Sleeve-type structured glue-impregnated fiber dry casing and manufacturing method thereof

Abstract

The present invention discloses a sleeve-type structure of a rubber-impregnated fiber dry-type bushing, which includes a conductive rod and multiple cylindrical bushings. The multiple cylindrical bushings are coaxially arranged, and each cylindrical bushing includes a demoulding protective layer, a capacitor plate layer, and an insulating layer. In each cylindrical bushing, the capacitor plate layer is wound around the outer ring of the demoulding protective layer, and the insulating layer is wound around the outer ring of the capacitor plate layer. In two adjacent cylindrical bushings, the demoulding protective layer of the outer cylindrical bushing is fixedly connected to the insulating layer of the inner cylindrical bushing through a glue injection layer, and the demoulding protective layer of the innermost cylindrical bushing is wound around the outer ring of the conductive rod. The rubber-impregnated fiber bushing of the present invention has the advantages of being oil-free, flame-retardant and explosion-proof, having high mechanical strength, and requiring little maintenance. In addition, the manufacturing method of the present invention solves the problem of intermittent failures occurring during the winding process of the rubber-impregnated fiber dry-type bushing core and requiring rewinding, thereby improving bushing production efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission and transformation equipment, and in particular to a sleeve-type structured glue-impregnated fiber dry-type bushing and a manufacturing method thereof. Background Art

[0002] High-voltage AC and DC bushings are used in power systems to pass current-carrying conductors through metal boxes or walls of equipment at a different electrical potential, introducing or extracting full voltage and current, providing insulation and mechanical support. Traditional oil-paper bushings carry the risk of oil leakage. SF6 gas-insulated bushings offer advantages such as a relatively simple structure, light weight, good heat dissipation, high current capacity, and easy operation and maintenance, but they carry the risk of gas leakage during operation. Glue-impregnated paper bushings have complex physical and chemical properties of their main insulating material, a difficult core impregnation and curing process, and are prone to moisture absorption, leading to increased dielectric loss and excessive partial discharge. In recent years, bushing accidents have been frequent in the system, ranging from minor damage to explosions, resulting in power outages and significant power losses, seriously impacting the safe operation of the power grid and causing significant economic losses and social impact. Summary of the Invention

[0003] The purpose of the present invention is to provide a sleeve-type structure of glue-impregnated fiber dry casing and a manufacturing method. The glue-impregnated fiber casing of the present invention has the advantages of being oil-free, flame-retardant and explosion-proof, having high mechanical strength and requiring little maintenance. In addition, the manufacturing method of the present invention solves the problem of intermittent failures occurring during the winding process of the core of the glue-impregnated fiber dry casing and requiring rewinding, thereby improving the casing production efficiency.

[0004] To achieve this purpose, the present invention designs a sleeve-type structured rubber-impregnated fiber dry-type bushing, which includes a conductive rod and multiple cylindrical bushings, which are coaxially arranged. Each cylindrical bushing includes a demoulding protective layer, a capacitor plate layer, and an insulating layer. In each cylindrical bushing, the capacitor plate layer is wound around the outer ring of the demoulding protective layer, and the insulating layer is wound around the outer ring of the capacitor plate layer.

[0005] In two adjacent cylindrical sleeves, the demoulding protective layer of the outer cylindrical sleeve is fixedly connected to the insulating layer of the inner cylindrical sleeve through the glue injection layer, and the demoulding protective layer of the innermost cylindrical sleeve is wrapped around the outer ring of the conductive rod.

[0006] A method for processing the above-mentioned sleeve-type structured rubber-impregnated fiber dry-type casing comprises the following steps:

[0007] Step 1: Impregnate the glass fiber bundle with epoxy resin and then wrap it around the conductive rod to form a demoulding protective layer of the innermost cylindrical sleeve;

[0008] Step 2: Winding a semiconductor material onto the release protective layer of the innermost cylindrical sleeve to form a capacitor plate layer of the innermost cylindrical sleeve;

[0009] Step 3: Impregnate the glass fiber bundle with epoxy resin and wrap it around the capacitor plate layer to form the insulation layer of the innermost cylindrical sleeve;

