Description

Manufacturing of transformer bushings for HV (VSTA) and LV bushings (VST) is one of the leading directions of our company. Removable high-voltage transformer bushings are used to connect power transformer bushings to the conductors of external electrical networks. Our company is also a supplier of equipment for a number of leading enterprises in Russia and neighboring countries related to the production and repair of transformers and high-voltage bushings. Design of transformer bushings: Transformer bushings consist of a porcelain insulator, a current-carrying rod (bushing stud), seal parts and support elements for seals, fasteners (nuts and washers) and are manufactured according to the technical requirements of the drawings. The bushings are installed on the lid or wall of the transformer tank in the structures of bushing installations, which have additional parts for fastening the bushing: bosses, fasteners, flange, cams, gaskets and disc (transport tank plug, if the bushing is dismantled). The bushings are installed at an angle to the vertical from 0 ° to 90 ° inclusive. Long-term console loads on the bushings comply with IEC 60137. High-voltage bushings installed on the transformer are operated under the pressure of transformer oil in the transformer conservator. All bushings are removable and allow the replacement of the IPT bushing in operation, if necessary, without dismantling the current-carrying rod (bushing stud). The service life of the bushings is 25 years.

Transformer bushing VST, VSTA VSTA 6-10 / 250 (VN bushing) Manufacturing of transformer bushings for HV (VSTA) and LV bushings (VST) is one of the leading directions of our company. Removable high-voltage transformer bushings are used to connect power transformer bushings to the conductors of external electrical networks. Our company is also a supplier of equipment for a number of leading enterprises in Russia and neighboring countries related to the production and repair of transformers and high-voltage bushings. Design of transformer bushings: Transformer bushings consist of a porcelain insulator, a current-carrying rod (bushing stud), seal parts and support elements for seals, fasteners (nuts and washers) and are manufactured according to the technical requirements of the drawings. The bushings are installed on the lid or wall of the transformer tank in the structures of bushing installations, which have additional parts for fastening the bushing: bosses, fasteners, flange, cams, gaskets and disc (transport tank plug, if the bushing is dismantled). The bushings are installed at an angle to the vertical from 0 ° to 90 ° inclusive. Long-term console loads on the bushing comply with IEC 60137. High-voltage bushings installed on the transformer are operated under the pressure of transformer oil in the transformer conservator. All bushings are removable and allow the replacement of the IPT bushing in operation, if necessary, without dismantling the current-carrying rod (bushing stud). The service life of the bushings is 25 years.

The bushings of power transformers are used to isolate the ends of the winding taken out from the tank and to connect them to various elements of the electrical installation. Bushings are distinguished by a wide variety of shapes and sizes, depending on voltage, power, location of the transformer, as well as on the requirements for it.

The product includes (brass parts with O-Wee coating): -
insulator IPT and IPTV;
- input hairpin;
- washers;
- nuts;
- cardboard spacers;
- brass bushing;
- seal OVER and UNDER the insulator.

Input of conventional transformer designs for 6 and 10 kV for indoor installation: 1 - current-carrying rod, 2 - brass nut, 3 - copper washer, 4 - steel cap, 5 - porcelain insulator, 6 - steel stud, 7 - steel nut, 8 - cast iron flange, 9 - rubber washer, 10 - electric cardboard washer, 11 - steel washer, 12 - cementing mass.

The bushing has a porcelain insulator 5, a cast-iron flange 8, which serves to fix the bushing on the wall or lid of the tank, and a current-carrying copper rod 1, electrically connecting the transformer winding with individual elements of the electrical installation. Indoor transformer bushing insulator has a smooth or finely ribbed surface.

The outdoor transformer bushing insulator has large umbrella-shaped ribs, which greatly increases the discharge distance and, even with heavy rain and heavy contamination of the insulator, avoids discharges along its surface.

In transformers of old designs, bushings were used, to replace which, in case of damage, it was necessary to remove the cover or remove the active part from the tank. Currently, to simplify the operation of replacing the bushing in transformers of the 1st and 2nd dimensions, removable bushings are used that do not have flanges and clips.

The damaged porcelain insulator of such bushings can be replaced without lifting the core. To do this, it is enough to unscrew the outer nuts from the current-carrying rod, unfasten the device that presses the input to the cover, remove the cap and the rubber sealing ring located under it from the input. Then remove the insulator, replace it with a new one and reassemble the bushing.

The passage of large currents through the current-carrying rod is accompanied by the creation of a strong magnetic field, which causes unacceptable heating of the flanges and the cover. To reduce heating, cast-iron and steel flanges of bushings for currents over 400 A are replaced with brass ones.

To reduce heating of the lid, use one of the following methods:

• increase the diameter of the hole in the cover for the input in order to increase the distance to the current-carrying rod and thereby weaken the magnetic field in the cover, and, consequently, its heating;
• place the inputs of the same voltage side by side, and a common hole is cut out in the cover for them. In this case, the total magnetic flux is zero and the lid does not heat up. To install the bushings in the common cutout of the cover, cast iron or brass clips are used.

