RU219735U1 - ELECTRIC REACTOR PHASE COIL CROSS - Google Patents

Abstract

The utility model relates to the field of electrical engineering and can be used, in particular, in the construction of dry-type electric reactors with an air core. The technical result is to increase the reliability of the reactor by preventing the possibility of electrical breakdown of the electrical reactor. The crosspiece of the phase coil of an electric dry-type reactor with an air core contains the rays of the crosspiece, made of a conductive material and rigidly connected to each other. In this case, each beam of the cross is covered with an electrically insulating material, which can be used as a heat-shrinkable tube. 3 w.p. f-ly, 3 ill.

Description

The utility model relates to the field of electrical engineering, namely, to the design of individual units of electrical reactors, in particular, crosses, and can be used, for example, in the construction of dry-type electrical reactors with an air core in order to prevent interfacial short circuit (i.e., breakdown between crosses of neighboring phases) and increase the reliability of the operation of the reactor as a whole.

The design of the electric reactor contains phase coils, each of which is a winding, on the end sides of which there are upper and lower multibeam crosses. The cross contains beams (ribs) that are rigidly connected to each other either by welding to the central sleeve or by welding directly to each other. The upper and lower crosses are pulled together in the axial direction to ensure the mechanical strength of the coil.

Crosses are usually made of conductive materials, such as non-magnetic steel or aluminum, as the crosspiece acts as a busbar to which the winding leads are connected.

It should be noted that in some cases, electrically insulating materials (for example, fiberglass or fiberglass) are used to manufacture the beams of the crosses. However, the execution of the crosspieces from electrical insulating materials is characterized by a significantly lower resistance to electrodynamic and mechanical stress compared to metal crosspieces.

Depending on the installation location and features of switchgears, the reactor can have a vertical, stepped (angular) or horizontal phase arrangement (web page address: https://elekom-ural.ru/reactor/?ysclid=l9dwgv5ljr516590922). With a vertical arrangement of the phases of the reactor, the phase coils are installed vertically one above the other and separated from each other by support insulators, while there is free space between adjacent phases.

Electric reactors are often installed in open space, in the "field conditions", because. installation of reactors in a separate isolated room requires significant financial costs and seems to be economically unjustified.

However, electrical equipment (equipment of transformer substations, electrical reactors), mounted in open space, is subject to the negative impact of external factors.

So, for example, when installing electric reactors in the open air, small animals, birds or foreign conductive objects can enter the space between the crosses of adjacent phase coils (with a vertical arrangement of the phases of the reactor) or between the lower cross of the phase coil and the ground (which is less common, since the lower phase coil tends to be placed on support insulators at a sufficiently high height from the ground). As a result of the above factors, a short circuit of the bare parts of different phases of the electrical installation (or a short circuit of a phase to earth) can occur and, as a result, an interfacial breakdown, which, in turn, will lead to an emergency and the failure of the reactor.

To protect the current-carrying elements of the phase windings, namely, the beams of the crosses, the electric reactor, the closure between which leads to a breakdown and failure of electrical equipment, it is known to use covers that cover the electric reactor from above, mesh fences that cover the interphase gaps, or casings that cover the reactor completely . Such technical solutions are known, for example, from patent no. 12/07/2021], containing a cap covering the upper part of the electric reactor, while a side mesh is installed at the junction of the cap and the reactor vessel around the perimeter, or according to patent No. CN212434393U ["Bird and small animal preventing device of dry-type hollow three-phase stacked electric reactor”, IPC H01F27/02, publ. 01/29/2021], according to which a hollow three-phase dry-type electric reactor contains two annular grids, each of which is installed around the circumference, along the perimeter closing the area (gap) between adjacent windings (phases), namely, between the first and second and between the second and the third winding, in addition, the upper surface of the upper (first) winding and the lower surface of the lower (third) winding are equipped with protective end grids.

However, it should be noted that although protective nets and other elements prevent the penetration of birds or small animals, increasing the safety and reliability of the reactor, but the presence of protective elements as additional elements of the reactor design can have a negative impact on the characteristics of the generated electromagnetic field, as well as the presence of protective elements requires a separate fastening to the elements of the reactor, which complicates its design and can also lead to distortion of electromagnetic parameters. In addition, it should be noted that the presence of a grid between the phases can reduce the specific length of the creepage path (especially when exposed to climatic factors - precipitation), which can lead to an interfacial circuit.

A three-phase electric reactor is known [patent No. RU2398301C1 "Three-phase current-limiting reactor for a soft starter of an electric motor", IPC H01F38/02, H01F27/30, date publ. 08/27/2010], containing phase windings (coils) located vertically. Each winding is located between 4-beam crosses. The ends of the beams of the upper and lower crosspieces of each winding are connected by tightening side bars. Crosspieces are made of electrically insulating material. However, as noted earlier, the implementation of the rays of the cross from a non-conductive material causes a low resistance of the structure to electrodynamic and mechanical stress compared to metal crosses, and is also characterized by an increased fire hazard.

