Anti-corona method for stator end part of high-voltage hydro-generator

Abstract

A high-voltage hydro-generator stator winding end portion anti-corona process method belongs to the field of high-voltage stator winding end portion anti-corona processes, and adopts optimization and innovation of a stator winding end portion binding process, and the end portion of the stator winding end portion is formed by adjusting the radial wrapping direction of a binding belt, adjusting the tightness of the belt, increasing auxiliary tools and the like. The surface of the end part of the stator winding after binding is flat, smooth and fit, the paint glue is smooth without accumulation points, the stator winding is beautiful and elegant, the construction is smooth, the high maintenance cost and the power generation loss of the stator winding are reduced, the operation safety of a unit and the stability of a power grid are maintained, the advanced anti-corona process eliminates hidden dangers in the bud, and the development of serious electrocorrosion is avoided. The method is suitable for installation of all high-voltage-grade stator windings, and has very high popularization and application values.

Description

Technical Field

[0001] This invention relates to a method for preventing corona at the stator end of a high-voltage hydro-generator, belonging to the field of stator winding installation of hydro-generator sets. Background Technology

[0002] Corona initiation, a type of partial discharge, begins in the outermost anti-corona layer, becoming a critical initiating link and accelerator in the failure chain of the insulation system. It gradually corrodes the insulation material itself, disrupts the electric field distribution, and triggers more severe partial discharges, ultimately potentially leading to catastrophic consequences such as main insulation breakdown and short-circuit burnout. This corrosion damage is irreversible and progressive, posing a significant threat, not only causing high maintenance costs and power generation losses but also seriously threatening the safe operation of the generating unit and the stability of the power grid. Therefore, it is imperative to attach great importance to the design and manufacturing quality of the anti-corona structure of the stator windings, eliminating potential hazards at their inception and preventing them from developing into severe electrochemical corrosion.

[0003] Currently, the stator winding end structures of domestic units in the same industry are quite similar. They are designed with external support end clamps, and internal support end clamps are designed between the upper and lower winding ends. The stator winding is reinforced with inclined pads at intervals. The binding materials are usually herringbone fiber tape, alkali-free glass fiber sleeves, and glass fiber ropes. The binding structures are quite similar. After binding, folds, gaps, burrs, and wrinkles are common. Among them, herringbone fiber tape is easier to bind and has fewer gaps, but it is also prone to burrs and wrinkles. This causes gaps, sharp points, and local unevenness at the stator winding ends and slots, resulting in local discharge. Over time, this leads to obvious haloing, whitening, and corrosion.

[0004] Therefore, there is an urgent need to propose a method for preventing corona at the stator end of a high-voltage hydro generator to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to solve the problem of partial discharge caused by gaps, sharp points, and local unevenness at the ends and slots of stator windings in hydro-generator units, which, over time, leads to obvious corrosive and whitening corrosion. Therefore, this invention provides a corrosive prevention process for the ends of stator windings in high-voltage hydro-generators. A brief overview of this invention is provided below to offer a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention.

[0006] The technical solution of this invention:

[0007] A method for preventing corona discharge at the stator end of a high-voltage hydro generator includes the following steps:

[0008] S1. Add inclined pads at intervals to the inclined side of the stator winding end. The stator is bound by connecting the whole round inclined side and locking the end of the binding tape. The inclined pads and the adjacent stator winding inclined side are wrapped in 4 layers using a needle plate and binding tape. Then the inclined pads are wrapped in 3 layers of half-overlap wrapping. After the third layer of half-overlap wrapping, the binding tape is wrapped around the inclined side of the stator winding layer to perform a bridging operation. Then move on to the next set of inclined pads for binding. The binding tape is flattened with a wooden wedge tool, flat and without wedge gaps.

