Multi-section multi-layer continuous transformer coil and winding method thereof

Abstract

The present application relates to a kind of transformer multi-section multi-layer continuous coil and its winding method.The transformer multi-section multi-layer continuous coil includes insulating cylinder, coil body wound on the insulating cylinder and end insulation arranged at the both ends of coil body, coil body is divided into N sections (N≥1) along the axial direction, each section is wound as M layers (M≥2) along the radial direction, each section is connected in series by continuous wire in turn, and the whole is integral structure without welding joint;The number of turns of each section is distributed in increasing, decreasing or equal from inner layer to outer layer or trapezoidal distribution;Pad, end ring and angle ring are provided between adjacent sections;Insulating layer and axial oil channel are provided between layers;Strut is provided between insulating cylinder and coil and outermost layer to form cooling oil channel;Starting lead and ending lead are provided at both ends of coil.The coil can reduce interlayer voltage and intersegment voltage, which is conducive to improving field strength distribution, improving heat dissipation efficiency and mechanical strength, reducing welding points, and suitable for oil-immersed and dry-type power transformers.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and more specifically, to a multi-segment, multi-layer continuous coil for a transformer and its winding method, applicable to the high-voltage or low-voltage coils of oil-immersed power transformers and dry-type transformers. Background Technology

[0002] The transformer coil is the core component of the transformer, and its structural design directly affects the transformer's electrical performance, mechanical strength, heat dissipation effect, and service life.

[0003] Currently, common transformer coils mainly fall into two categories: multi-layer cylindrical coils and continuous coils. Traditional multi-layer cylindrical coils are wound in one continuous section, divided into several layers connected in series. This structure has the following drawbacks: First, the interlayer voltage is high, requiring more interlayer insulation material, leading to an increase in the coil's axial dimension and manufacturing cost. Second, the internal electric field distribution is uneven, resulting in large partial discharge and reduced insulation strength. Third, the coil lacks effective lateral oil channels, hindering transformer oil flow and reducing heat dissipation area. Fourth, the potential difference between the beginning and end of the coil is large, resulting in insufficient short-circuit and impact resistance. While existing continuous coils have improved upon these problems to some extent, they are mostly single-layer disc structures. When higher voltage levels or larger capacities are required, the axial dimension of the coil becomes excessively large, and the inter-segment connections are complex. Although some segmented multi-layer cylindrical coils achieve segmented winding, the segments need to be connected by welding or tap changers, increasing the number of solder points, reducing coil reliability, and the insulation and cooling channel design between segments is inadequate, affecting the overall coil performance and heat dissipation efficiency. In summary, existing transformer coils cannot simultaneously meet the requirements of reducing interlayer and inter-segment voltage, improving field strength distribution, increasing heat dissipation efficiency, and reducing solder joints.

[0004] Therefore, there is an urgent need to develop a transformer multi-segment multi-layer continuous coil and its winding method that can reduce interlayer voltage and inter-segment voltage, improve field strength distribution, increase heat dissipation efficiency, and at the same time ensure continuous coil winding and reduce solder joints. Summary of the Invention

[0005] The technical problem to be solved by this invention is that transformer coils have high interlayer voltage, uneven field strength distribution, poor heat dissipation, and many solder joints. The invention addresses how to reduce interlayer and intersegment voltage, improve field strength distribution, and increase heat dissipation efficiency, while ensuring continuous coil winding and reducing solder joints. This invention relates to a multi-segment, multi-layer continuous coil for transformers and its winding method.