[0010] Step 4: Based on the size requirements of the dry-type sleeve, a glass fiber bundle impregnated with epoxy resin is wound around the surface of a metal cylindrical mold with various radii to form a demoulding protective layer for each non-innermost cylindrical sleeve;

[0011] Step 5: Winding a semiconductor material onto the release protective layer of each non-innermost cylindrical sleeve to form a capacitor plate layer of each non-innermost cylindrical sleeve;

[0012] Step 6: Impregnating a glass fiber bundle with epoxy resin glue and then winding the bundle around the capacitor plate layer of each non-innermost cylindrical sleeve to form an insulating layer of each non-innermost cylindrical sleeve;

[0013] Step 7: Demold the demoulding protective layer of each non-innermost cylindrical sleeve from the corresponding metal cylindrical mold, and coaxially mount each cylindrical sleeve in sequence according to the diameter size. Among the two adjacent cylindrical sleeves, the demoulding protective layer of the outer cylindrical sleeve is fixedly connected to the insulating layer of the inner cylindrical sleeve through the glue injection layer, and the demoulding protective layer of the innermost cylindrical sleeve is wrapped around the outer ring of the conductive rod.

[0014] Beneficial effects of the present invention:

[0015] The present invention adopts a coaxial arrangement of multiple cylindrical components, each of which is composed of a demoulding protective layer, a capacitor plate and an insulating layer. The length and thickness of the demoulding layers of each cylindrical component are equal, and the length and thickness of the insulating layer are also equal. The length of the capacitor plate of each cylindrical component is based on the insulation design requirements (consistent thickness), so that the electric field distribution inside the core of the glue-impregnated fiber dry-type bushing is reasonable, and the local field strength is not excessive. In addition, the glue-impregnated fiber bushing has the advantages of being oil-free, flame-retardant and explosion-proof, having high mechanical strength and requiring little maintenance. At the same time, this design solves the problem of intermittent failures occurring during the winding process of the glue-impregnated fiber dry-type bushing core and requiring rewinding, thereby improving the bushing production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a radial cross-sectional view of the dry-type casing of the present invention;

[0017] Figure 2 It is a radial cross-sectional view of two adjacent cylindrical sleeves in the present invention;

[0018] Figure 3 Schematic diagram of the winding method of the semi-conductive tape in the present invention.

[0019] Figure 1The cylindrical sleeves in the middle and outer circles are omitted.

[0020] Among them, 1 is a conductive rod, 2 is a cylindrical sleeve, 2.1 is a demoulding protective layer, 2.2 is a capacitor plate layer, 2.3 is an insulating layer, and 3 is a glue injection layer. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0022] like Figure 1 and 2 The illustrated sleeve-type rubber-impregnated fiber dry bushing comprises a conductive rod 1 and a plurality of cylindrical bushings 2 coaxially arranged in a sheath. Each cylindrical bushing 2 comprises a mold release protective layer 2.1, a capacitor plate layer 2.2, and an insulating layer 2.3. In each cylindrical bushing 2, the capacitor plate layer 2.2 is wound around the outer ring of the mold release protective layer 2.1, and the insulating layer 2.3 is wound around the outer ring of the capacitor plate layer 2.2.

[0023] In two adjacent cylindrical sleeves 2, the demoulding protective layer 2.1 of the outer cylindrical sleeve 2 is fixedly connected to the insulating layer 2.3 of the inner cylindrical sleeve 2 through the glue injection layer 3, and the demoulding protective layer 2.1 of the innermost cylindrical sleeve 2 is wrapped around the outer ring of the conductive rod 1.

[0024] In the above technical solution, cylindrical components of different diameters are first wound. Each cylindrical component is independently wound on a winding mold of a different diameter, so each cylindrical component requires a demolding layer to facilitate separation from the winding mold. Each cylindrical component includes a capacitive screen and an insulating layer. These three-layer structures are combined into independent cylindrical components. Then, multiple cylindrical components are put together, and epoxy resin glue is injected into the hollow part between each cylinder. After curing, multiple cylindrical components become a whole solid structure; compared with the traditional continuous winding of glue-impregnated fiber sleeves, it can avoid the need to rewind one layer due to winding errors, thereby improving the sleeve production efficiency.

