Transformer clamp composite support plate, assembly structure and application

Abstract

The invention relates to the field of transformer equipment structures, in particular to a transformer clamp composite support plate, an assembly structure and application, the composite support plate is formed by compositing a non-magnetic steel plate and a red copper plate, a non-magnetic steel and copper composite structure is adopted, stray loss can be remarkably reduced through complementation of electromagnetic performance of materials, and the reliability of the transformer clamp is improved. The overheating risk in the operation of the transformer is reduced, and a guarantee is provided for stable operation of the transformer. While the mechanical strength is guaranteed, the electromagnetic performance of the transformer is cooperatively optimized, and the method is an important technical means for high performance of the transformer.

Description

Technical Field

[0001] The present invention relates to the field of transformer equipment structures, and in particular to a transformer clamp composite support plate, an assembly structure and applications. Background Art

[0002] The stray losses of transformers are mainly distributed in metal structural parts such as oil tanks, clamps, and pull plates. If no leakage magnetic field prevention measures are taken, in areas with strong leakage magnetic fields and large-sized components, the leakage magnetic field will induce eddy currents in metal parts such as oil tanks and clamps, causing heat and additional losses. Under the action of the alternating magnetic field, the copper shield will generate reverse induced currents, forming a reverse magnetic field, thereby offsetting part of the leakage magnetic field, reducing its magnetic flux entering the structural parts, and reducing eddy currents in the metal structural parts. In parts where eddy current losses are too concentrated or in areas with poor heat dissipation conditions, there is a risk of causing serious local overheating, which seriously endangers the reliability of the safe operation of the transformer. For example, CN218513298U discloses a new magnetic shielding structure for the transformer body, which reasonably controls leakage magnetic field by arranging magnetic shielding.

[0003] CN221994269U discloses a novel transformer clamp comprising two support plates, each with several ventilation holes formed in its inner wall. The outer wall of a dust screen is fixed to the inner wall of a ring plate, securing the ring plate to the outer surface of the support plates. This prevents debris from the outside air from entering the inner wall of the ventilation holes and blocking the heat generated by the transformer core during operation. This facilitates faster heat dissipation from the core, which is fixed to the inner wall of the support plates, to the outside air. The cross plate is aligned with the inner wall of the recessed hole, and a retaining post passes through the inner wall of the cross plate and aligns with the inner wall of a circular groove formed on one side of the fixed plate. This strengthens the connection between the two support plates. The spring's rebound force pulls the rubber plate to securely attach to the external connecting bracket, effectively improving the stability of the connection between the transformer clamp and the transformer. The document describes the details of the clamp's support plate mounting and how to dissipate heat, but does not mention optimizing the material of the clamp's support plates, which directly affects the mechanical strength, corrosion resistance, thermal conductivity, and long-term operational reliability of the clamp.

[0004] Autotransformers have technical characteristics such as small structural capacity and stringent load loss requirements. Due to the limited core diameter and large radial coil dimensions, the main air path magnetic flux density is high, resulting in an extremely complex leakage magnetic field distribution. Large amounts of leakage flux intrude into structural components, causing local overheating and making it difficult to control stray losses. To reduce transformer stray losses and alleviate local overheating, electromagnetic shielding has been widely used in transformer design. To address overheating of clamps, the clamp magnetic shield is often placed within the clamp support plate. Existing clamp supports are often made of carbon steel (such as Q355). Conventional clamp supports and clamp magnetic shields using non-magnetic steel (such as 20Mn23AlV) are not as effective as expected in controlling losses and temperature rise. Internal transformer overheating can lead to thermal aging of the insulation material and abnormal oil chromatography, affecting the reliability and lifespan of the transformer. Furthermore, losses do not meet the requirements of the product technical agreement. Summary of the Invention

[0005] In response to the problems in the prior art of transformer overheating caused by leakage magnetic fields of clamps and support plates and excessive stray losses of transformers, the present invention provides a transformer clamp composite support plate, assembly structure and application, which realizes precise control of leakage magnetic fields through a special shielding structure.

[0006] The present invention is achieved through the following technical solutions: A transformer clamp composite support plate, the composite support plate is composed of a non-magnetic steel plate and a copper plate; The copper plate is U-shaped, and the non-magnetic steel plate fits the inner shape of the U-shaped plate formed by the copper plate; Alternatively, the copper plate is U-shaped, and the periphery of the non-magnetic steel plate fits the shape of the copper plate.

[0007] Preferably, the copper plate is formed by bending a long strip.

[0008] Preferably, the upper and lower ends of the copper plate and the bending transition are rounded, and the inner surface is chamfered.

