A reinforcing structure for an inner support cylinder of a low-voltage coil of a transformer

Abstract

The application discloses a low-voltage coil inner support cylinder reinforcing structure of a transformer, which comprises an electric core column body and an inner insulation cylinder, the inner insulation cylinder is installed on the surface of the electric core column body, the inner wall of the inner insulation cylinder is coated with insulating glue, and the insulating glue is in contact with the surface of the electric core column body, and the application relates to the technical field of transformers. The low-voltage coil inner support cylinder reinforcing structure of the transformer adopts a four-dimensional limiting structure of L-shaped supporting plate bottom bearing, bent clamping frame double-layer slot clamping, trapezoidal plug-in plate transverse locking and annular binding belt overall hoop tightening, the L-shaped supporting plate supports the winding bottom to prevent falling, the upper and lower independent clamping grooves separate two layers of conductors, and short-circuit interlayer movement extrusion and insulation damage are avoided; the trapezoidal plug-in plate cooperates with the side clamping opening to lock the clamping frame and prevent circumferential sliding, the annular recessed frame cooperates with the binding belt to form a closed loop constraint, single-point loosening will not cause the collapse of the whole coil, and the supporting rubber pad increases friction and buffers impact, so that the winding operation deformation amount can be obviously reduced.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, specifically to a reinforcement structure for the inner support cylinder of a transformer low-voltage coil. Background Technology

[0002] As a core electrical device in power transmission and distribution systems, the low-voltage coil of a power transformer is a key component for voltage transformation and carrying rated load current. The inner support cylinder (inner insulating cylinder) provides radial positioning, insulation isolation, and overall support for the low-voltage coil. The structural stability of the support cylinder and the reliability of the coil clamping directly determine the transformer's resistance to short-circuit impacts, long-term insulation life, and noise and vibration reduction performance. Currently, oil-immersed and dry-type distribution transformers and the low-voltage windings of main power transformers generally adopt a cylindrical inner insulation support structure. However, existing low-voltage coil inner support cylinder solutions in the industry have several inherent defects that restrict the reliability of transformer operation. Specific problems are as follows: 1. Existing conventional solutions simply place a paper or epoxy inner insulating sleeve on the outside of the core column. The inner wall of the sleeve is only bonded to the surface of the core column with a small amount of dotted insulating adhesive, without a uniform adhesive layer filling structure. The transformer experiences continuous vibration during factory transportation and hoisting. After commissioning, load fluctuations and short-circuit faults bring huge electromagnetic shocks. The interface between the insulating sleeve and the core column is prone to localized delamination and gaps. During operation, oil flow and air convection continuously erode the weak bonding areas, creating localized air gaps within the gaps. This leads to partial discharge, damaging the sleeve's insulation layer and significantly shortening its service life. Furthermore, the insulating sleeve loses the radial constraint of the core, causing radial offset and circumferential rotation, leading to overall misalignment of the outer low-voltage winding. This results in bending of the winding conductors, easily causing insulation damage and inter-turn short-circuit faults. Additionally, the traditional dotted adhesive application method cannot eliminate the assembly gap between the sleeve and the core, resulting in poor coaxiality, uneven radial thickness after coil winding, distorted magnetic field distribution, and excessive no-load losses and noise levels.

[0003] 2. Low-voltage coils are mostly multi-layered parallel windings. Traditional clips can only wrap all the conductors as a whole, and there is no separation or limiting between the upper and lower layers of windings. Under the action of short-circuit electrodynamics, the conductors of the upper and lower layers of windings are squeezed and displaced, causing the conductor insulation to be squeezed and damaged. Multi-strand transposed conductors become loose and scattered, causing inter-turn and inter-layer short circuits. At the same time, the metal or hard plastic clips directly and rigidly contact the winding conductors. Under the electromagnetic vibration and alternating stress of the load during transformer operation, the edge of the clip continuously rubs against the outer insulation of the conductor. Over long-term operation, the insulation will wear thin and crack. During short-circuit impact, the rigid clip will concentrate stress and easily damage the conductor. In addition, the clip assembly does not have a two-way locking structure. Traditional clips only clamp to the cylinder wall on one side, without the double limiting of the side lock of the insert plate and the bottom support. Under vibration conditions, the clip is easy to slide along the circumference and axial direction of the cylinder wall, lose the winding clamping function, and the coil as a whole becomes loose and deformed.

