A transformer clamping piece

Abstract

The present invention discloses a transformer clamping piece, which relates to the technical field of transformer accessories and includes an upper clamping piece and a lower clamping piece. Both the upper clamping piece and the lower clamping piece include a clamping piece web and clamping piece limb plates fixedly connected to the clamping piece web. The clamping piece web includes a web vertical plate, and notches are formed at the side edges of the web vertical plates of the upper clamping piece and the lower clamping piece that are close to each other. The transformer clamping piece provided by the present invention has notches formed in the clamping piece web, which can reduce the leakage magnetic flux entering the clamping piece web and reduce the closed area of the circulating current induced by the leakage magnetic flux in the clamping piece web, thereby being able to reduce the loss generated by the transformer leakage magnetic flux on the clamping piece and prevent local overheating of the clamping piece; an electric shielding plate is arranged on the web, and by utilizing the high electrical conductivity of the electric shielding plate, the eddy current distribution on the clamping piece web is improved, and the loss generated by the transformer leakage magnetic flux on the clamping piece can be further reduced, and local overheating of the clamping piece can be prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of transformer accessories, and particularly to a transformer clamping piece. Background Art

[0002] For extra-high voltage and large-capacity power transformers, especially high-impedance transformers, since the clamping pieces are relatively close to the winding ends, a large amount of leakage magnetic flux passes through the clamping pieces and closes in the clamping pieces, causing eddy currents, resulting in an increase in clamping piece losses and local overheating. The existing methods for preventing clamping piece losses and local overheating mainly include: 1. Setting a clamping piece magnetic shield can effectively prevent the clamping piece losses from exceeding the standard and local overheating, but its design is difficult, the structure is complex, and there is a problem that it cannot be arranged when the magnetic shield interferes with the lead; 2. Carving multiple magnetic isolation grooves on the clamping piece web can play a certain role in reducing the clamping piece losses and temperature rise, but its processing is complex, the workload is large, and the effect of improving local overheating of the clamping piece is limited; 3. Using non-magnetic steel plates (20Mn23Al) for the clamping piece web material, through simulation calculation and experimental verification, when the clamping piece web exceeds a certain thickness, the hot spot temperature rise of the clamping piece using non-magnetic steel plates is even greater. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a transformer clamping piece with a simple structure that can effectively prevent the clamping piece losses from exceeding the standard and local overheating in view of the above-mentioned defects in the prior art.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A transformer clamping piece includes an upper clamping piece and a lower clamping piece. Both the upper clamping piece and the lower clamping piece include a clamping piece web and clamping piece limb plates fixedly connected to the clamping piece web. The clamping piece web includes a web vertical plate. Notches are provided at the side edges of the web vertical plates of the upper clamping piece and the lower clamping piece that are close to each other.

[0006] The existing commonly used transformer clamping pieces mainly include an upper clamping piece and a lower clamping piece. Both the upper clamping piece and the lower clamping piece include a clamping piece web and clamping piece limb plates fixedly connected to the clamping piece web. During use, the upper clamping piece and the lower clamping piece are respectively clamped at the winding ends to achieve clamping. Since the upper clamping piece and the lower clamping piece of the clamping piece are relatively close to the winding ends, a large amount of leakage magnetic flux passes through the clamping piece and closes in the clamping piece, causing eddy currents, resulting in an increase in clamping piece losses and local overheating. Furthermore, it may cause damage or damage to the winding, affecting the safe and reliable operation of the transformer, and further affecting the safety of the power grid.