[0025] In the above technical solution, the length and thickness of the mold release protective layer 2.1 of all cylindrical sleeves 2 are equal, the length and thickness of the capacitor plate layer 2.2 of all cylindrical sleeves 2 are equal, and the length and thickness of the insulating layer 2.3 of all cylindrical sleeves 2 are equal. This uniform thickness design facilitates the winding machine to set the same winding program, reducing the cumulative error of glass fiber winding.

[0026] In the above technical solution, the thickness of the capacitor plate layer 2.2 is in the range of 0.3 to 0.5 mm. The thickness of the demoulding protective layer 2.1 is in the range of 0.5 to 1 mm. The thickness of the insulating layer 2.3 is in the range of 2.5 to 3.5 mm, and the length is based on the insulation design requirements. The electric field distribution inside the core of the resin-impregnated fiber dry-type bushing is reasonable, and there is no situation where the local field strength is too large. The above-mentioned size design is set according to the insulation performance of the material, and the minimum thickness is set to avoid discharge breakdown inside the bushing;

[0027] In the above technical solution, the demoulding protective layer 2.1 of the innermost cylindrical sleeve 2 is formed by winding a glass fiber bundle impregnated with epoxy resin glue on the conductive rod 1, the capacitor plate layer 2.2 is formed by winding a semiconductor material (semi-conductive tape) on the demoulding protective layer 2.1, and the insulating layer 2.3 is formed by winding a glass fiber bundle impregnated with epoxy resin glue on the capacitor plate layer 2.2.

[0028] In the above technical solution, the demolding protective layer 2.1 of the non-innermost cylindrical sleeve 2 is formed by winding a glass fiber bundle impregnated with epoxy resin glue on the surface of the corresponding metal cylindrical mold, and the surface of the metal cylindrical mold is coated with a demolding liquid. The capacitor plate layer 2.2 is formed by winding a semiconductor material on the demolding protective layer 2.1, and the insulating layer 2.3 is formed by winding a glass fiber bundle impregnated with epoxy resin glue on the capacitor plate layer 2.2.

[0029] In the above technical solution, the semi-conductive tape is wound on the demoulding protective layer 2.1 in a half-crimping manner, and the capacitor plate layer 2.2 has no gaps and has a uniform thickness. That is, the winding angle of the capacitor plate layer 2.2 is 30 to 60 degrees with the axial direction of the demoulding protective layer 2.1. When winding, the semi-conductive tape moves forward while winding, and the latter circle of semi-conductive tape is crimped to half the area of ​​the previous circle of semi-conductive tape. The axial width of the semi-conductive tape on the demoulding protective layer 2.1 is A. The latter circle of semi-conductive tape will cover the previous circle of semi-conductive tape, so that the exposed width of the previous circle of semi-conductive tape is only B, 2B=A, such as Figure 3 As shown, the semi-conductive tape is wound in a half-crimped manner to avoid gaps or uneven thickness, and to keep the capacitor plate layer 2.2 free of gaps.

[0030] In the above technical solution, the glue injection layer 3 is made of epoxy resin mixed glue.

[0031] A method for processing the above-mentioned sleeve-type structured rubber-impregnated fiber dry-type casing comprises the following steps:

[0032] Step 1: Impregnate a glass fiber bundle with epoxy resin glue and then wind it around the conductive rod 1 to form a demoulding protective layer 2.1 of the innermost cylindrical sleeve 2;

[0033] Step 2: Winding a semiconductor material onto the release protective layer 2.1 of the innermost cylindrical sleeve 2 to form a capacitor plate layer 2.2 of the innermost cylindrical sleeve 2;

[0034] Step 3: Impregnate the glass fiber bundle with epoxy resin glue and then wind it around the capacitor plate layer 2.2 to form the insulation layer 2.3 of the innermost cylindrical sleeve 2;

[0035] Step 4: Based on the size requirements of the dry-type sleeve, a glass fiber bundle impregnated with epoxy resin is wound around the surface of a metal cylindrical mold with various radii to form a demoulding protective layer 2.1 for each non-innermost cylindrical sleeve 2;

