Multi-membered conductor, use and method for producing the multi-membered conductor

Abstract

A multi-segment electrical conductor (2, 3, 4, 5) and a manufacturing process therefor, comprising conductor core regions (20, 30, 40, 50) comprising several individual conductors (10) and comprising conductor braid regions (21, 31, 41), which conductor braid regions (21, 31, 41, 51) are configured to form a definable outer geometry (h, b) of the multi-segment conductor (2, 3, 4, 5) by means of a conductor filling region. The proposed multi-segment conductor (2, 3, 4, 5) accordingly has an outer shape which can be optimized with respect to the fill factor in the application area of ​​electrical machines. In particular, the outer geometry (h, b) can remain constant over the length of the conductor (2, 3, 4, 5), despite the multi-core nature and Roebbel-like interweaving of the individual conductors (10, 12, 13, 14, 15). An additive manufacturing process is used for this purpose.

Description

[0001] The invention relates to a multi-element conductor, a use of the multi-element conductor and a manufacturing method therefor.

[0002] It is known that energy losses occur in a wide variety of electrical applications and products, particularly energy losses associated with electrical current flow, which can be attributed to various physical effects. Examples of such effects are the skin effect and the proximity effect. The skin effect is also referred to as the current displacement effect. This occurs in electrical conductors through which alternating current flows, particularly high-frequency alternating current. The alternating fields penetrating the conductor cause attenuation and, in a sense, displace the current flow from the interior of the conductor to the outer areas. The proximity effect is also based on current attenuation caused by a penetrating alternating field, but this field originates from a neighboring electrical conductor.

[0003] To avoid such effects and the associated energy losses, or at least minimize them as much as possible, cables with the largest possible surface area have been used, especially in high-frequency technology. These include waveguides, stranded conductors, or ribbon conductors.

[0004] The so-called Roebel conductor is used particularly in electrical windings, e.g., in large three-phase generators or three-phase motors. This represents a special form of multi-element conductor. It contains several parallel conductors that are insulated from each other and specially layered, twisted, or braided. The special arrangement and interweaving of the partial conductors alters the stray field in such a way that the current density in all parallel conductors is approximately constant, and a current displacement effect is virtually avoidable. However, the production of such conductors is quite complex and is currently only used for very large machines in the high power range of several kilowatts to megawatts.

[0005] A disadvantage of previous Roebel or Roebel-type conductors is that the total cross-sectional area of ​​such an interwoven multi-core conductor is larger than that of a corresponding solid conductor with the same total cross-section. Especially when using multi-core conductors in electrical machines, the conductor cross-section presents a further technical challenge. The better a slot in an electrical machine is filled by an electrical conductor, especially a strand of electrical subconductors, the better its performance. The so-called fill factor is a measure of this ratio of conductor cross-section to slot cross-section.

[0006] To address the challenge of adaptable conductor geometry, there are initial approaches to producing Roebel-type conductors using additive manufacturing processes. However, current losses in conductors manufactured in this way are not reduced to the same extent as in Roebel conductors manufactured using conventional methods.

[0007] Based on this, the object is to provide an electrical conductor and a manufacturing method for an electrical conductor that meets the requirements for a predeterminable external geometry and, at the same time, has electrical properties that are as good as or better than those of previous Roebel conductors. This object is solved by the features of independent patent claim 1. The object regarding the use is solved by the features of claims 11 and 12. The object regarding a manufacturing method is solved by the features of patent claim 13. Advantages and embodiments of the invention, which can be used individually or in combination with one another, are the subject of the dependent claims.

[0008] The multi-element electrical conductor according to the invention has a conductor core region comprising a plurality of individual conductors and a conductor braiding region. In particular, the multi-element electrical conductor according to the invention has a plurality of conductor core regions and conductor braiding regions, which, when arranged alternately in a row, form the multi-element electrical conductor. In particular, the multi-element electrical conductor has as many conductor braiding regions as there are individual conductors.

[0009] The conductor braiding regions of the multi-element conductor according to the invention are designed to form a predeterminable outer geometry of the multi-element conductor by means of at least one conductor filling region.

[0010] In particular, this predeterminable outer geometry can be specified by the conductor core areas. Depending on the application of the multi-element electrical conductor, multi-element conductors can also be manufactured with different outer geometries. The advantage of the multi-element conductor according to the invention lies in the particular fact that a high fill factor can be ensured for use in an electrical machine. The individual conductors are expediently arranged insulated from one another in the multi-element conductor.

