RU213364U1 - SCREW WINDING WITH ADDITIONAL SUPPORTS - Google Patents

Abstract

The utility model relates to the field of electrical engineering, in particular to the design of helical windings of electrical reactors or power transformers. The technical result is an increase in the structural strength of the helical winding. The helical winding contains turns, each of which contains parallel wires forming rows located in the radial direction. Between the rows of parallel wires there are vertical channels formed by installing rails arranged in a vertical direction. A concentrated transposition of parallel wires is made between the rows. In the area of concentrated transposition, in the horizontal channel formed between adjacent turns of the winding, support elements are installed, placed on rails located in the vertical direction, each of the support elements is made with a through hole through which the rail passes, located in the vertical direction, on which the specified reference element is placed. 4 w.p. f-ly, 6 ill.

Description

The utility model relates to the field of electrical engineering, namely to the design of electrical equipment elements, in particular, windings of electrical reactors of any type or power transformers, and can be used in the development of a helical winding design with concentrated transposition.

The coil winding is one of the main units in electrical reactors for various purposes (current-limiting, smoothing, shunting, switching, etc.), as well as in power transformer designs.

When developing winding designs, high requirements are imposed on them in terms of operational reliability.

The high electrodynamic and mechanical strength of the reactor or power transformer, necessary for resistance to dynamic loads that occur during the operation of electrical equipment, for example, short-circuit currents, external vibration effects, etc., is ensured when using screw windings.

The helical winding consists of a series of turns wound along a helical line. Each turn consists of several identical parallel wires, usually of rectangular cross section, laid in the radial direction.

Since the parallel wires of the helical winding are arranged concentrically and are at different distances from its axis, there is an inequality of their active and inductive resistances, and, consequently, an uneven distribution of current between them. To ensure a uniform distribution of current over the conductors (leveling the resistance) and, accordingly, to reduce additional losses, the helical windings are performed with transposition (i.e., with the relocation of the parallel wires of the coil during winding). The most commonly used concentrated transposition of parallel wires.

In the manufacture of a screw winding, air cooling channels are formed - horizontal (located in the radial direction) and vertical (located in the axial direction). Vertical channels are usually formed by means of laths (rods) installed in the axial direction, for example, between rows of parallel wires of a helical winding. Horizontal channels (channels between the turns of the winding) are usually formed using gaskets (slats, inserts) located between the turns of the winding and fastened to vertical rails. Reiki and gaskets are made of electrically insulating material.

During the operation of electrical reactors and power transformers, when an electric current flows through the winding, forces arise that compress the winding in the axial direction and stretch it in the radial direction. In addition, the windings experience dynamic loads at short-circuit currents, external vibration effects, etc. In this regard, an urgent task in the development of helical winding designs is to ensure structural strength, and, consequently, operational reliability, which, in turn, is aimed at ensuring the operational reliability of electrical equipment as a whole.

It should be noted that the gaskets that serve to create horizontal channels between the turns of the winding are supporting elements that perceive axial forces acting on the winding and carry a large mechanical load, especially during short circuits, while maintaining the geometry of the winding and eliminating the deflection of the conductors during operation, thereby preserving the parameters of the generated electromagnetic field and preventing the conductors of adjacent turns from shorting each other, which in turn allows solving the problem of ensuring the operational reliability of the helical winding.

Known helical winding of a power transformer [ed. St. USSR No. SU 1693647 A1 "Helical winding of a powerful transformer", IPC H01F27 / 28, publ. 11/23/1991], which provides an increase in the dynamic resistance of the winding to the action of tangential forces at short-circuit currents. On the outer surface of the winding along the helical line in the direction opposite to the winding of the turns, there are bandages attached to the turns of the winding.

However, this embodiment of the bandages does not limit the displacement of the conductors in the axial direction, but also increases the size of the winding in the radial direction.

Known technical solutions related to winding designs, in which insulating gaskets/inserts are installed between adjacent turns, holding the winding turns spaced apart from each other:

spiral winding [patent No. RU 2616591 C2 "Line filter for transmission systems on medium/high voltage AC power lines", IPC H01F27/28, H01F27/32, date publ. 04/18/2017], the turns of which have an H-shaped section in the axial direction, in the recesses of which there are gaskets that create a support for each turn;

power reactor, which is an inductor [patent No. RU 198556 U1 "High-frequency barrier", IPC H04B3/54, publ. 07/15/2020], between adjacent turns of which there are H- or T-shaped inserts tightly adjacent to them, in the grooves of which the turns (conductors) are tightly placed, the inserts are installed in the vertical direction one under the other, in the horizontal - equidistantly, which ensures uniform load distribution during the flow of short-circuit currents.