[0009] S2. The circumferential axial support end ring of the stator winding end is tied with a single-binding lock without bridging. Using a needle plate and binding tape, the end ring and the upper and lower stator winding inclined sides are wrapped radially with 4 layers of half-overlap, and then wrapped circumferentially with 2 layers of waist half-overlap. The lock at the end of the waist binding tape is hidden under the wrapping tape. Then start the binding of the next set of stator winding end rings again. The binding tape is flattened with a wooden wedge tool, and is flat without wedge gaps.

[0010] S3. Apply epoxy room temperature curing adhesive to the cable ties in three coats using a brush. For the first coat, mix the epoxy room temperature curing adhesive according to a ratio of virgin adhesive: curing agent: thinner = 2:1:5. For the second and third coats, mix the epoxy room temperature curing adhesive according to a ratio of virgin adhesive: curing agent: thinner = 2:1. After application, allow to cure at room temperature for 24-48 hours.

[0011] S4. The gaps between the binding straps and the stator windings and end clamps, and the gaps between the stator slot pads and the stator windings, are filled with putty and finished with epoxy board to make the appearance smooth, flat and full.

[0012] S5. Appearance treatment of the stator winding ends: remove sharp corners and edges of the binding tape with coarse sandpaper and a flat file; trim and remove the tail of the binding tape with scissors; sand the binding tape and gap filling surface at the stator winding ends to remove sharp corners and burrs, and smooth out sharp edges.

[0013] Preferably, in S1, the needle-threading board is a 4mm thick epoxy board with an external dimension of 300mm in length and 30mm in width; the tool wedge is a 20mm thick pine board with an external dimension of 250mm in length and 30mm in width; and the binding strap in S1 is a high-strength, anti-corona, alkali-free glass fiber tape with a thickness of 0.3mm and a width of 22mm.

[0014] Preferably: In step S1, the stator winding ends are intermittently padded with inclined pads, and the binding is performed in three steps using a method of connecting the stator's entire round inclined sides and locking the ends of the binding straps.

[0015] S11. Using a needle plate and binding straps, wrap the inclined side pad and the adjacent stator winding inclined side in 4 layers, and then wrap the inclined side pad in 3 layers of half-overlapping.

[0016] S12. After the third layer of the binding tape is cut across the waist, the binding tape is wrapped around the stator winding inclined side to perform the bridging operation and then proceed to the next set of inclined side pads for binding.

[0017] S13. Use wooden wedges to flatten the binding straps, ensuring a smooth surface without any wedge-shaped gaps.

[0018] Preferably, the circumferential axial support end ring of the stator winding in S2 is bound in three steps using a single-binding lock without bridging:

[0019] S21. Using a needle plate and binding straps, perform 4-layer semi-overlapping radial wrapping of the end rings and the inclined sides of the upper and lower stator windings.

[0020] S22. Then, perform two layers of half-overlapping wrapping around the waist of the bag, with the end buckle of the waist binding strap hidden under the wrapping strap;

[0021] S23. Then start the next set of stator winding end clamp binding again. Use a wooden wedge to flatten the binding tape, making sure it is flat and without wedge gaps.

[0022] Preferably, the brush in S3 is 2 inches in size, the bristles are made of non-shedding nylon, the length is 50mm, and the handle is made of wood and is 125mm long.

[0023] Preferably, the application of epoxy room temperature curing adhesive to the binding tape in step S3 consists of two steps:

[0024] S31. For the first coat, epoxy room temperature curing adhesive needs to be pre-mixed with thinner.

[0025] S32, the second and third epoxy room temperature curing adhesives are pre-mixed according to the original adhesive and curing agent. After application, they are cured at room temperature for 24-48 hours.

[0026] Preferably, the putty in S4 is a nano-modified epoxy putty, which consists of two components, A and B, and is cured at room temperature.

[0027] Preferably, the gaps between the binding straps and the stator windings and end clamps in S4, and the gaps between the stator slot pads and the stator windings, are filled with putty using the following steps:

[0028] S41. After thoroughly mixing the two components of nano-modified epoxy putty A and B, use it to fill gaps, and wipe away any excess putty.