[0006] To solve the above-mentioned technical problems, according to one aspect of the present invention, a multi-segment, multi-layer continuous coil for a transformer is provided, comprising: an insulating cylinder, a coil body wound on the insulating cylinder, and end insulation disposed at both ends of the coil body, wherein the coil body is divided into N segments along the axial direction, N≥1, each segment of the coil is wound radially into M layers, M≥2, and the segments of the coil are connected in series sequentially by a continuous conductor, and the coil body is wound by a single continuous conductor to form an integral structure without welded joints; the number of turns of each segment of the coil increases, decreases, or is equal or trapezoidal from the inner layer to the outer layer; an inter-segment insulation assembly is disposed between adjacent segments of the coil, the inter-segment insulation assembly including a pad, an end ring, and a corner ring; an interlayer insulation layer is disposed between adjacent layers of each segment of the coil, and at least some layers are provided with axial oil channels; axial oil channel support bars are disposed between the insulating cylinder and the coil body and on the outermost layer of the coil body, the axial oil channel support bars being used to form cooling oil channels; a starting lead and an ending lead are respectively disposed at both ends of the coil body.

[0007] According to an embodiment of the present invention, an oil channel between adjacent discs in each coil segment can be provided based on temperature rise calculations, and the oil channel between discs includes a single-ear pad and / or a double-ear pad.

[0008] According to an embodiment of the present invention, each segment of the coil may contain one or more discs, the number of discs in each segment of the coil may be the same or different, and the number of turns and the number of discs per layer of each segment of the coil are set independently according to the voltage distribution requirements.

[0009] According to an embodiment of the present invention, the number of coil layers in the same segment can be odd; when N>1, the number of layers in each coil segment is odd.

[0010] According to an embodiment of the present invention, the end ring may be an insulating paperboard or an insulating molded part, the corner ring is a threaded paper integrally molded structure, the two end faces of the corner ring are arranged at the ends of two adjacent coil segments, and the connecting surface of the corner ring is arranged on the radial inner or outer side of the coil.

[0011] According to an embodiment of the present invention, the axial oil passage may include axial oil passage support bars or pads disposed between layers, and the axial oil passage is filled with insulating oil or air.

[0012] According to an embodiment of the present invention, the coil body may be an oblong structure, an elliptical structure, or a circular structure.

[0013] According to an embodiment of the present invention, the coil body can be wound with multiple wires wound in parallel, and the wires are transposed between segments and layers.

[0014] According to an embodiment of the present invention, a tap may be provided on the coil body, and the tap is provided on the outermost layer of each coil segment.

[0015] According to another aspect of the present invention, a method for winding a multi-segment, multi-layer continuous coil of a transformer is provided, comprising the following steps: S1, mounting an insulating cylinder on a winding mold, and uniformly arranging axial oil channel supports along the circumference on the outer surface of the insulating cylinder; S2, starting from one end of the coil, using continuous wire to wind the first layer of the first segment of the coil on the insulating cylinder, after winding to a predetermined number of turns, laying an interlayer insulation layer and setting axial oil channel supports between the layers to form oil channels, and then winding the second layer of the first segment of the coil in the reverse direction, and so on to complete all M layers of the first segment of the coil; S3, setting an inter-segment spacer, an end ring and a corner ring at the end position of the first segment of the coil, and continuously transitioning the wire to the starting position of the second segment of the coil; S4, winding all M layers of the second segment of the coil in the manner of step S2; S5, repeating steps S3 and S4 to sequentially wind the Nth segment of the coil; S6, leading out a tap at the outermost layer of the predetermined segment, and leading out a starting lead and an ending lead at both ends of the coil body; S7, setting end insulation at both ends of the coil body to complete the coil winding.

[0016] According to an embodiment of the present invention, in step S2, the axial winding direction of each layer of coil can be alternately changed, adjacent layers are continuously transitioned by wires, and each layer of coil is set to an odd number of coils.

[0017] According to an embodiment of the present invention, in step S3, the wire can be continuously transitioned between the last layer of the first segment coil and the first layer of the second segment coil without being cut or welded in the middle; when N>1, the number of layers in each segment coil is an odd number of layers.

[0018] Compared with the prior art, the technical solution provided by the embodiments of the present invention can achieve at least the following beneficial effects:

[0019] The multi-segment, multi-layer continuous coil of the transformer according to the present invention, by dividing the coil body into multiple segments along the axial direction and winding each segment into multiple layers along the radial direction, can reduce the voltage level of each segment and the interlayer voltage of each layer, and reduce the amount of interlayer insulation material, thereby helping to reduce the coil radial dimension and reduce manufacturing costs.

