A transformer grading tube and a transformer

Abstract

The application discloses a transformer voltage-sharing tube and a transformer, and relates to the technical field of transformers. The transformer voltage-sharing tube comprises a voltage-sharing tube, an insulating formed corner ring and a semiconductor crepe paper. A magnetic separation groove is arranged on the tube wall of the voltage-sharing tube. The insulating formed corner ring is installed at the slotted groove of the magnetic separation groove of the voltage-sharing tube. The semiconductor crepe paper is wound around the voltage-sharing tube and the insulating formed corner ring. The method solves the problems of eddy current aggregation and excessive temperature rise of a large-size metal voltage-sharing tube in a strong magnetic leakage area, effectively reduces the eddy current loss and the local temperature rise under the premise of guaranteeing the voltage-sharing shielding performance, and meets the design and operation requirements of low loss and high reliability of the transformer.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, specifically to a transformer equalizing tube and a transformer. Background Technology

[0002] During transformer operation, significant eddy current losses occur in areas with strong leakage magnetic fields and large structural components, easily leading to localized overheating and seriously threatening equipment safety. The equalizing tube, as a metal shielding cylinder between the winding leads and the bushing equalizing ball, is at the same potential as the leads and is a core component of the outgoing line device. It primarily serves to homogenize the electric field, prevent partial discharge, and also provides insulation support, lead protection, and optimizes equipment size. In actual layouts, the equalizing tube is often laid in the outgoing line area at the coil end, its path crossing above the main conductor, and sometimes even in phase-to-phase bridging configurations. This area is precisely within the coverage of a strong leakage magnetic field, and the metal cylindrical structure significantly cuts through magnetic lines of force, generating considerable eddy current losses. Simultaneously, its external multiple layers of insulation material limit heat dissipation, making overheating a particularly prominent issue. Autotransformers, due to their small structural capacity, stringent load loss requirements, and the limited core diameter resulting in a larger radial coil dimension and higher magnetic flux density in the main conductor, exhibit extremely complex leakage magnetic field distribution. The large amount of leakage flux intruding into structural components not only makes stray loss control difficult but also exacerbates the risk of localized overheating. Currently, the traditional enclosed metal equalizing tubes widely used in the industry have a complete circular tube structure with a large conducting area and low magnetic reluctance. In environments with high leakage flux, they easily couple a large amount of leakage flux, forming a significant eddy current loss concentration effect. Especially in the high leakage flux region of autotransformers, the excessive temperature rise of conventional equalizing tubes is a prominent problem. Long-term high-temperature operation will accelerate the thermal aging of the insulating paperboard and insulating oil, shorten the overall lifespan of the insulation system, and easily cause internal overheating faults, leading to abnormal oil chromatography data and posing safety hazards. Furthermore, the increased additional losses may cause the overall load loss to exceed the technical agreement limits, making it difficult to meet the design requirements for performance improvement and product iteration in high-end, low-loss autotransformers. Summary of the Invention

[0003] To address the problems of high eddy current loss and uneven local temperature rise distribution of existing traditional voltammetric tubes under strong leakage flux conditions in autotransformers, this invention proposes a transformer voltammetric tube that solves the problems of eddy current accumulation and excessive temperature rise in large-size metal voltammetric tubes in strong leakage flux areas. While ensuring the voltammetric shielding performance, it effectively reduces eddy current loss and lowers local temperature rise, meeting the design and operation requirements of transformers for low loss and high reliability.

[0004] To achieve the above objectives, the present invention provides the following technical solution.

[0005] In a first aspect, the present invention provides a transformer equalizing tube, comprising an equalizing tube, an insulating molded corner ring, and semiconductor crepe paper; the tube wall of the equalizing tube is provided with a magnetic shielding groove; the insulating molded corner ring is installed at the slot of the magnetic shielding groove of the equalizing tube; the semiconductor crepe paper is wound around the equalizing tube and the insulating molded corner ring.

[0006] As a further improvement of the present invention, the slot of the magnetic shielding groove is rounded.