[0007] The clamping parts of the transformer of the present invention include an upper clamping part and a lower clamping part. Both the upper clamping part and the lower clamping part include a clamping part web and clamping part limb plates fixedly connected to the clamping part web. The clamping part web includes a web vertical plate. Notches are provided at the side edges of the web vertical plates of the upper clamping part and the lower clamping part that are close to each other. By providing notches at the side edges of the web vertical plates of the clamping part web that are close to each other, and these notches are close to the coil position when the transformer clamping parts clamp, it can reduce the leakage magnetic flux entering the clamping part web, and reduce the closed area of the circulating current induced by the leakage magnetic flux in the clamping part web, which can reduce the loss generated by the transformer leakage magnetic flux on the clamping parts, prevent local overheating of the clamping parts, and the present invention only needs to provide notches at the side edges of the clamping part web, with a simple structure and easy processing, having the advantages of easy processing and easy use, and there is no problem that magnetic shielding and lead interference prevent layout.

[0008] In a preferred transformer clamping part, the notch is in the form of a long strip notch. The notch should have a certain size, but its height should not be too large, so the length can be appropriately lengthened to form a long strip notch form.

[0009] In a preferred transformer clamping part, the notch is in the form of a rectangular notch, or the two ends of the notch are inclined so that the notch is in the form of a trapezoidal notch with a larger outer part and a smaller inner part. The selection of the notch can be made according to the specific form, such as opening according to the installation and cooperation of specific devices inside the transformer and based on basic requirements such as convenient installation and avoiding interference, and only the notch needs to be in the form of a long strip notch.

[0010] In a preferred transformer clamping part, the notch is located exactly in the middle of the side edge of the web vertical plate, that is, the notch is opened in the middle of the side edge of the web vertical plate, which helps to maintain temperature balance in the transformer clamping parts, avoid temperature imbalance, and helps to maintain the overall structural strength of the upper clamping part and the lower clamping part of the transformer clamping parts to ensure clamping strength, stability and firmness.

[0011] In a preferred transformer clamping part, an electric shielding plate is provided on the side surface of the web vertical plate close to the coil. By providing an electric shielding plate on the web, using the high electrical conductivity of the electric shielding plate, the eddy current distribution on the clamping part web is improved, thereby reducing the loss generated by the transformer leakage magnetic flux on the transformer clamping parts and preventing local overheating of the transformer clamping parts. The leakage magnetic flux on the transformer clamping parts is mainly concentrated on the side facing the coil. During use, the clamping part limb plates clamp the coil. Therefore, the electric shielding plate only needs to cover the side facing the coil, that is, the electric shielding plate is provided on the side surface of the web vertical plate on the side close to the clamping part limb plates, and using the high electrical conductivity of the electric shielding plate, the eddy current distribution on the clamping part web is improved.

[0012] In a preferred transformer clamping piece, the electric shielding plate is an L-shaped plate and covers the bottom of the notch. The electric shielding plate in the shape of an L-shaped plate not only helps to cover the bottom of the notch to achieve a greater coverage, but also helps the electric shielding plate to be stably installed on the web of the clamping piece.

[0013] In a preferred transformer clamping piece, the material of the electric shielding plate is copper or copper alloy. The electric shielding plate made of copper or copper alloy has a high electrical conductivity, which can help to improve the eddy current distribution on the web of the clamping piece, thereby reducing the losses generated by the leakage magnetic flux of the transformer on the transformer clamping piece and preventing local overheating of the transformer clamping piece.

