CONDUCTOR FOR ELECTRIC CURRENT, METHOD OF MANUFACTURING THE CONDUCTOR AND USE OF CONDUCTOR FOR CONDUCTING ELECTRIC CURRENT WITH AC COMPONENT

Abstract

A conductor for conducting electric current has along its length at least two main sections comprising at least a first main section and a second main section and at least one transposing junction connecting adjacent ones of the main sections The conductor comprises several partial conductors comprising at least a first partial conductor and a second partial conductor wherein in the first main section the first partial conductor has an outer diameter which is larger than an outer diameter of the second partial conductor and, in the second main section the second partial conductor has an outer diameter which is larger than an outer diameter of the first partial conductor.

Claims

1. A conductor for conducting electric current, comprising along its length at least two main sections comprising a first main section and a second main section, and comprising at least one transposing junction connecting adjacent ones of the main sections, the conductor comprising at least two partial conductors comprising at least a first partial conductor and a second partial conductor, each of the partial conductors running through the main sections and the transposing junction and being electrically insulated from each other in the main sections and the transposing junction, each of the partial conductors having in each of the main sections an outer diameter, wherein in the first main section, the outer diameter of the first partial conductor is larger than the outer diameter of the second partial conductor, and in the second main section the outer diameter of the second partial conductor is larger than the outer diameter of the first partial conductor, wherein the conductor comprises a first portion and a second portion, each of the portions comprising at least two main sections and at least one transposing junction between the main sections, and comprising a joining junction between the portions, wherein in the joining junction the partial conductors are electrically connected to each other.

2. The conductor of claim 1, wherein in the first main section the first partial conductor has a shape of a cylinder having a first outer radius and the second partial conductor has a shape of a cylinder of a second outer radius, wherein the first outer radius is larger than the second outer radius.

3. The conductor of claim 1, wherein in the first main section the first partial conductor encloses the second partial conductor and in the second main section the second partial conductor encloses the first partial conductor.

4. The conductor of claim 1, wherein the interior structure of the conductor is identical in the main sections and wherein the main sections have the same lengths.

5. The conductor of claim 1, wherein in each of the main sections the partial conductors have a constant geometry along the length of the respective main section.

6. The conductor of claim 1, wherein in the transposing junction each of the partial conductors has one or more openings in its wall to enable one or more transposing portions of the other one of the partial conductors to cross the wall.

7. The conductor of claim 1, wherein the partial conductors are separated by gaps from each other, wherein the gaps are air gaps and/or insulating inserts.

8. The conductor of claim 1, comprising a joining junction at each of its ends, wherein in the joining junction the partial conductors are electrically connected to each other.

9. The conductor of claim 1, wherein each of the partial conductors is formed as a single, integrally formed piece.

10. The conductor of claim 1, having a bend being provided by a joining junction electrically connecting the partial conductors or being provided by a transposing junction changing the outer diameters of the partial conductors.

11. The conductor of claim 1, further comprising: a number of partial conductors, the number being larger than two; and a number of main sections, wherein adjacent ones of the main sections are connected by transposing junctions, wherein m is a multiple of n.

12. The conductor of claim 1, wherein in each of the main sections each of the partial conductors has a tubular shape.

13. A method of manufacturing the conductor of claim 1, wherein at least a part of the conductor is manufactured by an additive manufacturing method or by a molding method.

14. The method of claim 13, wherein the conductor is at least partially formed by casting, wherein an insert is positioned in the mold, wherein the insert provides gaps insulating the partial conductors from each other.

15. A use of the conductor of claim 1 for conducting electric current with an AC component.

16. The use of the conductor of claim 15 wherein in a first main section of the conductor a first partial conductor has a shape of a cylinder having a first outer radius and a second partial conductor has a shape of a cylinder of a second outer radius, wherein the first outer radius is larger than the second outer radius.

17. The use of the conductor of claim 15, wherein in a first main section of the conductor, a first partial conductor encloses a second partial conductor and in a second main section the second partial conductor encloses the first partial conductor.

18. The use of the conductor of claim 15, wherein an interior structure of the conductor is identical in main sections of the conductor and wherein the main sections have the same lengths.

19. The use of the conductor of claim 15, wherein in each main section of the conductor, partial conductors have a constant geometry along the length of the respective main section.