Known technical solutions are aimed at increasing the resistance to deformation of the winding (i.e., increasing the strength of the winding structure), however, they are characterized by structural complexity (curly execution of turns and inserts in cross section), low-technological design (the need for accurate positioning of inserts and conductors when winding the coil), as well as insufficient reliability of fastening of gaskets / inserts, which can move under the influence of dynamic loads and even fall out of the installation sites, resulting in a decrease in the structural strength of the winding.

Known helical winding [patent No. RU 188932 U1 "Helical winding", IPC H03F1/00, H01F27/28, publ. 04/29/2019], in which a concentrated transposition of parallel wires is made between the rows of turns, while a horizontal channel is formed at the place of its execution, while at the place of the transposition the parallel wires are cut, their ends are located behind the outer diameter of the winding and are connected to each other.

However, it should be noted that the well-known technical solution does not provide for the installation of support elements between the turns in the places where the concentrated transposition is performed, which negatively affects the structural strength of the helical winding.

Known spiral (helical) winding, which is part of a dry-type electric reactor with an air core [patent No. CA 2102467 A1 "Air core reactor with conductor winding rigidly anchored to structural sleeve", IPC H01F27/32, H01F29/02, H01F41/04, date of publication May 6, 1994]. The helical winding is formed by turns, each of which contains individually insulated parallel wires, forming rows, which are located in the radial direction. In the winding, vertical cooling channels are formed with the help of rods reinforced with glass fiber and installed between the layers of the winding. A spacing strip is located between adjacent turns of the winding to provide a given distance between the turns, while the edge of the strip is located in the recess of the groove made in the body of the conductor.

However, it should be noted that the geometry of the conductor profile, corresponding to the profile of the spacer strip, causes high structural complexity, and the need for precise spatial alignment of the strip and conductor during winding, as well as the need for their tight fit to the frame on which the winding is wound, causes the technological complexity of manufacturing ( i.e. non-technological design). In addition, in the areas of concentrated transposition, the spacer strip cannot be placed, which reduces the strength characteristics of the winding.

As a technical solution (prototype), the closest in terms of essential features to the claimed utility model, a helical winding is proposed, which contains turns wound along a helical line, with each turn consisting of several parallel wires stacked in rows in the radial direction [address Internet pages: https://forca.ru/knigi/arhivy/proizvodstvo-obmotok-i-izolyacii-silovyh-transformatorov.html: Technology and mechanization of the production of windings and insulation of power transformers / Gerasimova L.S., Deinega I.A. ., Pshenichny G.I., Chechelyuk Ya.3. - Moscow: Energy, 1979. - 336 p. (Transformers; Issue 35)]. Vertical and horizontal channels are formed in the helical winding. Vertical channels are formed by installing rails arranged vertically. Horizontal channels (i.e. channels between the turns of the helical winding) are formed by spacers (support elements) located between adjacent turns of the winding and made of sheet electrical insulating cardboard in the form of flat plates, on one side or two opposite sides of which there are open bracket-shaped grooves with bends along the outer edge, which serve to clutch the spacer with the edge of the vertical rail (Fig. 1, 2): in Fig. 1 shows the spacer H1, in which the groove is made on one side; in fig. 2 shows the spacer H2, in which the grooves are made on two opposite sides. As noted above, in order to equalize the resistance of parallel wires and reduce losses, helical windings are performed with transposition, and the concentrated transposition of parallel wires is most often used. Winding can be performed single-pass, double-pass or multi-pass.

As noted earlier, the structural elements that serve to create horizontal channels between the turns of the helical winding perceive axial forces acting on the winding during the operation of electrical equipment, are subject to dynamic loads (arising, for example, from external vibration effects, short-circuit currents, etc.). and carry a large mechanical load, thereby ensuring the structural strength and, consequently, the operational reliability of the winding.

However, with regard to the well-known technical solution, the following should be noted.

The use of spacers requires high precision in their manufacture and precise positioning when installed in the winding, i.e. is a complex technological process, which negatively affects the manufacturability of the design.

The execution of the connecting elements of the spacer, with which the connection (coupling) with the vertical rail is provided, in the form of bends (“antennae”) along the edge of the groove does not ensure reliable fastening of the spacer, because under dynamic loads, such as short-circuit currents, the connecting elements (“antennae”) may be deformed and/or mechanically damaged, as a result of which the spacer may detach from the vertical rail and move or even fall out of the winding, which will weaken the structure windings, i.e. will reduce its strength. As a result, the geometry of the winding may change, the conductors of adjacent turns may close, or other negative consequences may occur, which may lead to a malfunction of the electrical equipment.

