Structure for improving short circuit capacity of three-dimensional wound core transformer

Abstract

The utility model relates to a structure of improving three -dimensional volume iron core transformer short -circuit capacity, belong to transformer manufacturing technical field, including a plurality of annular distribution's transformer winding, transformer winding upper end be equipped with upper clamp piece frame, transformer winding lower extreme be equipped with lower clamp piece frame, two adjacent transformer winding between with upper clamp piece frame, lower clamp piece frame all are equipped with respectively with upper clamp piece frame, lower clamp piece frame welding fixed pressure seat I, adopt nut locking's pull screw between two pressure seat I. Effectively solve the axial mechanical strength and anti -short -circuit failure ability of transformer body. The problem that the winding is easy to loosen or damage because of huge electric power under the short -circuit condition of three -dimensional volume iron core transformer. Through pull screw frame provides overall skeleton, through the double -row / multiple point pressure nail of pressure seat I and pressure seat II provides local compression force, cooperates with the positioning of the steel plate of the clamping groove type and laminated wood buffer, forms a set of high reliability's anti -short -circuit mechanical system.

Description

Technical Field

[0001] This utility model relates to the field of transformer manufacturing technology, specifically to a structure for improving the short-circuit capability of a three-dimensional wound core transformer. Background Technology

[0002] The three-dimensional wound core transformer is a new type of energy-saving distribution transformer. Compared with the traditional planar stacked core transformer, its three core columns are arranged in an equilateral triangle in a three-dimensional manner, and the magnetic circuit distribution is completely symmetrical.

[0003] From the perspective of current equipment operation, the design of traditional transformers often focuses on conventional performance indicators such as losses and temperature rise, while neglecting the optimization of winding support structure and material mechanical strength. Under the impact of short-circuit electromagnetic forces, problems such as winding deformation, insulation component cracking, and core loosening are very likely to occur. In severe cases, it can lead to transformer winding burnout, tank deformation and explosion, and even regional power outages, posing a significant threat to the safe and stable operation of the power system, while also generating high equipment maintenance and power outage losses.

[0004] When a transformer experiences a sudden short circuit during operation (such as an external load short circuit or a lightning strike), a huge short-circuit current (usually ten to twenty times the rated current) will flow through the windings. This will generate enormous axial and radial electrodynamic forces inside the windings.

[0005] Axial electrodynamic force: mainly acts on the upper and lower ends of the winding, attempting to "flatten" the winding or push the coils apart.

[0006] Radial electrodynamics: mainly causes the high-voltage winding to expand outward and the low-voltage winding to compress inward.

[0007] If the mechanical structure of the transformer is not robust enough, these electrodynamic forces can lead to: (1) winding deformation (such as axial collapse and radial bulging); (2) loosening of pads and damage to insulation components; (3) in severe cases, even inter-turn or inter-layer insulation breakdown, burning out the transformer.

[0008] Despite the superior performance of three-dimensional wound core transformers, traditional clamping structures often suffer from the following problems in terms of short-circuit withstand capability: (1) Insufficient clamping rigidity: Traditional clamping structures usually connect the upper and lower clamping parts only by a simple pull screw. When faced with huge short-circuit axial forces, the clamping parts are prone to bending deformation, resulting in failure of the clamping force on the winding.

[0009] (2) Uneven distribution of clamping points: Existing structures often only set clamping pins at the corners or specific locations of the windings. For three-dimensional wound core transformers, due to their special triangular arrangement, the space between the windings is limited, and traditional structures find it difficult to set effective clamping devices in the narrow area between two adjacent windings. This results in uneven force on the circumference of the windings, and under short-circuit impact, the un-clamped parts are prone to loosening or deformation.

[0010] (3) Unreliable positioning and fixing (pressure plate displacement problem): In the existing technology, the pressure plate (usually placed between the clamp and the winding) is often positioned by friction or simple placement. Under the vibration during the transportation of the transformer and the huge impact of the short circuit, the pressure plate is prone to slight displacement or movement. Once the pressure plate is misaligned, the clamping force will be applied to an ineffective position, directly causing damage to the winding.

