RU2575877C2 - Continuously transposed wire - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention relates to continuously transposed wire (2) containing several identical conductor strands (20) connected in parallel, at that each conductor strand (20) in sequence and repeatedly takes each potential position inside the whole cross-section of the wire. In compliance with this invention each conductor strand (20) represents a subset containing at least two conductors of rectangular cross-section jointed together by means of joining coating applied at least between two flat sides and to sides of the above conductors joining the above flat sides in order to form a subset. Inside the subset the conductors may be placed either by flat surface to flat surface or side by side.

EFFECT: improved design.

10 cl, 9 dwg

Description

Technical field

The present invention relates to split transposed wires.

State of the art

A continuously transposed wire, or STP, consists of a group of several identical elementary conductors, usually enameled conductors of rectangular cross section, which are connected in parallel at the ends, with each elementary conductor sequentially and repeatedly occupying every possible position within the entire cross section of the wire. Figure 1 depicts a well-known split transposed wire 1, disclosed, for example, in US 6657122, wherein said transposed wire 1 comprises a plurality of flat individual wires 3 of rectangular cross section, which are arranged in two packets 4 parallel to each other. Between two packets 4 can be paper strip 5. Each elementary conductor or separate wire 3 is coated with an insulating enamel coating. The individual wires 3 are completely offset by folding at predetermined intervals, so that their position within the entire cross section of the split parallel wire 1 is constantly changing at relatively short intervals. Displacement points are indicated by reference numeral 7. The main function of transposition is to balance the distribution of energy within the windings, reducing electrical losses, and, in addition, ensuring the flexibility of the wire. In accordance with the technical specifications of the customer, elementary conductors as a whole can usually be wrapped with paper tapes, from pure cellulose or other tapes, tapes from mesh material and monofilaments, if the continuously transposed wire does not need insulation. The main function of the winding is to provide electrical insulation and, in addition, the implementation of mechanical resistance and protection during operation.

Summary of the invention

Transposed wires are commonly used in windings of high-power transformers and other windings of electrical devices.

Indeed, for windings of high-power transformers, there is a need to limit the additional losses due to induced eddy currents in copper wires due to the alternating magnetic flux of the dispersion surrounding the windings. In the case of a continuously transposed wire, additional losses are reduced by dividing the copper cross section into a larger number of individual enameled elementary conductors of the same cross section.

However, at present, only a continuously transposed wire with a maximum number of about 85 elementary conductors can be found on the market. It would be necessary to increase the number of elementary conductors used in a continuously transposed wire to enable users to implement new or different windings to increase efficiency and improve other parameters of transformers and other electrical machines.

An increase in the number of elementary conductors in a continuously transposed wire, as previously disclosed, would be theoretically possible, but more complex and bulky machines for transposing, as well as investment costs, would be required.

An object of the present invention is to propose a new structure for a continuously transposed wire with an increased number of elementary conductors, which can be easily fabricated without unnecessary additional costs.

The problem is solved by providing a continuously transposed wire or STP containing several identical elementary conductors that are connected in parallel at the ends, each elementary conductor sequentially and repeatedly occupying every possible position inside the entire cross section of the wire, characterized in that each elementary conductor is a subset containing at least two conductors of rectangular cross-section, reliably joined together by means of a uniting conductor digging for the formation of said subset.

Mentioned at least two conductors can be combined together side by side or with a flat surface to a flat surface.

In a first embodiment, said combination coating completely surrounds the conductors of each subset.

Alternatively, said unifying coating surrounds the conductors of each subset, with the exception of the outer left and right edges of each subset.

Alternatively, said combining coating is located only between two flat sides of the conductors facing each other in each subset.

Brief Description of the Drawings

The invention is further explained in the description of the preferred embodiments of the invention with reference to the accompanying drawings, in which:

FIG. 1 shows a split transposed wire of the prior art;

FIG. 2 is a cross-sectional view of a transposed wire in accordance with a possible embodiment of the present invention;

FIG. 3 is an enlarged cross-sectional view of an elementary conductor in a transposed wire of FIG. one;

FIG. 4 is an enlarged cross-sectional view of an elementary conductor in a transposed wire in accordance with a second possible embodiment of the present invention;

FIG. 5 is a cross-sectional view of a third embodiment of a continuously transposed wire in accordance with the present invention;

FIG. 6-9 depict several other possible embodiments of a subset that can be used in a continuously transposed wire in accordance with the present invention.