20. The use of the conductor of claim 15, wherein in a transposing junction each partial conductor has one or more openings in its wall to enable one or more transposing portions of the other one of the partial conductors to cross the wall.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Further features, refinements and expediencies become apparent from the following description of the exemplary embodiments in connection with the figures.

[0040] FIG. 1 shows an embodiment of a conductor with two partial conductors in a schematic side view;

[0041] FIG. 2 shows an embodiment of a conductor with two partial conductors in a longitudinal sectional view;

[0042] FIGS. 3A to 3G are cross-sectional views of the conductor of FIG. 2 at different positions;

[0043] FIG. 4 shows an end section of a conductor with two partial conductors;

[0044] FIGS. 5A and 5B show a further embodiment of a conductor with two partial conductors in two longitudinal sectional views;

[0045] FIGS. 6A to 6G are cross-sectional views of the conductor of FIGS. 5A to 5B at different positions;

[0046] FIG. 7 shows an embodiment of a conductor with three partial conductors in a schematic side view;

[0047] FIG. 8 shows an embodiment of a conductor with three partial conductors in a longitudinal sectional view;

[0048] FIGS. 9A to 9I show cross-sectional views of the conductor of FIG. 8 at different positions;

[0049] FIG. 10 shows an end section of a conductor with three partial conductors;

[0050] FIG. 11 shows a further embodiment of a conductor with two partial conductors in a schematic view; and

[0051] FIG. 12 shows a further embodiment of a conductor with two partial conductors in a schematic view.

[0052] In the figures, elements of the same structure and/or functionality may be referenced by the same reference numerals. It is to be understood that the embodiments shown in the figures are illustrative and are not necessarily drawn to scale.

DETAILED DESCRIPTION

[0053] FIG. 1 shows an embodiment of a conductor 1 for conducting AC electric current or DC electric current with an AC component. The conductor 1 may be used for low-voltage, medium-voltage or high-voltage electric devices. As an example, the conductor 1 may be used in a power transmission or distribution system.

[0054] As examples, the conductor 1 may be used in switchgears, such as gas-insulated switchgears, generators or transformers. The conductor 1 may be used in bushings, such as high-current transformer or generator bushings, in gas-insulated lines, or in insulated current bars.

[0055] The conductor 1 has a round cross-sectional shape. The conducting parts of the conductor 1 comprise metals such as copper or aluminum, for example.

[0056] Along its length, the conductor 1 comprises two main sections 2, 3 and a transposing junction 4 between the main sections 2, 3. Furthermore, the conductor 1 comprises a first end section 5 and a second end section 6.

[0057] The conductor 1 comprises two partial conductors (see FIG. 2) insulated from each other along the entire lengths of the main sections 2, 3 and the transposing junction 4. The conductor 1 comprises exactly the two partial conductors and not more partial conductors. Accordingly, the shown conductor 1 is a double conductor. Each of the partial conductors provides a current path.

[0058] The partial conductors have structures such that in the main sections 2, 3 current flows in the direction of the length L of the conductor 1. In the transposing junction 4, current flows at least in parts of the transposing junction 4 in a thickness or radial direction R or at an angle toward the length L. In particular, current flowing in the direction of the length L in the first main section 2 is forced to flow in a thickness direction R. In the second main section 3, the current flows in the direction of the length L again, but at a different distance from the center of the conductor 1 than in the first main section 2. Accordingly, the transposing junction 4 serves to switch the distance of the current path from the center of the conductor 1.

[0059] This structure helps avoiding the skin effect and, thus, substantially the full thickness of the conductor can be used for conducting current. The skin effect leads to an AC current flowing substantially only in an outer region of a conductor, the outer region having a thickness of an order of the so-called skin depth.

[0060] For effectively cancelling the skin effect, the lengths 12 and 13 of the main sections 2, 3 are the same. In addition to that, the number of main sections 2, 3 for a double conductor 1 should be a multiple of two.

[0061] FIG. 2 shows an embodiment of a double conductor 1 in a longitudinal sectional view. FIGS. 3A to 3G show the conductor 1 in cross-sectional views at different positions marked by A-A to G-G in FIGS. 2 and FIGS. 3A to 3G, respectively. The conductor 1 may be the conductor 1 of FIG. 1, for example.