[0004] 3. In the existing technology, the winding clips are independent components, and there is no linkage and binding structure between the clips. After a single clip slips or loosens, the winding in the corresponding area is completely unrestrained. The huge radial and axial electrodynamic forces at the moment of short circuit will quickly spread to the surrounding windings, causing large-area coil collapse and wire bending and breakage. At the same time, the clips only rely on their own clamping force to stick to the cylinder wall, and lack the ring frame limit. After the clips are subjected to force, they are easy to warp outward and detach from the cylinder wall. The clamping force continues to decrease, and the failure rate of coil loosening increases significantly after the equipment has been running for a period of time.

[0005] 4. Traditional integrated binding and welding buckle structures cannot be disassembled and assembled individually for single-area windings. When repairing a partial fault in the transformer coil, the entire loop of binding tape must be completely removed, damaging the buckle structure. After repair, the fixing parts cannot be reused. Ordinary buckles do not have a convenient force-applying lifting structure, making it difficult to accurately align with the cylinder wall slot during assembly. The manual winding and fixing process is cumbersome, the batch production processing cycle is long, the manual assembly error is large, and the product consistency is poor.

[0006] Therefore, a low-voltage coil inner support cylinder reinforcement structure with strong adhesion, precise layered clamping, multiple locking reinforcement, and integrated vibration reduction and insulation is designed to solve this type of defect. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a reinforcement structure for the inner support cylinder of a transformer's low-voltage coil, which solves the problem of insufficient coil support force and easy discharge leading to damage.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a transformer low-voltage coil inner support cylinder reinforcement structure, comprising a core column body and an inner insulating cylinder, wherein the inner insulating cylinder is installed on the surface of the core column body, the inner wall of the inner insulating cylinder is coated with insulating adhesive, and the insulating adhesive is in contact with the surface of the core column body, the surface of the inner insulating cylinder is provided with rectangular notches, and several rectangular notches are arranged in a ring shape, the bottom of the inner cavity of the rectangular notches is provided with positioning slots, and the inner side of the positioning slots is provided with L-shaped support plates.

[0009] Preferably, a first rubber pad is fixedly installed on the surface of the L-shaped tray and on the inner side of the positioning slot through an opening, and the first rubber pad is in contact with the inner wall of the positioning slot.

[0010] Preferably, the top of the L-shaped tray and outside the rectangular recess is provided with a sliding groove that extends to the bottom. A curved card holder is slidably installed on the inner side of the sliding groove. The front of the curved card holder is provided with an upper locking groove, and the bottom of the curved card holder is provided with a lower locking groove. The winding wire body is installed on the inner side of both the upper and lower locking grooves.

[0011] Preferably, the top of both the upper and lower locking grooves is fixedly fitted with a second rubber pad through an opening, and the second rubber pad is in contact with the winding wire body.

[0012] Preferably, the rectangular recessed cavity has side slots on both sides, and the side slots extend to the outside of the inner insulating cylinder. The top of the curved card holder is fixedly installed with a trapezoidal insert plate that cooperates with the side slots by a fixing block, and the rear end of the trapezoidal insert plate extends to the inside of the side slots. The top of the trapezoidal insert plate has a third rubber pad fixedly installed on both sides by openings, and the third rubber pad fits against the inner wall of the side slots. The top of the trapezoidal insert plate has a circular pull opening that extends to the bottom.

[0013] Preferably, an annular recessed frame is fixedly installed on the surface of the inner insulating cylinder, and the annular recessed frame is provided with a plurality of recesses located between the upper and lower rectangular recesses respectively.