[0036] Step 5: Winding a semiconductor material onto the release protective layer 2.1 of each non-innermost cylindrical sleeve 2 to form a capacitor plate layer 2.2 of each non-innermost cylindrical sleeve 2;

[0037] Step 6: Impregnating a glass fiber bundle with epoxy resin glue and then winding the bundle around the capacitor plate layer 2.2 of each non-innermost cylindrical sleeve 2 to form an insulating layer 2.3 of each non-innermost cylindrical sleeve 2;

[0038] Step 7: demould the demoulding protective layer 2.1 of each non-innermost cylindrical sleeve 2 from the corresponding metal cylindrical mold, and coaxially mount each cylindrical sleeve 2 in sequence according to the diameter size (ensure that the center position of each cylindrical component is not offset). In the two adjacent cylindrical sleeves 2, the demoulding protective layer 2.1 of the outer cylindrical sleeve 2 is fixedly connected to the insulating layer 2.3 of the inner cylindrical sleeve 2 through the glue injection layer 3. The demoulding protective layer 2.1 of the innermost cylindrical sleeve 2 is wrapped around the outer ring of the conductive rod 1, and then the whole is placed in an oven for curing at a curing temperature of about 130 to 140 degrees Celsius. Then, mechanical processing (the coaxially installed sleeve needs to use a lathe to cut off the excess surface part according to the size) and parts assembly (assembly of flanges, tail equalizing balls, terminal blocks and other components) are completed to complete the production of the sleeve-type structured glue-impregnated fiber dry sleeve.

[0039] The glue injection layer 3 is filled with epoxy resin glue using a syringe, and then vacuum glue is injected to fill the gap between the two cylindrical parts.

[0040] In step 7 of the above technical solution, the surface of the metal cylindrical mold is coated with a demoulding liquid to facilitate subsequent separation from the metal mold.

[0041] The present invention solves the problem of intermittent failures and the need for rewinding during the winding process of the core of the glue-impregnated fiber dry-type bushing. Traditional glue-impregnated fiber bushings require continuous impregnation of glass fiber with epoxy resin glue, then winding an insulating layer of a certain length and thickness on a conductive rod, then winding a certain length of semiconductor material as a capacitor plate, then winding an insulating layer of a certain thickness, and then winding the capacitor plate, and so on. The specific number of layers is set according to different bushing models. This leads to a problem: if the size of a certain insulating layer and a capacitor plate is wound incorrectly, rewinding is required. The present invention treats each insulating layer and plate as a separate component, which can be wound separately and then assembled uniformly, thus avoiding this problem. The bushing production efficiency is improved.

[0042] The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

Claims

1. A sleeve-type rubber-impregnated fiber dry casing, characterized by: It comprises a conductive rod (1) and a plurality of cylindrical sleeves (2), wherein the plurality of cylindrical sleeves (2) are coaxially sleeved, and each cylindrical sleeve (2) comprises a demoulding protection layer (2.1), a capacitor plate layer (2.2) and an insulating layer (2.3); in each cylindrical sleeve (2), the capacitor plate layer (2.2) is wound around the outer ring of the demoulding protection layer (2.1), and the insulating layer (2.3) is wound around the outer ring of the capacitor plate layer (2.2); In two adjacent cylindrical sleeves (2), the demoulding protective layer (2.1) of the outer cylindrical sleeve (2) is fixedly connected to the insulating layer (2.3) of the inner cylindrical sleeve (2) through the glue injection layer (3), and the demoulding protective layer (2.1) of the innermost cylindrical sleeve (2) is wound around the outer ring of the conductive rod (1); The lengths of the demoulding protective layers (2.1) of all cylindrical sleeves (2) are equal, the thicknesses of the demoulding protective layers (2.1) of all cylindrical sleeves (2) are equal, the lengths of the capacitor plate layers (2.2) of all cylindrical sleeves (2) are equal, the thicknesses of the capacitor plate layers (2.2) of all cylindrical sleeves (2) are equal, the lengths of the insulating layers (2.3) of all cylindrical sleeves (2) are equal, and the thicknesses of the insulating layers (2.3) of all cylindrical sleeves (2) are equal; The demoulding protection layer (2.1) of the innermost cylindrical sleeve (2) is formed by winding a glass fiber bundle impregnated with epoxy resin glue on the conductive rod (1); the capacitor plate layer (2.2) is formed by winding a semiconductor material on the demoulding protection layer (2.1); and the insulating layer (2.3) is formed by winding a glass fiber bundle impregnated with epoxy resin glue on the capacitor plate layer (2.2).