[0011] Advantageously, the braided conductor regions of the multi-element electrical conductor according to the invention also comprise individual conductors in addition to the filler regions. A single conductor is understood to mean, in particular, a continuous electrical conductor, continuous in the sense of a conductor running through the multi-element conductor from beginning to end. This has the particular advantage that a certain number of continuous individual conductors ensures sufficient current flow, in particular the total current flow, through the multi-element electrical conductor.

[0012] In an advantageous embodiment of the invention, the conductor filler region of the multi-element electrical conductor is manufactured additively. In particular, there are a plurality of conductor filler regions along the multi-element electrical conductor. This has the advantage that the bulges and indentations on the outer geometry of the multi-element conductor strand caused by the interweaving of the individual conductors are filled in a single additive manufacturing step. In particular, the method for filling the conductor strand starts with the outer individual conductors, or the outer individual conductors or sections of the individual conductors are manufactured additively.

[0013] In a further advantageous embodiment of the multi-element electrical conductor according to the invention, the conductor filler regions comprise individual conductors of reduced height, widened individual conductors, and / or shape-adapted individual conductors. This means that a modified shape and / or a modified individual conductor cross-section are used to form the external geometry of the multi-element conductor strand. A single conductor of reduced height, or a single conductor section of reduced height, can be produced, for example, by material removal. A widened individual conductor, or a widened individual conductor section, can be produced by a drawing or pressing process starting from a continuous individual conductor. Specially shaped individual conductors or shape-adapted individual conductor sections are preferably manufactured additively.

[0014] In particular, the individual conductors present in the conductor filler area or forming the conductor filler area, whether they are individual conductors of reduced height, widened individual conductors, or shaped individual conductors, are each individual conductor sections. The individual conductor sections present in the conductor filler area, modified in each case, can continue to run in the adjacent conductor core areas in their original conductor cross-sectional area and / or cross-sectional shape.

[0015] In a further advantageous embodiment of the multi-element electrical conductor, the individual conductors comprise copper or are formed from copper.

[0016] In particular, the individual conductors are solid individual conductors, especially conventionally manufactured conductors, and have a material purity of at least 99.96%, in particular of at least 99.98%, preferably of at least 99.99%. The conductivity of the particularly preferably used electrical individual conductors is at least 5.8 × 10 7< S / m or higher.

[0017] In a further advantageous variant of the invention, the multi-element electrical conductor is designed as a Roebel conductor or the multi-element electrical conductor comprises regions that are designed as Roebel conductors or are designed similarly to Roebel.

[0018] In particular, variants with reduced conductor height and / or expanded conductor sections in the braided conductor area can largely be based on a conventional Roebel conductor, as this is preferably formed from strip-shaped individual conductors. However, other braiding forms, such as conductor twists similar to a stranded wire, are also conceivable.

[0019] Particularly preferred is the variant of the multi-element electrical conductor according to the invention in which the individual conductors have the same cross-sectional area along the length of the conductor. These are therefore expediently designed as conformal conductors in the conductor braiding areas to represent the conductor fill area. This has the advantage that a continuous conductor cross-sectional area is available for current flow across all individual conductors.

[0020] In a particularly advantageous embodiment of the multi-element electrical conductor according to the invention, the individual conductors have a constant cross-sectional shape over the respective length of the conductor core regions or across one conductor core region in each case.

[0021] The multi-element electrical conductor according to the invention also has, in particular, a conductor connection region in which the individual conductors are interconnected. This connection region is preferably manufactured additively. This conductor connection region can preferably also be adapted to the outer geometry of the conductor.

[0022] In an advantageous embodiment of the invention, the multi-element electrical conductor is arranged in a slot of an electrical machine. This has the advantage of providing a highly efficient system, since, on the one hand, a multi-element conductor is provided whose relative resistance is minimized, while, at the same time, the outer geometry ensures a high fill factor.

[0023] An alternative use of the multi-element electrical conductor according to the invention is proposed in a winding, in particular a winding of a transformer.

[0024] The invention also includes a method for producing a multi-element electrical conductor, as described above, which manufacturing method comprises the following steps: manufacturing a conductor core region and manufacturing at least one conductor braiding region, in particular its conductor filling region. Conventional manufacturing methods are preferably used to manufacture the conductor core regions and the continuous individual conductors. The production of the conductor braiding regions by braiding or twisting and the production of the conductor filling region takes place in the further manufacturing step, which can in particular include material removal for a reduced conductor height, which can widen the conductor by adding, for example,by means of additive processes to a conductor section in the outer conductor braiding area, which may include a mechanical process for conductor deformation in the conductor braiding area as well as additive processes for producing shape-adapted conductor sections in the entire conductor braiding area.

[0025] In particular, a step for producing the conductor connection area is also included in the manufacturing process, in which step the individual conductors in the conductor connection area are connected, in particular by means of an additive manufacturing process.

