Method for improving production qualification rate of dry-type bushing

Abstract

The invention discloses a method for improving the production qualification rate of a dry-type bushing, and belongs to the technical field of preparation of power transmission and transformation high-voltage bushings. The method comprises the steps of changing the traditional axial complete long polar plate arrangement of a glue-impregnated fiber capacitive dry-type bushing into alternate arrangement of long polar plates which are completely penetrated in the axial direction and short polar plates which are not completely penetrated in the axial direction; alternately arranging the long polar plates and the short polar plates in the peripheral axis direction of the dry-type bushing, and enabling epoxy resin glue solution to longitudinally and transversely flow between synthetic fiber woven mesh cloth; and finally, obtaining the glue-impregnated fiber capacitive dry-type bushing. According to the invention, the barrier effect of a plurality of layers of capacitor plates which are concentrically arranged in the core body of the bushing capacitor on the flowability of the epoxy resin glue solution is eliminated to the greatest extent, and the permeability and the mechanical strength of the dry-type bushing are further improved; the risk of forming defects and cracking in the curing shrinkage or thermal expansion and cold contraction process of the thick-wall capacitor core body is reduced, the electrical performance index and the operation reliability of the product are improved, and the production qualification rate of the dry-type bushing is improved.

Description

technical field [0001] The invention belongs to the technical field of high-voltage bushing preparation for power transmission and transformation, and in particular relates to a method for improving the qualified rate of dry bushing production. Background technique [0002] At present, the dry-type high-voltage bushings used in the power transmission and transformation industry mainly include glue-impregnated corrugated paper type and glass fiber winding type. [0003] The current problems of glue-impregnated crepe paper: ①. The production process requires a large amount of crepe paper, all of which need to be made of wood, which does not conform to the current environmental protection trend and trend; ②. The vacuum drying and insulation treatment period of crepe paper fibers is extremely long and the production cost is high; ③. It is difficult for the epoxy resin in the capillary tube of crepe paper fiber to be completely saturated. In the later stage of production, process...

AI Technical Summary

Problems solved by technology

[0003] The current problems of glue-impregnated crepe paper: ①. The production process requires a large amount of crepe paper, all of which need to be made of wood, which does not conform to the current environmental protection trend and trend; ②. The vacuum drying and insulation treatment period of crepe paper fibers is extremely long and the production cost is high; ③. It is difficult for the epoxy resin in the capillary tube of crepe paper fiber to be completely saturated. In the later stage of production, processing, transportation and operation, the exposed epoxy part must be sealed and protected by a special container, otherwise the paper fiber will be reabsorbed into the air. If there is too much water in the bushing, it will cause the dielectric loss of the bushing and the increase of partial discharge. Long-term operation will cause the bushing to fail and collapse, which will pose a major hidden danger to the equipment of the whole machine; It is difficult to control the tightness of the system, which has an important impact on the accuracy of the electrode layout and the degree of infiltration of the final epoxy resin, and requires high levels of process equipment and workers' operating proficiency; ⑤. There are many electrode layers, and the rolling In the process, any layer of electrode layout errors or other hidden defects will lead to the scrapping of the entire product, which is not convenient for mass industrial production

[0004] Glass fiber winding type: ①. The product is wound and manufactured in an open environment. The production process cannot be dried and insulated under vacuum conditions. The moisture contained in the insulating material itself and the moisture and impurities in the air cannot be removed, resulting in a relatively high dielectric loss of the product. Large, long-term operation will easily lead to thermal collapse of the product; ②, the edge treatment, flatness, concentricity and bonding performance of the aluminum foil metal capacitor electrode are poor, resulting in a large partial discharge of the product, often hundreds to thousands of picoku, Therefore, it cannot be used in conjunction with equipment that requires high electrical performance;

[0005] The traditional capacitor plate is made of aluminum foil, which has a dense structure and is an impermeable material, and it is often necessary to set multi-layer capacitor plates in a bushing according to the voltage level, which will cause the capacitor core to be vacuum impregnated During the process of epoxy resin, the flow direction of epoxy resin and the curing internal stress during the curing process are blocked and shielded by the metal plate (such as figure 1 It is a schematic diagram of the traditional structure that is all arranged by long plates), it is easy to form air gaps, or the internal stress of curing cannot be released, resulting in delamination and formation of defects, which often lead to partial discharge failure of the product, or breakdown by withstand voltage

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