[0007] As a further improvement of the present invention, the semiconductor crepe paper is wound around the outer surface of the equalizing tube, starting from the insulating molded corner ring at the tail of the equalizing tube, and returning after exceeding the set length of the magnetic shielding groove, and the edge of the semiconductor crepe paper is in close contact with the surface of the equalizing tube.

[0008] As a further improvement of the present invention, the number of magnetic isolation grooves, the circumferential angle, the groove width and the groove length are adjusted according to the diameter and length of the equalizing tube and the leakage magnetic field distribution of the transformer.

[0009] As a further improvement of the present invention, the length, thickness and angle of the insulating molded corner ring are adjusted according to the width and length of the magnetic shielding groove.

[0010] As a further improvement of the present invention, the end of the equalizing tube is rounded.

[0011] As a further improvement of the present invention, the end of the semiconductor crepe paper extends outward to form an insulating encapsulation region.

[0012] As a further improvement of the present invention, the insulating enclosure region has a gradually tapered transition.

[0013] As a further improvement of the present invention, the pressure equalizing tube is a metal pressure equalizing tube.

[0014] Secondly, the present invention provides a transformer, including the aforementioned transformer slotted equalizing tube.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention, by creating a magnetically insulating groove in the wall of the equalizing tube, fundamentally cuts off the closed-loop flow of eddy currents inside the tube, weakening the eddy current effect generated by strong leakage flux coupling. This solves the technical problem of high eddy current loss and excessive local temperature rise in conventional equalizing tubes under the condition of concentrated leakage flux in the main circuit of large-capacity autotransformers, ensuring that the stray loss of the entire unit meets the low-loss design requirements. At the same time, an insulating molded corner ring is installed at the groove to form a reliable electrical covering and isolation of the grooved section, avoiding the problem of sharp-corner electric field concentration caused by the groove in the tube wall. Combined with the semi-overlapping wrapping of semiconductor wrinkled paper on the outer surface of the tube, a gradually tapered insulating covering area is formed at the end of the insulating molded corner ring, effectively controlling the oil-paper composite electric field distribution in the grooved area of ​​the equalizing tube, eliminating the hidden danger of sharp discharge, and ensuring that the insulation tolerance level of the equalizing tube after grooved opening is not lower than that of the original circular structure, achieving a synergistic unity of low eddy current loss and high insulation reliability.

[0016] Furthermore, the number, circumferential angle, slot width, and slot length of the magnetic isolation slots can be flexibly adjusted according to the distribution of the leakage magnetic field inside the transformer. The length, thickness, and angle of the insulating forming corner rings can also be customized to match the slot size. The overall structure is simple to modify and easy to process and assemble. There is no need to make significant adjustments to the coil and main insulation layout. It has strong adaptability and can cover the mass production needs of autotransformers of different capacities and voltage levels. While significantly reducing the eddy current heating of the equalizing tube, extending the service life of the insulation material, and eliminating the risk of overheating faults such as abnormal oil chromatography, it also takes into account manufacturing costs and operational reliability, and effectively improves the long-term operational stability of the autotransformer. Attached Figure Description

[0017] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. In the drawings: Figure 1 This is a schematic diagram of the slotted pressure equalizing pipe structure of the present invention, wherein (a) is a cross-sectional view of the slotted pressure equalizing pipe and (b) is a side view of the slotted pressure equalizing pipe; Figure 2 This is a schematic diagram of the insulating molded corner ring structure of the present invention, wherein (a) is a cross-sectional view of the insulating molded corner ring, and (b) is a schematic diagram of the side view of the insulating molded corner ring; Figure 3 This is a schematic diagram of the assembly of the insulating molded corner ring and semiconductor crepe paper in the voltage equalization tube according to the present invention; wherein, (a) is a schematic diagram of the insulating molded corner ring and semiconductor crepe paper completed in the voltage equalization tube; (b) is a partial schematic diagram of region B after the insulating molded corner ring and semiconductor crepe paper are completed in the voltage equalization tube; Figure 4 The above are comparison diagrams of the temperature distribution cloud map of the equalizing tube before and after the improvement in Embodiment 1 of the present invention; wherein, (a) is the temperature distribution cloud map of the equalizing tube before the improvement; and (b) is the temperature distribution cloud map of the equalizing tube after the improvement. Figure 5This is a schematic diagram of the slotted pressure equalizing pipe structure in Embodiment 2 of the present invention; wherein, (a) is a side cross-sectional view of the pressure equalizing pipe in Embodiment 2; and (b) is a cross-sectional view of the pressure equalizing pipe in Embodiment 2. Figure 6 This is a schematic diagram of the slotted pressure equalizing pipe structure in Embodiment 3 of the present invention; wherein, (a) is a side cross-sectional view of the pressure equalizing pipe in Embodiment 3; and (b) is a cross-sectional view of the pressure equalizing pipe in Embodiment 3.

