Self-adhesive transposed conductor and winding coil manufacturing method thereof

Abstract

The invention relates to a self-adhesive transposed conductor and a manufacturing method of a winding coil of the self-adhesive transposed conductor, the transposed conductor is coated with an insulating layer, and the insulating layer is formed by alternately, continuously and tightly wrapping an insulating material without adhesive dispensing paper and the adhesive dispensing paper in multiple layers; the method comprises the following steps that in the paper wrapping link of the self-adhesive transposed conductor, adhesive dispensing paper and an insulating material without the adhesive dispensing paper alternately wrap the self-adhesive conductor in multiple layers, and the outermost layer is the insulating material without the adhesive dispensing paper; the wrapped transposed conductor is wound into a coil, when the coil is arranged, a plug cushion block is used in a horizontal oil duct of the conductor for pressing operation, then the coil is dried, and the insulation paper of the conductor turn at the position of the plug cushion block is firmly and flatly bonded on the conductor; after the plugged cushion block is removed, the size of the horizontal oil duct can be well guaranteed, turn insulation is guaranteed to be free of wrinkles and dead oil, and the temperature rise of the winding is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of power transmission and transformation equipment manufacturing and application, and in particular to a self-adhesive transposed conductor and a method for manufacturing a winding coil thereof. Background Art

[0002] In the design and manufacture of power transformers, transposed conductors are a widely used conductor structure, especially in large-capacity and high-voltage transformers. They can effectively reduce the current unevenness in the winding, reduce losses, and improve electrical performance. Traditional transposed conductors usually use self-adhesive insulating materials to ensure the structural stability of the conductor winding.

[0003] However, as transformers develop towards high capacity and high voltage, existing self-adhesive insulation materials gradually expose some problems, especially when the size and thickness are large, the turn insulation is prone to a large number of local bulges and poor adhesion, which in turn affects the smoothness and heat dissipation performance of the oil channel. This may not only cause overheating of the transformer, but also increase the risk of partial discharge, affecting the long-term operation reliability of the equipment.

[0004] In the prior art, see the attached Figure 1-2 , Figure 1 It is shown that the transposed conductor requires a hexagonal AF with paper insulation. Figure 2 The traditional self-adhesive transposed conductor structure is used for paper-wrapped insulation. It can be found that when the insulating material without dispensing paper is wound into a coil, there will inevitably be a gap between the conductor and the insulating paper, especially for large-sized conductors or coils with smaller diameters. In addition, in the subsequent process, Figure 1 The sides B and F shown in the figure are prone to cause insulation protrusions, which will reduce the oil channels between the cakes on the one hand, and on the other hand, the poor fluidity of the insulating oil inside the paper package will greatly affect the heat dissipation of the winding.

[0005] It can be seen that the traditional winding coil is prone to local expansion or deformation of the insulation layer due to the loose bonding between the insulation material and the surface of the wire in a high temperature environment, which in turn affects the performance and safety of the transformer. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a method for manufacturing a winding coil of a self-adhesive transposed conductor to solve the problem of temperature rise of a power transformer winding.

[0007] The present invention provides the following technical solutions:

[0008] A self-adhesive transposed conductor comprises a plurality of enameled flat wires combined into two rows whose wide surfaces are mutually contacting, and transposition is performed in the same direction along the narrow surface above and below the two rows of enameled flat wires, and the transposed conductor is coated with an insulating layer, wherein the insulating layer is formed by alternating and continuously and tightly wrapping multiple layers of insulating material without dotted paper and dotted paper; the dotted paper comprises a high temperature resistant fiber substrate.

[0009] Among them, the outermost layer of the wire insulation layer is dotted paper, and the thickness of each layer of dotted paper increases layer by layer from the inside to the outside; each layer of dotted paper includes glue dots on both sides, and the double sides of the dotted paper are coated with evenly distributed thermosetting adhesive.

[0010] A method for manufacturing a winding coil of a self-adhesive transposed conductor comprises the following steps:

[0011] Step S1, treating the surface of the transposed conductor before wrapping with paper;

[0012] Step S2, determining the type of the innermost turn insulation according to the number of layers of turn insulation paper, so as to ensure that the outermost layer after alternate wrapping is an insulation material without dotted paper;

[0013] Step S3, alternately wrapping the glue-dot paper and the insulating material without the glue-dot paper on the transposed conductor, and the outermost layer is the insulating material without the glue-dot paper;

[0014] Step S4, winding the coated wire into a coil, and before drying, inserting a pad in the horizontal oil channel where the insulation layer is located to perform a compacting operation;

[0015] Step S5, after the coil is dried, the dried coil is arranged and the pads plugged in the oil channel are removed.