[0062] As can be seen in FIG. 2 in connection with FIGS. 3A and 3G, the conductor 1 comprises in its main sections 2 and 3 two concentric partial conductors 7, 8 electrically insulated from each other. In the transposing junction 4, the outer diameters and the overall shape of the partial conductors 2, 3 switch between each other.

[0063] In the first main section 2, the first partial conductor 7 has the shape of a hollow cylinder with an outer diameter d.sub.1 corresponding to twice an outer radius r.sub.1 of the first partial conductor 7. Furthermore, the second partial conductor 8 has the shape of a filled cylinder, i.e., a solid rod. In other embodiments, an inner partial conductor portion may by a hollow tube. The second partial conductor 8 has an outer diameter d.sub.2 corresponding to twice an outer radius r.sub.2 of the second partial conductor 8. The second partial conductor 8 is positioned centrally in the conductor 1.

[0064] The radius r.sub.1 is larger than the radius r.sub.2. The outer radius r.sub.1 of the first partial conductor 7 is the outer radius of the conductor 1. The first partial conductor 7 fully encloses the second partial conductor 8. The first and second partial conductors 7, 8 are arranged concentrically and have closed outer surfaces in the entirety of the main sections 2, 3.

[0065] Along the entire length of the main sections 2, 3 and the transposing junction 4, the partial conductors 7, 8 are electrically insulated from each other by one or more gaps 11. In the main sections 2, 3, the gap 11 has the shape of a hollow tube. The gap 11 may be an air gap or filled with an insulating material to uphold the insulating distance of the partial conductors 7, 8 from each other.

[0066] As can be seen from a comparison of FIGS. 3A and 3G, the shape of the first partial conductor 7 switches between the main sections 2, 3 to the shape of the second partial conductor 8 and vice versa. Accordingly, the current paths provided by the partial conductors 7, 8 switch their distances from the center of the conductor 1.

[0067] As can be seen in FIG. 2 in connection with FIG. 3B, at the beginning of the transposing junction 4, the first partial conductor 7 changes from a closed tubular form to an open half tube. Accordingly, an opening 14 in the wall of the first partial conductor 7 is provided.

[0068] As can be seen in FIG. 2 in connection with FIG. 3C, the opening 14 provides a space through which a transposing portion 12 of the second partial conductor 8 can cross the wall of the first partial conductor 7 such that a current path leads radially outwards.

[0069] As can be seen in FIG. 2 in connection with FIG. 3D, the second partial conductor 8 has now switched its shape from a filled cylinder with the second outer radius r.sub.2 to a hollow half cylinder with the first radius r.sub.1.

[0070] Following further down the length of the conductor 1 to the position shown in FIG. 2 in connection with FIG. 3E, a further junction portion 13 switches the shape of the first partial conductor 7 from a hollow cylinder with the outer radius r.sub.1 to a filled cylinder with the outer radius r.sub.2.

[0071] As can be seen in FIG. 2 in connection with FIG. 3F, at the end of the transposing junction 4, the first partial conductor 7 has fully switched its shape, leaving an opening 14 which can be filled by the second partial conductor 8.

[0072] As can be seen in FIG. 2 in connection with FIG. 3G, the second partial conductor 8 now has a shape of a hollow cylinder of an outer radius r.sub.1 and the first partial conductor 7 has a shape of a filled cylinder with an outer radius r.sub.2.

[0073] Each of the partial conductors 7, 8 may be formed as a single, integrally formed piece. It is also possible that one or each of the partial conductors 7, 8 are formed as multiple pieces. As an example, a solid rod may be connected via a transposing junction to a hollow cylinder.

[0074] By same lengths of the first and second main sections 2, 3, and by providing two main sections 2, 3 or a number of main sections 2, 3 being a multiple of two, the current paths in the partial conductors 7, 8 run over equal portions of the conductor length at a distance closer to the center and at a distance farer away from the center. Therefore, loop currents are not generated, or at least minimized, and the current is not fully cancelled out in a central part of the conductor 1, thus significantly reducing the skin effect. In general, for the whole length of the conductor 1 there should be the same total length where the first partial conductor 7 runs at the smaller radius and the total length where the first partial conductor 7 runs at the larger radius. The same should be the case for the second partial conductor 8.

