RU2723637C1 - High-voltage insulator with invar geometrical stabilizer - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to high-voltage equipment, namely to high-voltage insulators, and is aimed at improvement of their operation reliability. Insulator comprises geometric stabilizer to compensate thermal expansions of conductor, which is performed by shell made of invar alloy. Invar shell retains stable dimensions at change of thermal mode of insulator, which allows maximum reduction of mechanical action on insulation and avoiding such damages as peeling and cracking.

EFFECT: invention provides maximum effect when using it for insulators with RIP insulation intended for operation in areas with cold climate.

1 cl, 2 dwg

Description

Field of Technology:

The invention relates to high-voltage technology, namely, to high-voltage insulators that allow conductors to pass through a partition, such as a wall, the body of an electric machine or apparatus, and insulate the conductors from it. The invention is aimed at improving the reliability of insulators through the use of a geometric stabilizer. The invention provides the greatest effect when applied to insulators with solid (dry) insulation made of insulating paper impregnated with resin, and designed to work in areas with a cold climate.

The prior art:

Most high-voltage insulators that allow conductors to pass through the bulkhead and insulate the conductors from it are made up of oil-paper insulators (OIP insulation). With all the positive properties of such insulators, they have a number of disadvantages associated, first of all, with the control and care of them during operation. Also their disadvantages are explosion and fire hazard. These shortcomings have been eliminated by insulators with solid insulation - paper-coated resin (RBP insulation) or paper-impregnated resin (RIP), which have been in use since the end of the last century. At the same time, a certain type of isolation cannot be considered predominant, since each type has its own positive qualities. So paper-oil insulation is better manifested in difficult climatic conditions of work, with large temperature differences in the environment. Oil, impregnating the paper, provides some mobility to the insulation layers, avoiding the occurrence of mechanical stresses, which can cause the appearance of insulation breaks. Since solid insulation can concentrate all the mechanical stresses associated with thermal expansion, the operation of insulators with solid insulation at low temperatures carries certain risks. This is one of the reasons why the Russian standard GOST R 55187-2012 “INPUTS ISOLATED TO RATED VOLTAGE OVER 1000 V AC. General technical conditions ”, developed on the basis of the international standard IEC 60137: 2008“ Insulated bushings for alternating voltages above 1000V ”, in clause 5.4.1, limits the maximum temperature rise of the contact parts of the insulator over the ambient temperature to no more than 65 ° С. In conditions of low ambient temperatures, for example, in the Far North, this circumstance complicates the operation, forcing to put up with a possible decrease in reliability.

Thus, the technical task of improving the reliability of insulators in a wide range of environmental temperatures can be reduced to reducing mechanical stresses in the insulating material caused by thermal expansion. In the invention, the problem is solved by placing the current-carrying elements of the insulator in the shell of alloys of the Invar group, which assumes the forces associated with the thermal expansion of the conductor and eliminates the transfer of these forces to the insulation. Such a solution to the problem of improving reliability significantly distinguishes the present invention from previously known, in which the increase in reliability is provided by a special insulation device. An example of a high-voltage insulator, in which the increase in reliability is provided by the special organization of the insulation layers, may be patent RU 2406174.

Disclosure of the invention:

The subject of the invention is a high-voltage insulator that allows conductors to pass through the partition and insulate the conductors from it, the live part of which has a shell made of Invar alloy. Inside it are one or more conductors of a material with high electrical conductivity, the space around which is filled with an elastomer.

The novelty of the insulator is the use of a geometric stabilizer to compensate for the thermal expansion of the conductor. The role of the geometric stabilizer is performed by the invar shell. Invar alloys, alloys of the iron-nickel system, with a nickel content of 30 to 40% with alloying, chromium, cobalt, copper, titanium or manganese are precision alloys with a temperature coefficient of linear expansion having an anomalously low value. The exact value of the linear expansion coefficient depends on the alloy composition, quenching methods and machining. The Invar shell maintains stable dimensions when the thermal regime of the insulator changes, which minimizes the mechanical effect on the insulation and avoids such damage as peeling and cracking.

The invention is illustrated by drawings, where Fig. 1 shows a perspective view of a fragment of an insulator with layer-wise cuts revealing its structure, and Fig. 2 shows a cross-section of an insulator. The main element that ensures the passage of electric current through the insulator is one or more conductors 1 of metal with high electrical conductivity. The conductors are located inside the geometric stabilizer 2, which is a closed shell made of Invar alloy. The space between the conductors and the sheath is filled with elastomer 3. The volume of the elastomer and its placement in the space between the conductors and the sheath is selected so that the thermal expansion of the conductors is compensated by a decrease in the volume of the elastomer and does not lead to an increase in the external size of the geometric stabilizer. The main insulation 4 is applied to the geometric stabilizer. Depending on the environment in which the insulator will operate, in addition to the main insulation, the insulator can also have an external insulation 5 of porcelain or polymer.

Brief Description of the Drawings

FIG. 1 is an axonometric image of a fragment of an insulator with layered cuts.

The drawing indicates:

Position 1 - conductors made of metal with high electrical conductivity;

Position 2 - geometric stabilizer;

Position 3 - elastomer;

Position 4 - main insulation;

Position 5 - External Insulation.

FIG. 2 - cross section of the insulator.

The drawing indicates:

Position 1 - conductors made of metal with high electrical conductivity;

Position 2 - geometric stabilizer;

Position 3 - elastomer;

Position 4 - main insulation;

Position 5 - External Insulation.

The implementation of the invention

The invention is implemented by standard equipment and technologies available in the electrical industry used for the production of insulators. The production of precision alloys is also well developed by industry. The use of well-known and proven technologies in the invention allows the invention to be realized in a short time on an industrial scale.

Sources of information

1. GOST R 55187 - 2012 “INPUTS INSULATED TO RATED VOLTAGE OVER 1000 V AC. General specifications ";

2. Patent RU 2406174 "HIGH VOLTAGE PASS-INSULATOR".

Claims (1)

A high-voltage insulator that allows conductors to pass through the baffle and insulates the conductors from it, the current-carrying part of which has a geometric stabilizer, which is a shell made of an invar alloy, inside of which there are one or more conductors of material with high electrical conductivity, the space around which is filled with an elastomer.

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