[0016] Furthermore, the heating temperature of the drying equipment is controlled between 120°C±5°C and the duration is more than 24 hours.

[0017] Furthermore, the thermal expansion coefficient of the transposed conductor matches that of the dispensing paper.

[0018] Furthermore, in step S4, uniform mechanical pressure is applied to the gasket block to ensure that the turn insulation at the horizontal oil channel is flatly and firmly bonded to the conductor.

[0019] The present invention has the following beneficial technical effects:

[0020] The present invention proposes an innovative method for manufacturing a self-adhesive transposed conductor and a winding coil thereof, which can effectively reduce the temperature rise of the power transformer winding, ensure the stability of the winding under high load, and reduce the transformer oil channel to improve economy; the present invention uses dispensing paper that can be firmly bonded to the surface of the conductor after high-temperature drying to form a uniform insulation layer, effectively avoiding local bulging of the insulation layer during coil winding.

[0021] The present invention also uses a plugging block to perform a compacting operation in the oil channel formed on the surface of the insulating layer. The plugging block applies uniform mechanical pressure during the drying process to ensure close adhesion between the insulating layer and the surface of the wire, ensure the flatness of the winding oil channel, and prevent the oil channel from being blocked.

[0022] The present invention also designs a multi-layer structure for the insulation layer, and the glue point distribution and thickness of each layer of glue paper are optimized to improve the tensile strength and mechanical deformation resistance of the insulation layer, thereby enhancing the structural stability of the wire winding under the impact of short-circuit current. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the edge structure of the transposed conductor in the prior art;

[0024] Figure 2 It is a structural schematic diagram of a common insulating paper self-adhesive transposed conductor in the prior art;

[0025] Figure 3 It is a structural schematic diagram of the self-adhesive transposed conductor of the dispensing paper of the present invention.

[0026] The reference numerals in the figure are:

[0027] 1. Transposed conductor; 2. Paper-wrapped insulation; 3. Insulation layer. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example

[0030] See attached Figure 1 , 3 The present invention discloses a self-adhesive transposed conductor, comprising a plurality of enameled flat wires combined into two rows whose wide sides are in contact with each other, and transposition is made in the same direction along the narrow side above and below the two rows of enameled flat wires, and the transposed conductor 1 is coated with an insulating layer 3, and the insulating layer 3 is formed by multiple layers of alternating, continuous and tight wrapping of insulating material without dotted paper and dotted paper; the dotted paper includes a high-temperature resistant fiber substrate. The dotted paper is a special material that combines a high-viscosity thermosetting adhesive and a high-temperature resistant fiber substrate, which can provide excellent adhesion at high temperatures and ensure the uniformity and stability of the insulating layer 3. The structural design of the dotted paper enables it to firmly bond with the surface of the conductor during the drying process to avoid local expansion or falling off during the temperature rise process (see attached Figure 2 The protrusion caused by the traditional paper-wrapped insulation 2) 。

[0031] The outermost layer of the insulating layer 3 is an insulating material without dotted paper, that is, ordinary insulating paper, and the innermost layer is dotted paper-ordinary insulating paper-dotted paper-ordinary insulating paper... until the innermost layer (the innermost layer is in contact with the wire), and the innermost layer can be either with or without dotted paper. After the alternating self-adhesive transposed conductor of the dotted paper and the insulating material without dotted paper is wound into a coil, the insulating layer 3 is ensured to be completely flatly adhered to the wire by plugging the horizontal oil channel with a pad.

[0032] The distribution and thickness of the glue dots of each layer of glue paper are optimized and designed according to actual use requirements to ensure the bonding effect and electrical performance, so as to ensure the stability and long-term durability of the insulation of the turn coil. In this embodiment, the thickness of each layer of glue paper increases layer by layer from the inside to the outside, and the distribution density of the glue dots of each layer of glue paper increases layer by layer from the inside to the outside.

