Transformer coil mounting structure and manufacturing method thereof

Abstract

The invention discloses a transformer coil installation structure and a manufacturing method thereof, and relates to the technical field of transformer manufacturing, the transformer coil installation structure comprises an iron core column, the iron core column is sleeved with a coil, outer supporting strips are fixedly installed on the two sides of the iron core column, and the outer supporting strips are fixedly connected with the coil; the outer supporting strip is used for clamping an iron core column and radially tensioning a coil, a pressing plate is relatively fixed below the coil, a bottom plate is fixedly mounted at the bottom of the pressing plate, and the pressing plate, the bottom plate and the outer supporting strip are matched to form a three-dimensional constraint structure for supporting the coil. According to the transformer coil mounting structure, the pressing plate, the bottom plate and the outer supporting strips jointly form a more perfect frame of a three-dimensional constraint structure, the mechanical stability of the coil when bearing sudden short-circuit current can be remarkably improved, the bottom of the coil is fundamentally prevented from moving downwards through rigid jacking force provided by the outer supporting strips, and the coil mounting structure is more stable. The insulation distance change between turns and cakes caused by drooping of the coil is effectively prevented, and the service life of the transformer is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transformer manufacturing, in particular to a transformer coil mounting structure and a manufacturing method thereof. BACKGROUND

[0002] As the core equipment of power system, the reliability of transformer during long-term operation is crucial. During operation, the transformer coil (winding) will continuously bear the electric force, including the sudden huge stress during short circuit, electromagnetic vibration and the action of its own gravity. Under the combined influence of these forces, the coil is prone to deformation, collapse or sag, which may further cause a series of serious consequences. Coil failure may result in insulation damage, deteriorated heat dissipation, decreased electrical performance and lost mechanical strength.

[0003] To solve the above problems, insulation stay and some coil fixing members such as pressure plate, clamp and band are commonly used in existing transformer manufacturing. The stay is used to establish support points between the coil and the core column inside the coil, form a cooling channel and bear the radial force, and the fixing member is used to press and fix the coil from the axial and lateral directions to prevent its loosening and deformation. However, this method may cause lack of rigid support at the bottom of the coil and still cause stress concentration, and it is still difficult to solve the problem of sagging and deformation of the coil. SUMMARY

[0004] The present application provides a transformer coil mounting structure and a manufacturing method thereof, which can solve the problem of coil sagging and deformation in the prior art.

[0005] A transformer coil mounting structure, comprising: a core column, the core column being sleeved with a coil; An outer stay is fixedly installed on both sides of the core column, and the outer stay is fixedly connected with the coil, and the outer stay is used to clamp the core column and radially tension the coil; A pressure plate is fixedly arranged below the coil, and a bottom plate is fixedly installed at the bottom of the pressure plate, and the pressure plate, the bottom plate and the outer stay cooperate to form a three-dimensional constraint structure for supporting the coil.

[0006] The transformer coil mounting structure provided by the present application has the following beneficial effects, but is not limited to the following: The transformer coil mounting structure establishes a solid bearing system from bottom to top for the coil by driving the outer stay on both sides of the core column, directly resisting the sagging tendency of the coil and achieving uniform support. The outer stay uniformly transmits the upward force to the bottom of the coil and stably disperses the reaction force to the pressure plate and the bottom plate.

[0007] Through the cooperation of the pressing plate, the bottom plate and the outer support bar to form a more perfect three-dimensional constraint structure frame, the mechanical stability of the coil under the sudden short-circuit current can be significantly improved, and the rigid jacking force provided by the outer support bar fundamentally prevents the downward displacement of the bottom of the coil, effectively prevents the change of the turn-to-turn and cake-to-cake insulation distance caused by the sag of the coil, and prolongs the service life of the transformer.

[0008] Further, the outer support bar comprises a horizontal plate and a vertical plate, the horizontal plate and the vertical plate are fixedly connected, the horizontal plate disperses the pressure in the form of surface contact, and the vertical plate is used for transmitting the pressure downward.

