Machining method for high-voltage capacitive dry-type bushing

Abstract

The invention provides a machining method for a high-voltage capacitive dry-type bushing. According to the method, Radial field intensity is the most uniform when partial discharge margins are equal, the method is different from a method for an oil-filled bushing with average field intensity, and the bushing machined by the method has a smaller structural size and better electrical performance as compared with an existing bushing. The machining method for the high-voltage capacitive dry-type bushing mainly includes the steps of core rolling, vacuum gum dipping and forming.

Description

technical field [0001] The invention relates to a high-voltage bushing used in the power transmission and transformation industry, in particular to a processing method for a high-voltage capacitive dry bushing. Background technique [0002] At present, the dry high-voltage bushings used in the power transmission and transformation industry mainly include glue-impregnated crepe paper type and glass fiber winding type, but the above two methods have the following problems: [0003] The current problems of glue impregnated crepe paper type: [0004] 1. The production process requires a lot of crepe paper, all of which need to be made of wood, which does not conform to the current environmental protection trend and trend; [0005] 2. The vacuum drying and insulation treatment cycle of crepe paper fiber is very long, and the production cost is high; [0006] 3. It is difficult for the epoxy resin in the capillary tube of crepe paper fiber to be completely saturated. During the ...

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Problems solved by technology

[0004] 1. The production process requires a lot of crepe paper, all of which need to be made of wood, which does not conform to the current environmental protection trend and trend;

[0005] 2. The vacuum drying and insulation treatment cycle of crepe paper fiber is very long, and the production cost is high;

[0006] 3. It is difficult for the epoxy resin in the capillary tube of crepe paper fiber to be completely saturated. During the later production, processing, transportation and operation, the exposed epoxy part needs to be sealed and protected by a special container, otherwise the paper fiber will be reabsorbed into the air. If there is too much moisture, the dielectric loss and partial discharge of the bushing will increase, and long-term operation will lead to bushing failure and collapse, which will pose a major hidden danger to the whole equipment;

[0007] 4. Capacitor plates need to be alternately arranged between crepe papers. It is difficult to control the degree of tightness of crepe paper rolls, which has an important impact on the accuracy of capacitor electrode layout and the degree of final epoxy resin infiltration, and on process equipment and workers. High operating proficiency is required;

[0008]5. There are many layers of capacitor electrodes, any layer of capacitor electrode layout errors or other hidden defects in the rolling process will lead to the scrapping of the entire product, Not convenient for mass industrial production

[0010] 1. The product is wound with glass fiber impregnated with epoxy resin 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 dielectric loss of the product. Relatively large, long-term operation is likely to cause thermal collapse of the product;

[0011]2. The edge treatment, flatness, concentricity and bonding performance of the capacitor electrode are poor, resulting in a large partial discharge of the product, often hundreds to thousands Pi library, so it cannot be used with equipment that requires high electrical performance

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