Description of Preferred Options

the implementation of the invention

Referring first to FIG. 2 and 3, a first embodiment of a continuously transposed wire 2 in accordance with the present invention will be described. In this embodiment, wire 2 contains five identical elementary conductors 20 that are classically transposed to form a continuously transposed wire 2. Therefore, as mentioned above, the said elementary conductors are connected in parallel at the ends, and each elementary conductor sequentially and repeatedly occupies every possible position within wire cross section to form a transposed wire.

However, while each of the elementary conductors of known transposed wires corresponds to an enameled rectangular conductor, each elementary conductor 20 in this first embodiment is a subset comprising two rectangular cross-section conductors 30a, 30b joined together by a combination coating 50.

As best shown in FIG. 3, each conductor 30a, 30b, typically made of copper, is preferably coated with one or more layers of different varnishes or insulating films to form an insulated wire. The two conductors 30a, 30b are combined side by side. The unifying coating can contain different types of varnishes and can be applied entirely around two conductors and on the side of the association. Each subset 20 here forms a double wire.

Thus, a continuously transposed wire 2 consists of five double wires, then a sum of ten conductors can be determined, while a classic continuously transposed wire would have only a sum of five conductors.

Although the subset 20 shown in FIG. 3 contains two conductors, the principle of the present invention can be generalized to any subset containing three or more conductors combined together.

In addition, the conductors in the same subset can be arranged with a flat surface on a flat surface instead of side by side. The layout of this embodiment is shown in FIG. 4, in which the subset 20 ′ comprises two conductors 30a and 30b, each of which is coated with an insulated layer 40′a and 40b, which are joined together by a flat surface to a flat surface by a combining coating 50.

Thanks to the present invention, it is thus possible to realize a continuously transposed wire with a large number of wires, usually twice or three times the standard number, depending on the composition of the subset (for example, 85 × 2 = 170 conductors).

The choice of layout (side by side or flat surface to flat surface) in the subset depends on the application for which the use of each continuously transposed wire is implied.

For example, in the central part of rod transformers, an induced electric current is generated with maximum intensity when the cross section of a wire coil is located in the axial direction (perpendicular) inside the magnetic field lines, while the intensity is minimal when the wire cross section is longitudinal inside the magnetic field . For this reason, the central part of the rod transformer requires transposed wires with a thickness of the conductor as small as possible (taking into account the actual level of technology, allowing about 1.0-1.1 mm), while the width of the conductor is not the original.

However, at the ends of the transformer, the dispersion flux goes to the outside of the windings. In this case, it is advisable to reduce the width instead of the thickness.

As regards the first application (the central part of the rod transformer), a layout with a flat surface to a flat surface of conductors in one subset of a continuously transposed wire can advantageously be used. As an example, compared with a continuously transposed wire in accordance with the prior art, in which each elementary conductor (single conductor) can have a minimum thickness of 1 mm, the use of subsets of two conductors with a thickness of 0.5 mm, United flat surface to a flat surface, makes it possible to double for the same cross section the ratio of width to thickness for each conductor, which is an advantage for magnetic flux.

Otherwise, with regard to the second application (end portion of the rod transformer), a side-by-side arrangement of conductors in one subset of the continuously transposed wire will be preferred. As an example, compared with a continuously transposed wire in accordance with the prior art, in which each elementary conductor (single conductor) can have a minimum width of about 2.8 mm, the use of subsets of two conductors 1.4 mm thick, combined side by side , makes it possible to divide by two for the same cross-section the ratio of width to thickness for each conductor.