[0009] Further, the outer support bar is an I-shaped steel, the horizontal plate is an upper flange plate and a lower flange plate of the I-shaped steel, and the vertical plate is a web plate of the I-shaped steel.

[0010] Further, the outer support bar is a support member formed by welding at least two I-shaped steels.

[0011] Further, the outer support bar is a rectangular hollow steel pipe, the horizontal plate is a top plate and a bottom plate of the rectangular hollow steel pipe, and the vertical plate is a side plate of the rectangular hollow steel pipe.

[0012] Further, the core column parts located at the top and the bottom of the coil are covered with an iron yoke.

[0013] Further, the iron yoke is fixedly installed with a mounting plate.

[0014] Further, the mounting plate is fixedly installed with an aluminum row.

[0015] Further, the mounting plate is fixedly provided with an epoxy plate through bolts.

[0016] A manufacturing method of a transformer coil mounting structure, the method is applied to the transformer coil mounting structure as described above, and comprises the following steps: S1, a wound coil is sleeved on a core column, so that the coil and the core column are coaxially arranged; S2, an outer support bar is punched on both sides of the core column, so that the outer support bar is tightly attached to the coil and the core column, the radial positioning of the coil is realized and there is no looseness; S3, the outer support bar is uniformly arranged on the top of the pressing plate at a predetermined interval, the pressing plate is welded to the bottom plate through argon arc welding, and it is ensured that the welding points are firm and there is no virtual welding; S4, other structures above the coil are assembled; S5, the overall structure is subjected to paint immersion treatment, so that the insulation layer uniformly covers the surfaces of the components.

[0017] Since the technical improvement and beneficial effects of the method are at least the same as those of the transformer coil mounting structure, the method will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Structure diagram of a transformer coil mounting structure according to an embodiment of the present application; Figure 2 Structure diagram of a support according to an embodiment of the present application; Figure 3 Structure diagram of a support according to an embodiment of the present application; Figure 4 Structure diagram of a support according to an embodiment of the present application; Figure 5 Flow chart of a manufacturing method of a transformer coil mounting structure according to an embodiment of the present application.

[0019] BRIEF DESCRIPTION OF DRAWINGS 1. coil; 2. iron yoke; 3. pressing plate; 4. bottom plate; 5. epoxy plate; 6. outer support; 61. horizontal plate; 62. vertical plate; 7. aluminum bar; 8. mounting plate. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings which show the embodiments according to the present application. It should be understood that the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments described in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort shall fall within the scope of protection of the present application.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification herein is for describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, all terms used in disclosing the application, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms used in the description of the present application are used for illustrative purposes only and are not intended to limit the scope of the application. The terms "comprise", "comprising", "include", "including", "have" and "having" are used in the specification to mean "including but not limited to".

[0022] In the description of the application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "back", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the application and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the application.

[0023] In the description of the application, it should be noted that unless otherwise specified and limited, the terms "mounting", "connecting", "connecting", "attaching" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication between the two elements inside. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0024] It should be emphasized that when the term "comprise / contain" is used in this specification, it is used to explicitly indicate the presence of the features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps, components or groups of features, integers, steps, components.

[0025] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0026] During operation, transformer coils are highly susceptible to deformation, collapse, or sagging under the combined influence of various forces, leading to a series of serious consequences. Coil failures can result in insulation damage, deteriorated heat dissipation, decreased electrical performance, and loss of mechanical strength. Insulation damage: Changes in the insulation distance between conductors can easily lead to partial discharge, insulation wear, and ultimately short-circuit faults. Deteriorated heat dissipation: For dry-type transformers, coil deformation can cause localized overheating, accelerating the aging of insulation materials. Deteriorated electrical performance: Changes in coil shape affect electromagnetic parameters such as inductance and leakage reactance, causing transformer performance to deviate from design values. Loss of mechanical strength: The mechanical strength of a deformed coil is further reduced, posing a risk of complete failure during subsequent operation, especially when subjected to short-circuit currents.