[0014] Preferably, the surface of the annular recessed frame is provided with a U-shaped opening, and there are several U-shaped openings, each of which is located directly below the rectangular recess, and the rear part of the curved card holder is located inside the annular recessed frame.

[0015] Preferably, the inner side of the annular concave frame is provided with a binding strap, and the binding strap is in contact with the surface of several curved card holders.

[0016] This invention provides a reinforcement structure for the inner support cylinder of a transformer's low-voltage coil. Compared with existing technologies, it has the following advantages: (1) The low-voltage coil inner support cylinder reinforcement structure of the transformer adopts a four-dimensional limiting structure with L-shaped support plate bottom load bearing, double-layer slotted clamping of bent card frame, lateral locking of trapezoidal insert plate, and overall tightening of ring binding strap. The L-shaped support plate supports the bottom of the winding to prevent it from falling. The upper and lower independent locking slots separate the two layers of conductors to avoid interlayer movement and compression and insulation damage during short circuit. The trapezoidal insert plate and the side card slot lock the card frame to prevent circumferential slippage. The ring concave frame and the binding strap form a closed loop constraint. Single point loosening will not cause the entire coil to collapse. The matching rubber pad increases friction and buffers impact, which can significantly reduce the winding deformation and greatly improve the coil's ability to withstand short circuit electrodynamics. The accessories support individual disassembly and reuse, making maintenance convenient.

[0017] (2) The low-voltage coil inner support cylinder reinforcement structure of the transformer is achieved by fully coating the inner wall of the inner insulating cylinder with insulating glue, completely filling the gap between the core column and the cylinder wall, preventing delamination and cylinder body displacement, eliminating air gaps to suppress partial discharge, optimizing the magnetic circuit to reduce losses, and setting rubber buffer pads at the slot, wire slot and side bayonet to absorb vibration energy, block rigid vibration transmission, reduce operating noise, isolate hard components and insulating parts, avoid scratching the wires and cylinder wall, disperse stress and uniform electric field, which not only relaxes the processing tolerance of parts and improves assembly efficiency, but also provides long-term protection for the entire insulation system and extends the service life of the transformer. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the battery cell column body, inner insulating cylinder, and rectangular notch structure of the present invention; Figure 3 For the present invention Figure 2 A magnified view of a section at point A in the middle; Figure 4 This is a schematic diagram of the inner insulating cylinder and insulating adhesive structure of the present invention; Figure 5 For the present invention Figure 4 A magnified view of a section at point B in the middle; Figure 6 This is a cross-sectional view of the battery cell column body and inner insulating cylinder structure of the present invention; Figure 7 For the present invention Figure 6 A magnified view of a section at point C; Figure 8 This is a side view of the internal structure of the inner insulating cylinder of the present invention; Figure 9 For the present invention Figure 8 A magnified view of a section at point D; Figure 10 This is a schematic diagram of the L-shaped tray, card groove, and curved card holder structure of the present invention.

[0019] In the diagram: 1. Battery cell column body; 2. Inner insulation cylinder; 3. Winding wire body; 4. Rectangular notch; 5. Positioning slot; 6. L-shaped support plate; 7. Slotted groove; 8. Bent clip frame; 9. Upper locking groove; 10. Lower locking groove; 11. Side locking slot; 12. Trapezoidal insert plate; 13. Round pull opening; 14. Annular recessed frame; 15. U-shaped opening; 16. Binding strap; 17. Insulating adhesive; 18. First rubber pad; 19. Second rubber pad; 20. Third rubber pad. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figures 1-10 This invention provides a technical solution: a reinforcement structure for the inner support cylinder of a transformer low-voltage coil, comprising a core column body 1 and an inner insulating cylinder 2. The inner insulating cylinder 2 adopts a three-layer composite insulating cylinder structure, consisting of, from the inside out: an inner epoxy fiberglass insulation layer, a middle honeycomb buffer interlayer, and an outer rigid insulating bearing layer. The inner insulating cylinder 2 is installed on the surface of the core column body 1. The inner wall of the inner insulating cylinder 2 is coated with insulating adhesive 17, which is epoxy insulating adhesive, and the insulating adhesive 17 is in contact with the surface of the core column body 1. A rectangular notch 4 is provided on the surface of the inner insulating cylinder 2. Several rectangular notches 4 are arranged in a ring shape. A positioning slot 5 is provided at the bottom of the inner cavity of the rectangular notch 4, and an L-shaped support plate 6 is provided on the inner side of the positioning slot 5.

