A transformer high voltage winding end insulation support structure

Abstract

The application discloses a transformer high-voltage winding end insulation support structure, which comprises two winding clamps arranged in an up-down mode, and three core supports are fixedly connected to opposite sides of the two winding clamps, winding coils are fixedly installed on surfaces of the core supports, and pressure wire insulation discs are arranged at the top and the bottom of the winding coils respectively. The application relates to the technical field of transformers. The transformer high-voltage winding end insulation support structure comprises a circumferential limiting structure formed by the up-down pressure wire insulation discs, the arc-shaped insertion grooves, the limiting wire fixing plates, the arc-shaped supporting plates and the annular hoops, the circumferential limiting structure uniformly and tightly restrains the outer periphery of the high-voltage winding, effectively prevents the winding bulging and sliding problems caused by the radial electric force under the short-circuit working condition, and simultaneously comprises an external adjustable axial compression mechanism formed by the support plate frames, the threaded rotating rods, the arc-surface pressing block seats, the pressure bearing plates and the lifting cylinders, so that the axial compression force can be accurately adjusted according to the size of the winding during the assembly stage.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, specifically to an insulation support structure for the end of a transformer high-voltage winding. Background Technology

[0002] As a core piece of equipment in power transmission and distribution systems, the high-voltage winding of a power transformer is a crucial component responsible for high-voltage power transmission and electromagnetic coupling. Its end insulation support structure directly determines the transformer's operational insulation reliability, resistance to short-circuit impacts, and long-term service life. Currently, oil-immersed power transformers generally employ multi-layered windings of conductors for their high-voltage windings. The upper and lower ends of the winding rely on insulating pads, insulating discs, and binding tapes for end positioning and insulation support. However, existing support structures in the industry have revealed multiple structural defects under long-term operation, sudden short-circuit impacts, and temperature rise cycles. Specific problems are as follows: 1. Poor reliability of winding end fixing, prone to coil loosening, displacement and deformation. Existing conventional support schemes rely solely on upper and lower insulating pressure plates to simply press against the winding end face, with circumferential binding and limitation only through narrow insulating straps, lacking integrated circumferential limiting components. After the transformer is put into operation, it continuously withstands alternating electromagnetic forces and cyclic stresses from thermal expansion and contraction. When encountering a system short-circuit fault, the high-voltage winding generates huge radial and axial electrodynamic forces. The tensile strength of a single layer of straps is insufficient, making it extremely easy for the straps to loosen and break, leading to circumferential slippage and axial movement of the winding conductors. Displacement of the high-voltage winding conductors will directly cause inter-turn insulation compression damage, triggering inter-turn short circuits and winding discharge, and in severe cases, directly burning out the transformer. At the same time, traditional insulating pressure plates lack independent segmented limiting components, resulting in uneven distribution of clamping force around the winding circumference. Local coils remain in a loose state for a long time, and vibration and wear continuously damage the insulation layer.

[0003] 2. The end clamping force is not adjustable, and secondary clamping is not possible, resulting in poor adaptability to operation and maintenance. Traditional winding end insulation support structures are one-time assembly structures, with a fixed clamping amount after the insulation pressure plate and support components are assembled. During long-term operation of transformers, insulation materials and binding components will continuously undergo thermal aging and shrinkage, and insulation pads will experience compression creep. The clamping force on the winding end face will gradually decrease, and the risk of coil loosening will continue to increase. The existing structure does not have an external adjustable clamping mechanism. Once the winding becomes loose, the winding clamps must be completely disassembled, the insulation pressure plate removed, and the binding tape untied before it can be tightened again. The disassembly process is cumbersome, requiring lifting from the transformer body and draining the insulating oil. The maintenance period is long, and the power outage losses are large, significantly increasing the substation operation and maintenance costs and failing to meet the needs of rapid maintenance of power grid equipment.

