Corona protection assembly for stator winding of large generator

Abstract

The utility model discloses a large-scale generator stator winding corona protection assembly, which relates to the technical field of generator stator windings and comprises a plurality of groups of winding bars and cushion blocks distributed among the winding bars, first filling layers are arranged on the outer sides of the winding bars and the cushion blocks, and first binding layers are arranged on the outer sides of the cushion blocks and the joints of the winding bars and the cushion blocks. A first binding layer is arranged on the outer side of the cushion block, a second binding layer is arranged on the outer side of the first binding layer, a second filling layer is arranged on the outer side of the first binding layer and the outer side of the second binding layer, an inner protection layer is arranged on the outer side of the first filling layer and the outer side of the second filling layer, and an outer protection layer is arranged on the outer side of the inner protection layer. The first binding layer and the second binding layer are formed, all gaps between the winding bar and the cushion block are filled fully, and the winding bar, the cushion block, the glass tape, the first filling layer and the second filling layer are dried at the same time to form a whole, so that the gaps can be prevented from being formed, and the gap problem that corona is easily caused is thoroughly eliminated.

Description

Technical Field

[0001] This utility model relates to the field of generator stator winding technology, specifically to a large generator stator winding corona protection component. Background Technology

[0002] As my country's hydropower development progresses, hydropower station sites are gradually extending into the middle and upper reaches of rivers, leading to the entry of power stations into deep mountain and canyon areas, which gradually restricts the external transportation conditions of the projects. The overall size and weight of the stator of large hydro-generators often exceed the transportation restrictions of the projects. The stator base is often transported to the site in segments, then assembled into a circle, followed by processes such as stator core lamination and stator bar unwinding.

[0003] After installation, the stator windings of large generators need to be filled with putty. After the putty is filled, hardened, and sanded, it is bound again. Because the putty contains mica powder, it is very easy to produce sharp corners and burrs after hardening, which increases the difficulty of subsequent sanding. It is very difficult to sand the pad after filling the putty smoothly, resulting in gaps between the binding and the putty during subsequent binding. These gaps reduce the radius of curvature of the electric field on the coil surface and increase the surface electric field strength, which makes it easy for corona discharge to occur. To address this, we propose a corona protection component for the stator windings of large generators. Utility Model Content

[0004] This utility model addresses the shortcomings of existing technologies by providing a corona protection component for the stator winding of a large generator. By binding the outer side of the pad and the connection between the rod and the pad in a softened state of the first filling layer, a first binding layer and a second binding layer are formed, which fully fills all gaps between the rod and the pad. Moreover, the rod, the pad, the glass ribbon, the first filling layer and the second filling layer are dried simultaneously to form a whole, thus preventing the formation of gaps and completely eliminating the gap problem that easily causes corona.

[0005] To solve the above-mentioned technical problems, this utility model solves the stator winding corona problem of large generators through the following technical solution.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A corona protection assembly for a large generator stator winding includes multiple sets of rods and spacers distributed between the rods. A first filling layer is provided on the outside of the rods and spacers, filling the gaps on the surface of the rods and the gaps between the rods and spacers. A first binding layer is provided on the outside of the spacers and at the connection between the rods and spacers. A second binding layer is provided on the outside of the first binding layer. A second filling layer is provided on the outside of the first binding layer and the second binding layer, filling the gaps on the outside of the first binding layer and the second binding layer. An inner protective layer is provided on the outside of the first filling layer and the second filling layer. An outer protective layer is provided on the outside of the inner protective layer to protect the rods and spacers.

[0008] Preferably, the first filling layer is a putty layer, which is used to fill the gap between the wire rod and the pad, and the right angle of contact between the wire rod and the pad is rounded with putty.

[0009] Preferably, both the first binding layer and the second binding layer are composed of glass ribbon. Wrapping glass ribbon at the end of the generator winding can enhance the winding end's resistance to corona corrosion, oil corrosion, air corrosion, etc., thereby extending the service life of the motor.