[0018] 1. Equalizing tube; 2. Insulating molded corner ring; 3. Semiconductor crepe paper; Detailed Implementation To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0019] 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 invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0020] To address the problems of high eddy current loss and uneven local temperature rise distribution of existing traditional voltage equalizing tubes under strong leakage magnetic field conditions in autotransformers, this invention proposes a transformer voltage equalizing tube, comprising a voltage equalizing tube 1, an insulating molded corner ring 2, and semiconductor corrugated paper 3.

[0021] The wall of the equalizing pipe 1 is provided with a magnetic shielding groove; the insulating molded corner ring 2 is installed at the groove of the magnetic shielding groove of the equalizing pipe 1; the semiconductor crepe paper 3 is wrapped around the equalizing pipe 1 and the insulating molded corner ring 2.

[0022] like Figure 1 As shown, grooves are cut into the wall of the equalizing pipe 1 to form magnetic shielding grooves, and the corners of the grooves are rounded. The inner and outer walls are polished smooth, without burrs or sharp corners. The number and angle of the grooves can be adjusted according to the characteristics of the equalizing pipe, such as diameter, length, and layout.

[0023] like Figure 2 As shown, the insulating molded corner ring 2 is bent into an angle shape, and the chamfer at the sharp corner is fitted with the chamfer of the magnetic shielding groove of the equalizing pipe 1 to ensure that there is still a gap after fitting. The length, thickness and angle of the insulating molded corner ring 2 can be adjusted according to the characteristics of the groove width, length and other features.

[0024] like Figure 3As shown, after installing the insulating forming corner ring 2, inspect the equalizing tube 1 and the insulating forming corner ring 2 to ensure there are no burrs, unevenness, or dirt. Begin wrapping the semiconductor crepe paper 3, starting from the insulating forming corner ring 2 at the tail of the equalizing tube 1, extending 50mm beyond the magnetic shielding groove, and then returning, completing one half-overlap round trip. Ensure the edge of the semiconductor crepe paper 3 is tightly attached to the metal surface of the equalizing tube, and perform insulation wrapping as required, extending the end outwards in a gradually tapered transition area.

[0025] Under the influence of an alternating magnetic field, the leakage magnetic field induces closed-loop currents in metal components, generating eddy currents, leading to heat generation and additional losses. Cutting off discontinuous conductive paths and segmenting eddy current regions significantly reduces eddy current losses and heat generation. The molded insulating corner ring 2 uses molded insulating components and modulates the oil-paper composite electric field through the insulating material, solving the problem of high-distortion electric fields at insulating ends, small-curvature tips, and edges. This avoids high concentration of electric fields, suppresses partial discharge, and improves tolerance levels.