[0075] As a result, the current flows in almost the whole cross section of the conductor 1, except from the gaps 11 between the partial conductors 7, 8. This leads to a much smaller AC resistance of the conductor 1 compared to a conventional solid or tubular conductor 1 of the same outer diameter. The gaps 11 are as small as possible. In particular, the gap thickness can be much smaller than the thickness of each of the partial conductors 7, 8. Also the length of the transposing junction 4 can be much smaller than the length of each of the main sections 2, 3.

[0076] FIG. 4 shows an end section 5 of the double conductor 1 shown in FIG. 1. The other end section 6 has a corresponding structure.

[0077] In the end section 5, the partial conductors 7, 8 are electrically connected to each other. In particular, a joining junction 9 is provided which may have the shape of a solid circular plate, a solid bolt or a threaded connector, for example. By the joining junction 9, the current is divided into the two current paths provided by the two partial conductors 7, 8 or joined together.

[0078] In the end sections 5, 6 the conductor 1 can be electrically connected to an electric contact by any known method such as clamping, a threaded connection or a plug-in connection, for example.

[0079] FIGS. 5A and 5B shows a further embodiment of a double conductor 1 in two sectional views, the second view in FIG. 5B being rotated about the length direction by 90?. FIGS. 6A to 6G show the conductor 1 in cross-sectional views at different positions marked by A-A to G-G.

[0080] The conductor 1 may have the general structure as shown in FIG. 1, wherein in the joining junctions 5, 6 the current is split into two current paths provided by the partial conductors 7, 8. In the transposing junction 4, the current paths switch from a first radial distance to a second radial distance and vice versa.

[0081] As can be seen from FIGS. 5A, 5B in connection with FIGS. 6A to 6G, in the main sections 2, 3 the conductor 1 has the same structure as the conductor 1 of the embodiment shown in FIGS. 2 and 3A to 3G. In particular, in the first main section 2, the first partial conductor 7 has the shape of a hollow cylinder with an outer radius r.sub.1 and the second partial conductor 8 has the shape of a solid rod with an outer radius 12. In the second main section 3, the first partial conductor 7 has the shape of a solid rod with an outer radius r.sub.2 and the second partial conductor 8 has the shape of a hollow cylinder with an outer radius r.sub.1.

[0082] In the transposing junction 4, the shapes of the partial conductors 7, 8 switch with help of a first transposing portion 12 and a second transposing portion 13, as can be seen in FIGS. 5A and 5B in connection with FIGS. 6C and 6E. In difference to the first embodiment, the cylindrical wall of the first partial conductor 7 first opens up into two opposite quarter cylindrical openings 14, see FIG. 6B. Correspondingly, each of the transposing portions 12, 13 comprise oppositely arranged quarter portions. Otherwise, the switching of shapes in the transposing junction 4 corresponds to the switching of shapes of the foregoing embodiment.

[0083] Due to the transposing portions 12, 13 each comprising quarter portions being opposite to each other, the current flows more uniformly from one radial distance to the other radial distance. Furthermore, this makes the parts of the conductors 7, 8 more mechanically stable and resistant to bending. The transposing portions 12, 13 are arranged with the current running to two sides of the conductors 7, 8. It is also possible to arrange the transposing portions 12, 13 in other ways, with the current running to three, four or more sides, to distribute the current even more homogenously and to add rigidity to the construction.

[0084] FIG. 7 shows a further embodiment of a conductor 10. In difference to the foregoing embodiments, the conductor 10 has three partial conductors forming three separate current paths. Accordingly, the conductor 10 is a triple conductor.

[0085] The conductor 10 has three main sections 18, 19, 20. As in the foregoing embodiments, in each of the main sections 18, 19, 20, each of the partial conductors and, thus, each of the current paths runs at a fixed radial distance, homogenously along the length of the conductor 10. In the transposing junctions 21, 22 between the main sections 18, 19, 20, each of the current paths switches its radial position.

