RU163184U1 - HIGH-VOLTAGE INPUT ISLAND WITH SECTED RIP-INSULATION AND ELECTRODES ON EQUAL DIMENSIONS - Google Patents

Abstract

A core of a high-voltage input containing a metal pipe, sections of paper insulation impregnated with epoxy resin, with equalizing linings, a support cylinder with a connecting sleeve mounted on it, a support flange, a cover, a spring coupling assembly and an insulating gel that fills the free space in the core after assembly of the input , characterized in that in the insulation sections on the edges of the equalizing plates installed metal electrodes insulated with resin, which are electrically connected to the plates, and the place of installation and electrodes, and they are filled with resin, the mechanical fastening of insulation sections, except the section situated around a conductive pipe employed upper and lower support sleeve of insulating material.

Description

The utility model relates to electrical engineering, namely, to bushings in transformers and other high-voltage apparatuses.

Solid RIP bushings are manufactured for voltages up to 500 kV.

The solid RIP insulation is made of copy paper, which is wound on a conductive metal pipe together with leveling plates made of aluminum foil.

The wound skeleton undergoes thermal vacuum treatment, resin impregnation, cooling to ambient temperature and mechanical processing.

After fitting the connecting sleeve onto the insulation, the input assembly and its electrical tests are carried out.

In the insulation of the core during its manufacture / cooling of the core after impregnation with resin, mechanical processing of the insulation /, as well as during cooling of the insulation at the installation site of the connecting sleeve heated to a temperature of 250-300 C, mechanical stresses can occur that can lead to microcracks. When operating the bushings under the influence of electric voltage, discharges occur in them,

“This is especially true for large bushings of 220 kV and above.” / Thermomechanical stresses in solid RIP insulation. Tests of high-voltage bushings 220-500 kW for resistance to external influences. Kassikhin S.D., Sipilkin K.G., Slavyanskiy A.Z., Electro 2, 2007 /.

Leveling plates in the input insulation regulate the voltage distribution in the insulation of the inputs in the radial and axial directions.

“At the sharp edges of the plates there is a very uneven field with a significant component of tension directed along the insulation layers.

The field strength at a distance r from the edge of the electrode for r <0.1d can be estimated by the following formula

where u is the voltage between the plates,

d is the thickness of the insulation.

/ M.A. Greysukh, G.S. Kuchinsky, A.A. Kaplan, G.T. Messerman. “Paper-oil insulation in high-voltage structures”, Gosenergoizdat, Moscow-Leningrad, 1963, p. 24 /.

With increasing input voltage, the number of equalizing plates in the input increases, which means that the insulation region with a sharply inhomogeneous field increases.

The core for a voltage of 500 kV has an outer diameter of 320 mm, a length of 7.5 meters and a weight of 680 kg.

In the patent for utility model “High-voltage input core with sectioned RIP isolation” for No. 157606, the input core design is given, which allows 3 sections / to be insulated by isolation / isolation, as well as by introducing a new element into the design - the support cylinder, on which the connecting sleeve is mounted, to reduce mechanical stresses in the insulation, and thereby eliminate the formation of microcracks in the insulation and increase its reliability during operation.

However, the disadvantage of this design is a sharply inhomogeneous field that occurs at the edges of equalizing plates.

The specified design of the core of the high voltage input is taken as a prototype.

The disadvantage of the prototype can be eliminated by installing electrodes at the edges of equalization plates.

The utility model patents Nos. 110862 and 139426 show the designs of electrodes made of electrically conductive tapes by winding them together with insulating tapes, and the utility model patents Nos. 150647 show the design of the core, in which insulated metal electrodes are installed .

In this application, it is assumed that metal electrodes insulated with resin are installed at the edges of the leveling plates in the sections. The installation of electrodes is carried out after the manufacture of sections of insulation and the necessary processing of the installation sites of the electrodes. The electrodes and their installation sites are filled with resin.

The sections of the skeleton have different lengths. The section located near the conductive pipe has the longest length, and the section near the supporting cylinder has the shortest length.

For mechanical fastening of insulation sections having a length shorter than the longest section, upper and lower bushings of insulating material are provided. They can be made of crepe paper impregnated with resin.

In FIG. 1 shows the core of a high-voltage input with sectionalized RIP insulation and leveling electrodes.

The core comprises a conductive metal pipe 1, a support cylinder 2 with a connecting sleeve 3 mounted thereon, insulation sections 4, which are electrically connected to each other by terminals 5, as well as with the conductive pipe and connecting sleeve. In the insulation sections on equalizing plates 6, electrodes 7 made of metal and insulated with resin are installed, which are electrically connected to the plates, and then filled with resin 8.

The mechanical connection of the support cylinder, the conductive pipe and the insulation sections is carried out using the support flange 9 and the cover 10 mounted on the conductive pipe, the spring coupling unit 11, as well as the upper support sleeves 12 and the lower support sleeves 13. The space in the core between the conductive pipe , the supporting cylinder and the insulation sections, as well as between the insulation sections and the supporting sleeves, is filled with insulating gel 14. The core is filled with gel after the input assembly.

Claims (1)

A core of a high-voltage input containing a metal pipe, sections of paper insulation impregnated with epoxy resin, with equalizing linings, a support cylinder with a connecting sleeve mounted on it, a support flange, a cover, a spring coupling assembly and an insulating gel that fills the free space in the core after assembly of the input , characterized in that in the insulation sections on the edges of the equalizing plates installed metal electrodes insulated with resin, which are electrically connected to the plates, and the place of installation and electrodes, and they are filled with resin, the mechanical fastening of insulation sections, except the section situated around a conductive pipe employed upper and lower support sleeve of insulating material.

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