Glass fiber composite capacitor bushing core body and preparation method thereof

Abstract

The invention belongs to the technical field of electrical equipment, and particularly relates to a glass fiber composite capacitor bushing core and a preparation method thereof, the glass fiber composite capacitor bushing core comprises a central conductive tube, a composite material layer, a capacitor plate layer and a composite fiber layer; the composite material layer and the capacitor plate layer alternately coat the outer surface of the central conductive tube from inside to outside, and the outermost layer is the composite material layer; the composite material layer comprises a glass fiber cloth and polyester non-woven fabric composite structure; the capacitor plate layer is an aluminum foil; the aluminum foil is adopted to replace a traditional semi-conductive band to serve as a capacitor plate, so that the problem that carbon powder falls off is fundamentally solved; and in combination with a vacuum impregnation process, the epoxy resin is uniformly and compactly filled in the glass fiber cloth and polyester non-woven fabric composite layer, so that the insulating strength, the partial discharge voltage and the lightning impulse resistance of the product are remarkably improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrical equipment, and particularly relates to a glass fiber composite capacitor bushing core and a preparation method. BACKGROUND

[0002] The glass fiber composite bushing is a composite material capacitor core made of a metal pipe (bar) as a central guide pipe, a winding composite material and an aluminum foil shielding layer, and a vacuum impregnation epoxy resin curing process, and the outermost layer is a gel impregnated composite fiber.

[0003] The composite fiber bushing is mainly applied to power equipment and electrical devices to isolate charged components and grounded components, fix lead wires and ensure safe operation of the circuit.

[0004] 1. The capacitor screen material is a semi-conductive tape produced by a carburizing process, which causes carbon powder to fall off during use, affecting the insulation performance of the product insulation layer, and only the increase of the capacitor screen can maintain the insulation performance;

[0005] 2. The bubbles mixed in the material and the production process cannot be eliminated during the wet winding process, and the partial discharge level is low;

[0006] 3. The wet winding glass fiber bushing has uneven epoxy resin content in the insulation layer due to the production process, production equipment, internal sanding process and other factors, and has weak lightning impulse voltage resistance;

[0007] 4. There is environmental pollution such as large amount of waste epoxy resin flowing during production and turning processing.

[0008] 5. The production environment is poor, and it is impossible to guarantee the cleanliness of the production environment required by high-voltage electrical products;

[0009] To solve the above problems, the application provides a glass fiber composite capacitor bushing core and a preparation method. SUMMARY

[0010] The application aims to provide a glass fiber composite capacitor bushing core and a preparation method, which solves the problems in the background art.

[0011] To solve the above technical problems, the application is realized by the following technical scheme:

[0012] The application is a glass fiber composite capacitor bushing core, which comprises a central conductive pipe, a composite material layer, a capacitor plate layer and a composite fiber layer.

[0013] Preferably, the composite material layer comprises a glass fiber cloth and polyester non-woven fabric composite structure; and the capacitor plate layer is aluminum foil.

[0014] Preferably, the thickness of the composite material layer is greater than or equal to 1.5 mm.

[0015] Preferably, the thickness of the composite material layer between adjacent capacitor plates is 1.5 mm to 4 mm.

[0016] Preferably, the polyester non-woven fabric in the composite material layer is polyethylene terephthalate.

[0017] Preferably, the center conductive pipe is an aluminum pipe or a copper pipe with an outer diameter of 45 mm to 90 mm.

[0018] Preferably, the composite fiber layer is an insulation material after impregnation and curing, and the composite fiber layer can comprise glass fiber cloth and polyester non-woven fabric.

[0019] A glass fiber composite capacitor sleeve core preparation method according to the sleeve core described above, comprising the following steps:

[0020] S1. Brushing a coupling agent on the surface of the center conductive pipe and air-drying;

[0021] S2. Wrapping a layer of aluminum foil or semi-conductive tape on the outer surface of the conductive pipe;

[0022] S3. Alternately wrapping the composite material layer and the aluminum foil capacitor plate layer;

[0023] S4. Vacuum drying the wrapped core;

[0024] S5. Impregnating the epoxy resin glue under vacuum conditions;

[0025] S6. Programmed curing to obtain a cured sleeve core.

[0026] Preferably, the composite material layer is a layer of glass fiber cloth + a layer of polyester non-woven fabric wrapped simultaneously, and the whole roll is wrapped.

[0027] Preferably, the glue is a mixture of epoxy resin glue and curing agent, the glue temperature is 70±3℃, the impregnation speed is 2L / min to 3L / min, and the vacuum degree is 95Pa to 105Pa.