[0029] S42. Use epoxy boards to smooth and make the appearance flat and full.

[0030] Preferably, the sandpaper in S5 is 400-grit coarse sandpaper and 600-grit fine sandpaper.

[0031] Preferably, the external treatment of the S5 stator winding ends consists of two steps:

[0032] S51. Remove sharp corners and edges of the cable ties using coarse sandpaper and a flat file; trim the ends of the cable ties with scissors.

[0033] S52. The binding tape and gap filling surface at the ends of the stator windings are sanded with sandpaper to remove sharp corners and burrs, and the sharp edges are sanded smooth.

[0034] The present invention has the following beneficial effects:

[0035] 1. This invention, through an integrated binding, gluing, filling, and polishing process, completely eliminates the partial discharge (corona) phenomenon caused by uneven binding, gaps, and sharp burrs at the stator winding ends. It cuts off the initiation chain of electro-corrosion at its source, effectively preventing irreversible damage to the insulation material and ensuring the long-term operational safety of the unit and the stability of the power grid.

[0036] 2. This invention employs specific binding methods such as "stator full-circle oblique edge binding" and "single-binding lock without bridging," combined with the auxiliary flattening of a needle-threading plate and wooden wedges, to achieve extremely high conformity and flatness between the binding tape and the winding surface, realizing "flatness without wedge gaps" and "no flared openings or bends." This not only reduces partial discharge points but also lays a perfect foundation for subsequent gluing and polishing.

[0037] 3. This invention employs a "three-coat, two-ratio" adhesive application method. The first application uses diluted adhesive to ensure deep penetration, while subsequent applications use undiluted adhesive to guarantee structural strength. This allows the binding tape to bond with the windings into a robust, rigid, circular ring after curing, greatly enhancing the mechanical strength and integrity of the end structure and further improving its resistance to corona discharge and loosening.

[0038] 4. This invention uses nano-modified epoxy putty to precisely fill all gaps, combined with two rounds of sanding with coarse and fine sandpaper, to ensure that the stator winding ends ultimately achieve the ultimate state of "flatness, smoothness, and fullness". All sharp corners, burrs, and nodules are thoroughly removed, maximizing the uniformity of the electric field distribution and eliminating any minor defects that may cause partial discharge;

[0039] 5. The steps of this invention are clear and highly operable. Although strict requirements are placed on details, it greatly reduces the amount of rework and repair work in the later stages. Construction is smooth, shortening the installation cycle, and the first-time success rate is high, saving labor and time costs. Its long-term maintenance-free operation further avoids high maintenance costs and power generation losses caused by electro-corrosion, resulting in significant comprehensive economic benefits. It not only solves the long-standing technical problem of corona electro-corrosion at the stator ends of high-voltage hydro-generators, but also forms a standardized, high-quality process applicable to the installation and maintenance of stator windings of all high-voltage levels, possessing extremely high reliability and widespread application value. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the stator winding end binding according to the present invention;

[0041] Figure 2 for Figure 1 EE sectional view;

[0042] Figure 3 for Figure 1 DD sectional view;

[0043] Figure 4 This is a schematic diagram of the needle-threading plate described in this invention;

[0044] Figure 5 This is a schematic diagram of the wooden wedge tool described in this invention.

[0045] In the diagram: 1-Stator winding; 2-Hydraulic pad; 3-Needle plate; 4-Binding strap; 5-Tool wedge; 6-End hoop; 7-Slot pad. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0047] The connections mentioned in this invention are divided into fixed connections and detachable connections. Fixed connections (i.e., non-detachable connections) include, but are not limited to, conventional fixed connection methods such as folded connections, riveted connections, adhesive connections, and welded connections. Detachable connections include, but are not limited to, conventional disassembly methods such as threaded connections, snap-fit ​​connections, pin connections, and hinged connections. When a specific connection method is not explicitly defined, it is assumed that at least one existing connection method can always be found to achieve the function, and those skilled in the art can choose according to their needs. For example, a welded connection can be chosen for fixed connections, and a hinged connection can be chosen for detachable connections.