[0004] 3. The insulation support structure has a low degree of integration, resulting in insufficient insulation and heat dissipation performance and excessive local temperature rise. Conventional insulation plates only have a few simple oil channels, with narrow and unevenly distributed oil flow channels. A large area of ​​oil stagnation is formed at the contact surface between the winding end and the insulation plate. The large amount of heat generated at the winding end during short-circuit impact and rated load operation cannot be quickly dissipated, resulting in persistently high local temperatures. This accelerates the thermal aging of insulation paper, insulation discs, and binding components, shortening the service life of the insulation system. At the same time, the existing support, limiting, and clamping components are assembled independently and separately, with a large number of parts. The alignment during assembly is difficult, and manual assembly errors can easily cause misalignment of insulation components, creating weak points in the insulation. Furthermore, the lack of a circumferential rigid support frame makes the insulation plate prone to warping and deformation under the action of short-circuit electrodynamics, further blocking the oil channels and worsening heat dissipation conditions.

[0005] 4. The insulation support has poor versatility and low assembly positioning accuracy. There are differences in the outer diameter of high-voltage windings of different capacities and specifications. Traditional insulation pressure plates and support frames have no adaptive adjustment structure. One set of support structure can only be adapted to a single specification of winding. The versatility of parts is poor, and the cost of mold development and spare parts inventory is high. During assembly, it is difficult to accurately align the insulation pressure plate with the center of the winding. There is no guide and limit structure for axial and circumferential positioning. Assembly deviation will cause the winding to be subjected to eccentric force, which will increase the risk of local insulation damage.

[0006] Therefore, a high-voltage winding end insulation support structure with adaptive clamping, circumferential all-round limiting, sufficient heat dissipation channels, and buffering and shock resistance capabilities is designed. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an insulation support structure for the end of a transformer high-voltage winding, which solves the problems of poor winding fixation and weak edge support in existing technologies.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a transformer high-voltage winding end insulation support structure, comprising two winding clamps arranged vertically, with a core support fixedly connected to one side of each of the two winding clamps, and three core supports are provided. A winding coil is fixedly mounted on the surface of the core support. A pressure wire insulation disc is provided at the top and bottom of the winding coil, and the pressure wire insulation disc is sleeved on the surface of the core support. An arc-shaped slot extending to the bottom is provided at the top edge of the pressure wire insulation disc, and several arc-shaped slots are arranged in a ring. A limiting wire fixing plate is installed between the inner sides of the upper and lower arc-shaped slots, and several limiting wire fixing plates are provided. The limiting wire fixing plate is in contact with the surface of the winding coil.

[0009] Preferably, each of the limiting and fixing plates has an arc-shaped support plate fixedly installed on its surface. The upper and lower parts of the surface of the arc-shaped support plate are provided with concave grooves, and an annular hoop is installed between the inner sides of the concave grooves at the same height.

[0010] Preferably, a support plate frame is slidably installed on one side of each of the two winding clamps, and the number of support plate frames is the same as the number of winding coils. A U-shaped groove is opened on the side of the support plate frame near the winding clamp, and the winding clamp is located inside the U-shaped groove. A rectangular through groove is opened on one side of the U-shaped groove, extending to the other side. Lateral grooves are opened at the front and rear of the support plate frame. A threaded bolt is connected to the top of the inner cavity of the lateral groove by opening a threaded connection, and several threaded bolts are provided. The end of the threaded bolt away from the winding coil contacts the adjacent winding clamp.

[0011] Preferably, a lifting cylinder is slidably installed on both sides of the inner cavity of the rectangular through slot near the winding coil by openings. The end of the lifting cylinder near the winding coil is fixedly connected to an annular pressure frame by a fixing plate, and the annular pressure frame is fixedly connected to one side of the adjacent pressure wire insulation disc. A pressure plate is fixedly connected to the inner side of the lifting cylinder located in the rectangular through slot.