[0086] In other embodiments for a conductor 10 with three partial conductors the number of main sections can be larger than three and a multiple of three. When the number of main sections is a multiple of three (including three) and the main sections are of the same lengths, the current in each of the partial conductors flows in the same portion of the length of the conductor at the innermost radius, the intermediate radius and the outermost radius. Thereby, the loop currents induced by the magnetic flux between the conductors are minimized and the skin effect can be avoided or at least significantly reduced.

[0087] FIG. 8 shows an embodiment of a triple conductor 10 in a longitudinal sectional view. The conductor 10 can be the conductor shown in FIG. 7. FIGS. 9A to 9I show cross-sectional views of the conductor 10 at different positions denoted by A-A to I-I.

[0088] The conductor 10 has three partial conductors 15, 16, 17. As in a double conductor, the partial conductors 15, 16, 17 are electrically insulated from each other along the length of the conductor 10, except from the end sections 5, 6, where the partial conductors 15, 16, 17 are joined together.

[0089] In FIG. 8, only the first two main sections 18, 19 and only one transposing junction 21 of the three main sections 18, 19, 20 and two transposing junctions 21, 22 (see FIG. 7) are depicted. The third main section 20 adjoins the end of the first or second main section 18, 19, with the second transposing junction 22 there between. The third main section 20 has the same structure as the first and second main sections 18, 19. The second transposing junction 22 has the same structure as the first transposing junction 21.

[0090] As can be seen from FIG. 8 and FIGS. 9A and 9I, in each of the main sections 18, 19, 20, each of the conductors 15, 16, 17 has the shape of a homogeneous hollow cylinder with a fixed outer diameter d.sub.1, d.sub.2, d.sub.3 corresponding to twice the outer radius r.sub.1, r.sub.2, r.sub.3, and a fixed thickness of the cylinder wall. The three hollow cylinders are concentrically arranged. An innermost cylinder is enclosed by a middle cylinder. The middle cylinder is enclosed by an outer cylinder. It is also possible that in each of the main sections 18, 19, 20, the inner one of the conductors 15, 16, 17 has the shape of a solid rod instead of a hollow cylinder.

[0091] In the transposing junctions 21, 22, the outer radius of each of the partial conductors 15, 16, 17 changes. In particular, as can be seen from FIG. 8, in the first main section 18, the first conductor 15 has the outer radius r.sub.1. The second conductor 16 is enclosed by the first conductor 15 and has the outer radius r.sub.2. The third conductor 17 is enclosed by the first and second conductors 15, 16 and has the smallest outer radius r.sub.3. Within the main sections 18, 19, 20, the walls of each of the partial conductors 15, 16, 17 is homogenous and is not interrupted.

[0092] In the shown embodiment, the conductors 15, 16, 17 have the same wall thickness in each of the main sections 18, 19, 20. It is also possible that the wall thickness is different, depending on the specific outer radius r.sub.1, r.sub.2, r.sub.3.

[0093] In the transposing junctions 21, 22 the walls of the partial conductors 15, 16, 17 are stepwise transposed from one radius to another radius. As in the double conductor, the walls of the partial conductors 15, 16, 17 open up and give room for transposing portions 23, 24, 25, 26.

[0094] As can be seen from FIG. 8 and FIGS. 9B, 9C and 9D, at the start of the transposing junction 21, the wall of the outermost, first partial conductor 15 opens up such that the middle, second partial conductor 16 can be partially transposed by a transposing portion 23 from the middle radius r.sub.2 to the outer radius r.sub.1. The opening 14 has the shape of a half circle.

[0095] As can be seen from FIG. 8 and FIGS. 9D, 9E and 9F, at a second part of the transposing junction 21, the outermost, first partial conductor 15 is partially transposed by a transposing portion 24 from an outer radius r.sub.1 to a middle radius r.sub.2. At the same time, the innermost, third partial conductor 17 is partially transposed by a transposing portion 25 from the inner radius r.sub.3 to the middle radius r.sub.2.

[0096] As can be seen from FIG. 8 and FIG. 9G, the now outermost, second partial conductor 16 then closes its wall to a closed tubular form.

[0097] As can be seen from FIG. 8 and FIGS. 9F to 9H, in a further step, the first conductor 15 completes its transposal by a transposing portion 26 from the middle radius r.sub.2 to the inner radius r.sub.13. Furthermore, the third partial conductor 17 completes its transposal to the middle radius r.sub.2.