[0048] Specific implementation method one: Combining Figures 1-5 This embodiment describes a method for preventing corona discharge at the stator end of a high-voltage hydro-generator. The method is implemented through the following steps:

[0049] S1. Add inclined pads 2 at intervals to the inclined side of the stator winding 1. Bind the stator winding 1 by connecting the inclined side of the whole circle and locking the end of the binding strap. Use the needle plate 3 and binding strap 4 to wrap the inclined pads 2 and the adjacent inclined side of the stator winding 1 in 4 layers. Then wrap the inclined pads 2 in 3 layers of half-overlap wrapping. After the third layer of half-overlap wrapping, the binding strap 4 is wrapped around the inclined side of the winding 1 to perform the bridging operation. Then move on to the next set of inclined pads 2 for binding. The binding strap 4 should be flattened with a wooden wedge 5 and flat without wedge gaps.

[0050] S2. The end circumferential axial support hoop 6 of stator winding 1 is tied with a single-binding lock without bridging. The end hoop 6 and the upper and lower stator winding 1 are radially wrapped with 4 layers of half-overlap using the needle plate 3 and the binding tape 4. Then, 2 layers of waist half-overlap circumferential wrapping are performed. The end lock of the waist binding tape 4 is hidden under the wrapping tape. Then, the next set of stator winding 1 end hoop binding is started again. The binding tape should be flattened with a wooden wedge 5, and flat without wedge gaps.

[0051] S3. Apply epoxy room temperature curing adhesive to the cable ties 4 in 3 coats using a 2-inch flat brush. For the first coat, pre-mix the epoxy room temperature curing adhesive according to the ratio of raw adhesive: hardener: thinner = 2:1:5. For the second and third coats, pre-mix the epoxy room temperature curing adhesive according to the ratio of raw adhesive: hardener: thinner = 2:1. After application, cure at room temperature for 24-48 hours.

[0052] S4, the gap between the binding strap 4 and the stator winding 1 and the end clamp 6, and the gap between the stator slot pad 7 and the stator winding 1 are filled with putty and the appearance is smoothed and full with epoxy board.

[0053] S5. Appearance treatment of the end of stator winding 1: Remove the sharp corners and edges of the binding tape 4 with coarse sandpaper and a flat file; trim and remove the tail of the binding tape 4 with scissors; sand the binding tape and gap filling surface at the end of the stator winding to remove sharp corners and burrs, and smooth the sharp edges.

[0054] In this embodiment, the stator end binding process has been improved and innovated. By adjusting the radial wrapping direction of the binding tape, adjusting the tape tightness, and adding tool assistance, the end surface after binding is flat, smooth, and fits well. The paint and glue flow smoothly without accumulation points, making it beautiful and elegant. It fully meets the high standard requirements for anti-corrosion of high-voltage units and effectively plays a role in long-term anti-corrosion and anti-electrochemical corrosion.

[0055] Specific Implementation Method Two: Combining Figures 1-5 This embodiment further defines S1 as described in Specific Embodiment 1. In this embodiment, the needle-threading plate 3 in S1 is a 4mm thick epoxy board with an external dimension of 300mm in length and 30mm in width; the tool wedge 5 is a 20mm thick pine board with an external dimension of 250mm in length and 30mm in width; and the binding strap 4 in S1 is a high-strength, anti-corona, alkali-free glass fiber strap with a thickness of 0.3mm and a width of 22mm.