[0009] Preferably, the non-magnetic steel plate and the copper plate are welded together using copper welding wire as solder.

[0010] Preferably, the welding surface of the non-magnetic steel plate is beveled.

[0011] Preferably, the non-magnetic steel plate is provided with openings corresponding to the magnetic shielding holes of the clamps. An assembly structure includes a clamp web, a clamp magnetic shield, silicon steel sheets, and the transformer clamp composite support plate. The transformer clamp composite support plate and the silicon steel sheets are stacked into a whole through epoxy resin to form a clamp box. The transformer clamp composite support plate is welded to the clamp web, the clamp magnetic shield is placed in the clamp box, and the clamp magnetic shield and the clamp composite support plate are fixed using insulating screws and nuts.

[0012] An application of the transformer clamp composite support plate in an autotransformer.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The transformer clamp composite support plate of the present invention adopts a composite structure of non-magnetic steel and copper. Through the complementarity of the electromagnetic properties of the materials, it can significantly reduce stray losses and reduce the risk of overheating during transformer operation, providing protection for the smooth operation of the transformer. While ensuring mechanical strength, it synergistically optimizes the electromagnetic performance of the transformer, which is an important technical means for improving the high performance of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of the transformer clamp composite support plate in Example 1 of the present invention; Figure 2 Schematic diagram of a transformer clamp composite support plate in Example 2 of the present invention; Figure 3 This is a schematic diagram of the assembly of the clamp composite support plate of the present invention; Figure 4 This is a schematic diagram of the assembly of the clamp composite support plate during simulation of Example 1 of the present invention; Figure 5 This is a schematic diagram of the assembly of the clamp composite support plate during simulation of Example 2 of the present invention; Figure 6 This is the temperature distribution cloud diagram of the conventional clamp support plate; Figure 7 This is a temperature distribution cloud diagram of the composite support plate of the transformer clamp of the present invention.

[0015] In the figure, 1. Copper plate; 2. Non-magnetic steel plate; 3. Clamp composite support plate; 4. Clamp magnetic shield; 5. Clamp web. DETAILED DESCRIPTION

[0016] The present invention will be further described in detail below with reference to specific embodiments, which are intended to explain the present invention rather than to limit it.

[0017] In view of the fact that the core diameter is limited and the radial size of the coil is large during the design of the autotransformer, the magnetic density of the main air channel increases, resulting in an extremely complex distribution of the leakage magnetic field. A large amount of leakage magnetic flux invades the structural parts, causing local overheating, and making it difficult to control the stray loss. The conventional use of non-magnetic steel plates 2 (such as 20Mn23AlV) clamps, support plates and clamp magnetic shields 4 to control losses and temperature rise cannot achieve the expected effect. There are problems such as overheating inside the transformer leading to thermal aging of the insulation material and abnormal oil chromatography. A new leakage magnetic control structure is invented. Through a special shielding structure, precise control of the leakage magnetic field is achieved to solve the problems of overheating of the clamps and support plates and excessive stray loss of the transformer.

[0018] Example 1 The present invention discloses a transformer clamp composite support plate, referring to Figure 1 The composite support plate is composed of a non-magnetic steel plate 2 and a copper plate 1. The non-magnetic steel plate 2 and the copper plate 1 are welded together using copper welding wire as solder and polished smooth after welding. The welding surface of the non-magnetic steel plate 2 is beveled 5mm to facilitate welding.

[0019] The non-magnetic steel plate 2 is made of 20Mn23AlV; the copper plate 1 is bent into a U-shape from a long strip, and the upper and lower ends of the copper plate 1 and the bending transition are all rounded. The rounded corners are considered to be prone to discharge and breakdown at metal corners under the influence of the electric field, and a chamfer C1 is set on the inner surface.

[0020] The non-magnetic steel plate 2 and the copper plate 1 are bonded together in the U-shaped interior.

[0021] The non-magnetic steel plate 2 is provided with openings corresponding to the hole positions of the clamp magnetic shield 4 , and the number and spacing of the holes can be adjusted according to the width, length and other characteristics of the clamp magnetic shield 4 .

[0022] Example 2 Reference Figure 2 The present invention discloses a composite support plate for transformer clamps. The composite support plate is composed of a non-magnetic steel plate 2 and a copper plate 1. The non-magnetic steel plate 2 and the copper plate 1 are welded together using copper welding wire as solder and polished smooth after welding. The weld surface of the non-magnetic steel plate 2 has a 5mm chamfer to facilitate welding.