[0022] Furthermore, a first rubber pad 18 is fixedly installed on the surface of the L-shaped tray 6 and inside the positioning slot 5 by opening an opening, and the first rubber pad 18 is in contact with the inner wall of the positioning slot 5.

[0023] Furthermore, the top of the L-shaped tray 6 and the outside of the rectangular recess 4 are provided with a sliding groove 7 that extends to the bottom. A curved card holder 8 is slidably installed on the inner side of the sliding groove 7. An upper locking groove 9 is provided at the front of the curved card holder 8, and a lower locking groove 10 is provided at the bottom of the curved card holder 8. The winding wire body 3 is installed on the inner side of both the upper locking groove 9 and the lower locking groove 10.

[0024] The top of the inner cavity of both the upper locking groove 9 and the lower locking groove 10 is fixedly installed with a second rubber pad 19 through an opening, and the second rubber pad 19 is in contact with the winding wire body 3.

[0025] The rectangular notch 4 has side slots 11 on both sides of its inner cavity, and the side slots 11 extend to the outside of the inner insulating cylinder 2. The top of the curved bracket 8 is fixedly installed with a trapezoidal insert plate 12 that cooperates with the side slots 11 by a fixing block, and the rear end of the trapezoidal insert plate 12 extends to the inside of the side slots 11. The top of the trapezoidal insert plate 12 has a third rubber pad 20 fixedly installed on both sides by openings, and the third rubber pad 20 fits against the inner wall of the side slots 11. The top of the trapezoidal insert plate 12 has a circular pull opening 13 that extends to the bottom.

[0026] The inner insulating cylinder 2 has an annular recessed frame 14 fixedly installed on its surface, and the annular recessed frame 14 has several recesses located between the upper and lower rectangular recesses 4.

[0027] The annular recessed frame 14 has a U-shaped opening 15 on its surface, and there are several U-shaped openings 15. The several U-shaped openings 15 are located directly below the rectangular recess 4, and the rear part of the curved bracket 8 is located inside the annular recessed frame 14.

[0028] The inner side of the annular concave frame 14 is provided with a binding strap 16, and the binding strap 16 is in contact with the surface of several curved card holders 8.

[0029] In use, first apply insulating adhesive 17 to the inner wall of the inner insulating cylinder 2. Then, place the inner insulating cylinder 2 onto the surface of the core column body 1 until the insulating adhesive 17 solidifies, filling the space between the core column body 1 and the inner insulating cylinder 2. Simultaneously, use the solidified insulating adhesive 17 to fix the inner insulating cylinder 2 to the surface of the core column body 1. Next, insert several L-shaped support plates 6 into the inner side of the positioning slot 5 through the rectangular notch 4. Utilize the expansion of the first rubber pad 18 to generate friction with the L-shaped support plates 6, thereby fixing the L-shaped support plates 6 as a whole. After all the L-shaped support plates 6 are installed, install the first winding wire body 3 into the inner side of the upper engaging slot 9, and then install the second winding wire body 3 into the inner side of the lower engaging slot 10, using the second rubber pad 18... After the installation of the winding wire body 3 is completed, the trapezoidal insert plate 12 is pushed backward by hand in the guide of the bent clip 8, so that the upper locking groove 9 and the lower locking groove 10 are used to press the winding wire body 3 onto the surface of the inner insulating cylinder 2. At the same time, the trapezoidal insert plate 12 is also inserted into the inside of the side locking slot 11, and the third rubber pad 20 generates friction with the inside of the side locking slot 11 by its expansion. At the same time, the bent clip 8 is also attached to the inside of the U-shaped opening 15. At this time, all the bent clips 8 are located inside the U-shaped opening 15. Then, the binding strap 16 is tightened and bound to the inside of the annular concave frame 14. The binding force of the binding strap 16 is used to clamp several bent clips 8, and the fixing of the bent clips 8 and the winding wire body 3 is completed.