[0010] Preferably, the glass ribbon in the first binding layer is longitudinally wrapped around the outside of the pad and at the connection between the pad and the wire rod, and the glass ribbon in the second binding layer is transversely wrapped around the outside of the pad and the first binding layer. The two sets of glass ribbons are wrapped in a cross shape at the end of the winding, which can improve the binding strength of the two sets of binding layers and reduce the exposure of the internal wire rod when the glass ribbon in the binding group breaks.

[0011] Preferably, the portion of the first binding layer at the connection between the wire bar and the pad is rounded, so that the glass ribbon is evenly wrapped around the outside of the first filling layer, avoiding gaps after binding. At the same time, the rounded corners can also make the stress distribution more uniform, reduce stress concentration, improve the impact and vibration resistance of the area, and thus enhance the overall structural strength.

[0012] Preferably, the second filler layer is a resin layer. After the resin dries, sharp corners and burrs can be removed, making all winding surfaces smooth, thereby preventing corona discharge caused by burrs.

[0013] Preferably, the inner protective layer is an auxiliary paint layer. The auxiliary paint layer is fine and is applied to the outside of the second filler layer to achieve the effect of corona protection.

[0014] Preferably, the outer protective layer consists of a primer layer and a topcoat layer to achieve the purpose of dustproofing and moisture-proofing.

[0015] Preferably, the inner protective layer has two auxiliary paint layers. The second layer is applied after the first auxiliary paint layer has cured. The superposition of the two paint layers can more effectively cover the defects and unevenness of the substrate, making the coating surface smoother and more even.

[0016] Preferably, the resin of the second filler layer penetrates into the gap between the glass ribbons in the first and second binding layers, preventing gaps from forming between the glass ribbons in the binding layers. The glass ribbons and resin form a whole, resulting in higher strength.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This invention binds the outer side of the pad and the connection between the wire rod and the pad in the softened state of the first filling layer, forming a first binding layer and a second binding layer, which fills all the gaps between the wire rod and the pad. Moreover, the wire rod, the pad, the glass ribbon, the first filling layer and the second filling layer are dried at the same time to form a whole, which can avoid the formation of gaps and completely eliminate the gap problem that is very easy to cause corona.

[0019] By setting two sets of binding layers, with the glass ribbons of the two sets of binding layers intersecting in a cross shape, the strength of the binding layer after binding can be guaranteed. At the same time, the glass ribbons of the binding layer are soaked in resin in advance to ensure that there are no gaps in the binding layer after binding, and that it forms a whole with the outer second filling layer after drying.

[0020] By setting two sets of inner protective layers consisting of auxiliary paint layers on the outside of the second filler layer, and applying the second layer after the first auxiliary paint layer has cured, the superposition of the two paint layers can more effectively cover the defects and unevenness of the substrate, making the coating surface smoother and more even, thereby preventing the occurrence of corona discharge. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0023] Figure 2 This is a schematic diagram showing the connection between the wire rod and the pad block of this utility model;

[0024] Figure 3 This is a front view schematic diagram of the overall structure of this utility model;

[0025] Figure 4 This is a cross-sectional view of the overall structure of this utility model;

[0026] Figure 5 This is a schematic diagram showing the distribution of the first and second binding layers of this utility model;

[0027] Figure 6 This is a schematic diagram showing the distribution of glass ribbons within the first and second binding layers of this utility model.

[0028] Drawing number explanation: 1. Wire rod; 2. Pad block; 3. First filling layer; 4. First binding layer; 5. Second binding layer; 6. Second filling layer; 7. Inner protective layer; 8. Outer protective layer. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings.

[0030] The following description is intended to disclose the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious modifications will be apparent to those skilled in the art. The basic principles of the present invention defined in the following description can be used in other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0031] Those skilled in the art should understand that in the disclosure of this utility model, the terms "longitudinal", "lateral", "up", "down", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or position based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of simplifying the description of this utility model and do not indicate or imply that the device or gear component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on this utility model.

[0032] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0033] Example:

[0034] Please see Figures 1-6 A large generator stator winding corona protection component includes multiple sets of rods 1 and pads 2 distributed between the rods 1. A first filling layer 3 is provided on the outside of the rods 1 and the pads 2. The first filling layer 3 is a putty layer. The putty is used to fill the gap between the rods 1 and the pads 2. The right angle of contact between the rods 1 and the pads 2 is rounded with putty. The first filling layer 3 fills the gap on the surface of the rods 1 and the gap between the rods 1 and the pads 2.