In addition, it should be noted that in the area of concentrated transposition of the helical winding, the installation of spacers that run across the entire width of the winding (in the radial direction) is not possible due to the constructive implementation of the relocation of the conductors during the transposition (the installation of the spacer will be prevented by the transition points of the conductors), which will lead to a weakening (reduction in strength) of the helical winding in the area of concentrated transposition. And the use of spacers, the length of which will correspond to the distance between adjacent transitions (that is, limited by the distance to the place where the conductors transition into transposition), will not provide sufficient strength of the winding in the zone of concentrated transposition due to the factors described above (under dynamic loads, there is a high probability of deformations, mechanical damage and, as a result, displacement or loss from the winding), which will reduce the structural strength of the winding as a whole.

The technical result, the achievement of which is provided by the claimed utility model, is to increase the structural strength of the helical winding.

To achieve the above technical result, a helical winding is proposed, which contains turns, each of which contains parallel wires forming rows located in the radial direction. Between the rows of parallel wires there are vertical channels formed by installing rails arranged in a vertical direction. A concentrated transposition of parallel wires is made between the rows.

At the same time, according to the claimed utility model, in the area of concentrated transposition in a horizontal channel formed between adjacent turns of the winding, support elements are installed, placed on rails located in the vertical direction, each of the support elements is made with a through hole through which the rail passes, located in the vertical direction, on which the specified support element is placed (ie, the support elements are strung on vertically arranged rails).

Thus, due to the fact that in the claimed design of the helical winding, in which (unlike the prototype) in the horizontal channel formed between adjacent turns of the winding, support elements are installed in the area of concentrated transposition as described above (namely: each of the support elements is made with a through hole, through which it is strung on a corresponding vertically located rail) provides reliable support of the conductors on the support elements (moreover, one element will be a support for the conductors located on both sides of the vertical rail) in the area of concentrated transposition as in the operation of the winding in normal mode (when axial compressive forces act on the winding during the flow of current), and under the influence of external vibration loads, under dynamic loads that occur in the event of the flow of short-circuit currents, etc., since the support element strung on vertical rail through its own a through hole is more firmly and reliably connected to the rail than a spacer connected to the rail with the help of bends ("antennae") of the edge groove made in the form of a bracket, and will be more securely held in place under the action of external dynamic loads. Thus, the inventive helical winding has a higher structural strength compared to the known technical solution (prototype), which makes it possible to preserve the geometry of the winding and exclude the short circuit of the conductors of adjacent turns, between which the support elements are installed, during the operation of electrical equipment, thereby increasing operational reliability .

The most technological implementation of the support elements and at the same time providing high structural strength of the winding (due to the developed area of the support surface) is the implementation in which the support elements are made of a cylindrical shape with an axial hole, and the support elements are made with a closed outer surface.

To increase the mechanical strength of the winding design (by eliminating sagging of wires in the area of concentrated transposition during normal operation of the winding), each of the support elements can be installed in such a way that its end surfaces are adjacent to the corresponding surfaces of parallel wires, between which a vertical rail is located, passing through the through hole of the specified support element.

In order to ensure higher structural strength, as well as the manufacturability of the winding design, a horizontal channel between adjacent turns of the winding can be formed by installing rails located in the radial direction.

Graphic materials contain drawings and diagrams explaining the state of the art, as well as an example of the inventive helical winding with additional supports.

In FIG. 1 and 2 are images (general view) of spacers used in the construction of a known winding (in the prototype) and serving to create horizontal channels; in fig. 1 shows the spacer H1, in which the groove is made on one side; in fig. 2 shows the spacer H2, in which the grooves are made on two opposite sides.

In FIG. 3 shows a schematic representation of the location of the supporting elements of the winding, the main view (outside the winding).

In FIG. Figure 4 shows the layout of the areas (zones) for performing transposition, top view.

In FIG. 5 shows a schematic representation of the location of the supporting elements of the winding on the layout of the conductors of the transposition (top view in cross section along the horizontal channel).

In FIG. 6 shows a schematic representation of a vertical rail with a supporting element placed on it.

In the exemplary embodiment shown (FIGS. 3-6), the helical winding 1 comprises turns 2, each of which is formed by insulated parallel wires (conductors) 3, which form rows 4 in the radial direction.

To ensure the required insulation and cooling characteristics, air vertical (axial) 5 and horizontal (radial) 6 channels are formed in the winding. Vertical channels 5 are made between rows 4 of parallel wires 3 and are formed by installing rails 7 located in the vertical direction. Between the turns 2 of the winding 1, horizontal channels 6 are made. The number of channels to be performed (vertical and horizontal) is determined by the required parameters of the winding. Known designs of helical windings, made with one horizontal channel, and with several. In the example shown, the horizontal channels 6 are formed by installing rails 8 arranged in the radial direction. Such an implementation is simpler and more technologically advanced than, for example, the formation of horizontal channels using spacers (or inserts) from sheet electrical insulating cardboard. Vertical and horizontal slats can be made, for example, from glass fiber STEF-I grade GOST 12652-74 or fiberglass profile electrical insulating GOST 27380-87.

