connecting pillars.

3. The radial reinforcement device for AC phase coils to improve the short-circuit withstand capability of an oil-immersed transformer as described in claim 1, characterized in that: A number of connecting vertical rods (9) are evenly fixed between the upper clamping bracket (2) and the lower clamping bracket (3). The upper and lower ends of the connecting vertical rods (9) are fixedly connected to the upper clamping bracket (2) and the lower clamping bracket (3) respectively by locking nuts.

4. The radial reinforcement device for AC phase coils to improve the short-circuit withstand capability of an oil-immersed transformer as described in claim 1, characterized in that: The lower clamp bracket (3) is symmetrically provided with two second long channel steels (10) with outer openings on the front and rear sides. The bottoms of the two second long channel steels (10) are fixedly connected together by multiple support bases (11). The support base (11) is a long strip-shaped overhead base with a raised block on the top. The raised block is fixedly connected to the bottom of the second long channel steel (10). The two ends of the support base (11) are vertically provided with connecting holes.

5. The radial reinforcement device for AC phase coils to improve the short-circuit withstand capability of an oil-immersed transformer as described in claim 1, characterized in that: The surface of the insulating support strip oil channel plate (4) is provided with an insulating paperboard layer, and epoxy support strips are uniformly pasted on the insulating paperboard layer, with the spacing of the epoxy support strips being less than 25mm.

6. The radial reinforcement device for AC phase coils to improve the short-circuit withstand capability of an oil-immersed transformer as described in claim 1, characterized in that: The reinforcing plate (5) and the reinforcing fold (6) are an integral structure. There are multiple reinforcing plates (5). Adjacent reinforcing plates (5) are welded together. Several reinforcing ribs (7) are uniformly welded onto the reinforcing plate (5).

7. The radial reinforcement device for AC phase coils to improve the short-circuit withstand capability of an oil-immersed transformer as described in claim 1, characterized in that: The reinforcing plate (5) is symmetrically provided with bent reinforcing plates at its left and right ends. The bent reinforcing plates are provided with mounting holes at their upper and lower ends. The upper clamping bracket (2) and the lower clamping bracket (3) are respectively fixedly connected to the mounting holes by fixing bolts.

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