Anti-pollution flashover type sleeve

Abstract

An anti-pollution flashover type sleeve belongs to the technical field of sleeves for transformer substations and comprises an upper-end metal accessory, an upper-end cement adhesive layer, a porcelain piece and a semiconductor glaze layer. A plurality of first umbrellas are integrally arranged above the outer side of the porcelain piece, and a plurality of second umbrellas are integrally arranged below the outer side of The surface of the first umbrella is provided with a semiconductor glaze layer. The surface of the second umbrella is provided with an electric porcelain glaze layer. The first umbrella with a large diameter is arranged to be an umbrella with a larger diameter, so that the rain-proof and icing-proof capabilities of the sleeve can be improved; and meanwhile, the creepage distance and the large umbrella surface area are increased, and the specific capacitance of the first umbrella porcelain surface is reduced, so that the gliding lightning voltage of the sleeve is improved. The semiconductor glaze is applied to improve the electric field distribution around the high-voltage metal accessory at the upper end, so that the discharge is not easy to develop, and the flashover voltage and the corona initial voltage are improved. The surface temperature of the porcelain is increased by 1-5 DEG C higher than the ambient temperature, so that a dirt layer absorbing moisture and dust can be dried, ice melting is promoted, ice flashover is prevented, and the purpose of pollution flashover prevention is achieved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to bushing technical field for transformer substation, especially relates to a kind of anti-pollution flashover bushing, it is a bushing for transformer substation. BACKGROUND

[0002] With the development of power transmission system and power technology, China has mastered the manufacturing capability of high-voltage direct current transmission technology and complete equipment, and is developing towards higher voltage and higher technology. The construction of direct current transmission system requires a large amount of bushings. Circuit breakers, transformers and other power equipment need bushings as support and insulation. The operation experience of converter stations at home and abroad shows that adverse weather and poor design margin of external insulation lead to many flashover accidents. External insulation flashover accident has become one of the key factors affecting the reliable operation of power transmission system. The diameter of the traditional bushing umbrella skirt is the same, and the anti-pollution ability is poor. The original conductor (upper end metal accessory 1) is directly connected to the insulator (electric porcelain enamel) electric field concentration. UTILITY MODEL CONTENTS

[0003] The utility model aims to provide a kind of anti-pollution flashover bushing, the first umbrella of the upper end of the bushing has larger umbrella type, which can improve the anti-pollution ability of the bushing, and semiconductor enamel is applied to the bottom end of the lowermost first umbrella of the metal accessory, which improves the electric field around the metal accessory and improves the safety of the bushing operation.

[0004] The technical scheme adopted is:

[0005] An anti-pollution flashover bushing includes an upper end metal accessory, an upper end cement adhesive layer, a porcelain piece and a semiconductor enamel layer. The upper end metal accessory is fixed to the outer side of the upper end of the porcelain piece by the upper end cement adhesive layer.

[0006] A plurality of first umbrellas are integrally provided on the outer side of the porcelain piece, and the plurality of first umbrellas are located below the upper end metal accessory.

[0007] A plurality of second umbrellas are integrally provided below the outer side of the porcelain piece, and the plurality of second umbrellas are located below the first umbrellas. The anti-pollution flashover bushing is characterized in that:

[0008] The diameter of each first umbrella is at least 20mm larger than the diameter of the second umbrella.

[0009] The surface of the plurality of first umbrellas has a semiconductor enamel layer.

[0010] The surface of the plurality of second umbrellas has an electric porcelain enamel layer.

[0011] The diameters of the plurality of first umbrellas gradually decrease from top to bottom.

[0012] The anti-pollution flashover bushing has the following advantages:

[0013] The upper end of the bushing has multiple large-diameter first umbrellas configured into larger diameter umbrella shapes, which can improve the bushing's ability to prevent rain and icing; at the same time, it increases the creepage distance and the surface area of ​​the large umbrellas, reduces the specific capacitance of the ceramic surface of the first umbrella, thereby improving the flashover voltage of the bushing.

[0014] Applying a semiconductor glaze from the upper metal attachment to the bottom of the first umbrella reduces the surface resistance of the large umbrella ceramic. This changes the original direct connection between the conductor (metal attachment) and the insulator (ordinary electric porcelain glaze) to a transition between the conductor and the insulator via a semiconductor (semiconductor glaze), transforming the electric field from concentrated to uniform and improving the electric field distribution around the upper high-voltage metal attachment. Applying the semiconductor glaze at the location of maximum capacitive current density between the upper metal attachment and the bottom of the first umbrella further reduces the surface resistance of the ceramic surface, thus reducing the surface potential gradient and making discharge less likely to develop, thereby increasing the flashover voltage and corona initiation voltage.

[0015] A resistance of 10 is applied between the upper metal fitting and the bottom of the first umbrella. 6 ~10 9 The Ω-type semiconductor glaze has a conductivity that differs from that of ordinary electrical porcelain glaze by about 10,000 times. By heating the surface with a uniform leakage current, the surface temperature of the porcelain is raised by 1°C to 5°C compared to the surrounding temperature. This can dry the moisture-absorbing and dust-absorbing dirt layer, promote the melting of ice, prevent ice flashover, and achieve the purpose of preventing pollution flashover.

[0016] In summary, this utility model of anti-flashover bushing ensures the electrical performance of the bushing and the safe operation of the converter station, providing important theoretical and engineering guidance for the design, operation and maintenance of bushings. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the anti-flashover sleeve of this utility model.

[0018] Figure 2 This is a schematic diagram of a traditional bushing.