Between the rows, a concentrated transposition of parallel wires is made, which ensures a uniform distribution of current along the conductors and a reduction in additional losses in the winding. A possible layout of areas (zones) for performing transposition is shown in Fig. 4. An example of a lumped transposition conductor layout is shown in FIG. 5.

Horizontal strips, forming a horizontal channel between the turns of the helical winding and serving as a support for the conductors that are in contact with them, pass between adjacent turns along all rows of the turn along the radius of the winding (i.e., the width of the winding along the radius), however, in the areas D of the transposition (Fig. 4) a horizontal rail cannot be freely installed along all rows of conductors due to the relocation of wires, in relation to which the transposition is performed. In this regard, in the process of winding wires in the manufacture of a helical winding (when the lower turn of the horizontal channel is wound), a support element 9 made with a through hole is put on (threaded) on each vertical rail 7 in the area D of the concentrated transposition. Support elements 9 can be made in various shapes, for example, in the form of a cylinder, barrel, ring, cube, etc. However, the most technologically advanced is the implementation of the support element 9 of a cylindrical shape with a closed outer surface and a through axial hole (Fig. 6), and such a structural design of the support element ensures its high strength. The support element 9 with its lower end surface (not shown in Fig.) is located on the surface 10 (Fig. 3) of the lower turn of the horizontal channel. In this case, the position "top" - "bottom" is determined by the location of the winding during its normal operation, when the winding axis is located vertically. After the support elements 9 are installed, the next turn (the upper turn of the horizontal channel) is wound, which, with its lower surface 11, will be adjacent to the upper end surfaces (not shown in Fig.) of the support elements 9. The diameter of the through hole of the support element 9 is such that the element 9 can be easily mounted on a vertical rail 7 (without significant friction on the surface of the rail). The size of the support element 9 in the radial direction (for a cylindrical element, this is the outer diameter of the cylinder) is selected depending on the number of parallel conductors forming a row and the layout of the support elements. It is preferable to choose the specified size of the support element 9 so that all the conductors of the coil are able to interact with the end surfaces of the support elements (i.e., rely on them). The height of the support element 9 corresponds to the height of the horizontal channel 6. The support elements can be made, for example, from fiberglass profile electrically insulating GOST 27380-87, or fiberglass epoxyphenolic tubes of the TSEF brand according to GOST 12496-88, or fiberglass tubes D TSPP-E TU U 25.2- 25462405-004:2007 where D is the outside diameter of the tube.

The operation of the inventive helical winding is carried out as part of an electric reactor or power transformer.

When an electric current flows in normal mode, compressive forces act on the screw winding 1 in the axial direction. These are stationary loads acting on the winding, for which the margin of safety of the conductors is calculated, and, in addition, these loads are evenly distributed between the supporting surfaces of the horizontal rails 8 and supporting elements 9. During the operation of electrical equipment, external vibration loads, dynamic loads that occur during a short short circuit, etc.

In this case, the supporting elements 9 installed in the horizontal channels 6 in the areas D of the transposition (where the wires 3 are switched and there are places of their transitions/bends, which is a risk factor in emergency situations), additionally provide the strength of the screw winding 1; eliminate (in the areas of concentrated transposition) sagging and shorting each other wires 3 adjacent turns, between which a horizontal channel is formed; ensure the preservation of the winding geometry.

Thus, the proposed technical solution provides, in comparison with the prototype, an increase in structural reliability, which, in turn, improves the operational reliability of the helical winding and electrical equipment as a whole.

Claims (5)

1. A helical winding, characterized in that it contains turns, each of which contains parallel wires forming rows located in the radial direction, between the rows of parallel wires there are vertical channels formed by installing rails located in the vertical direction, a concentrated transposition is made between the rows parallel wires, in the area of concentrated transposition in a horizontal channel formed between adjacent turns of the winding, support elements are installed, placed on rails located in the vertical direction, each of the support elements is made with a through hole through which the rail passes, located in the vertical direction The on which the specified reference element is placed. 2. Screw winding according to claim 1, characterized in that the supporting elements are cylindrical in shape with an axial hole. 3. Screw winding according to claim 2, characterized in that the supporting elements are made with a closed outer surface. 4. Screw winding according to claim 1, characterized in that each of the support elements is installed in such a way that its end surfaces are adjacent to the corresponding surfaces of the parallel wires, between which there is a vertical rail passing through the through hole of the specified support element. 5. Screw winding according to claim 1, characterized in that the horizontal channel between adjacent turns of the winding is formed by installing rails located in the radial direction.

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