[0030] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

Claims

1. A reinforcement structure for the inner support cylinder of a transformer low-voltage coil, comprising a core column body (1) and an inner insulating cylinder (2), characterized in that: The inner insulating cylinder (2) is installed on the surface of the battery cell body (1). The inner wall of the inner insulating cylinder (2) is coated with insulating glue (17), and the insulating glue (17) is in contact with the surface of the battery cell body (1). A rectangular notch (4) is opened on the surface of the inner insulating cylinder (2). Several rectangular notches (4) are arranged in a ring shape. A positioning slot (5) is opened at the bottom of the inner cavity of the rectangular notch (4). An L-shaped support plate (6) is provided on the inner side of the positioning slot (5).

2. The transformer low-voltage coil inner support cylinder reinforcement structure according to claim 1, characterized in that: The L-shaped tray (6) has a first rubber pad (18) fixedly installed on its surface and inside the positioning slot (5) by opening an opening, and the first rubber pad (18) is in contact with the inner wall of the positioning slot (5).

3. The transformer low-voltage coil inner support cylinder reinforcement structure according to claim 2, characterized in that: The L-shaped tray (6) has a sliding groove (7) extending to the bottom at the top and outside the rectangular notch (4). A curved card holder (8) is slidably installed on the inner side of the sliding groove (7). An upper locking groove (9) is provided at the front of the curved card holder (8), and a lower locking groove (10) is provided at the bottom of the curved card holder (8). The winding wire body (3) is installed on the inner side of both the upper locking groove (9) and the lower locking groove (10).

4. The transformer low-voltage coil inner support cylinder reinforcement structure according to claim 3, characterized in that: The top of the inner cavity of the upper locking groove (9) and the lower locking groove (10) are fixedly installed with a second rubber pad (19) by opening, and the second rubber pad (19) is in contact with the winding wire body (3).

5. The transformer low-voltage coil inner support cylinder reinforcement structure according to claim 4, characterized in that: The rectangular recess (4) has side slots (11) on both sides of its inner cavity, and the side slots (11) extend to the outside of the inner insulating cylinder (2). The top of the curved card holder (8) is fixedly installed with a trapezoidal insert plate (12) that cooperates with the side slots (11) by a fixing block, and the rear end of the trapezoidal insert plate (12) extends to the inside of the side slots (11). The top of the trapezoidal insert plate (12) has a third rubber pad (20) fixedly installed on both sides by openings, and the third rubber pad (20) fits against the inner wall of the side slots (11). The top of the trapezoidal insert plate (12) has a circular pull opening (13) that extends to the bottom.

6. The transformer low-voltage coil inner support cylinder reinforcement structure according to claim 5, characterized in that: The inner insulating cylinder (2) is fixedly mounted with an annular recessed frame (14), and the annular recessed frame (14) is provided with several recesses located between the upper and lower rectangular recesses (4).

7. The transformer low-voltage coil inner support cylinder reinforcement structure according to claim 6, characterized in that: The surface of the annular recessed frame (14) is provided with a U-shaped opening (15), and there are several U-shaped openings (15). The several U-shaped openings (15) are located directly below the rectangular recess (4), and the rear part of the curved card holder (8) is located inside the annular recessed frame (14).

8. The transformer low-voltage coil inner support cylinder reinforcement structure according to claim 7, characterized in that: The inner side of the annular concave frame (14) is provided with a binding strap (16), and the binding strap (16) is in contact with the surface of several curved card holders (8).

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