[0026] In a further advantageous variant of the method, two additive manufacturing steps are used, in particular to additively manufacture an upper and a lower conductor filling area or areas on the outer sides of the conductor braiding areas.

[0027] Further features, properties and advantages of the present invention will become apparent from the following description with reference to the accompanying figures. In the exemplary embodiments and figures, identical or similarly acting elements may be provided with the same reference numerals. The illustrated elements and their relative sizes are generally not to be considered true to scale; rather, individual elements may be shown larger in size for better illustration and / or better understanding. The figures schematically show Figure 1a perspective view of a section of a multi-element conductor 1 with Roebel-like interweaving of the individual conductors 10, Figure 2a longitudinal section through a Figure 1 shown multi-element conductor 1, Figure 3 a cross section through a as in Figure 1illustrated multi-element conductor 1, Figure 4 shows a longitudinal section through a multi-element conductor 2 with a conductor braiding area 21, the outer individual conductors 12 of which have a reduced height, Figure 5 shows a cross section through a conductor 2, as also in Figure 4 with a single conductor section 12 of reduced height, Figure 6 a perspective view of a conductor 3 in cross section with recognizable conductor core 30 and conductor braiding area 31 with widened single conductor 13, Figure 7 a corresponding cross-sectional view of the in Figure 6 shown conductor 3, Figure 8 a perspective view of a section of a multi-element conductor 4 with shaped conductors 14, Figure 9 a cross section through the in Figure 8shown conductor 4 in the conductor braiding area 41, Figure 10 several cross sections AA, BB, etc. along a conductor braiding area 51, in which all the individual conductors 15 passing through the conductor braiding area 51 are adapted to their shape, Figure 11 in a comparable manner to Figure 10 the cross-sections AA, BB, etc. for a multi-element conductor 5 consisting of six individual conductors 15.

[0028] In the Figure 1, a multi-element conductor 1 is shown in perspective, which is constructed like a Roebel conductor. Shown are 16 individual conductors 10, which are arranged in eight layers, two per layer. The individual conductors 10 are insulated from one another. There are conductor sections in which the individual conductors 10 run parallel to one another along the entire conductor assembly 1. There are sections in which one of the individual conductors 10 of the upper layer is transferred to the position of the adjacent individual conductor 10, so that an interweaving of the individual conductors 10 occurs. Typically, there are as many interweavings along the entire length of the multi-element conductor 1 as there are individual conductors 10 in the conductor assembly 1. The individual conductors 10 in such a Roebel interweaving serve the particular purpose of reducing so-called skin effects and thus energy losses.

[0029] Already in Figure 1 , but even more clearly in the Figures 2 and 3, which shows a longitudinal and a cross-sectional view through the Figure 1 shown conductor 1, one of the significant disadvantages of the Roebel conductor becomes clear, namely that the total cross-section bxh` through the braided areas, or in the braided areas, is larger than the cross-section of a solid conductor with a comparable effective conductor cross-sectional area sum of the individual conductors 10. For this reason, such Roebel conductors have so far only been used in very large electrical machines. In smaller electrical machines, the use of such conductors has not yet been realized, since the fill factor plays a major role here. The use of such a designed multi-element conductor strand 1 in small electrical machines would enormously reduce the degrees of freedom with regard to conductor height and number of turns. Figures 2 and 3 h` indicates the height that would result from continuous conductors 10 without interweaving.

[0030] Since a high fill factor has a significant impact on the performance of the electrical machine, and the slot for the winding must be optimally filled, it is not particularly practical to use a conductor strand 1 with numerous bulges or indentations on the top and bottom due to interweaving. This effect is so significant that, for a comparable electrical machine performance, up to 20% more electrically conductive individual conductors must be installed to compensate for the reduced fill factor.

[0031] In the Figures 4 and 5A variant of the invention is shown schematically: a multi-segment conductor 2, again shown in a conductor cross-section and longitudinal section. The figures show the constant conductor strand height h and constant conductor strand width b, continuous individual conductors 10, as well as, in the conductor braiding area 21, top and bottom conductor filling areas formed from conductor sections 12 with a reduced height. Such a multi-segment conductor 2 therefore has conductor sections 12 with a reduced conductor cross-section in the conductor braiding areas 21. In the conductor core areas 20 adjoining the conductor braiding area 21 on both sides, as well as internally in the conductor braiding area, the individual conductors 10 have consistently constant conductor cross-sections and, as in the case shown, also consistent cross-sectional shapes.The outer geometry of the conductor strand 2 is optimized with a constant width b and almost constant height h for a high fill factor when used in an electrical machine.