[0098] In a further transposing junction 22 (see FIG. 7), the radii of the partial conductors 15, 16, 17 are correspondingly transposed. Thus, in three main sections 18, 19, 20 each of the partial conductors 15, 16, 17 has the first radius r.sub.1 in one of the main sections, the second radius r.sub.2 in one of the main sections and the third radius r.sub.3 in one of the main sections. This ensures that the magnetic flux flowing through surface area portions between pairs of the conductors 15, 16, 17 cancel out in large part, the induced loop currents in the partial conductors are minimized and the skin effect can be prevented or at least reduced.

[0099] Also, in the case of the triple conductor 10, the transposing junctions 21, 22 can be formed in a more symmetrical way, such that the walls of the partial connections open up into several symmetrically arranged parts, similar to the embodiment of the double conductor 1 shown in FIGS. 6C and 6E.

[0100] The principle of the transposal in conductors with more than three partial conductors corresponds to the transposal shown for the double and triple conductors.

[0101] FIG. 10 shows an end section 5 of a conductor 10 with three partial conductors 15, 16, 17. The conductor 1 may be the triple conductor 10 shown in FIGS. 8 to 9I.

[0102] As for the double conductor 1 of FIG. 4, the partial conductors 15, 16, 17 are connected by a joining junction 9.

[0103] FIG. 11 shows a further embodiment of a double conductor 1 in a schematic view. In difference to the double conductor 1 of FIG. 1, the double conductor 1 has two portions 27, 28, each consisting of two main sections 2, 3 and 2, 3, respectively, and a transposing junction 4 and 4, respectively. The portions 27, 28 are connected to each other by a further transposing junction 29, which has the same structure of the transposing junctions 4, 4 but a different allocations of the partial conductors.

[0104] In the first main section 2 and the further first main section 2, the conductor 1 has the same inner structure with the same allocation of the partial conductors to the inner structure. The same applies for the second main section 3 and the further second main section 3. Accordingly, the first portion 27 composed by the first main section 2, the transposing junction 4 and the second main section 3 is identically repeated in the second portion 28 composed by the further first main section 2, further transposing junction 4 and further second main section 3.

[0105] In the case of a triple conductor 10, two portions can be provided, with each of the portions comprising three main sections and two transposing junctions.

[0106] In further embodiments of double conductors 1 or triple conductors 10, more portions containing main sections and transposing junctions can be provided. Generally, the number of main sections should be a multiple of the number of partial conductors. In addition to that, the main sections should have lengths such that each of the partial conductors takes up each outer radius over the same total length. In this case, each of the current paths runs over equal portions of the conductor length at each of the radii, thus minimizing the loop currents and avoiding or at least reducing the skin effect. Each of the main sections can have the same length. It is also possible that the main sections 2, 3 have different lengths than the further main sections 2, 3.

[0107] FIG. 12 shows a further embodiment of a double conductor 1, the double conductor 1 having a bend 30 between two portions 27, 28 of the conductor 1.

[0108] The bend 30 is provided by a joining junction 9 joining the partial conductors in each of the adjacent main section 2, 3. The joining junction 9 may be a portion of a rigid rod, for example. Due to the joining junction 9, the first portion 27 is decoupled from the second portion 28 with respect to the loop currents generated in each of the portions.

[0109] The main sections 2, 3 of the first portion 27 have the same lengths. The main sections 2, 3 of the second portion 28 have the same lengths. However, the main sections 2, 3 of the first portion 27 have a different length than the main seconds 2, 3 of the second portion. In further embodiments, portions 27, 28 of different lengths may be connected by a joining junction without that a bend is present.

[0110] In other embodiments, a bend 30 can be provided by a transposing junction, in which the partial conductors switch their shapes but are not electrically connected to each other.

[0111] The conductors 1, 10 of all embodiments, and in particular the partial conductors including transposing portions, can be manufactured by additive manufacturing technologies, wherein thin layers of the partial conductors are added one by one. This process can run in the direction along the length of the conductor and the shapes of the layers which have to be added in each part of the process are visible from FIGS. 2 to 3G, 5A to 6G and 8 to 9I, respectively.