[0014] In a preferred transformer clamping piece, the height of the notch is 1 / 5 to 1 / 4 of the height of the vertical plate of the web, the thickness of the electric shielding plate is 4 to 6 mm, and the covering height is 50 to 150 mm. Combining the structural design of the transformer and the simulation calculations of the magnetic field, temperature field, and mechanical field, with the hot spot temperature rise of the web of the clamping piece meeting the protocol requirements and the mechanical strength of the web of the clamping piece meeting the requirements of the mechanical parameters of the material as boundary conditions, the width, height, etc. of the notch are determined. Mainly, the height of the notch is determined, and the height of the notch is generally 1 / 5 to 1 / 4 of the total height of the web. Combining the structural design of the transformer and the simulation calculations of the magnetic field and temperature field, with the hot spot temperature rises of the web of the clamping piece and the electric shielding plate meeting the protocol requirements as boundary conditions, the size of the electric shielding plate is determined. The thickness of the electric shielding plate is generally 4 to 6 mm, and the covering height is generally 50 to 150 mm.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The transformer clamping piece provided by the present invention has a notch on the web of the clamping piece, which can reduce the leakage magnetic flux entering the web of the clamping piece and reduce the closed area of the circulating current induced by the leakage magnetic flux in the web of the clamping piece, thereby reducing the losses generated by the leakage magnetic flux of the transformer on the clamping piece and preventing local overheating of the clamping piece; an electric shielding plate is arranged on the web, and by using the high electrical conductivity of the electric shielding plate, the eddy current distribution on the web of the clamping piece is improved, and the losses generated by the leakage magnetic flux of the transformer on the clamping piece can be further reduced, preventing local overheating of the clamping piece. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the description of the embodiments.

[0017] Figure 1 It is a schematic structural diagram of a preferred embodiment of the present invention;

[0018] Figure 2 It is a schematic structural diagram of the electric shielding plate installed on the vertical plate of the web in the preferred embodiment of the present invention;

[0019] Figure 3 It is a schematic structural diagram of the vertical plate of the web in the preferred embodiment of the present invention;

[0020] Figure 4 This is a schematic structural diagram of the electric shielding plate in a preferred embodiment of the present invention.

[0021] Among them, the marks shown in the figure are: 10 - upper clamp; 20 - lower clamp; 30 - clamp web; 31 - web cross plate; 32 - web vertical plate; 40 - clamp limb plate; 50 - notch; 60 - electric shielding plate. Detailed implementation manners

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0023] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "middle", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0024] In the present application, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0025] In the present application, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under" and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0026] Please refer to Figures 1 to 4 , a preferred embodiment of the present invention provides a transformer clamping piece, including an upper clamping piece 10 and a lower clamping piece 20. Both the upper clamping piece 10 and the lower clamping piece 20 include a clamping piece web 30 and a clamping piece limb plate 40 fixedly connected to the clamping piece web 30. When using the transformer clamping piece, the upper clamping piece 10 and the lower clamping piece 20 are respectively clamped at the upper and lower ends of the winding to achieve clamping. It can be understood that the clamping of the transformer winding can be achieved through a set of upper clamping piece 10 and lower clamping piece 20. However, in actual use, for large transformers, multiple sets of upper clamping piece 10 and lower clamping piece 20 are used to achieve the clamping of the transformer winding, that is, multiple sets of transformer clamping pieces are used to achieve the clamping of the transformer winding. The upper clamping piece 10 and the lower clamping piece 20 in multiple sets of transformer clamping pieces can be directly connected and fixed or connected and fixed through some external components to maintain the stability between the upper clamping piece 10 and the lower clamping piece 20 in multiple sets of transformer clamping pieces and maintain the clamping effect. The clamping piece web 30 includes a web transverse plate 31 and a web vertical plate 32 vertically fixedly connected to the web transverse plate 31. At this time, the web transverse plate 31 and the web vertical plate 32 integrally form an L-shaped plate structure. The web transverse plate 31 and the web vertical plate 32 can be integrally formed or fixed by welding or other means. The clamping piece limb plate 40 is installed on the clamping piece web 30, with the end fixedly connected to the web vertical plate 32 and the side fixedly connected to the web transverse plate 31. During implementation, like the existing transformer clamping pieces, the clamping piece web 30 clamps the iron core part, and the clamping piece limb plate 40 clamps the coil part. The clamping piece limb plate 40 is fixed to the clamping piece web 30 by welding. The clamping piece web 30 is made of ordinary steel plate Q235 or high-strength steel plate Q345 according to the mechanical strength requirements, and the clamping piece limb plate 40 is made of low-magnetic steel. During implementation, the web vertical plate 32 is vertically arranged, while the web transverse plate 31 and the clamping piece limb plate 40 are horizontally arranged. At this time, the web transverse plates 31 of the upper clamping piece 10 and the lower clamping piece 20 are respectively located on the side far from each other of the web transverse plate 31, and there are multiple notches on the web transverse plate 31 of the upper clamping piece 10 to facilitate the cooperation of the web transverse plate 31 on the upper clamping piece 10 with other components and avoid interference. Notches 50 are provided at the side edges of the web vertical plates 32 of the upper clamping piece 10 and the lower clamping piece 20 close to each other. The notch 50 is in the form of a long strip-shaped notch opened at the side edge of the web vertical plate 32.