[0035] A first binding layer 4 is provided on the outer side of the pad 2 and at the connection between the rod 1 and the pad 2. A second binding layer 5 is provided on the outer side of the first binding layer 4. Both the first binding layer 4 and the second binding layer 5 are made of glass ribbon. At the end of the generator winding, the glass ribbon can enhance the winding end's ability to resist corona corrosion, oil corrosion, air corrosion, etc., thereby extending the service life of the motor.

[0036] A second filling layer 6 is provided on the outside of the first binding layer 4 and the second binding layer 5. The second filling layer 6 is a resin layer. After the resin dries, it can remove sharp corners and burrs, making all winding surfaces smooth, thereby preventing corona discharge caused by burrs. The second filling layer 6 fills the gaps on the outside of the first binding layer 4 and the second binding layer 5.

[0037] An inner protective layer 7 is provided on the outside of the first filler layer 3 and the second filler layer 6. The inner protective layer 7 is an auxiliary paint layer. The auxiliary paint layer is fine and is applied to the outside of the second filler layer 6. At the same time, two auxiliary paint layers are set. The second layer is applied after the first auxiliary paint layer has cured. The superposition of the two paint layers can more effectively cover the defects and unevenness of the substrate, making the coating surface smoother and reducing the occurrence of corona discharge. An outer protective layer 8 is provided on the outside of the inner protective layer 7 to protect the wire rod 1 and the pad 2. The outer protective layer 8 consists of a primer layer and a topcoat layer that can improve the dustproof and moisture-proof effect.

[0038] The following describes some embodiments of this application in detail with reference to the accompanying drawings:

[0039] Please see Figures 1-6 In the softened state of the first filling layer 3, the outer side of the pad 2 and the connection between the wire rod 1 and the pad 2 are bound to form the first binding layer 4 and the second binding layer 5, which fills all the gaps between the wire rod 1 and the pad 2. Moreover, the wire rod 1, the pad 2, the glass ribbon, the first filling layer 3 and the second filling layer 6 are dried at the same time to form a whole. This can avoid the formation of gaps and completely eliminate the gap problem that is very easy to cause corona.

[0040] In addition, the glass ribbon in the first binding layer 4 is longitudinally wrapped around the outside of the pad 2 and the connection between the pad 2 and the wire rod 1. The glass ribbon in the second binding layer 5 is transversely wrapped around the outside of the pad 2 and the first binding layer 4. The glass ribbons in the first binding layer 4 and the second binding layer 5 are fully impregnated with the prepared EP274 resin in advance until the cross-section of the glass ribbon no longer turns white after being cut. After the glass ribbon is wrapped around the outside of the wire rod 1 and the pad 2, the resin of the second filling layer 6 is used to fill the gaps between the first binding layer 4 and the second binding layer 5. The resin of the second filling layer 6 penetrates into the gaps between the glass ribbons in the first binding layer 4 and the second binding layer 5 and fuses with the resin on the surface of the glass ribbon, avoiding gaps between the glass ribbons in the binding layers. The glass ribbon and the resin form a whole with higher strength. The two sets of glass ribbons are wrapped in a cross shape at the end of the winding, which can improve the binding strength of the two sets of binding layers and reduce the exposure of the wire rod 1 when the glass ribbon in the binding group breaks.

[0041] To prevent corona discharge, the implementation method of this application will be described as follows:

[0042] First, thoroughly clean the stator windings to remove oil, dust, and other contaminants from the winding surface. Then, polish away any discharge traces and polish the coating on the surface of the corona wire rod 1.

[0043] Then, putty is used to fill and clean the discharge traces, as well as the gaps on the surface of the filler rod 1 and the step between the filler rod 1 and the pad 2, forming the first filling layer 3. The pad 2 is immediately tied with glass ribbon while the putty is softened, forming the first binding layer 4 and the second binding layer 5. Then, resin is applied to the outside of the first binding layer 4 and the second binding layer 5 to form the second filling layer 6. After the glass ribbon is tightened and stressed, the softened putty is squeezed and fills all the gaps between the filler rod 1 and the inclined pad 2. Moreover, the resin on the surface of the filler rod 1, the pad 2, the glass ribbon, the putty, and the resin of the second filling layer 6 dry at the same time to form a whole. This can avoid the formation of gaps and completely eliminate the gap problem that is very easy to cause corona.