[0012] Preferably, the inner cavity of the U-shaped groove is provided with strip grooves on both sides near the winding coil. A T-shaped slider is slidably installed on the inner side of the strip groove. An arc-shaped pressure block seat is fixedly connected to one side of the T-shaped slider, and the arc-shaped pressure block seat is located inside the rectangular through groove. The arc-shaped pressure block seat is in contact with one side of the pressure plate.

[0013] Preferably, the surface of the arc-shaped pressure block seat is provided with an inner buffer groove extending to the rear. Both sides of the support plate frame are fixedly connected with internal threaded bending frames by fixing blocks. One side of the internal threaded bending frame is rotatably mounted with a threaded rotating rod through an opening. One end of the threaded rotating rod passes through the arc-shaped pressure block seat and extends to the inner side of the inner buffer groove. The threaded rotating rod is threadedly connected to the arc-shaped pressure block seat.

[0014] Preferably, both the inner sides of the wire insulation disc and the support plate frame are provided with iron core supports for use in conjunction with the iron core supports, and the surface of the wire insulation disc is provided with oil guide grooves that extend to the outside of the wire insulation disc, and there are several oil guide grooves arranged in a ring.

[0015] This invention provides an insulation support structure for the end of a transformer high-voltage winding. Compared with existing technologies, it has the following advantages: (1) The high-voltage winding end insulation support structure of the transformer is composed of upper and lower pressure wire insulation discs, arc slots, limit fixing plates, bow-shaped support plates and ring rings to form a circumferential limiting structure around the winding, which can uniformly tighten and constrain the outer periphery of the high-voltage winding, effectively resisting the coil bulging and slippage caused by radial electrodynamics under short-circuit conditions; at the same time, it is equipped with a support plate frame, threaded rotating rod, arc-shaped pressure block seat, pressure plate and lifting cylinder to form an external adjustable axial pressing mechanism. During the assembly stage, the axial pressing force can be precisely adjusted according to the winding size. When the insulation material creeps and shrinks and the pressing force decreases after long-term operation of the equipment, there is no need to lift out the transformer body and disassemble the overall support structure. Only the external operation of the threaded rotating rod can complete the secondary pressing and continuously lock the winding. The arc-shaped pressure block seat is equipped with an inner buffer groove, which can buffer the instantaneous axial impact stress generated by the short circuit, avoid the stress rigid transmission damage to the conductor insulation, suppress the loosening and displacement of the winding in all aspects, greatly reduce the risk of inter-turn short circuit and partial discharge faults, and significantly reduce the workload of equipment maintenance and power outage maintenance costs.

[0016] (2) The high-voltage winding end insulation support structure of this transformer integrates support positioning, coil limiting, axial clamping, and circulating heat dissipation functions into an integrated combined support structure. The components are highly modularized. The pressure wire insulation disc is arranged with multiple sets of through-type oil guide grooves in a ring, opening up the oil flow channel at the winding end, eliminating the dead corners of oil stagnation in traditional pressure plates, accelerating the heat dissipation at the end, alleviating the insulation aging and deterioration caused by high temperature, and ensuring the long-term dielectric performance of the insulation. The support plate frame can be positioned by lateral sliding with U-shaped grooves, which can be adapted to high-voltage windings of various outer diameters. One set of support structure can be compatible with multiple specifications of products, reducing mold development and spare parts inventory investment. With the help of strip grooves, T-shaped sliders, and threaded bolts, precise coaxial positioning is achieved, reducing the insulation weakness caused by assembly eccentricity error, and simultaneously improving the factory assembly efficiency and the long-term insulation stability of the transformer. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the core support, winding coil, and pressure wire insulation disk structure of the present invention; Figure 3 This is a schematic diagram of the bow-shaped support plate, concave hoop groove, and annular hoop structure of the present invention; Figure 4 This is a cross-sectional view of the wire insulation disc and support plate frame structure of the present invention; Figure 5 This is a schematic diagram of the U-shaped groove, threaded bolt, and rectangular through-slot structure of the present invention; Figure 6 This is a schematic diagram of the lifting cylinder, pressure plate, and annular pressure frame structure of the present invention; Figure 7This is a schematic diagram of the internal buffer groove, internal threaded bending frame, and threaded rotating rod structure of the present invention. Figure 8 This is a side view of the winding clamp, wire insulation disc, and support plate frame structure of the present invention.