[0011] (4) Difficulty in pressure regulation: The welded fixed structure lacks a fine-tuning mechanism. As the transformer operates for a long time, the insulating parts (such as pads) will dry out and shrink, resulting in a decrease in clamping force. The existing structure is often difficult to "re-tighten" easily, resulting in a decrease in short-circuit withstand capability over time. Summary of the Invention

[0012] This invention primarily addresses the shortcomings of existing technologies by providing a structure that improves the short-circuit capability of three-dimensional wound core transformers. It effectively solves the problem of axial mechanical strength and short-circuit fault resistance of the transformer body. Specifically, it addresses the issue that the windings of three-dimensional wound core transformers are prone to loosening or damage due to the enormous electrodynamic force during short circuits. An overall skeleton is provided by a tie rod frame, and localized clamping force is provided by double-row / multi-point clamping nails on pressure seats I and II. Combined with slotted steel plate positioning and laminated wood cushioning, a highly reliable short-circuit resistance mechanical system is formed.

[0013] The above-mentioned technical problems of this utility model are mainly solved by the following technical solutions: A structure for improving the short-circuit capability of a three-dimensional wound core transformer includes several transformer windings arranged in a ring. The upper end of each transformer winding is provided with an upper clamping frame, and the lower end of each transformer winding is provided with a lower clamping frame. A pressure seat I is provided between two adjacent transformer windings and between the upper and lower clamping frames, respectively welded and fixed to the upper and lower clamping frames. A pull screw is used to lock the upper and lower pressure seats I together with a nut.

[0014] The pull screws on pressure seat I are tightened up and down to ensure the compression of the transformer body and to form the entire transformer body into a whole, thus ensuring the safe operation of the transformer.

[0015] Preferably, a pressure seat II is provided between two adjacent pressure seats I, which is welded and fixed to the upper clamping frame and the lower clamping frame.

[0016] Preferably, pressure plates are provided at both ends of the pressure seat I and between the transformer windings, and between the pressure seat II and the transformer windings. Pressure bolts that press against the pressure plates are provided on both the pressure seat I and the pressure seat II.

[0017] Preferably, both the pressure base II and the pressure plate are provided with steel plates that are slotted and inserted into the pressure plate. The circular hole of the pressure bolt on the pressure plate has a small force-bearing area. When the transformer is short-circuited, axial force will be generated, which can easily break and tear the pressure plate. By increasing the force-bearing area with steel plates, the short-circuit resistance of the pressure plate will be greatly improved, ensuring the safe operation of the transformer.

[0018] Preferably, the pressure plate material is laminated wood.

[0019] Preferably, the upper clamping frame is provided with a wire rack connected to the phase circuit of the transformer winding.

[0020] This invention can achieve the following effects: This invention provides a structure to improve the short-circuit capability of a three-dimensional wound core transformer. Compared with the prior art, by adding a welded and fixed pressure seat II between adjacent windings, forming a multi-point support frame with tie rods, and using pressure nail bolts for precise clamping, and especially by using slotted steel plates to prevent pressure plate displacement, the survivability and operational stability of the three-dimensional wound core transformer under short-circuit faults are significantly improved. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model.

[0022] In the diagram: 1. Wire rod frame; 2. Upper clamping frame; 3. Pressure seat I; 4. Pressure seat II; 5. Pressure bolt; 6. Steel plate; 7. Pressure plate; 8. Transformer winding; 9. Pull screw; 10. Lower clamping frame. Detailed Implementation