Arrangement of inputs for a current of 1000 A in a common cage:

1 - input,
2 - annular projection of the cage,
3 - clip,
4 - bolt,
5 - cementing mass.

Bushings 1 are put into the cage 3, which is then installed on a sealing gasket made of oil-resistant rubber and fixed on the tank lid with bolts 4 and nuts.

Transformer bushings ВСТ - 1/400 are intended for connecting windings with the outer part of conductors. The elements provide reliable protection for the structural components of the network.

Design parameters

Introductory elements are designed for outdoor and indoor use, depending on the category of placement and climatic design. For efficient and safe operation of the equipment, a non-explosive environment is required, in which there are no conductive dust particles, and there are no aggressive concentrations of dust and gases that can damage the insulating part or metal components.

VST bushings are bushings and are structurally represented by brass circles with a cut on both sides carving, and washer, which secures the lower insulator, and other components:

• top brass high nut;
• bottom brass nut;
• gaskets under and above the rubber insulator;
• cap;
• insulator.

Brass is used for the production of the bushing stud. The bushing is the conductive part between damperand busbar... The dimensions of the bushing can be made according to individual parameters.

Each of the structural elements performs its own functions:

• the current-carrying pipe takes over the incoming voltage;
• using an insulator, the rod is fixed and protected;
• a metal insert ensures reliable fastening due to the presence of a flange in the structure;
• the upper shielding element ensures the alignment of the intense field;
• the bottom shield stabilizes the field parameters at the bottom of the contact assembly, improving electrical resistance.

To ensure the required parameters of electrical equipment, additional components are added to the bushings.

Decoding

The following designations are used for bushing marking:

• TSA - removable transformer input;
• 1 - rated voltage in kV;
• 400 - rated current in A.

Installation methods

When installing bushings, consider the following rules:

• installation of structures is carried out on the wall of the tank or converters or on its lid;
• vertical tilt is allowed in the range from 0 to 90 degrees;
• the inside of the bushings is always under low pressure.

Products can be produced in collapsible and non-collapsible modifications.

Our company offers the manufacture of bushings of various climatic designs for several categories of placement. We produce equipment in a short time, we take into account the individual wishes of customers.

Removable bushings of VST, VSTA, VSTB types are used in power transformers to connect the transformer windings to the conductors of external electrical networks in the open air or in closed bus systems. Operating conditions: moderately cold climate, the environment is non-explosive and does not contain conductive dust, corrosive gases and vapors in concentrations that can lead to destruction of electrical porcelain and glaze.

The high-voltage bushing is a structure with external and internal insulation. The design of the internal insulation has a great influence on the overall insulation performance of the bushing. The insulation and the quality of its manufacture largely determine the reliability and, accordingly, the service life of the high-voltage bushing.

The base of the high-voltage bushing is a porcelain insulator, in the inner hole of which a current-carrying copper rod is threaded and hermetically fixed. The upper contact of the copper rod is used for connection to external electrical networks, and the lower contact is for connection to the winding taps. It is allowed to mount the bushings on the lid or wall of the transformer tank at an angle not exceeding 90 degrees. Inside, the high-voltage bushing is filled with oil and is always under a slight overpressure created by the oil level in the conservator. The top and bottom bushing contacts are tin plated.

Overall dimensions of bushings

According to the method of connection to the branch of the winding of high-voltage bushings, it is produced in the following version, for example, VSTA-1 / 2500-1 (collapsible version), VSTA-1 / 2500-2 (non-collapsible version)

Removable high-voltage transformer bushings are used to connect the bushings of power transformers to the conductors of external electrical networks.

Our company is also a supplier of equipment for a number of leading enterprises in Russia and neighboring countries related to the production and repair of transformers and high-voltage bushings.

Transformer bushings design:

Transformer bushings consist of a porcelain insulator, a current-carrying rod ( input studs), seal parts and support elements for seals, fasteners (nuts and washers) and are manufactured according to the technical requirements of the drawings.

The bushings are installed on the lid or wall of the transformer tank in the structures of bushing installations, which have additional parts for fastening the bushing: bosses, fasteners, flange, cams, gaskets and disc (transport tank plug, if the bushing is dismantled).
The bushings are installed at an angle to the vertical from 0 ° to 90 ° inclusive. Continuous cantilever input loads comply with IEC 60137.

High-voltage bushings installed on the transformer are operated under the pressure of transformer oil in the transformer conservator. All bushings are removable and can be replaced in operation bushing IPT, if necessary, without dismantling the current-carrying rod (bushing stud).

The service life of the bushings is 25 years.

The main faults of transformer bushings are as follows:

Scientific and Production Association "EnergoKomplekt" It will also help to carry out the delivery of transformer bushings VST, VSTA to any point in Russia, as well as neighboring countries by road or rail.

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