[0027] During implementation, the winding is clamped by the upper clamping member 10 and the lower clamping member 20. By opening notches 50 at the side edges close to each other on the web vertical plate 32 of the clamping member web 30, these notches 50 are close to the coil position when the transformer clamping member clamps, which can reduce the leakage magnetic flux entering the clamping member web 30 and reduce the closed area of the circulating current induced by the leakage magnetic flux in the clamping member web 30. It can reduce the losses generated by the transformer leakage magnetic flux on the clamping member, prevent local overheating of the clamping member; and only need to open notches at the side edges of the web vertical plate 32, with a simple structure and easy processing, having the advantages of easy processing and easy use, and there is no problem that magnetic shielding and leads interfere with each other and cannot be arranged.

[0028] The notch 50 is mainly in the form of a long strip-shaped notch, which can be in the form of a rectangular notch, or the two ends of the notch 50 are inclined so that the notch 50 is in the form of a trapezoidal notch with a larger outer side and a smaller inner side. Of course, it can also be in other forms. In this preferred embodiment, the two ends of the notch 50 are inclined so that the notch 50 is in the form of a trapezoidal notch with a larger outer side and a smaller inner side, and the transition at the upper end of the trapezoidal notch is gentle.

[0029] The notch 50 is located exactly in the middle of the side of the web vertical plate 32, that is, the notch 50 is opened in the middle of the side of the web vertical plate 32, which helps to maintain temperature balance in the transformer clamping member, avoid temperature imbalance, and helps to maintain the overall structural strength of the upper clamping member 10 and the lower clamping member 20 of the transformer clamping member to ensure the clamping strength, stability and firmness.

[0030] In the preferred embodiment, an electric shielding plate 60 is provided on the side of the web vertical plate 32 facing the coil. By providing the electric shielding plate 60 on the web vertical plate 32, using the high electrical conductivity of the electric shielding plate 60, the eddy current distribution on the clamping member web 30 is improved, thereby reducing the losses generated by the transformer leakage magnetic flux on the transformer clamping member and preventing local overheating of the transformer clamping member. The leakage magnetic flux on the transformer clamping member is mainly concentrated on the side facing the coil. During use, the clamping member limb plate 40 clamps the coil. Therefore, the electric shielding plate 60 only needs to cover the side facing the coil. At this time, the electric shielding plate 60 is provided on the side of the web vertical plate 32 close to the clamping member limb plate 40. Using the high electrical conductivity of the electric shielding plate 60, the eddy current distribution on the clamping member web 30 is improved to reduce the losses generated by the transformer leakage magnetic flux on the transformer clamping member and prevent local overheating of the transformer clamping member. The material of the electric shielding plate 60 is copper or copper alloy, preferably pure copper material, to improve the eddy current distribution on the clamping member web 30 through the electric shielding plate 60 with high electrical conductivity. Of course, the electric shielding plate 60 can also use other metals or alloys with high electrical conductivity. The electric shielding plate 60 is fixed on the side of the web vertical plate 32 by welding and keeps close contact with the side of the web vertical plate 32. The electric shielding plate 60 is an L-shaped plate and covers the bottom of the notch 50, that is, the electric shielding plate 60 in the form of an L-shaped plate has a horizontal part, and this part covers the bottom of the notch 50.