[0056] Specific implementation method three: Combining Figures 1-5 This embodiment further defines S1 as described in Specific Embodiment 1. In this embodiment, the stator winding 1 is spaced with inclined edge pads 2 at intervals at its end, and the binding is performed using a method of connecting the stator's entire round inclined edge and locking the end of the binding strap, which consists of three steps:

[0057] S11. Using the needle plate 3 and the binding strap 4, wrap the inclined side pad block and the adjacent winding inclined side in 4 layers, and then wrap the inclined side pad block 2 in 3 layers of half-overlap wrapping.

[0058] S12. After the third layer is cut in the middle, the binding strap 4 is wrapped around the inclined side of the stator winding 1 to perform the bridging operation and then enters the next set of inclined side pads 2 for binding.

[0059] S13. The binding strap 4 should be flattened with a wooden wedge 5, and the surface should be smooth without any wedge-shaped gaps.

[0060] In this embodiment, the key points of the binding technique are: the side of the binding strap is flush with the edge of the inclined pad, the binding strap is unfolded flat and taut, and not loose. The binding strap fits snugly against the stator winding 1, without any flared openings or folded gaps, resulting in high construction efficiency and minimal grinding. The end of the binding strap buckle is free of exposed burrs.

[0061] Specific implementation method four: Combination Figures 1-5 This embodiment further defines S2 as described in Specific Embodiment 1. In this embodiment, the circumferential axial support end ring 6 of the stator winding 1 in S2 is bound in three steps using a single-binding lock without a bridging mechanism:

[0062] S21. Using the needle plate 3 and binding strap 4, the end rings 6 and the inclined sides of the upper and lower stator windings 1 are used to perform 4-layer half-overlap radial wrapping.

[0063] S22. Then, perform two layers of half-overlapping wrapping around the waist of the bag, with the end buckle of the waist binding strap 4 hidden under the wrapping strap;

[0064] S23. Then start the next set of stator winding 1 end clamp binding again. The binding strap should be flattened with a wooden wedge 5, and flat without wedge gaps.

[0065] In this embodiment, the key points of the binding technique are as follows: when wrapping the binding tape, the tape should be moderately tight and not too tight to avoid wrinkles at the binding end when binding the waist. The tape should be pulled and flattened along the diagonal side of the stator winding. After optimization, the binding tape has no flared end and fits snugly against the diagonal side of the winding. The contact area between the tape and the winding is large, and it is more secure after applying glue. The single binding end hiding process is as follows: pull the tape to one side and cut it. Use the elasticity to make the tape end quickly spring back and retract under the waist tape to hide it, without any exposed burrs.

[0066] Specific Implementation Method Five: Combining Figures 1-5 This embodiment further defines S3 as described in Specific Embodiment 1. In this embodiment, the application of epoxy room temperature curing adhesive to the cable ties 4 in S3 is divided into two steps, with three coats applied:

[0067] S31. For the first coat, the epoxy room temperature curing adhesive is pre-mixed according to the following ratio: raw adhesive: curing agent: thinner = 2:1:5;

[0068] S32, the second and third epoxy room temperature curing adhesives are pre-mixed according to the ratio of raw adhesive to curing agent = 2:1. After application, cure at room temperature for 24-48 hours.

[0069] In this embodiment, the key technology is that the epoxy curing adhesive needs to thoroughly soak the binding tape in order to ensure that the binding tape forms a rigid circular support and anti-scintillation effect after curing. Therefore, for the first application, in order to better penetrate the binding tape, the adhesive needs to be diluted before application to lay a good foundation for the penetration of the original adhesive. After the diluted adhesive has soaked through, the original adhesive is applied and soaked repeatedly until it is completely filled with adhesive. After curing, a rigid circular whole is formed.

[0070] Specific Implementation Method Six: Combination Figures 1-5 This embodiment further defines S4 as described in Specific Embodiment 1. In this embodiment, the gaps between the binding strap 4 and the stator winding 1 and the end clamp 6, and the gaps between the stator slot pad 7 and the stator winding 1, are filled with putty using the following steps:

[0071] S41. After thoroughly mixing the two components of nano-modified epoxy putty A and B, use it to fill gaps, and wipe away any excess putty.