[0028] The present application has the following beneficial effects:

[0029] 1. The aluminum foil is used to replace the traditional semi-conductive tape as the capacitor plate, which fundamentally eliminates the problem of carbon powder falling off; combined with the vacuum impregnation process, the epoxy resin is uniformly and densely filled in the glass fiber cloth and polyester non-woven fabric composite layer, which significantly improves the insulation strength, partial discharge voltage and lightning impact resistance of the product;

[0030] 2. Composite material structure and vacuum impregnation process, while reducing the weight of the product, retains excellent bending and shock resistance; the introduction of polyester non-woven fabric and the dense impregnation and curing layer together build a high-efficiency moisture barrier, improving the long-term operation reliability of the bushing in a humid environment;

[0031] 3. Vacuum impregnation process greatly improves the production environment, reduces epoxy resin waste and processing dust, and realizes clean production; at the same time, the process makes the resin content and distribution highly controllable, ensuring the consistency and stability of product performance, and is more conducive to industrialized batch manufacturing.

[0032] Of course, any product implementing the present application does not necessarily need to achieve all the advantages described above at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0034] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0035] Figure 2 It is Figure 1 schematic diagram of side view structure;

[0036] In the drawings, the components represented by each number are listed as follows:

[0037] In the drawings: 1, center conductive tube; 2, composite material layer; 3, capacitor plate layer; 4, composite fiber layer. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0039] In the description of this invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "around", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0040] Please see Figures 1-2 As shown, the present invention is a glass fiber composite capacitor sleeve core, comprising a central conductive tube 1, a composite material layer 2, a capacitor electrode layer 3, and a composite fiber layer 4.

[0041] The central conductive tube 1 is an aluminum tube or a copper tube, and the central conductive tube 1 is a hollow central conductive tube or a solid central conductive rod with an outer diameter of 45mm-90mm.

[0042] The composite material layer 2 and the capacitor electrode layer alternately cover the outer surface of the central conductive tube from the inside to the outside, with the outermost layer being the composite material layer; the composite material layer 2 includes a composite structure of glass fiber cloth and polyester non-woven fabric; the capacitor electrode layer is aluminum foil, and the polyester non-woven fabric in the composite material layer is polyethylene terephthalate.

[0043] The composite fiber layer 4 is an insulating material that has been impregnated and cured. The composite fiber layer may include glass cellulose cloth or polyester nonwoven fabric.

[0044] Furthermore, the thickness of the composite material layer is ≥1.5mm; the thickness of the composite material layer between adjacent capacitor plates is 1.5mm to 4mm.

[0045] This invention also provides a method for preparing a glass fiber composite capacitor sleeve core, the steps of which are as follows:

[0046] Coupling agent is applied to the surface of the central conductive tube and dried; an aluminum foil or semi-conductive tape is wound around the outer surface of the conductive tube; the composite material layer and the aluminum foil capacitor plate layer are wound alternately; the composite material layer is a layer of glass fiber cloth + a layer of polyester non-woven fabric wound together, and the whole roll is used to obtain the composite fiber capacitor sleeve core.

[0047] The wound core is placed into a casting mold and then into a vacuum chamber. It is heated to 95-106°C, or more specifically, 98-103°C. The drying time is not specifically limited in this invention; drying to constant weight is sufficient. The vacuum degree of the vacuum drying can be 20-40 Pa, or 25-35 Pa, or more specifically, 30 Pa. The vacuum drying can be carried out in a vacuum drying chamber. In this invention, the purpose of the first drying step is to completely remove moisture and volatiles from the composite insulating material.

[0048] The first impregnation uses an adhesive solution that may include epoxy resin and a curing agent; the epoxy resin has a temperature resistance >120℃; the curing agent may include methyltetrahydrophthalic anhydride and / or methylhexahydrophthalic anhydride, and the mass ratio of the epoxy resin to the curing agent may be 1:0.9~1, specifically 1:0.9, 1:0.95, or 1:1; the first impregnation speed may be 2~3 L / min, or even 2.5 L / min; the first impregnation temperature may be 70±3℃; the first impregnation is a vacuum impregnation, and the vacuum degree of the vacuum impregnation is 100±3 Pa. The vacuum is broken after maintaining a temperature of 70℃ and a vacuum degree of 100±5 Pa for 3 hours.

[0049] The first curing process can be programmed curing, which may include sequentially performing the following: maintaining at 70±3℃ for 12 hours, maintaining at 90℃ for 2 hours, maintaining at 110℃ for 4 hours, and maintaining at 130℃ for 10 hours. In this invention, during the first curing process, the central conductive tube, the composite material layer, the capacitor electrode layer, and the composite fiber layer are firmly bonded together as a whole to obtain a vacuum-impregnated composite material capacitor sleeve core.