[0027] To mitigate this phenomenon, those skilled in the art typically employ insulating support strips in conjunction with coil fixing components such as pressure plates, clamps, and straps to secure the coil by binding or clamping. Due to the lack of rigid support at the bottom of the coil, it sags and deforms. Binding or clamping relies on the coil's own strength and the support of internal pads, but a suspended area often exists between the bottom of the coil and the fittings. Under long-term gravity and sudden short-circuit electrodynamic forces (which can reach many times or even tens of times the rated value), the conductors at the bottom of the coil will slowly but continuously undergo plastic deformation, ultimately leading to overall sinking and changes in the inter-turn insulation distance.

[0028] Moreover, the binding or local clamping method can create a tightening effect, causing excessive local stress on the coil, squeezing and damaging the wire insulation layer, and creating new weak points in the insulation.

[0029] Furthermore, adjusting the position of the internal pads of the coil and ensuring consistent tension in all straps during manufacturing or maintenance is a time-consuming and labor-intensive task. Deviations during installation can lead to support system failure, creating potential problems with the coil even before it is put into operation.

[0030] like Figure 1 As shown in the figure, an embodiment of the present invention provides a transformer coil installation structure, including: an iron core column, on which a coil 1 is sleeved.

[0031] External support bars 6 are fixedly installed on both sides of the iron core column, and the external support bars 6 are fixedly connected to the coil 1. The external support bars 6 are used to clamp the iron core column and to radially tension the coil 1.

[0032] A pressing plate 3 is fixed below the coil 1, and a bottom plate 4 is fixedly installed at the bottom of the pressing plate 3. The pressing plate 3, the bottom plate 4 and the outer support strip 6 cooperate to form a three-dimensional constraint structure for supporting the coil 1.

[0033] In this embodiment, the outer support strip 6 is punched on both sides of the core column to establish a top-down and firm bearing system for the coil 1, directly resist the tendency of sagging and achieve uniform support. The outer support strip 6 transmits the jacking force to the bottom of the coil 1 in a large area and uniformly, and stably disperses the reaction force to the pressing plate 3 and the bottom plate 4. By forming a more perfect three-dimensional constraint structure frame through the pressing plate 3, the bottom plate 4 and the outer support strip 6, the mechanical stability of the coil 1 when bearing the sudden short-circuit current can be significantly improved. Moreover, the rigid jacking force provided by the outer support strip 6 fundamentally prevents the downward displacement of the bottom of the coil 1, effectively prevents the change of the turn-to-turn and disc-to-disc insulation distance caused by the sagging of the coil 1, and prolongs the service life of the transformer.

[0034] In the structure of the transformer coil 1 (winding), turn-to-turn and disc-to-disc are industry terms describing the winding level and spacing of the wire, which are directly related to the insulation performance and operation safety of the transformer. The specific meanings are as follows: A turn refers to a complete loop (a circle of wire) of a single wire winding around the core column in the transformer coil 1. The turn-to-turn refers to the space and insulation structure between adjacent two turns of wire. When winding the transformer coil 1, the wire will be closely arranged one turn after another (or arranged according to the designed spacing). Each turn is a turn. For example, when winding the coil with flat copper foil, the area between the first turn of copper foil and the second turn of copper foil, and the area between the second turn and the third turn, is the turn-to-turn. The turn-to-turn must maintain a fixed insulation distance, which is usually filled with insulation paper and insulation paint. The purpose is to isolate the potential difference between adjacent two turns of wire, avoid partial discharge due to too small spacing, and prevent direct contact of the wire insulation layer after abrasion, which may cause short circuit failure.