[0072] S42. Use epoxy boards to smooth and make the appearance flat and full.

[0073] In this embodiment, the two components of nano-modified epoxy putty A (putty adhesive) and B (curing agent) are mixed using a dual-tube applicator. To ensure curing, the first and last portions of the adhesive are discarded to prevent uneven mixing of the curing agent, which could lead to incomplete curing and power generation. After the filling process, the stator winding ends have a smooth, even, and full appearance, minimizing the risk of corona corrosion during long-term power generation and ensuring stable long-term power generation operation of the stator.

[0074] Specific implementation method seven: Combination Figures 1-5 This embodiment further defines S5 as described in Specific Embodiment 1. In this embodiment, the external processing of the stator winding 1 end in S5 is divided into two steps:

[0075] S51. Remove the sharp corners and edges of the cable ties using coarse sandpaper and a flat file; trim the ends of the cable ties with scissors.

[0076] S52. The binding tape and gap filling surface at the ends of the stator windings are sanded with sandpaper to remove sharp corners, burrs, glue nodules, etc., and the sharp edges are sanded smooth.

[0077] In this embodiment, firstly, use 400-grit coarse sandpaper or a flat file to clean the sharp corners and burrs at the binding point, removing larger paint nodules and sharp edges. Then, use scissors to trim folds and sharp corners. Finally, use 600-grit fine sandpaper to bind and solidify the rope, and simultaneously use a vacuum cleaner to remove dust, ensuring the stator winding end surface is smooth and free of sharp points. After this polishing and beautification process, the stator winding end has a flat, smooth, and full appearance, minimizing the risk of corona corrosion during long-term power generation and ensuring stable long-term power generation operation of the stator.

[0078] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be permuted and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutation and combination. Therefore, the present invention will not describe the technical solutions after permutation and combination one by one, but it should be understood that the technical solutions after permutation and combination have been disclosed by the present invention.

[0079] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preventing corona discharge at the stator end of a high-voltage hydro-generator, characterized in that, Includes the following steps: S1. The stator winding (1) is tied with the inclined side spacer (2) at intervals. The inclined side spacer (2) and the adjacent stator winding (1) are wrapped in 4 layers using the needle plate (3) and the binding tape (4). Then the inclined side spacer (2) is wrapped in 3 layers of half-overlap. After the third layer of half-overlap, the binding tape (4) is wrapped around the inclined side of the stator winding (1) to perform the bridge operation. Then the next set of inclined side spacers (2) is tied. The binding tape (4) is flattened with a wooden wedge (5) and flat without wedge gaps. S2. The end circumferential support end ring (6) of the stator winding (1) is tied. Using the needle plate (3) and the binding tape (4), the end ring (6) and the upper and lower stator windings (1) are wrapped radially with 4 layers of half-overlap, and then wrapped circumferentially with 2 layers of half-overlap. The end buckle of the binding tape (4) is hidden under the wrapping tape. Then start the next set of stator windings (1) end ring binding again. The binding tape (4) is flattened with a wooden wedge (5) and is flat without wedge gaps. S3. Apply epoxy room temperature curing adhesive to the cable ties (4) in 3 coats. The application tool is a brush. S4. The gap between the binding strap (4) and the stator winding (1) and the end clamp (6), and the gap between the stator slot pad (7) and the stator winding (1) are filled with putty and the appearance is smoothed and full with epoxy board. S5. Appearance treatment of the end of the stator winding (1): remove the sharp corners and edges of the binding tape (4) with coarse sandpaper and flat file; trim the end of the binding tape (4) with scissors; sand the binding tape (4) and gap filling surface at the end of the stator winding (1) with sandpaper to remove sharp corners and burrs, and smooth the sharp edges.