[0112] It is also possible to manufacture one or more transposing junctions or portions as separate components. In this case the transposing junctions can be fixed subsequently to the main sections of the conductor. The transposing junctions can be manufactured using additive manufacturing methods. Parts of the transposing junction can also be manufactured by machining, i.e., by removing material, and subsequent assembling.

[0113] In order to prevent the parts of the conductor to move with respect to each other, and coming into electrical contact, electrically insulating spacers may be inserted between the neighboring partial conductors in the main sections, especially in the areas close to the transposing junctions.

[0114] Additionally, the whole space between the partial conductors in the main sections and between separate parts of the transposing junctions can be filled with an insulating material. Suitable materials are hardenable resin such as epoxy, acrylic or silicone-based resin, for example. The resin may contain a filler, in particular a high-thermal-conductivity electrically insulating filler, such as, for example, boron nitride or aluminum nitride.

[0115] An alternative method to manufacture the conductor is a metal casting process. This is particularly suitable for conductors made of aluminum and its alloys. In this method, a core insert is prepared, for example made of a ceramic material. The core insert is in the shape of the gaps between the parts of the conductor. The shape of this empty space in the area of the transposing junction is easily derivable from the embodiments shown in FIGS. 2 to 3G, 5A to 6G and 8 to 9I. In the area of the end sections, the core insert can have elements protruding further upward than the slits visible in FIGS. 4 and 10 so that the core insert can be mechanically fixed in the mold.

[0116] The core insert itself can be manufactured using additive manufacturing methods. After casting, the conductor is machined, so that the elements of the core insert located in the slits reaching the outer surface of the transposing junctions are exposed. In this way, the partial conductors providing the separate current paths become electrically insulated from each other.

[0117] A number of calculations have been made, in order to assess how much more current can be conducted by the conductors according to the invention in comparison to standard conductors. In particular, standard rod-shaped and tubular conductors are compared to the conductors according to the invention, with the same outer diameters. In case of the standard tubular conductors, the inner diameter of the conductor was optimized so as to minimize its AC resistance, so that the optimized standard conductor is used for the comparison.

[0118] As an example, the calculations show that replacing a 60 mm standard copper rod conductor with a double conductor of the same outer diameter, an AC resistance reduction factor of 0.69 is achieved. This provides the possibility to increase the operating current in the same device by up to 120% without increasing ohmic losses and, thus, without increasing the temperature. For a 90 mm copper rod conductor the corresponding numbers are 0.60 and 130%. When replacing the standard 90 mm conductor with a triple conductor, the AC resistance is half the AC resistance of the standard conductor and the operating current can be increased up to more than 140%.

[0119] Also for larger diameter aluminum conductors, which are commonly used in high-current applications, e.g., in components of generator circuits in power plants, such as generator bushings, LV step-up transformer bushings, generator circuit breakers, double conductors can provide operating current gains of between 130% and 140%. By using triple conductors, gains between 150% and 170% can be achieved without that the outer diameter of the conductor or the dimensions of the insulating components around the conductors is increased.

REFERENCE NUMERALS

[0120] 1 double conductor [0121] 2, 2 first main section [0122] 3, 3 second main section [0123] 4, 4 transposing junction [0124] 5 end section [0125] 6 end section [0126] 7 first partial conductor [0127] 8 second partial conductor [0128] 9 joining junction [0129] 10 triple conductor [0130] 11 gap [0131] 12 transposing portion [0132] 13 transposing portion [0133] 14 opening [0134] 15 first partial conductor [0135] 16 second partial conductor [0136] 17 third partial conductor [0137] 18 first main section [0138] 19 second main section [0139] 20 third main section [0140] 21 transposing junction [0141] 22 transposing junction [0142] 23 transposing portion [0143] 24 transposing portion [0144] 25 transposing portion [0145] 26 transposing portion [0146] 27 first portion [0147] 28 second portion [0148] 29 further transposing junction [0149] 30 bend [0150] L length direction [0151] R radial direction [0152] r.sub.1 first outer radius [0153] r.sub.2 second outer radius [0154] r.sub.3 third outer radius [0155] d.sub.1 first outer diameter [0156] d.sub.2 second outer diameter [0157] d.sub.3 third outer diameter [0158] m number of main sections [0159] n number of partial conductors