[0019] 1. Upper metal fittings, 2. Upper cement adhesive layer, 3. Ceramic component, 4. Semiconductor glaze layer, 5. Electric porcelain glaze layer, 6. First umbrella, 7. Second umbrella. Detailed Implementation

[0020] The specific implementation scheme of this utility model is described in detail below with reference to the accompanying drawings:

[0021] like Figure 1 As shown, this utility model provides a flashover-proof sleeve, which includes an upper metal fitting 1 (ductile iron upper flange), an upper cement adhesive layer 2, a ceramic part 3 (cylindrical hollow ceramic tube), and a semiconductor glaze layer 4.

[0022] The upper end of the porcelain 3 is fixed with an upper end metal accessory 1 by an upper end cement adhesive layer 2 (a silicate cement adhesive layer) on the outside.

[0023] The porcelain 3 is integrally provided with a plurality of first umbrellas 6 (porcelain) on the outside above, and the plurality of first umbrellas 6 are located below the upper end metal accessory 1.

[0024] The porcelain 3 is integrally provided with a plurality of second umbrellas 7 (porcelain) on the outside below, and the plurality of second umbrellas 7 are located below the first umbrellas 6.

[0025] The plurality of circular second umbrellas 7 have the same diameter, and the plurality of circular first umbrellas 6 have diameters greater than that of the plurality of second umbrellas 7.

[0026] The diameters of the plurality of first umbrellas 6 gradually decrease from top to bottom, and the umbrella roots are relatively thick.

[0027] For example, the first umbrellas 6 are three, and the diameters gradually decrease by 20 mm from top to bottom.

[0028] The diameter of the third first umbrella 6 is greater than that of the second umbrella 7 below by 20 mm.

[0029] The diameter of the second first umbrella 6 is greater than that of the third first umbrella 6 below by 20 mm.

[0030] The diameter of the first first umbrella 6 is greater than that of the second first umbrella 6 below by 20 mm.

[0031] The diameters of the upper three first umbrellas 6 are greater than that of the second umbrella 7 by 60 mm, 40 mm and 20 mm, respectively.

[0032] The surfaces of the plurality of first umbrellas 6 have a semiconductor glaze layer 4.

[0033] The surfaces of the plurality of second umbrellas 7 have an electric porcelain glaze layer 5.

[0034] The lower end of the porcelain 3 is fixed with a lower end metal accessory (a nodular cast iron lower flange) by a lower end cement adhesive layer (a silicate cement adhesive layer) on the outside, and is located below the plurality of second umbrellas 7.

[0035] After the drying of the trimming, the semiconductor glaze 4 is applied between the upper end metal accessory 1 and the umbrella bottom end of the lowermost first umbrella 6 of the porcelain 3 during the glazing process of the porcelain 3. The porcelain 3 after firing is cemented into the upper end metal accessory 1. The surfaces of the plurality of second umbrellas 7 have a common electric porcelain glaze, and the semiconductor glaze 4 is an iron-titanium type semiconductor glaze. The content of the iron-titanium compound can be selected to be 30%, and the content of the common electric porcelain glaze is 70% of the iron-titanium type semiconductor glaze. The semiconductor glaze is low in price and simple in process operation. The resistance of the semiconductor glaze is 10 6 ~ 10 9

[0036] Ω, about 10000 times different from ordinary electric porcelain glaze, so that the porcelain surface can be heated by uniform leakage current, and the wet conductive layer is dried, and the pollution layer is prevented from absorbing moisture and accumulating dust. The temperature rise of the porcelain surface can also promote the melting of the ice, which is not conducive to the formation of ice column under warm conditions, thereby preventing the occurrence of ice flashover. The reduction of the porcelain surface resistance reduces the potential gradient of the porcelain surface, improves the electric field environment around the upper metal accessory 1, thereby improving the flashover voltage and corona inception voltage. The electrical performance of the bushing and the safe operation of the converter station are ensured.

[0037] The anti-pollution flashover bushing is designed according to the voltage grade and the pollution degree to determine the size, such as the height, the main body diameter, the umbrella diameter and the creepage distance and the like. According to the above bushing size parameters, according to the design experience of the traditional bushing, the diameters of the first plurality of large umbrellas and the root thickness are determined. The diameter of the first umbrella 6 is at least greater than 20mm than the diameter of the second umbrella 7, so as to play a certain anti-pollution ability.

Claims

1. A type of anti-pollution flash bushing, comprising an upper end metal accessory (1), an upper end cement adhesive layer (2), a porcelain piece (3) and a semi-conductive glaze layer (4); the upper end metal accessory (1) is fixed on the outer side of the upper end of the porcelain piece (3) through the upper end cement adhesive layer (2); a plurality of first sheds (6) are integrally arranged on the outer side of the upper end of the porcelain piece (3), and the plurality of first sheds (6) are located below the upper end metal accessory (1); a plurality of second sheds (7) are integrally arranged on the outer side of the lower end of the porcelain piece (3), and the plurality of second sheds (7) are located below the first sheds (6); characterized in that: the diameter of each first shed (6) is at least 20mm larger than the diameter of the second shed (7); the surface of the plurality of first sheds (6) has the semi-conductive glaze layer (4); the surface of the plurality of second sheds (7) has an electric porcelain glaze layer (5).

2. The type of anti-pollution flash bushing according to claim 1, characterized in that: the diameters of the plurality of first sheds (6) gradually decrease from top to bottom.

3. The type of anti-pollution flash bushing according to claim 2, characterized in that: the diameters of the plurality of first sheds (6) gradually decrease by 20mm from top to bottom.

4. The type of anti-pollution flash bushing according to claim 3, characterized in that: the first sheds (6) are three.

5. The type of anti-pollution flash bushing according to claim 1, characterized in that: the upper end metal accessory (1) is a nodular cast iron upper flange.

6. The type of anti-pollution flash bushing according to claim 1, characterized in that: the upper end cement adhesive layer (2) is a silicate cement adhesive layer.

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