[0018] In the diagram: 1. Winding clamp; 2. Core support; 3. Winding coil; 4. Wire insulation disc; 5. Arc-shaped slot; 6. Limiting and fixing plate; 7. Bow-shaped support plate; 8. Concave hoop groove; 9. Annular hoop; 10. Support plate frame; 11. U-shaped slide groove; 12. Threaded bolt; 13. Rectangular through slot; 14. Lifting cylinder; 15. Pressure plate; 16. Annular pressure frame; 17. Strip slide groove; 18. T-shaped slider; 19. Arc-shaped pressure block seat; 20. Inner buffer groove; 21. Inner threaded bending frame; 22. Threaded rotating rod; 23. Oil guide mesh groove; 24. Lateral groove; 25. Rectangular sleeve. Detailed Implementation

[0019] 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.

[0020] Please see Figures 1-8 This invention provides a technical solution: a transformer high-voltage winding end insulation support structure, including two winding clamps 1 arranged vertically, and a core support 2 fixedly connected to one side of each of the two winding clamps 1. There are three core supports 2. A winding coil 3 is fixedly installed on the surface of the core support 2. A wire-pressing insulation plate 4 is respectively provided at the top and bottom of the winding coil 3. The wire-pressing insulation plate 4 is sleeved on the surface of the core support 2. An arc-shaped slot 5 extending to the bottom is opened at the top edge of the wire-pressing insulation plate 4. Several arc-shaped slots 5 are arranged in a ring. A limiting wire fixing plate 6 is installed between the inner sides of the upper and lower arc-shaped slots 5. The limiting wire fixing plate 6 is vertically inserted to form a continuous fitting support surface around the winding, replacing the traditional narrow binding strap single-point constraint. Several limiting wire fixing plates 6 are provided. The limiting wire fixing plate 6 is in contact with the surface of the winding coil 3.

[0021] Furthermore, several limiting and fixing plates 6 are fixedly installed with bow-shaped support plates 7. The upper and lower parts of the surface of the bow-shaped support plates 7 are provided with concave grooves 8. Annular rings 9 are installed between the inner sides of the concave grooves 8 at the same height. The bow-shaped support plates 7 provide rigid arc support. The annular rings 9 are inserted into the concave grooves 8 to form an annular tension skeleton, which applies a uniform radial preload to the outer periphery of the winding.

[0022] In this configuration, a support frame 10 is slidably mounted on one side of each of the two winding clamps 1, and the number of support frames 10 is the same as the number of winding coils 3. A U-shaped groove 11 is formed on the side of the support frame 10 closest to the winding clamp 1, and the winding clamp 1 is located inside the U-shaped groove 11. A rectangular through groove 13 is formed on one side of the U-shaped groove 11, extending to the other side. Lateral grooves 24 are formed at the front and rear of the support frame 10. Threaded bolts 12 are threadedly connected to the top of the inner cavity of the lateral grooves 24 through an opening. Several threaded bolts 12 are provided, and the end of the threaded bolt 12 away from the winding coil 3 contacts the adjacent winding clamp 1. In this section, a lifting cylinder 14 is slidably installed on both sides of the inner cavity of the rectangular through groove 13 near the winding coil 3 through openings. The end of the lifting cylinder 14 near the winding coil 3 is fixedly connected to an annular pressure frame 16 through a fixing plate, and the annular pressure frame 16 is fixedly connected to one side of the adjacent pressure wire insulation disc 4. A pressure plate 15 is fixedly connected to the inner side of the lifting cylinder 14 located in the rectangular through groove 13.