[0020] The multi-segment, multi-layer, continuous coil of the transformer of the present invention, by making the number of turns of each segment of the coil increase, decrease, or be equal or trapezoidal from the inner layer to the outer layer, and by combining the setting of corner rings between segments, helps to make the electric field distribution inside the coil more uniform and reduce the amount of partial discharge.

[0021] The multi-segment, multi-layer continuous coil of the transformer of the present invention forms multiple cooling channels by setting up inter-segment oil channels, inter-layer axial oil channels, and oil channels between the insulating cylinder and the coil, which is conducive to smooth oil flow in the transformer, increasing the heat dissipation area and improving heat dissipation efficiency.

[0022] The multi-segment, multi-layer continuous coil of the transformer according to the present invention has the advantages of improving the overall compactness of the coil, balancing the ampere-turn distribution, and reducing leakage flux, thereby enhancing mechanical strength and short-circuit withstand capability.

[0023] The transformer multi-segment multilayer continuous coil of the present invention uses continuous wires to connect the coil segments in series, and the whole structure is an integral structure without welding joints, which can reduce the number of welding points and improve the electrical reliability of the coil.

[0024] The transformer of the present invention has a multi-segment, multi-layer continuous coil, which eliminates the need for turning the coil around or welding between segments during the coil winding process, thereby reducing the difficulty of operation and saving winding time. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0026] Figure 1 This is a schematic diagram illustrating the structure of a multi-segment, multi-layer, continuous coil of a transformer according to an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. Based on the described 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.

[0028] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a limitation of quantity, but rather indicate the presence of at least one.

[0029] Figure 1 This is a schematic diagram illustrating the structure of a multi-segment, multi-layer, continuous coil of a transformer according to an embodiment of the present invention.

[0030] like Figure 1 As shown, the multi-segment, multi-layer, continuous coil of the transformer includes: an insulating cylinder 1, a coil body 2 wound on the insulating cylinder 1, and end insulation 7 disposed at both ends of the coil body 2.

[0031] The coil body 2 is divided into N segments along the axial direction, where N≥1. Each segment is wound radially into M layers, where M≥2. The segments are connected in series by a continuous wire. The coil body 2 is formed by a single continuous wire, creating an integral structure without welded joints. The number of turns in each segment increases, decreases, or is equal or trapezoidal from the inner to the outer layers. Inter-segment insulation components are provided between adjacent segments, including pads, end rings 3, and corner rings 4. Inter-layer insulation layers 5 are provided between adjacent layers of each segment, and at least some layers have axial oil channels. Axial oil channel support bars 6 are provided between the insulating cylinder 1 and the coil body 2, as well as on the outermost layer of the coil body 2. These support bars form cooling oil channels. Starting leads 9 and ending leads 8 are provided at both ends of the coil body 2.

[0032] The multi-segment, multi-layer continuous coil of the transformer according to the present invention, by dividing the coil body into multiple segments along the axial direction and winding each segment into multiple layers along the radial direction, can reduce the voltage level of each segment and the interlayer voltage of each layer, and reduce the amount of interlayer insulation material, thereby helping to reduce the coil radial dimension and reduce manufacturing costs.

[0033] The multi-segment, multi-layer, continuous coil of the transformer of the present invention, by making the number of turns of each segment of the coil increase, decrease, or be equal or trapezoidal from the inner layer to the outer layer, and by combining the setting of corner rings between segments, helps to make the electric field distribution inside the coil more uniform and reduce the amount of partial discharge.

[0034] The multi-segment, multi-layer continuous coil of the transformer of the present invention forms multiple cooling channels by setting up inter-segment oil channels, inter-layer axial oil channels, and oil channels between the insulating cylinder and the coil, which is conducive to smooth oil flow in the transformer, increasing the heat dissipation area and improving heat dissipation efficiency.