It is known that electrical reactors are widely used, in particular three-phase, with an air core, formed by phase coils containing crosses made in the form of a star-shaped structure, the rays of which are made of a conductive material, in particular, aluminum, copper, non-magnetic steel. Such designs are known, for example, from patents No. RU 129320 U1 ["High-frequency barrier", IPC H04B3/54, publ. 06/20/2013]; US3902147A ["Air core duplex reactor", IPC H01F27/02, H01F27/32, H01F30/08, publ. 08/26/1975]; CN216435595U ["Star-shaped frame structure of air-core reactor", IPC H01F27/06, H01F27/29, pub. 05/03/2022]; CN202110913 U ["Star frame structure dry type air core reactor", IPC H01F17/02, H01F27/30, pub. 01/11/2012]. However, the well-known technical solutions do not provide for the isolation of the beams of the crosses or other design measures that provide protection against interfacial short circuit (breakdown between the crosses of adjacent phases) in case of penetration of birds, small animals or foreign objects, in particular, into the space between adjacent phases during operation. electrical reactor.

Also known is an electric reactor according to patent No. RU156365U1 [“Current-limiting reactor”, IPC H01F38/02, date publ. 11/10/2015], which includes phase coils made in the form of helical windings, on the end sides of each of which there are upper and lower crosses connected to each other by tie elements. The crosspiece is a rigid welded structure formed by beams welded to the central sleeve and made of non-magnetic steel. However, with regard to the well-known design of the cross, it should be noted that it, as well as in the technical solutions described above, does not provide for the implementation of insulation or other elements for protecting conductive rays, which, under the operating conditions of an electric reactor, can lead to a short circuit between the crosses as a result of external adverse influences. adjacent phases or to a breakdown between the cross of the lower phase and the ground (installation platform).

As a technical solution (prototype) closest to the claimed utility model in terms of essential features, a crosspiece of the phase coil of an electric reactor is proposed, the implementation of which is disclosed in patent No. RU2075809C1 [“Reactor block for electrical distribution networks”, IPC H02H9 / 02, H01F32 / 02, date published 03/20/1997]. According to the known technical solution, an air-core electric reactor contains coil blocks (phase coils). At the same time, at the opposite ends of each phase coil (from the side of the upper and lower ends of the winding made of an insulated conductor), respectively, the upper and lower crosses are installed, having a similar design. The crosspiece contains ribs (beams of the crosspiece), which are interconnected, in particular, by welding with a central sleeve. The beams (ribs) extend in a star-like manner from the axis of the coil (reactor) to the outer surface of the winding and are located in the horizontal plane of the coil. The rays of the cross are electrically conductive, i.e. made of conductive material.

However, as in the technical solutions described above, this design does not provide for the implementation of an insulating coating of conductive rays, which during the operation of an electric reactor in case of penetration of birds, small animals or foreign objects into the space between adjacent phases (when the windings are vertically installed one above each other another) or between the lower phase and the installation site ("ground"), as well as between the upper and lower cross of one winding, can lead to an interphase short circuit (breakdown) or short circuit to the "ground", which, in turn, will lead to an emergency and , possibly leading to reactor failure (damage to the insulation of the conductors and destruction of the reactor structure).

The technical result, which the claimed utility model is aimed at, is to prevent the possibility of electrical breakdown of the reactor elements during the operation of an electric reactor, in particular, between the conductive rays of the crosses of adjacent phases (phase coils), or between the conductive rays of the lower cross of the lower phase coils and ground (conductive base), or between the lower and upper crosses of one phase, which would allow, under the operating conditions of the reactor, in particular, in open space in case of penetration of birds, small animals or foreign conductive objects into the space between adjacent phases or between the lower phase coil and the ground or between the crosses of one phase to exclude the possibility of breakdown (interphase short circuit) due to these reasons and thereby increase the reliability of the reactor.

In order to achieve the above technical result, a crosspiece is proposed for the phase coil of a dry-type electric reactor with an air core, which contains the rays of the crosspiece rigidly connected to each other. Cross beams are made of conductive material. At the same time, according to the claimed utility model, each beam of the cross is covered with an electrically insulating material.

The inventive cross is one of the nodes (structural elements) of the phase coil of an electric reactor, and its operation is carried out as part of an electric reactor.

The proposed execution of the cross, according to which the conductive rays of the cross are covered with electrically insulating material, allows, in comparison with the prototype, when the reactor is operating (under operating conditions in open space), to exclude a short circuit between the rays of the crosses of adjacent phase coils or between the conductive rays of the lower cross of the lower phase coil and the ground , which, in turn, makes it possible, in the event that birds, small animals or foreign objects get into the space between adjacent phases or between the lower phase coil and the "ground" or between the crosspieces of one phase, to exclude the possibility of breakdown and increase the safety and reliability of the reactor.