[0031] Combined with the structural design of the transformer and the simulation calculations of the magnetic field, temperature field, and mechanical field, with the hot-spot temperature rise of the clamping plate web meeting the protocol requirements and the mechanical strength of the clamping plate web meeting the requirements of the material mechanical parameters as boundary conditions, determine the width, height, etc. of the notch 50, mainly to determine the height of the notch 50. The height of the notch 50 is generally 1 / 5 to 1 / 4 of the total height of the web, and the opening length of the notch 50 is 2 / 5 to 3 / 5 of the length of the web. Combined with the structural design of the transformer and the simulation calculations of the magnetic field and temperature field, with the hot-spot temperature rises of the clamping plate web 30 and the electrical shielding plate 60 meeting the protocol requirements as boundary conditions, determine the size of the electrical shielding plate 60. According to the dimensions of the existing transformer, the thickness of the electrical shielding plate 60 is generally 4 to 6 mm, and the covering height is generally 50 to 150 mm. The sizes of the notch 50 and the electrical shielding plate 60 need to be determined according to specific circumstances, but within a suitable and reasonable size range, they can all reduce the magnetic leakage flux entering the clamping plate web 30, reduce the closed area of the circulating current induced by the magnetic leakage flux in the clamping plate web 30, and utilize the high electrical conductivity of the electrical shielding plate 60 to improve the eddy current distribution on the clamping plate web 30, thereby being able to reduce the losses generated by the magnetic leakage flux of the transformer on the clamping plate and prevent local overheating of the clamping plate.

[0032] For the transformer clamping plate provided by the present invention, a notch 50 is opened on the clamping plate web 30, which can reduce the magnetic leakage flux entering the clamping plate web 30 and reduce the closed area of the circulating current induced by the magnetic leakage flux in the clamping plate web 30, thereby being able to reduce the losses generated by the magnetic leakage flux of the transformer on the clamping plate and prevent local overheating of the clamping plate; an electrical shielding plate 60 is provided on the web, and by utilizing the high electrical conductivity of the electrical shielding plate 60, the eddy current distribution on the clamping plate web 30 is improved, and the losses generated by the magnetic leakage flux of the transformer on the clamping plate can be further reduced, preventing local overheating of the clamping plate.

[0033] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claimed rights.

Claims

1. A transformer clamping piece, comprising an upper clamping piece (10) and a lower clamping piece (20), wherein both the upper clamping piece (10) and the lower clamping piece (20) include a clamping piece web (30) and clamping piece limb plates (40) fixedly connected to the clamping piece web (30), and is characterized in that: The clamping part web (30) includes a web vertical plate (32). Notches (50) are formed at the side edges of the web vertical plates (32) of the upper clamping part (10) and the lower clamping part (20) that are close to each other, and the notches (50) are located exactly in the middle of the side edges of the web vertical plates (32). The notches (50) are in the form of long-strip notches, including that the notches (50) are in the form of rectangular notches, or the two ends of the notches (50) are inclined so that the notches (50) are in the form of trapezoidal notches with a larger outer side and a smaller inner side; the notches (50) are in the form of a whole-piece notch, and the opening length of the notches (50) is 2 / 5 to 3 / 5 of the length of the clamping part web (30). An electric shielding plate (60) is arranged on the side surface of the web vertical plate (32) close to the coil. The electric shielding plate (60) is an L-shaped plate and covers the bottom of the notch (50).

2. The transformer clamping part according to claim 1, characterized in that: The material of the electric shielding plate (60) is copper or copper alloy.

3. The transformer clamping part according to claim 1, characterized in that: The height of the notch (50) is 1 / 5 to 1 / 4 of the height of the web vertical plate (32).

4. The transformer clamping part according to claim 1, wherein: The thickness of the electric shielding plate (60) is 4 to 6 mm, and the covering height is 50 to 150 mm.

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