[0035] The sagging of the coil 1 will cause plastic deformation of the wire at the bottom. The originally uniformly arranged adjacent turns of wire will be squeezed or stretched. The turn-to-turn distance at the squeezed place becomes smaller, the insulation layer is compressed and thinned, and is easy to be punctured. The turn-to-turn distance at the stretched place becomes larger, which will cause the wire to loosen and vibrate, accelerate the insulation aging, and eventually damage the turn-to-turn insulation reliability.

[0036] The cake is also called a line cake, which is a middle layer structure unit of a transformer coil 1, that is, a plurality of turns of wire are wound into a disc-shaped wire group (which can be understood as a stack of turns). The cake is the space between the adjacent two line cakes and the insulation structure. The coil 1 of a large transformer, especially a high-voltage transformer, is not wound all at once, but is wound into multiple independent line cakes in stages, and then these line cakes are stacked and spliced along the core column axis to form a complete coil 1. For example, a coil is composed of twenty line cakes, the area between the first line cake and the second line cake, and the area between the second line cake and the third line cake is the cake interval. The insulation distance of the cake interval is usually larger than that of the turn-to-turn interval, because the line cake is a collection of multiple turns of wire, the potential difference is higher, and it needs to be supported by insulation paper, support bar and other fixed parts. Therefore, the cake interval will also be supported and separated by the outer support bar 6 inserted into the core column to transfer the pressure between the various cake units of the coil 1. The core function is to isolate the high potential difference between adjacent line cakes to prevent arc discharge; form a cooling channel to allow transformer oil or air to flow, avoiding local overheating of the line cake.

[0037] The sagging of the coil will cause the line cakes stacked axially to be misaligned, tilted or squeezed. At the misaligned position: the insulation structure of the cake interval is unevenly stressed, and the supporting support bar is prone to loosen and shift. At the squeezed position: the distance between the cake intervals is reduced, and the insulation paper is crushed or damaged, causing short circuit between the cake intervals. At the tilted position: the cooling channel is blocked, the heat dissipation is deteriorated, and the aging of the insulation material is accelerated.

[0038] The sagging of the coil will directly destroy the uniformity and stability of the turn-to-turn and cake-to-cake gaps, eventually leading to insulation failure and transformer failure. Therefore, the rigid jacking force provided by the outer support bar 6 can effectively prevent the downward displacement of the bottom of the coil 1, and prevent the change of the turn-to-turn and cake-to-cake insulation distance caused by the sagging of the coil 1.

[0039] Optionally, as shown in Figure 2 , the outer support bar 6 includes a horizontal plate 61 and a vertical plate 62, the horizontal plate 61 and the vertical plate 62 are fixedly connected, the horizontal plate 61 disperses the pressure in the form of surface contact, and the vertical plate 62 is used for downward transmission of the pressure.

[0040] In this embodiment, the outer support bar 6 is an I-beam, the horizontal plate 61 is the upper flange plate and the lower flange plate of the I-beam, and the vertical plate 62 is the web of the I-beam.

[0041] Specifically, the I-beam at the bottom of the coil 1 is fixedly welded with the pressing plate 3 through the lower flange plate, and the upper flange plate is fully attached to the bottom of the coil 1 to form a rigid jacking system from bottom to top, which directly resists the gravity of the coil 1 itself and the electric force in the running process, and fundamentally prevents the coil from sagging. Moreover, the contact forms of the upper flange plate and the lower flange plate are both surface contact, and such large-area contact design makes the support force uniformly transmitted to the bottom of the coil 1, and the reaction force is dispersed to the pressing plate 3 and the bottom plate 4, avoiding stress concentration caused by point contact or line contact.

[0042] In a static state, the structure of the coil 1 remains compact and does not sag; in a dynamic state (i.e. during a short-circuit fault), the pressing plate 3, the bottom plate 4 and the outer support strip 6 work together to effectively suppress the radial and axial displacement of the coil 1, and conduct the electric force to the pressing plate 3, the bottom plate 4 and the main structure of the transformer, thereby effectively reducing the risk of distortion, deformation or even damage of the coil 1.