[0050] The present invention also provides the application of the glass fiber composite capacitor bushing core of the above-mentioned technical solution in electrical equipment, wherein the electrical equipment may include 10kV~1100kV AC dry-type transformer bushing, dry-type AC through-wall bushing, AC GIS bushing, ±10~±1100kV DC through-wall bushing or DC valve-side transformer bushing.

[0051] To further illustrate the present invention, the glass fiber composite capacitor sleeve core, its preparation method, and its application provided by the present invention are described in detail below with reference to embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0052] Example 1

[0053] In this embodiment, the adhesive used for impregnation consists of 100g of epoxy resin and 90g of curing agent. The epoxy resin adhesive has a temperature resistance >120℃. The moisture-proof reinforcing materials are fiberglass cloth and polyester nonwoven fabric.

[0054] Taking the production of 126kV transformer bushings as an example:

[0055] Coupling agent is brushed onto the outer surface of the central aluminum tube (inner diameter 35mm, outer diameter 45mm). After drying, a layer of aluminum foil is first wound around it, and then the composite material layer is wound around. The composite material layer consists of two materials wound around simultaneously (one layer of glass fiber cloth + one layer of polyester non-woven fabric). The entire roll is wound around, alternating with the aluminum foil capacitor plate layer. When the composite material is 2mm thick, a layer of aluminum foil is wound around it to obtain the composite fiber capacitor sleeve core.

[0056] The obtained core was placed in a vacuum chamber and vacuum dried to constant weight at 100±10℃ and 30±10Pa. It was then placed in a vacuum drying chamber for vacuum impregnation and programmed curing to obtain the resin-impregnated fiber composite capacitor bushing core. The vacuum impregnation conditions were: resin temperature 70±3℃, impregnation rate 2.5±0.5L / min, vacuum degree 100±2Pa, and the amount of epoxy resin used was sufficient to completely fill all gaps between the insulating paper layers. The epoxy resin curing program involved maintaining the temperature at 70℃ and the vacuum degree at 100±5Pa for 3 hours, followed by automatic cooling after maintaining the temperature at 70℃ for 12 hours, at 90℃ for 2 hours, at 110℃ for 4 hours, and at 130℃ for 10 hours, resulting in the glass fiber composite capacitor bushing core.

[0057] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0058] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A glass fiber composite capacitor sleeve core, characterized in that, It includes a central conductive tube, a composite material layer, a capacitor electrode layer, and a composite fiber layer; The composite material layer and the capacitor electrode layer alternately cover the outer surface of the central conductive tube from the inside out, with the outermost layer being the composite material layer.

2. The glass fiber composite capacitor sleeve core according to claim 1, characterized in that: The composite material layer comprises a composite structure of glass fiber cloth and polyester nonwoven fabric; the capacitor electrode layer is aluminum foil.

3. The glass fiber composite capacitor sleeve core according to claim 2, characterized in that: The thickness of the composite material layer is ≥1.5mm.

4. The glass fiber composite capacitor sleeve core according to claim 1, characterized in that: The thickness of the composite material layer between adjacent capacitor plates is 1.5 mm to 4 mm.

5. The glass fiber composite capacitor sleeve core according to claim 2, characterized in that: The polyester nonwoven fabric in the composite material layer is polyethylene terephthalate.

6. The glass fiber composite capacitor sleeve core according to claim 1, characterized in that: The central conductive tube is an aluminum or copper tube with an outer diameter of 45mm-90mm.

7. The glass fiber composite capacitor sleeve core according to claim 1, characterized in that: The composite fiber layer is an insulating material that has been impregnated and cured. The composite fiber layer may include glass cellulose cloth or polyester nonwoven fabric.

8. A method for preparing a glass fiber composite capacitor sleeve core, the sleeve core according to any one of claims 1-7, characterized in that: Includes the following steps: S1. Apply coupling agent to the surface of the central conductive tube and let it dry; S2. Wrap a layer of aluminum foil or semi-conductive tape around the outer surface of the conductive tube; S3. Alternately wound composite material layers and aluminum foil capacitor electrode layers; S4. Vacuum dry the wound core; S5. Impregnate with epoxy resin solution under vacuum conditions; S6. The process of curing the process yields the cured sleeve core.

9. The method for preparing the glass fiber composite capacitor sleeve core according to claim 8, characterized in that: The composite material layer consists of a layer of glass fiber cloth and a layer of polyester nonwoven fabric wound together, and is wound in a whole roll.

10. The method for preparing the glass fiber composite capacitor sleeve core according to claim 8, characterized in that: The adhesive solution is a mixture of epoxy resin and curing agent, with an adhesive solution temperature of 70±3℃, an impregnation rate of 2L / min~3L / min, and a vacuum degree of 95Pa~105Pa.

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