2. The sleeve-type rubber-impregnated fiber dry casing according to claim 1, characterized in that: The thickness of the capacitor plate layer (2.2) ranges from 0.3 to 0.5 mm.

3. The sleeve-type rubber-impregnated fiber dry casing according to claim 1, characterized in that: The thickness of the demoulding protective layer (2.1) ranges from 0.5 to 1 mm.

4. The sleeve-type rubber-impregnated fiber dry casing according to claim 1, characterized in that: The thickness of the insulating layer (2.3) ranges from 2.5 to 3.5 mm.

5. The sleeve-type rubber-impregnated fiber dry casing according to claim 1, characterized in that: The demoulding protection layer (2.1) of the non-innermost cylindrical sleeve (2) is formed by winding a glass fiber bundle impregnated with epoxy resin glue on the surface of a corresponding metal cylindrical mold, and the surface of the metal cylindrical mold is coated with a demoulding liquid. The capacitor plate layer (2.2) is formed by winding a semiconductor material on the demoulding protection layer (2.1). The insulating layer (2.3) is formed by winding a glass fiber bundle impregnated with epoxy resin glue on the capacitor plate layer (2.2).

6. The sleeve-type rubber-impregnated fiber dry-type casing according to claim 1, characterized in that: The glue injection layer (3) adopts epoxy resin mixed glue.

7. A method for processing the sleeve-type rubber-impregnated fiber dry casing according to claim 1, characterized in that: It includes the following steps: Step 1: impregnating a glass fiber bundle with epoxy resin glue and then winding it around the conductive rod (1) to form a demoulding protective layer (2.1) of the innermost cylindrical sleeve (2); Step 2: Winding a semiconductor material onto the demoulding protective layer (2.1) of the innermost cylindrical sleeve (2) to form a capacitor plate layer (2.2) of the innermost cylindrical sleeve (2); Step 3: impregnating a glass fiber bundle with epoxy resin glue and then winding the bundle onto the capacitor plate layer (2.2) to form an insulating layer (2.3) of the innermost cylindrical sleeve (2); Step 4: According to the size requirements of the dry-type sleeve, a glass fiber bundle impregnated with epoxy resin glue is wound on the surface of a metal cylindrical mold with various radii to form a demoulding protective layer (2.1) of each non-innermost cylindrical sleeve (2); Step 5: Winding the semiconductor material onto the demoulding protective layer (2.1) of each non-innermost cylindrical sleeve (2) to form the capacitor plate layer (2.2) of each non-innermost cylindrical sleeve (2); Step 6: impregnating the glass fiber bundle with epoxy resin glue and winding the bundle around the capacitor plate layer (2.2) of each non-innermost cylindrical sleeve (2) to form an insulating layer (2.3) of each non-innermost cylindrical sleeve (2); Step 7: demoulding the demoulding protective layer (2.1) of each non-innermost cylindrical sleeve (2) from the corresponding metal cylindrical mold, and coaxially fitting each cylindrical sleeve (2) in sequence according to the diameter size. In two adjacent cylindrical sleeves (2), the demoulding protective layer (2.1) of the outer cylindrical sleeve (2) is fixedly connected to the insulating layer (2.3) of the inner cylindrical sleeve (2) through the injection layer (3), and the demoulding protective layer (2.1) of the innermost cylindrical sleeve (2) is wound around the outer ring of the conductive rod (1).

8. The method for processing the sleeve-type rubber-impregnated fiber dry-type casing according to claim 7, characterized in that: In step 7, the surface of the metal cylindrical mold is coated with a release liquid.

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