[0023] The non-magnetic steel plate 2 is made of 20Mn23AlV; the copper plate 1 is bent into a U-shape from a long strip, and the upper and lower ends of the copper plate 1 and the bending transition are all rounded. The rounded corners are considered to be prone to discharge and breakdown at metal corners under the influence of the electric field, and a chamfer C1 is set on the inner surface.

[0024] The present invention discloses a transformer clamp composite support plate using a composite structure of non-magnetic steel and copper. Through the complementary electromagnetic properties of the materials, the non-magnetic steel plate 2 has an extremely low magnetic permeability, close to that of air, and its loss and temperature rise are significantly lower than those of carbon steel in the same magnetic leakage environment, which can effectively reduce the loss and temperature rise of the structural parts; the non-magnetic steel plate 2 is in shape with the copper plate 1, which can ensure the mechanical strength of the clamp support plate on the one hand, and can also be used to place a magnetic shield inside.

[0025] The invention also discloses an application of a transformer clamp composite support plate in an autotransformer.

[0026] The transformer clamp composite support plate in Example 1 was tested and simulated.

[0027] Reference Figure 3Assemble the composite support plate 3: Epoxy resin is applied to the silicon steel sheets, stacking them into the composite support plate 3 to form a single unit. The composite support plate 3 is then placed horizontally and welded to the web 5. The magnetic shield 4 is placed inside the clamp box and secured to the composite support plate 3 using insulated screws and nuts. The magnetic shield 4 protects the composite support plate 3 and web 5, controlling the temperature rise caused by magnetic flux leakage.

[0028] The leakage magnetic field will induce eddy currents in metal parts such as fuel tanks and clamps, causing heat and additional losses. Under the action of the alternating magnetic field, the copper shield will generate reverse induced currents and form reverse magnetic fields, thereby offsetting part of the leakage magnetic field, reducing the magnetic flux entering the structural parts, and reducing the eddy currents in the metal structural parts.

[0029] Through three-dimensional magnetic thermal coupling simulation (such as Figure 4 、 5 ), reasonably control the transformer leakage flux, and intuitively reflect the heating phenomenon of the leakage flux in the structural parts, to prevent the overheating problem of the structural parts caused by the leakage flux. Figure 6 ) Compared with conventional non-magnetic steel plate 2 (such as 20Mn23AlV) structure (such as Figure 7 ) is reduced by about 10K.

[0030] The transformer clamp composite support plate disclosed in this invention reduces temperature rise and stray losses. Its composite structure of non-magnetic steel and copper significantly reduces stray losses and the risk of overheating during transformer operation by leveraging the complementary electromagnetic properties of the materials, ensuring stable operation. While ensuring mechanical strength, it also synergistically optimizes the transformer's electromagnetic performance, making it a key technical approach to achieving high transformer performance.

[0031] The above description is merely a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and replacements, and these modifications and replacements are also within the scope of protection covered by the claims.

Claims

1. A transformer clip composite support plate, characterized in that: The composite support plate is composed of a non-magnetic steel plate (2) and a copper plate (1); The copper plate (1) is U-shaped, and the non-magnetic steel plate (2) fits the inner shape of the U-shaped plate formed by the copper plate (1); Alternatively, the copper plate (1) is U-shaped, and the periphery of the non-magnetic steel plate (2) is in close contact with the copper plate (1).

2. The transformer clamp composite support plate according to claim 1, characterized in that: The copper plate (1) is formed by bending a long strip.

3. The transformer clamp composite support plate according to claim 1, characterized in that: The upper and lower ends of the copper plate (1) and the bending transition are all rounded, and the inner surface is provided with a chamfer.

4. The transformer clamp composite support plate according to claim 1, characterized in that: The non-magnetic steel plate (2) and the red copper plate (1) are welded together using copper welding wire as solder.

5. The transformer clamp composite support plate according to claim 4, characterized in that: The welding surface of the non-magnetic steel plate (2) is beveled.

6. The transformer clamp composite support plate according to claim 1, characterized in that: The non-magnetic steel plate (2) is provided with an opening corresponding to the hole position of the magnetic shielding (4) of the clamp.

7. An assembly structure, characterized in that: The invention comprises a clamp web (5), a clamp magnetic shield (4), a silicon steel sheet and a transformer clamp composite support plate (3) as described in any one of claims 1 to 6, wherein the transformer clamp composite support plate (3) and the silicon steel sheet are stacked into a whole by epoxy resin to form a clamp box; the transformer clamp composite support plate (3) and the clamp web (5) are welded, the clamp magnetic shield (4) is placed in the clamp box, and the clamp magnetic shield (4) and the clamp composite support plate (3) are fixed by using insulating screws and nuts.

8. Use of the transformer clamp composite support plate according to any one of claims 1 to 6 in an autotransformer.

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