[0043] Optionally, as shown in Figure 3 the outer support strip 6 is a support member formed by welding at least two I-beams.

[0044] In this embodiment, when the cross-sectional area of the coil is large and the mass is also large, although multiple outer support strips 6 can improve stability, the single outer support strip 6 will be subjected to greater pressure, which will affect its service life. At this time, two or more I-beams are welded in parallel, so that the contact area of the upper flange plate and the lower flange plate is larger, and the pressure transmitted by the coil 1 can be dispersed. Moreover, the increase in the number of webs can improve the overall stiffness of the outer support strip 6, which can disperse the pressure in the direction of the pressing plate 3 and further improve the service life of the outer support strip 6.

[0045] Optionally, as shown in Figure 4 the outer support strip 6 is a rectangular hollow steel pipe, the horizontal plate 61 is a top plate and a bottom plate of the rectangular hollow steel pipe, and the vertical plate 62 is a side plate of the rectangular hollow steel pipe.

[0046] In this embodiment, the rectangular hollow steel pipe has an additional vertical plate 62 compared to the I-beam, which effectively increases the stiffness of the outer support strip 6, but the width of the horizontal plate 61 remains unchanged, so that the contact area remains unchanged, and it is more suitable for coils and core columns with large mass due to high height, and scenarios with higher demand for the load bearing capacity of the outer support strip 6.

[0047] Optionally, as shown in Figure 1 the core column portion at the top and bottom of the coil 1 is covered with an iron yoke 2, the iron yoke 2 is fixedly installed with a mounting plate 8, the mounting plate 8 is fixedly installed with an aluminum bar 7, and the mounting plate 8 is fixedly installed with an epoxy plate 5 through bolts.

[0048] In this embodiment, the mounting plate 8, the pressing plate 3 and the bottom plate 4 are all made of Q235 metal fittings.

[0049] In the present application, the insulation performance and heat dissipation can be optimized, the integrity of the conductor insulation layer is protected due to the avoidance of stress concentration, and the reasonable layout of the outer support strip 6 does not significantly hinder the flow of transformer oil and can even guide the oil flow to improve the heat dissipation condition. In terms of production and installation, the outer support strip 6, as an independent component, can be precisely positioned on the pressing plate 3 in advance before the lower yoke 2 or the installation of the coil 1, the installation process is clear and simple, the installation process is simplified, the reliability is improved, the dependence on the experience of the operator is reduced, the consistent support effect can be ensured every time the installation is performed, and the consistency of the product quality is improved. During the maintenance of the transformer suspension cover, the structure of the outer support strip 6 is clear and visible, the state thereof is easy to check, and the outer support strip 6 can be replaced when necessary, and the maintainability is better.

[0050] The present application forms a three-dimensional constraint structure by combining the pressing plate 3, the bottom plate 4 and the outer support strip 6, accurately solves a long-term pain point in the design of a transformer, realizes a technical leap from passive constraint to active support, and can significantly improve the mechanical reliability, electrical safety and production and maintenance convenience of the transformer.

[0051] As shown in Figure 5 The manufacturing method of the transformer coil installation structure provided by the present application comprises the following steps: S1, the wound coil 1 is sleeved on the core column, and the coil 1 is coaxially arranged with the core column.

[0052] S2, the outer support strip 6 is punched into the core column, the outer support strip 6 is tightly attached to the coil 1 and the core column, the radial positioning of the coil 1 is realized, and the coil 1 is not loose.

[0053] Specifically, the outer support strip 6 is punched into the core column and is bonded with the coil 1 to realize fixation, and the coaxial positioning of the coil 1 and the core column is realized at the same time, and the radial deviation of the coil 1 is prevented.

[0054] S3, the outer support strip 6 is uniformly arranged on the top of the pressing plate 3 at a predetermined interval, the pressing plate 3 is welded to the bottom plate 4 by argon arc welding, and it is ensured that the welding points are firm and have no virtual welding.