[0026] The transformer equalizing tube described in this invention is manufactured by slotting, which reduces eddy current losses and lowers the temperature rise of the equalizing tube. Addressing the pain points of concentrated leakage flux in the main channel of autotransformers and the high eddy current losses of conventional round equalizing tubes, this invention, without compromising the basic functions of equalizing shielding and electric field balancing, uses a slotted structure in the metal equalizing tube wall to cut off the closed-loop flow of eddy currents inside the tube. This significantly weakens the eddy current effect generated by leakage flux coupling, significantly reduces the heat loss of the equalizing tube itself, avoids accelerated thermal aging of internal insulation components and insulating oil due to long-term high temperatures, eliminates the risk of overheating faults such as abnormal oil chromatography, and improves the long-term operational stability of the transformer and the service life of the insulation system. Simultaneously, it reduces the additional stray losses caused by the equalizing tube, keeping the overall load loss within the technical specification range, meeting the low-loss design requirements of autotransformers. Furthermore, this invention has a simple structural modification and is convenient to manufacture and assemble, requiring no major adjustments to the existing coil and main insulation layout. It can be adapted for mass production of various large-capacity, high-leakage-fluidity autotransformers, controlling manufacturing costs while ensuring electrical performance and operational reliability.

[0027] In summary, existing large-capacity autotransformers, constrained by design and cost, have limited core diameter and excessively large coil radial dimensions, resulting in high main channel magnetic flux density, complex internal leakage magnetic field distribution, and localized leakage flux concentration. Traditional integral metal equalizing tubes, under strong leakage flux conditions, easily couple a large amount of leakage flux, generating significant eddy current losses. This leads to excessively high local temperature rise and difficulty in controlling stray losses. Prolonged localized overheating accelerates the thermal aging of internal insulation materials, easily causing transformer oil chromatography abnormalities and other potential faults, severely impacting equipment reliability and service life, and failing to meet the technical requirements for low-loss products. Therefore, this invention provides a novel slotted equalizing tube structure. By creating through slots in the conventional equalizing tube wall, this invention effectively cuts off the closed loop of eddy currents inside the tube, reduces the effective conduction area of ​​eddy currents, fundamentally reduces the eddy current effect induced by leakage flux, and significantly reduces eddy current losses and localized temperature rise in the equalizing tube. Meanwhile, the matching structural design of the slotted insulating corner ring and the outer coating of the tube with semiconductor corrugated paper effectively optimizes the electric field distribution at the slotted position, ensuring the insulation performance and voltage equalization shielding effect of the equalizing tube. This invention features a simple structure and strong adaptability, allowing for flexible adjustment of the slotted angle, width, and length according to the transformer's leakage magnetic field distribution. Without compromising the transformer's insulation reliability and electrical performance, it effectively solves the technical problems of overheating and excessive stray losses in traditional equalizing tubes, significantly improving the operational stability and economic efficiency of autotransformers, and is suitable for the widespread application of various high-leakage-magnetic ...

[0028] The present invention will be further explained and illustrated below with reference to specific embodiments.

[0029] Example 1 In this embodiment, the equalizing tube 1 adopts a slotted structure. By reducing the eddy current area, the eddy current loss can be significantly reduced, the overheating risk during transformer operation can be reduced, and the stable operation of the transformer can be guaranteed.

[0030] Three-dimensional magnetic-thermal coupling simulation can accurately simulate the leakage magnetic field distribution under transformer operating conditions, and intuitively present the concentrated heating phenomenon caused by leakage magnetic cutting of conventional equalizing tubes and novel slotted equalizing tubes. Figure 4 The above, Figure 4 (b) The overall temperature rise of the slotted, optimized pressure equalizing pipe is much smaller than that of the others. Figure 4 (a) Traditional cylindrical pressure equalizing tubes, according to simulation and quantitative calculations, the maximum temperature rise of the slotted pressure equalizing tube can be reduced by about 50K compared with the conventional structure, with a significant cooling effect, which can solve the overheating problem caused by concentrated eddy current loss in the outgoing pressure equalizing components.

[0031] Example 2: Round off the end of the equalizing pipe 1, groove it into the wall to form a magnetic shielding groove, and round off the corners at the groove. Polish the inner and outer walls smooth, removing any burrs or sharp corners. For example... Figure 5As shown, the number and angle of the slots can be adjusted according to the diameter and length of the equalizing tube 1. The insulating forming corner ring 2 is bent into an angle, with the sharp corner chamfered to fit snugly against the chamfer of the slot in the equalizing tube 1, ensuring a gap remains after fitting. The length, thickness, and angle of the insulating forming corner ring 2 can be adjusted according to the width and length of the slot. After installing the insulating forming corner ring 2, inspect the equalizing tube 1 and the insulating forming corner ring 2 to ensure there are no burrs, unevenness, or dirt. The semiconductor crepe paper 3 begins to wrap, starting from the end of the equalizing tube 1 at the insulating forming corner ring 2, extending 50mm beyond the magnetically shielding groove, and then returning, completing one half-overlap round trip. Ensure the edge of the semiconductor crepe paper 3 is tightly attached to the metal surface of the equalizing tube, and perform insulation wrapping as required, extending the end outwards in a gradually tapered transition area.