[0044] Afterwards, all repaired surfaces were brushed with LL16 paint again and allowed to cure at room temperature for more than 24 hours. During the first layer of LL16 paint, after drying at room temperature for about 4 hours, all surfaces were again soaked with LL16 paint to remove sharp corners and burrs, making all surfaces smooth, thus forming the inner protective layer 7.

[0045] Finally, the windings are coated with primer and topcoat to achieve dust and moisture protection. GK128 can be used for primer and DK222 for topcoat.

[0046] like Figure 5 As shown, in some embodiments, in order to improve the strength of the right-angle connection between the wire rod 1 and the pad 2 and avoid stress concentration at the right-angle connection, the part of the first binding layer 4 at the connection between the wire rod 1 and the pad 2 is set as a rounded corner, so that the glass ribbon is evenly wrapped around the outside of the first filling layer 3, avoiding gaps after binding. At the same time, the rounded corner can also make the stress distribution more uniform, reduce the phenomenon of stress concentration, improve the impact and vibration resistance of the area, and thus enhance the strength of the overall structure.

[0047] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functions and structural principles of the present invention have been shown and explained in the embodiments. Without departing from the principles, the implementation of the present invention may have any modifications or variations.

Claims

1. A large generator stator winding corona protection assembly comprising a plurality of groups of bars (1) and spacers (2) distributed between said bars (1), characterized in that, Also includes: A first filling layer (3) is provided on the outside of the rod (1) and the pad (2), the first filling layer (3) fills the gap on the surface of the rod (1) and the gap between the rod (1) and the pad (2); The first binding layer (4) and the second binding layer (5) are provided on the outside of the pad (2) and at the connection between the wire rod (1) and the pad (2), and the second binding layer (5) is provided on the outside of the first binding layer (4). A second filling layer (6) is provided on the outside of the first binding layer (4) and the second binding layer (5), and the second filling layer (6) fills the gaps on the outside of the first binding layer (4) and the second binding layer (5); Inner protective layer (7), the inner protective layer (7) is disposed outside the first filling layer (3) and the second filling layer (6); The outer protective layer (8) is provided outside the inner protective layer (7) to protect the wire rod (1) and the pad (2).

2. A large generator stator winding corona protection assembly according to claim 1, characterized in that: The first filling layer (3) is a putty layer.

3. A large generator stator winding corona protection assembly according to claim 2, characterized in that: Both the first binding layer (4) and the second binding layer (5) are composed of glass ribbons wrapped around each other.

4. A large generator stator winding corona protection assembly according to claim 3, characterized in that: The glass ribbon in the first binding layer (4) is longitudinally wrapped around the outside of the pad (2) and at the connection between the pad (2) and the wire rod (1), and the glass ribbon in the second binding layer (5) is transversely wrapped around the outside of the pad (2) and the first binding layer (4).

5. A large generator stator winding corona protection assembly according to claim 3 wherein: The portion of the first binding layer (4) at the connection between the wire rod (1) and the pad (2) is rounded.

6. A large electric generator stator winding corona protection assembly as recited in claim 4 wherein: The second filler layer (6) is a resin layer.

7. A large electric generator stator winding corona protection assembly as in claim 1 wherein: The inner protective layer (7) is an auxiliary paint layer.

8. A large electric generator stator winding corona protection assembly as in claim 1 wherein: The outer protective layer (8) consists of a primer layer and a topcoat layer.

9. A large electric generator stator winding corona protection assembly as in claim 7 wherein: The inner protective layer (7) has two auxiliary paint layers.

10. A large electric generator stator winding corona protection assembly as recited in claim 6 wherein: The resin of the second filler layer (6) penetrates into the gap between the glass ribbons in the first binding layer (4) and the second binding layer (5).

Images