[0023] Among them, the inner cavity of the U-shaped slide groove 11 is provided with strip-shaped slide grooves 17 on both sides near the winding coil 3. A T-shaped slider 18 is slidably installed on the inner side of the strip-shaped slide groove 17. An arc-shaped pressure block seat 19 is fixedly connected to one side of the T-shaped slider 18. The arc-shaped pressure block seat 19 is located inside the rectangular through groove 13 and is in contact with one side of the pressure plate 15.

[0024] The surface of the arc-shaped pressure block seat 19 is provided with an inner buffer groove 20 that extends to the rear. Both sides of the support plate frame 10 are fixedly connected with an internal threaded bending frame 21 by a fixing block. A threaded rotating rod 22 is rotatably installed on one side of the internal threaded bending frame 21 through an opening. One end of the threaded rotating rod 22 passes through the arc-shaped pressure block seat 19 and extends to the inner side of the inner buffer groove 20. The threaded rotating rod 22 is threadedly connected to the arc-shaped pressure block seat 19.

[0025] The inner sides of the wire insulation disk 4 and the support plate frame 10 are provided with iron core brackets 2 for use in conjunction with the iron core brackets 2. The surface of the wire insulation disk 4 is provided with oil guide grooves 23 that extend to the outside of the wire insulation disk 4, and there are several oil guide grooves 23 arranged in a ring.

[0026] In use, first, several support plate frames 10 are respectively fitted onto the upper and lower parts of the surface of the iron core bracket 2 using rectangular sleeves 25. Then, two winding clamps 1 are respectively installed on the top and bottom of the iron core bracket 2. The winding coil 3 is then installed on the surface of the iron core bracket 2, with the winding coil 3 positioned between the upper and lower pressure insulation discs 4. Then, the U-shaped slide groove 11 is used to slightly move laterally on the surface of the winding clamp 1, so that the pressure insulation disc 4 is aligned with the top and bottom centers of the winding coil 3. Then, tools are used to make lateral concave... Several threaded bolts 12 are screwed into the inner side of the groove 24, so that one end of the threaded bolt 12 in the U-shaped groove 11 abuts against one side of the winding clamp 1, thereby fixing the support plate frame 10 to the surface of the winding clamp 1 using the threaded bolts 12. Then, the bottom ends of several limiting wire fixing plates 6 are inserted into the arc-shaped slots 5 of the bottom wire pressing insulation disc 4. Then, two annular rings 9 are respectively inserted into the inner sides of the upper and lower concave ring grooves 8, and the arc-shaped bow of the bow-shaped support plate 7 abuts against the tight clamp of the annular rings 9, thereby fixing several limiting wire fixing plates 10 to the inner side of the winding clamp 1. The wire plate 6 presses tightly against the surface of the winding coil 3 for positioning. Then, the two threaded rods 22 at the top and bottom are turned respectively. After the threaded rods 22 are turned, the T-shaped slider 18 and the strip groove 17 guide the arc-shaped pressure block seat 19 to move inward to the inside of the rectangular through groove 13. This allows the arc-shaped surface of the arc-shaped pressure block seat 19 to press against the pressure plate 15. In turn, the lifting cylinder 14 and the annular pressure frame 16 push the wire insulation disk 4 to press against the top and bottom of the winding coil 3. This, together with the positioning and fixing wire plate 6, compresses the winding coil 3. The locking mechanism prevents loosening during prolonged use. Even if the winding coil 3 becomes loose during later use, the threaded rod 22 can push the arc-shaped pressure block seat 19 to press the pressure plate 15, allowing the wire insulation disc 4 to continue pressing the winding coil 3 and extending its service life. Furthermore, the opposing movement of the wire insulation disc 4 can maintain the limit of the wire fixing plate 6 using the arc-shaped slot 5. The function of the oil guide groove 23 ensures that the oil enters the inner side of the winding coil 3 stably for cooling.