[0032] Example 3: After welding, the equalizing tube 1 is polished smooth, and grooves are cut into its wall to form magnetic shielding grooves. The corners of these grooves are rounded, and both the inner and outer walls are polished smooth, free of burrs and sharp corners. The number and angle of the grooves can be adjusted according to the diameter and length of the equalizing tube. The insulating forming angle ring 2 is bent into an angle shape, with the chamfered corners fitting snugly against the chamfered grooves of the equalizing tube 1, ensuring a gap remains after fitting. The length, thickness, and angle of the insulating forming angle ring 2 can be adjusted according to the width and length of the grooves. After installing the insulating forming angle ring 2, inspect the equalizing tube 1 and the insulating forming angle ring 2 to ensure there are no burrs, unevenness, or dirt. The semiconductor crepe paper 3 begins to wrap, starting from the end of the equalizing tube 1 near the insulating forming angle ring 2, extending 50mm beyond the magnetic shielding groove length, and then returning, completing one half-overlap round trip. Ensure the edge of the semiconductor crepe paper 3 is tightly attached to the metal surface of the equalizing tube, and perform insulation wrapping as required, extending the end outwards in a gradually tapered transition area.

[0033] In summary, this invention creates a through-slot in the wall of a traditional integrated metal voltage equalizing tube, cutting off the closed path of eddy currents and suppressing eddy current heating induced by leakage flux at its source. This effectively weakens the eddy current loop inside the voltage equalizing tube, significantly reducing the temperature rise of structural components and additional eddy current losses, making it suitable for the high leakage flux operation of autotransformers. A molded insulating corner ring is fitted at the slot opening of the voltage equalizing tube to cover and isolate the slotted section, ensuring the electrical insulation strength at the slot opening and preventing local electric field concentration. The entire outer layer of the voltage equalizing tube is wrapped with multiple layers of semiconductor corrugated paper to optimize the overall electric field distribution and prevent partial discharge. The circumferential angle, slot width, and slot length of the voltage equalizing tube slot can be flexibly matched and adjusted according to the leakage flux density and leakage flux distribution area inside the transformer, adapting to autotransformers of different capacities and structures. The molded insulating corner ring can be custom-made to match the transformer insulation structure, coil size, and voltage level, ensuring precise assembly with the slot opening of the voltage equalizing tube.

[0034] Secondly, the present invention provides a transformer, including a transformer equalizing tube.

[0035] The transformer body and the slotted equalizing tubes assembled inside the transformer body, especially in the outgoing line area or near the main air circuit. The slotted equalizing tube includes equalizing tube 1, insulating molded corner ring 2, and semiconductor corrugated paper 3.

[0036] The equalizing pipe 1 is made of seamless steel pipe or welded formed pipe through integral processing. After welding, the weld is finely ground to ensure that the inner and outer surfaces of the pipe wall are smooth and flat, without any protrusions or pits. The ends of the equalizing pipe 1 are rounded to avoid electric field concentration at the sharp points. At least one magnetic isolation groove is opened through the circumference of the pipe wall of the equalizing pipe 1. The magnetic isolation groove is a through groove structure, and its opening direction can extend along the axial direction of the equalizing pipe. It can also be designed as an inclined groove or a segmented groove according to the actual leakage magnetic distribution. The edges of the magnetic isolation groove are all rounded, and the inner and outer walls of the equalizing pipe 1 are ground to a rough surface. The roughness is not higher than the set value. All burrs, sharp corners and metal flash are completely removed to prevent partial discharge caused by processing defects. The number of magnetic isolation grooves is determined according to the diameter of the equalizing tube 1 and the spatial distribution characteristics of the leakage magnetic field. For large-diameter equalizing tube 1 or strong leakage magnetic area, multiple uniform or non-uniform magnetic isolation grooves can be set. The circumferential angle can be flexibly adjusted within the range of 0° to 180° so that the groove opening direction forms the optimal cutting relationship with the main leakage magnetic path to cut off the eddy current closed loop to the greatest extent. Customized slotting design for autotransformers with different capacities and leakage magnetic characteristics.