[0033] The present invention also discloses a method for manufacturing a winding coil of a self-adhesive transposed conductor, comprising the following steps:

[0034] First, the conductor material is pretreated, and the surface of the wire is treated before insulation wrapping to enhance its adhesion with the insulation layer 3; the type of the innermost turn insulation is determined according to the number of layers of turn insulation paper to ensure that the outermost layer after alternating wrapping is an insulation material without dotted paper;

[0035] See attached Figure 3 Ordinary insulating paper (insulating material without dotted paper) and dotted paper are alternately and continuously wrapped tightly in multiple layers along the six sides AF of the conductor. The surface of the ordinary insulating paper is coated with self-adhesive glue, and the surface of the dotted paper is coated with evenly distributed thermosetting adhesive. Each layer of dotted paper includes glue dots on both sides; the dotted paper can be firmly bonded to the surface of the conductor after high-temperature drying and pressing to form a uniform insulating layer 3, effectively avoiding local bulging of the insulating layer 3 during thermal expansion and contraction.

[0036] The transposed conductor 1 coated with the insulating layer 3 is placed in a drying device, and the heating temperature is controlled at 120°C ± 5°C for more than 24 hours to ensure that the thermosetting adhesive in the dispensing paper is completely cured.

[0037] During the drying process, a plugging block is used to perform a pressing operation in the horizontal oil channel on the surface of the conductor insulation layer 3. During the drying process, a uniform mechanical pressure is applied to the plugging block to ensure that the insulation layer 3 fits tightly with the surface of the conductor, and to ensure the flatness of the winding oil channel to prevent the oil channel from being blocked. Through the combined effect of temperature and pressure, the turn insulation layer 3 and the conductor achieve the best bonding effect, while enhancing the insulation layer 3's ability to resist electrical breakdown and mechanical stress.

[0038] After the conductor and the insulating layer 3 are coated, the conductor is wound into a coil. After the above process, the surface of the conductor is inspected to ensure uniform adhesion between the turn insulating layer 3 and the conductor surface to avoid possible delamination, bulging or deformation of the insulating layer 3 during curing.

[0039] By using the insulating layer 3 with dotted paper as the turn insulation and using plugging blocks to compact the oil channels on the conductor surface during the drying process, significant improvements have been achieved in improving the conductor structure strength, ensuring the patency of the oil channels and improving the overvoltage resistance.

[0040] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A self-adhesive transposed conductor, comprising a plurality of enameled flat wires combined into two rows whose wide sides are in contact with each other, transposition is performed in the same direction along the narrow side on the upper and lower sides of the two rows of enameled flat wires, and the transposed conductor is covered with an insulating layer, characterized in that: The insulating layer is formed by alternately and continuously wrapping insulating material without dotted paper and dotted paper in multiple layers; the dotted paper includes a high-temperature resistant fiber substrate.

2. A self-adhesive transposed conductor according to claim 1, characterized in that: The outermost layer of the insulating layer is an insulating material without glue-dotting paper.

3. A self-adhesive transposed conductor according to claim 1, characterized in that: The thickness of each layer of dispensing paper increases gradually from the inside to the outside.

4. A self-adhesive transposed conductor according to claim 1, characterized in that: Each layer of the dotted glue paper includes glue dots on both sides, and both sides of the dotted glue paper are coated with evenly distributed thermosetting adhesive.

5. A method for manufacturing a winding coil of a self-adhesive transposed conductor according to any one of claims 1 to 4, characterized in that: The following steps are included: Step S1, treating the surface of the transposed conductor before insulation; Step S2, determining the type of the innermost turn insulation according to the number of layers of turn insulation paper, so as to ensure that the outermost layer after alternately wrapping the paper is insulation without dotted paper; Step S3, alternately wrapping the glue-dot paper and the insulating material without the glue-dot paper on the transposed conductor, wherein the surface of the glue-dot paper is coated with a thermosetting adhesive evenly distributed; Step S4, winding the coated wire into a coil, inserting a pad into the horizontal oil passage of the coil before drying to perform a compacting operation and then drying; Step S5, after the coil is baked, remove the pads plugged in the horizontal oil channel.

6. The method for manufacturing a winding coil of a self-adhesive transposed conductor according to claim 5, characterized in that: The heating temperature of the drying equipment is controlled at 120°C ± 5°C, and the duration is more than 24 hours.

7. The method for manufacturing a winding coil of a self-adhesive transposed conductor according to claim 5, characterized in that: The self-adhesive transposed conductor matches the thermal expansion coefficient of the dispensing paper.

8. The method for manufacturing a winding coil of a self-adhesive transposed conductor according to claim 5, characterized in that: In step S4, uniform mechanical pressure is applied to the gasket block to ensure that the turn insulation at the horizontal oil channel is flatly and firmly bonded to the conductor.

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