[0055] The pressing plate 3 and the outer support strip 6 can be welded or locked by hardware, and form a three-dimensional constraint frame with the bottom plate 3, limit the axial, radial and circumferential displacement of the coil 1, and improve the overall structural stability.

[0056] S4, the upper yoke 2, the mounting plate 8, the aluminum row 7 and the epoxy plate 5 of the coil 1 are assembled.

[0057] S5, the overall structure is subjected to paint dipping treatment, the insulation layer uniformly covers the surfaces of the components, the insulation layer uniformly covers the surfaces of the components, and the installation and manufacturing of the transformer coil 1 are completed.

[0058] The above disclosed are only several specific embodiments of the present application, but the embodiments of the present application are not limited thereto, and any changes that can be thought of by any person skilled in the art shall fall within the protection scope of the present application.

Claims

1. A transformer coil installation structure, characterized in that, include: Iron core column, wherein the iron core column is fitted with a coil (1). External support bars (6) are fixedly installed on both sides of the iron core column, and the external support bars (6) are fixedly connected to the coil (1). The external support bars (6) are used to clamp the iron core column and to radially tension the coil (1). A pressure plate (3) is fixedly positioned below the coil (1), and a base plate (4) is fixedly installed at the bottom of the pressure plate (3). The pressure plate (3), the base plate (4), and the outer support strip (6) cooperate to form a three-dimensional constraint structure to support the coil (1).

2. The transformer coil installation structure as described in claim 1, characterized in that, The outer support bar (6) includes a horizontal plate (61) and a vertical plate (62). The horizontal plate (61) and the vertical plate (62) are fixedly connected. The horizontal plate (61) disperses the pressure in a surface contact manner, and the vertical plate (62) is used to transmit the pressure downward.

3. The transformer coil installation structure as described in claim 2, characterized in that, The outer support bar (6) is an I-beam, the horizontal plate (61) is the upper flange and lower flange of the I-beam, and the vertical plate (62) is the web of the I-beam.

4. The transformer coil installation structure as described in claim 3, characterized in that, The outer support bar (6) is a support member formed by welding at least two I-beams.

5. The transformer coil installation structure as described in claim 2, characterized in that, The outer support strip (6) is a rectangular hollow steel pipe, the horizontal plate (61) is the top and bottom plate of the rectangular hollow steel pipe, and the vertical plate (62) is the side plate of the rectangular hollow steel pipe.

6. The transformer coil installation structure as described in claim 1, characterized in that, The iron core column portions located at the top and bottom of the coil (1) are covered with iron yokes (2).

7. The transformer coil installation structure as described in claim 6, characterized in that, The yoke (2) is fixedly mounted with a mounting plate (8).

8. The transformer coil installation structure as described in claim 7, characterized in that, The mounting plate (8) is fixedly mounted with aluminum strips (7).

9. The transformer coil installation structure as described in claim 7, characterized in that, The mounting plate (8) is fixed with an epoxy board (5) by bolts.

10. A method for manufacturing a transformer coil installation structure, characterized in that, The method is applied to the transformer coil mounting structure as described in any one of claims 1-9, and includes the following steps: S1. Place the wound coil (1) onto the iron core post, so that the coil (1) and the iron core post are arranged coaxially; S2. Insert outer support strips (6) into both sides of the iron core column so that the outer support strips (6) are tightly attached to the coil (1) and the iron core column, so as to achieve radial positioning of the coil (1) without loosening. S3. Arrange the outer support strips (6) evenly on the top of the pressure plate (3) at a preset spacing, and weld the pressure plate (3) to the bottom plate (4) by argon arc welding, and ensure that the welding point is firm and without false welding. S4, Other structures above the assembly line package (1); S5. Impregnate the entire structure with varnish to ensure that the insulation layer evenly covers the surface of each component.

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