2. The method for preventing corona at the stator end of a high-voltage hydro-generator according to claim 1, characterized in that: The needle board (3) in S1 is a 4mm thick epoxy board with an external dimension of 300mm in length and 30mm in width; the tool wedge (5) is a 20mm thick pine board with an external dimension of 250mm in length and 30mm in width; the binding strap (4) in S1 is a high-strength anti-corona alkali-free glass fiber tape with a thickness of 0.3mm and a width of 22mm.

3. The method for preventing corona at the stator end of a high-voltage hydro-generator according to claim 1, characterized in that: In S1, the stator winding (1) is intermittently filled with inclined pads (2) at the end of the inclined side. The binding is carried out in three steps using the method of connecting the stator full circle inclined side and locking the end of the binding strap: S11. Using the needle plate (3) and binding strap (4), wrap the inclined side pad (2) and the adjacent stator winding (1) in 4 layers, and then wrap the inclined side pad (2) in 3 layers of half-overlap wrapping. S12, after the third layer of waist-cutting, the binding tape (4) is wrapped around the stator winding (1) on the inclined side to perform the bridge operation and then enter the next set of inclined side pad binding; S13. Use a wooden wedge (5) to flatten the binding strap (4) until it is smooth and without any wedge-shaped gaps.

4. The method for preventing corona at the stator end of a high-voltage hydro-generator according to claim 1, characterized in that: The circumferential axial support end ring (6) of the stator winding (1) in S2 is bound in three steps using a single-binding lock without a bridging method: S21. Using the needle plate (3) and binding strap (4), perform 4-layer half-overlap radial wrapping of the end ring (6) and the upper and lower stator windings (1) on the hypotenuse; S22, then perform two layers of half-overlapping wrapping around the circumference, with the end buckle of the waist binding strap (4) hidden under the wrapping strap; S23. Then start the next set of stator windings (1) end clamp binding, use a wooden wedge (5) to flatten the binding tape, flat and without wedge gap.

5. A method for preventing corona at the stator end of a high-voltage hydro-generator according to claim 1, characterized in that: The S3 brush is 2 inches long, made of non-shedding nylon bristles, and has a handle that is 125 mm long.

6. A method for preventing corona at the stator end of a high-voltage hydro-generator according to claim 1, characterized in that: The application of epoxy room temperature curing adhesive to the binding strap (4) in S3 is divided into two steps: S31. For the first coat, epoxy room temperature curing adhesive needs to be pre-mixed with thinner. S32, the second and third epoxy room temperature curing adhesives are pre-mixed according to the original adhesive and curing agent. After application, they are cured at room temperature for 24-48 hours.

7. The method for preventing corona at the stator end of a high-voltage hydro-generator according to claim 1, characterized in that: The putty in S4 is a nano-modified epoxy putty, which consists of two components, A and B, and is cured at room temperature.

8. A method for preventing corona at the stator end of a high-voltage hydro-generator according to claim 1, characterized in that: The gaps between the binding strap (4) and the stator winding (1) and the end clamp (6) in S4, and the gaps between the stator slot pad (7) and the stator winding (1), are filled with putty in the following steps: S41. After thoroughly mixing the two components of nano-modified epoxy putty A and B, use it to fill gaps, and wipe away any excess putty. S42. Use epoxy boards to smooth and make the appearance flat and full.

9. A method for preventing corona at the stator end of a high-voltage hydro-generator according to claim 1, characterized in that: The sandpaper in S5 is 400-grit coarse sandpaper and 600-grit fine sandpaper.

10. A method for preventing corona at the stator end of a high-voltage hydro-generator according to claim 1, characterized in that: The external treatment of the end of the S5 stator winding (1) is divided into two steps: S51. Remove the sharp corners and edges of the cable ties (4) with coarse sandpaper and a flat file; trim the end of the cable ties (4) with scissors. S52, the binding strap (4) at the end of the stator winding (1), the gap filling surface, use sandpaper to polish the whole, remove sharp corners and burrs, and polish the sharp edges smooth.

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