[0035] The transformer multi-segment multilayer continuous coil of the present invention uses continuous wires to connect the coil segments in series, and the whole structure is an integral structure without welding joints, which can reduce the number of welding points and improve the electrical reliability of the coil.

[0036] According to one or more embodiments of the present invention, an oil channel is provided between adjacent discs in each coil segment based on temperature rise calculations, and the oil channel between discs includes a single-ear pad and / or a double-ear pad.

[0037] According to one or more embodiments of the present invention, each segment of the coil comprises one or more discs, the number of discs in each segment of the coil may be the same or different, and the number of turns and the number of discs per layer of each segment of the coil are independently set according to voltage distribution requirements.

[0038] The multi-segment, multi-layer continuous coil of the transformer according to the present invention has the advantages of improving the overall compactness of the coil, balancing the ampere-turn distribution, and reducing leakage flux, thereby enhancing mechanical strength and short-circuit withstand capability.

[0039] According to one or more embodiments of the present invention, the number of coil layers in the same segment is set to an odd number; when N>1, the number of layers in each segment of coil is an odd number.

[0040] According to one or more embodiments of the present invention, the end ring 3 is an insulating paperboard or an insulating molded part, the corner ring 4 is a threaded paper integrally molded structure, the two end faces of the corner ring 4 are arranged at the ends of two adjacent coil segments, and the connecting surface of the corner ring 4 is arranged on the radial inner or outer side of the coil.

[0041] According to one or more embodiments of the present invention, the axial oil passage includes axial oil passage support strips 6 or pads disposed between layers, and the axial oil passage is filled with insulating oil or air.

[0042] According to one or more embodiments of the present invention, the coil body 2 is an oblong, elliptical or circular structure.

[0043] According to one or more embodiments of the present invention, the coil body 2 is wound with multiple wires wound in parallel, and the wires are transposed between segments and layers.

[0044] According to one or more embodiments of the present invention, a tap 10 is provided on the coil body 2, and the tap 10 is provided on the outermost layer of each coil segment.

[0045] According to another aspect of the present invention, a method for winding a multi-segment, multi-layer, continuous coil of a transformer is provided, comprising the following steps:

[0046] S1. An insulating cylinder 1 is fitted onto the winding mold, and axial oil channel support strips 6 are evenly arranged along the circumference on the outer surface of the insulating cylinder 1.

[0047] S2. Starting from one end of the coil, the first layer of the first section of the coil 21 is wound on the insulating cylinder 1 using a continuous wire. After winding to the predetermined number of turns, the interlayer insulation layer 5 is laid and the axial oil channel support strip 6 is set between the layers to form an oil channel. Then, the second layer of the first section of the coil 21 is wound in the opposite direction. The entire M layers of the first section of the coil 21 are wound in this way.

[0048] S3. Set an inter-segment spacer, end ring 3 and corner ring 4 at the end of the first segment coil 21, and the wires continuously transition to the starting position of the second segment coil 22;

[0049] S4. Wind all M layers of the second section of coil 22 in the manner described in step S2;

[0050] S5. Repeat steps S3 and S4 to wind the Nth segment of the coil in sequence;

[0051] S6. Draw out tap 10 from the outermost layer of the predetermined section, and draw out starting lead 9 and ending lead 8 from both ends of the coil body 2.

[0052] S7. Set end insulation 7 at both ends of the coil body 2 to complete the coil winding.

[0053] According to one or more embodiments of the present invention, in step S2, the axial winding direction of each layer of coils alternates, adjacent layers are continuously transitioned by wires, and each layer of coils is set to an odd number of coils.

[0054] According to one or more embodiments of the present invention, in step S3, the wires are continuously transitioned between the last layer of the first coil segment 21 and the first layer of the second coil segment 22 without being cut or welded in the middle; when N>1, the number of layers in each coil segment is an odd number of layers.

[0055] The transformer of the present invention has a multi-segment, multi-layer continuous coil, which eliminates the need for turning the coil around or welding between segments during the coil winding process, thereby reducing the difficulty of operation and saving winding time.

[0056] The above description is merely an exemplary embodiment of the present invention and is not intended to limit the scope of protection of the present invention, which is determined by the appended claims.