[0027] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

Claims

1. A transformer high-voltage winding end insulation support structure, comprising two winding clamps (1) arranged vertically, characterized in that: Two winding clamps (1) are fixedly connected to a core support (2) on opposite sides, and there are three core supports (2). A winding coil (3) is fixedly installed on the surface of the core support (2). A wire insulation disc (4) is provided at the top and bottom of the winding coil (3). The wire insulation disc (4) is sleeved on the surface of the core support (2). An arc-shaped slot (5) extending to the bottom is opened at the top edge of the wire insulation disc (4). Several arc-shaped slots (5) are arranged in a ring. A limiting wire fixing plate (6) is installed between the inner sides of the upper and lower arc-shaped slots (5). Several limiting wire fixing plates (6) are provided. The limiting wire fixing plate (6) is in contact with the surface of the winding coil (3). A bow-shaped support plate (7) is fixedly installed on the surface of several of the limiting and fixing plates (6). The upper and lower parts of the surface of the bow-shaped support plate (7) are provided with concave grooves (8). An annular hoop (9) is installed between the inner sides of the concave grooves (8) at the same height. Support plate frames (10) are slidably installed on opposite sides of the two winding clamps (1), and the number of support plate frames (10) is the same as that of the winding coils (3). A U-shaped groove (11) is provided on the side of the support plate frame (10) near the winding clamp (1), and the winding clamp (1) is located inside the U-shaped groove (11). A rectangular through groove (13) is provided on one side of the U-shaped groove (11) and extends to the other side. Lateral grooves (24) are provided at the front and rear of the support plate frame (10). A threaded bolt (12) is connected to the top of the inner cavity of the lateral groove (24) by opening a threaded connection. Several threaded bolts (12) are provided. The end of the threaded bolt (12) away from the winding coil (3) is in contact with the adjacent winding clamp (1).

2. The transformer high-voltage winding end insulation support structure according to claim 1, characterized in that: The inner cavity of the rectangular through groove (13) is slidably mounted with lifting cylinders (14) on both sides near the winding coil (3) through openings. The end of the lifting cylinder (14) near the winding coil (3) is fixedly connected to an annular pressure frame (16) through a fixing plate, and the annular pressure frame (16) is fixedly connected to one side of the nearby pressure wire insulation disc (4). The lifting cylinder (14) is fixedly connected to a pressure plate (15) on the inner side of the rectangular through groove (13).

3. The transformer high-voltage winding end insulation support structure according to claim 2, characterized in that: The inner cavity of the U-shaped groove (11) is provided with strip grooves (17) on both sides near the winding coil (3). A T-shaped slider (18) is slidably installed on the inner side of the strip groove (17). An arc-shaped pressure block seat (19) is fixedly connected to one side of the T-shaped slider (18), and the arc-shaped pressure block seat (19) is located inside the rectangular through groove (13). The arc-shaped pressure block seat (19) is in contact with one side of the pressure plate (15).

4. The transformer high-voltage winding end insulation support structure according to claim 3, characterized in that: The surface of the arc-shaped pressure block seat (19) is provided with an inner buffer groove (20) that extends to the rear. Both sides of the support plate frame (10) are fixedly connected with an internal threaded bending frame (21) by a fixing block. A threaded rotating rod (22) is rotatably installed on one side of the internal threaded bending frame (21) by opening. One end of the threaded rotating rod (22) passes through the arc-shaped pressure block seat (19) and extends to the inner side of the inner buffer groove (20). The threaded rotating rod (22) is threadedly connected to the arc-shaped pressure block seat (19).

5. The transformer high-voltage winding end insulation support structure according to claim 4, characterized in that: The inner sides of the pressure wire insulation disk (4) and the support plate frame (10) are provided with iron core brackets (2) that cooperate with the iron core brackets (2). The surface of the pressure wire insulation disk (4) is provided with oil guide grooves (23) that extend to the outside of the pressure wire insulation disk (4), and there are several oil guide grooves (23) arranged in a ring.

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