[0037] The insulating molded corner ring 2 is made of high-density insulating paperboard or molded insulating parts, and is processed into an angled cross-section by hot pressing or bending. Its bending angle is adapted to the shape of the groove opening of the magnetic shielding groove, usually a right angle or obtuse angle structure. The sharp corner of the corner ring is also processed with a chamfer. The chamfer radius is consistent with the chamfer radius of the slot of the voltage equalizing pipe magnetic shielding groove, ensuring that the two can fit tightly during assembly, but still retain a uniform gap after fitting. This gap facilitates installation and operation, and can also form an oil gap after oil immersion, optimizing the local electric field distribution. The length, thickness and bending angle of the insulating molded corner ring 2 can be adjusted according to the actual groove width and length of the magnetic shielding groove and the diameter of the voltage equalizing pipe. The length of the corner ring should not be less than the length of the magnetic shielding groove, and it usually extends 10mm to 30mm beyond each end of the groove to ensure complete coverage and isolation of the grooved cross-section. The thickness of the insulating molded corner ring 2 is selected according to the voltage level, and the bending angle matches the chamfer of the groove opening, so that the insulating molded corner ring 2 can be stably fitted into the groove opening without slippage. During assembly, the insulating molded corner ring 2 is snapped into the magnetic shielding groove position of the equalizing tube, so that the inner surface of the insulating molded corner ring 2 is against the chamfered surface of the groove opening, and the outer surface of the insulating molded corner ring 2 smoothly transitions with the outer wall of the equalizing tube, thereby completely covering the sharp metal edge of the groove opening and avoiding distortion and concentration of the electric field at the edge of the groove opening. After installing the insulating forming corner ring 2, a comprehensive cleaning inspection of the equalizing tube and corner ring is required to ensure that the surface is free of burrs, unevenness, oil stains, or metal dust and other contaminants. Then, the winding of the semiconductor crepe paper 3 begins. The winding starting position of the semiconductor crepe paper 3 is set at the tail of the equalizing tube, near the root of the insulating forming corner ring on the side close to the outlet end. The winding direction is along the axial direction of the equalizing tube towards the magnetic isolation groove area. The winding length must exceed the edge of the magnetic isolation groove end by at least 50mm. Then, it returns along the same path, maintaining the same overlap rate as the forward direction, completing one half-overlap round trip, meaning each layer of paper covers half the width of the previous layer. During the winding process, it is essential to ensure that the edges of the semiconductor crepe paper are tightly attached to the metal surface of the equalizing tube 1, without any lifting, air bubbles, or other defects. The paper tape is wrinkled and has uniform tension, with tight interlayer compaction to ensure good electrical contact and potential balance between the semiconductor crepe paper and the wall of the equalizing tube. After the semiconductor crepe paper 3 is wound, its end continues to extend outward for a certain length to form an insulating wrapping area. This wrapping area gradually narrows outward along the axis of the equalizing tube. A stepped decreasing winding method of multi-layer insulating paper tape is used to create a gradually tapered transition structure to smoothly release the surface potential gradient and prevent electric field concentration at the end of the wrapping area. The entire semiconductor crepe paper 3 wrapping layer covers the magnetic shielding groove of the equalizing tube 1, the insulating forming corner ring 2, and part of the adjacent metal tube wall, so that the slotted area is completely wrapped within the semiconductor crepe paper. At the same time, it connects with the adjacent insulating structure through the gradually tapered transition to form a continuous and smooth insulating barrier.