For other applications, a wire user may need two or more continuously transposed wires connected in parallel. In such cases, a separate continuously transposed wire is covered with paper or special ribbons, making unnecessary use of space. In the case of the present invention, a plurality of continuously transposed wires connected in parallel can advantageously be replaced by a single continuously transposed wire containing identical subsets with two or more conductors, which allows the same function to be performed, but in a more efficient manner. An example of such a continuously transposed wire is shown in FIG. 5. Here, the continuously transposed wire 2 has the same structure as the continuously transposed wire 2 in FIG. 2, with five identical subsets 20, each containing two conductors connected side by side. However, as indicated by either dashed lines or solid lines, the five conductors, taken from the right, respectively from the left of each subset, are used together, as if they belong to the same continuously transposed wire. Other correlations are possible without departing from the scope of the present invention. In this case, the paper needed for insulation will be saved, since the paper is only needed to wrap around the entire continuously transposed wire.

Although the bonding coating 50 is always shown in FIG. 2-6, as completely surrounding the conductors of each subset, other arrangements are possible to ensure that the conductors are firmly fixed together in the same subset. FIG. 6-9 depict several alternative arrangements.

FIG. 6 and 8 illustrate, for example, a configuration in which a bonding coating 50 surrounds the conductors with the exception of the outer left and right edges, respectively, for side-by-side and flat surface dispositions to the flat surface of the conductors.

FIG. 7 shows a side-by-side arrangement of conductors, where the combining coating 50 comprises two gaps in the combining circuit.

FIG. 9 shows the arrangement of conductors with a flat surface to a flat surface with a unifying coating 50 located only between two flat sides of the conductors facing each other.

The unifying coating can be made of any material with binding properties at specific temperatures, including, but not limited to, epoxy enamels, such as epoxy-phenoxide enamels, aromatic polyamides, polyester (PE) or polyether imide (PEI) enamels, or polyvinyl formal ( PVA) enamels.

Thanks to the present invention, it is thus possible to provide users with a continuously transposed wire with an increased number of conductors with greater flexibility of use depending on the application.

Making such a continuously transposed wire is easy to implement. Only a new tool is needed to make subsets of two or more conductors combined together using a bonding coating 50. Subsequently, the subsets are placed together to produce a continuously transposed wire due to some modifications of known machines for manufacturing a continuously transposed wire.

Claims (10)

1. A continuously transposed wire or STP (2; 2 ″) containing several identical elementary conductors (20; 20 ′) that are connected in parallel at the ends, with each elementary conductor (20; 20 ′) sequentially and repeatedly occupying every possible position inside the entire cross-section of the wire, each elementary conductor (20; 20 ′) is a subset containing at least two conductors (30a, 30b; 30′a, 30′b) of rectangular cross-section with two flat sides of two conductors facing another ug to each other in each subset, characterized in that at least two conductors are firmly joined together by a combining coating (50) applied between at least the two flat sides and the sides of said conductors adjacent to said flat sides to form mentioned subset. 2. A continuously transposed wire (2; 2 ″) according to claim 1, wherein at least two conductors (30a, 30b) are joined together side by side. 3. A continuously transposed wire (2; 2 ″) according to claim 1, wherein at least two conductors (30′a, 30′b) are joined together by a flat surface to a flat surface. 4. Continuously transposed wire (2; 2 ″) according to any one of paragraphs. 1-3, in which each of the at least two conductors is an insulated wire. 5. Continuously transposed wire according to any one of paragraphs. 1-3,
in which the unifying coating (50) completely surrounds the conductors of each subset. 6. Continuously transposed wire according to any one of paragraphs. 1-3, in which the combining coating (50) completely surrounds the conductors of each subset with the exception of the outer left and right edges of each subset. 7. The continuously transposed wire according to claim 1, wherein said at least two conductors (30a, 30b) are joined together side by side, and said unifying coating (50) completely surrounds the conductors of each subset except for the outer edges opposite to said flat sides . 8. A continuously transposed wire according to claim 4, wherein the unifying coating (50) completely surrounds the conductors of each subset. 9. A continuously transposed wire according to claim 4, in which the unifying coating (50) completely surrounds the conductors of each subset with the exception of the outer left and right edges of each subset. 10. The continuously transposed wire according to claim 4, wherein said at least two conductors (30a, 30b) are joined together side by side, and said unifying coating (50) completely surrounds the conductors of each subset with the exception of external edges opposite to said flat sides .

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