[0023] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0024] Example: Figure 1As shown, a structure for improving the short-circuit capability of a three-dimensional wound core transformer includes three transformer windings 8 arranged in a ring. An upper clamping frame 2 is provided at the upper end of each transformer winding 8, and a wire rack 1 connected to the transformer windings 8 is located above the upper clamping frame 2. A lower clamping frame 10 is provided at the lower end of each transformer winding 8. A pressure seat I3, welded and fixed to the upper clamping frame 2 and the lower clamping frame 10, is provided between each two adjacent transformer windings 8 and between the upper and lower clamping frames 2 and 10, respectively. A pull screw 9, secured with a nut, is used to lock the upper and lower pressure seats I3 together. A pressure seat II4, welded and fixed to the upper clamping frame 2 and the lower clamping frame 10, is provided between each two adjacent pressure seats I3. Pressure plates 7, made of laminated wood, are provided at both ends of pressure seats I3 and between pressure seats II4 and the transformer windings 8. Pressure bolts 5, which press against the pressure plates 7, are provided on both pressure seats I3 and pressure seats II4. Both the pressure base II4 and the pressure plate 7 are provided with steel plates 6 that are inserted into the pressure plate 7 in a slotted manner.

[0025] Multiple rigid supports: Pressure is applied not only at the tie rod position (pressure seat I), but also at the adjacent pressure seat II position. This means that the winding is subjected to multiple points of dense clamping force in the circumferential direction, which greatly improves its ability to resist short-circuit electrodynamic forces.

[0026] Anti-loosening design (slotted connection): A slotted steel plate 6 is specially designed between the pressure base II and the pressure plate. This solves the problem that the pressure plate, which is fixed by friction alone in traditional structures, is prone to displacement under short-circuit impact. The slotted structure provides mechanical restraint, ensuring that the pressure plate position does not shift during long-term operation and short-circuit vibration.

[0027] Balance between insulation and mechanical properties: Laminated wood is selected as the pressure plate 7, which not only meets the requirements of electrical insulation, but also has the necessary hardness to transmit the clamping force, avoiding eddy current loss or insulation damage that may be caused by using pure metal pressure plates.

[0028] In summary, this structure for improving the short-circuit capability of a three-dimensional wound core transformer, through the combination of tie rods (tension), pressure seats (support), pressure bolts (thrust / adjustment), and laminated wood boards (buffering / insulation), forms a robust cage-like structure. This effectively resists the enormous axial electrodynamic force generated during a short circuit, prevents transformer winding deformation, and improves the transformer's short-circuit withstand capability and operational reliability.

[0029] It will be apparent to those skilled in the art that this invention is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0030] In summary, the above description is only a specific embodiment of the present utility model, but the structural features of the present utility model are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present utility model are covered by the patent scope of the present utility model.

Claims

1. A structure for improving the short-circuit capability of a three-dimensional wound core transformer, characterized in that: The transformer includes several transformer windings (8) arranged in a ring. The upper end of the transformer winding (8) is provided with an upper clamping frame (2), and the lower end of the transformer winding (8) is provided with a lower clamping frame (10). Between two adjacent transformer windings (8) and between the upper clamping frame (2) and the lower clamping frame (10), there are pressure seats I (3) that are welded and fixed to the upper clamping frame (2) and the lower clamping frame (10) respectively. The upper and lower pressure seats I (3) are locked with a pull screw (9) by a nut.

2. The structure for improving the short-circuit capability of a three-dimensional wound core transformer according to claim 1, characterized in that: Between two adjacent pressure bases I (3), there is a pressure base II (4) that is welded and fixed to the upper clamping frame (2) and the lower clamping frame (10).

3. The structure for improving the short-circuit capability of a three-dimensional wound core transformer according to claim 2, characterized in that: Pressure plates (7) are provided between the two ends of the pressure seat I (3) and the transformer winding (8), and pressure plates (7) are provided between the pressure seat II (4) and the transformer winding (8). Pressure bolts (5) that press against the pressure plates (7) are provided on the pressure seat I (3) and the pressure seat II (4).

4. The structure for improving the short-circuit capability of a three-dimensional wound core transformer according to claim 3, characterized in that: The pressure base II (4) and the pressure plate (7) are both provided with a steel plate (6) that is inserted into the pressure plate (7) in a slot-like manner.

5. The structure for improving the short-circuit capability of a three-dimensional wound core transformer according to claim 3, characterized in that: The pressure plate (7) is made of laminated wood.

6. The structure for improving the short-circuit capability of a three-dimensional wound core transformer according to claim 1, characterized in that: The upper clamping frame (2) is provided with a wire rack (1) connected to the phase circuit of the transformer winding (8).

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