[0038] The structural design of the transformer slotted equalizing tube can be flexibly adjusted according to parameters such as leakage magnetic field distribution, voltage level, and insulation distance under the actual operating conditions of the transformer. The width, length, number, and angle of the magnetic isolation slots can be optimized according to the magnitude and concentration area of ​​the leakage magnetic field density. The size and material thickness of the insulating molded corner ring 2 can be customized according to the requirements of withstand voltage and partial discharge initiation voltage. The number of layers of semiconductor corrugated paper 3 can be selected according to the surface potential distribution requirements of the equalizing tube, thereby achieving personalized adaptation for different models and capacities of autotransformers. By integrating the aforementioned slotted equalizing tube assembly, the transformer effectively cuts off the eddy current closed loop in the metal body of the equalizing tube while ensuring that the equalizing shielding and electric field balancing functions are not affected. This significantly reduces eddy current losses and local overheating caused by leakage flux coupling. At the same time, with the help of the electric field regulation effect of the insulating molded corner ring 2 and the potential balancing effect of the semiconductor wrinkled paper, the insulation strength of the slotted area is ensured to be no less than that of the traditional round equalizing tube. This keeps the stray losses of the entire transformer within the range specified in the technical agreement, ensures stable temperature rise during long-term operation, slows down the thermal aging rate of the insulation material, and eliminates potential overheating faults such as abnormal oil chromatography. As a result, the reliability and service life of the transformer under strong leakage flux conditions are greatly improved.

[0039] This invention does not require changes to the existing coil main insulation layout and core structure of the transformer, and is suitable for the mass production of various large-capacity, high leakage flux autotransformers, enabling significant performance improvements with relatively low cost.

[0040] Many embodiments and applications beyond the examples provided will be apparent to those skilled in the art upon reading the foregoing description. Therefore, the scope of this teaching should not be determined by reference to the foregoing description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including disclosures in patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed inventive subject matter.

[0041] The above content provides a further detailed description of the present invention. It should not be construed that the specific embodiments of the present invention are limited to this. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the scope of protection of the present invention as defined by the submitted claims.

Claims

1. A transformer equalizing tube, characterized in that, Including equalizing tube (1), insulating molded corner ring (2) and semiconductor crepe paper (3); The wall of the equalizing tube (1) is provided with a magnetic shielding groove; the insulating molded corner ring (2) is installed at the slot of the magnetic shielding groove of the equalizing tube (1); the semiconductor crepe paper (3) is wrapped around the equalizing tube (1) and the insulating molded corner ring (2).

2. The transformer equalizing tube according to claim 1, characterized in that, The groove of the magnetic shielding groove has rounded corners.

3. A transformer equalizing tube according to claim 1, characterized in that, The semiconductor crepe paper (3) is wrapped around the outer surface of the equalizing tube (1), starting from the insulating shaped corner ring (2) at the tail of the equalizing tube (1), and returning after exceeding the set length of the magnetic shielding groove, with the edge of the semiconductor crepe paper (3) closely attached to the surface of the equalizing tube (1).

4. A transformer equalizing tube according to claim 1, characterized in that, The number of magnetic isolation grooves, their circumferential angle, groove width, and groove length are adjusted according to the diameter and length of the equalizing pipe (1) and the distribution of the transformer leakage magnetic field.

5. A transformer equalizing tube according to claim 1, characterized in that, The length, thickness and angle of the insulating molded corner ring (2) are adjusted according to the width and length of the magnetic shielding groove.

6. A transformer equalizing tube according to claim 1, characterized in that, The end of the equalizing pipe (1) is rounded.

7. A transformer equalizing tube according to claim 1, characterized in that, The end of the semiconductor crepe paper (3) extends outward to form an insulating encapsulation area.

8. A transformer equalizing tube according to claim 7, characterized in that, The insulation enclosure area has a gradually tapered transition.

9. A transformer equalizing tube according to claim 1, characterized in that, The equalizing pipe (1) is a metal equalizing pipe.

10. A transformer, characterized in that, Includes the slotted equalizing tube for transformers as described in any one of claims 1 to 9.

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