Claims

1. A transformer with a multi-segment, multi-layer, continuous coil, wherein, include: The insulating cylinder, the coil body wound on the insulating cylinder, and the end insulation disposed at both ends of the coil body. The coil body is divided into N segments along the axial direction, where N≥1. Each segment of the coil is wound radially into M layers, where M≥2. The coil segments are connected in series by a continuous conductor. The coil body is formed by winding a single continuous conductor to create an integral structure without welded joints. The number of turns in each coil segment increases, decreases, or is equal or trapezoidal from the inner layer to the outer layer. An inter-segment insulation assembly is provided between adjacent coil segments, including a pad, end ring, and corner ring. An interlayer insulation layer is provided between adjacent layers of each coil segment, and at least some layers have axial oil channels. Axial oil channel support bars are provided between the insulating cylinder and the coil body, as well as on the outermost layer of the coil body. These axial oil channel support bars are used to form cooling oil channels. A starting lead and an ending lead are provided at both ends of the coil body.

2. The transformer multi-segment multi-layer continuous coil as described in claim 1, wherein, Each section of the coil has an oil channel between adjacent discs based on temperature rise calculations. The oil channel between discs includes a single-ear pad and / or a double-ear pad.

3. The transformer multi-segment multi-layer continuous coil as described in claim 1, wherein, Each coil segment contains one or more discs. The number of discs in each coil segment may be the same or different. The number of turns and the number of discs per layer in each coil segment are set independently according to the voltage distribution requirements.

4. The transformer multi-segment multi-layer continuous coil as described in claim 1, wherein, Within the same segment, each layer of coil is set to an odd number of layers; when N>1, the number of layers in each coil segment is an odd number.

5. The transformer multi-segment multi-layer continuous coil as described in claim 1, wherein, The end ring is an insulating paperboard or an insulating molded part, the corner ring is a threaded paper integrally molded structure, the two end faces of the corner ring are arranged at the ends of two adjacent coil segments, and the connecting surface of the corner ring is arranged on the radial inner or outer side of the coil.

6. The transformer multi-segment multi-layer continuous coil as described in claim 1, wherein, The axial oil passage includes axial oil passage support bars or pads disposed between layers, and the axial oil passage is filled with insulating oil or air.

7. The transformer multi-segment multi-layer continuous coil as described in claim 1, wherein, The coil body is provided with taps, which are located on the outermost layer of each coil segment.

8. A method for winding a multi-segment, multi-layer continuous coil for a transformer, wherein, Includes the following steps: S1. An insulating cylinder is fitted onto the winding die, and axial oil passage support bars are evenly arranged along the circumference on the outer surface of the insulating cylinder; S2. Starting from one end of the coil, the first layer of the first section of the coil is wound on the insulating cylinder using a continuous wire. After winding to the predetermined number of turns, an interlayer insulation layer is laid and an axial oil channel support bar is set between the layers to form an oil channel. Then, the second layer of the first section of the coil is wound in the opposite direction. The entire M layers of the first section of the coil are wound in this manner. S3. An inter-segment spacer, an end ring, and a corner ring are set at the end of the first segment coil, and the conductor continuously transitions to the starting position of the second segment coil. S4. Wind all M layers of the second section of the coil in the manner described in step S2; S5. Repeat steps S3 and S4 to wind the Nth segment of the coil in sequence; S6. Lead out a tap at the outermost layer of the predetermined section, and lead out a starting lead and an ending lead at both ends of the coil body; S7. End insulation is provided at both ends of the coil body to complete the coil winding.

9. The winding method as described in claim 8, wherein, In step S2, the axial winding direction of each layer of coils changes alternately, adjacent layers are continuously transitioned by wires, and each layer of coils is set to an odd number of coils.

10. The winding method as described in claim 8, wherein, In step S3, the wires transition continuously between the last layer of the first coil segment and the first layer of the second coil segment without being cut or welded in between; when N>1, the number of layers in each coil segment is an odd number.

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