A heat-shrinkable tube can be used as an electrically insulating material covering the beam of the cross, since for applying an electrically insulating coating on the surface of an extended part (in the form of a rod, rod, etc.), the most technologically advanced is the use of insulating heat-shrinkable materials, namely, a heat-shrinkable tube. It should be noted that it is also possible to use other materials to insulate the surface of the arms of the cross, for example, the use of heat-shrinkable tape, insulating tape, as well as liquid rubber or a non-conductive material that can be applied to the surface to be protected, for example, by spraying, but the process of their application is less technological.

In order to increase the reliability of the connection, the cross beams can be connected to each other by welding, namely, each beam with its neighbors. It is also possible to perform, in which the beams of the cross can be connected to each other through the central sleeve, to which each beam of the cross is welded.

Graphic materials contain an example of a specific implementation of the proposed design of the cross, which is part of an electric reactor with an air core.

In FIG. 1 shows a schematic representation of a three-phase electric reactor with a vertical arrangement of phases, a general view.

In FIG. 2 is a schematic representation of a coil containing a winding and crosses.

In FIG. 3 shows a schematic representation of the beam of the cross, which is covered with insulation, a local section is made.

The inventive cross is a part of the phase coil of an electric reactor.

Shown in FIG. 1 air-core dry-type electric reactor contains three phase coils 1, 2, 3 installed vertically. The coils are placed on the support insulators 4, 5, 6. Each coil contains a winding formed by an insulated conductor, and upper and lower crosses mounted on the side of the end surfaces of the winding.

In FIG. 2 shows the winding 7 (for example, the second phase coil 2), on the side of the upper end of which the upper cross 8 is installed, and on the side of the lower end - the lower cross 9. The crosses are interconnected by tie elements (not marked with a separate position).

The crosspieces of all phase coils have a similar design.

In FIG. 3 shows the beam of the cross, which is covered with insulation. In the presented example of execution of the cross (Fig. 2) contains a Central sleeve 10, which is welded to the beams 11 of the cross. Usually, the arms are welded to the sleeve or directly to each other so that when the spider is installed in the coil, they are located perpendicular to the vertical axis of the coil, which is caused by ensuring the strength of the structure. Cross beams are made of conductive material, for example, non-magnetic steel 12Kh18N9T-M2b GOST 7350-77. The sleeve can be made of the same material. Each beam 11 of the cross is covered with an electrically insulating material 12, which in the presented example used a heat-shrinkable tube (for example, Heat-shrinkable tube VT-220).

The surface of the beams is covered with insulating heat-shrinkable material as follows. After the beams 11 are welded to the central sleeve 10, a heat-shrinkable tube is put on each beam 11 along its entire length, the diameter of which is chosen depending on the dimensions (height, width) of the beam. Heat shrinkage is produced as a result of temperature exposure. When heated, the tube shrinks, and it tightly wraps around the entire surface of the beam.

The operation of the inventive cross is carried out as part of an electric reactor during its operation.

During the operation of an electric reactor, a breakdown may occur between the phases of the reactor when the bare conductive sections of the rays of the crosses are shorted to the bare conductive sections of the rays of an adjacent phase or to the "ground" (conductive base) or between the crosses of one phase. However, due to the execution of the beams of the crosses covered with insulating material, the probability of an interphase short circuit or a phase to ground short circuit or a breakdown between the crosses of one phase is significantly reduced in case of penetration of birds or small animals or foreign objects into the space between the phase coils or between the lower coil and the ground. or between crosses of the same phase.

Thus, the proposed implementation of the crosspiece of the phase coil of an electric reactor according to the claimed solution, namely, with conductive beams coated with electrically insulating material, makes it possible to prevent the possibility of electrical breakdown of the reactor elements, in particular, between the conductive beams of the crosspieces of adjacent phases (phase coils), or between conductive beams of the lower cross of the lower phase coil and the ground (conductive base), or between the lower and upper crosses of one phase, which, in turn, improves the reliability of the reactor.

Claims (4)

1. The cross of the phase coil of an electric reactor of a dry type with an air core, containing the rays of the cross, made of a conductive material and rigidly connected to each other, characterized in that each beam of the cross is covered with an electrically insulating material. 2. A cross according to claim 1, characterized in that a heat-shrinkable tube is used as an electrically insulating material covering the beam of the cross. 3. The cross according to claim 1, characterized in that the rays of the cross are connected to each other by welding. 4. Cross according to claim 1, characterized in that the cross beams are interconnected through a central sleeve, to which each cross beam is welded.