[0032] The Figures 6 and 7 The embodiment of a multi-element conductor 3 shown can advantageously also be used with the embodiment according to the Figures 4 and 5 be combined, in particular by simultaneously widening the conductor section in the conductor braiding area 31 with reduced height 12, as in Figure 6 Accordingly, such a combination could lead to a shape-adapted conductor 13, which is widened in the conductor braiding area 31 and, due to the reduced height, retains the same conductor cross-section as in the conductor core area 30. Figure 6 The multi-section ladder 3 shown is shown in perspective, analogous to Figure 1, and once again illustrates the different conductor section areas, namely conductor core areas 30 alternating with conductor braiding areas 31. Both conductor section area types can comprise individual conductors 10, in particular continuous individual conductors 10 that remain uniform in their cross-sectional area and shape. The widening of the conductor section 13 in the conductor braiding area 31 also ensures that the surface structures, which are still irregular due to the braiding, are further minimized or adapted to a homogeneous external geometry.

[0033] The production of a conductor section 12 with a reduced height as well as a conductor section 13 which is widened, in particular with a simultaneously reduced height, can be carried out in particular mechanically by removal or mechanical material deformation.

[0034] In the Figure 8 and Figure 9A variant of the multi-element conductor 4 according to the invention is shown, which has parallel individual conductors 10 in its core regions 40 and continuous individual conductors 10 in its conductor braiding region, which, however, only change the conductor level, so that their conductor cross-section and cross-sectional shape remain the same, while the conductor sections 14, which change into the adjacent level in the conductor braiding region, are designed to be shaped accordingly. In particular, these conductor filling regions are additively manufactured and almost completely fill the cavities created by the braiding or create a conductor braiding region 41 whose outer geometry is almost completely adapted to the outer geometry of the conductor core region 40.

[0035] In cross-section of the Figure 9The variant of the multi-segment conductor 4 is shown again, which has continuous conductors 10 and conformal conductors 14 in the braided area, but which have a consistent cross-sectional area throughout. Such a multi-segment conductor has the advantage that no protruding or empty sections would reduce the fill factor, while simultaneously enabling high conductivity due to the continuous conductor cross-section.

[0036] In the Figures 10 and 11 Finally, variants of the multi-element conductor 5 are shown, which are spun in the conductor braiding areas 51 in such a way that they continuously change their cross-sectional shape, but not their cross-sectional area. This is shown in two examples in Figure 10 with a four-core conductor and in Figure 11with a six-core conductor. Within the conductor braiding area 51, five cross-sectional areas AA to EE are shown, starting at AA with rectangular individual conductors 10 running parallel to one another, which have been rotated one place in the conductor layering up to section EE. The direction of rotation is indicated by an arrow. The continuous advancement of the individual conductors 10, 15 is indicated by Roman numerals. Such a conductor braiding area 51 is expediently produced using an additive manufacturing process. Advantageously, the manufacturing process can be used only for the conductor braiding area 51 and can be followed by solid, conventionally manufactured individual conductors 10. This hybrid manufacturing, a combination of conventionally manufactured conductor areas and additively manufactured orFilled conductor areas have the advantage that all areas where additive manufacturing is not necessary or advantageous can be prefabricated using conventional methods, thus speeding up production. In the embodiments shown in Figures 8, 6, and 4, additive manufacturing is preferably performed only, if at all, in the conductor filling area, above and below the continuous conductors 10.

[0037] In all variants shown, the individual conductors 10 are arranged insulated from one another. This can be ensured by electrically insulating layers, coatings, and / or surface treatments, particularly oxidized aluminum layers.

[0038] In summary, the achieved predeterminable external geometry h / b of the multi-element conductor 2, 3, 4, 5 should be noted again. This is realized by the conductor filler areas of the conductor braiding areas 21, 31, 41, 51. Conductor filler areas can therefore be height-reduced 12, widened 13, and / or shape-adapted 14, 15 individual conductors. The proposed multi-element conductor 2, 3, 4, 5 accordingly has an external shape that is optimized with regard to fill factor for the application area of ​​electrical machines. In particular, the external geometry h / b of the multi-element conductor strand 2, 3, 4, 5 can remain constant over the length of the conductor, despite the multi-core structure and Roebel-like interweaving of the individual conductors 10. Reference symbol:

[0039] 1Multi-element electrical conductor 10Single conductor 12Single conductor of reduced height 13Widened single conductor 14Shape-adapted single conductor with optionally variable cross-sectional area 15Shape-adapted single conductor with constant conductor cross-sectional area h'Varying conductor height, depending on the cross-sectional area hConstant conductor height, over the entire length of the conductor 2, 3, 4 bConstant conductor width, over the entire length of the conductor 2, 3, 4 2Multi-element electrical conductor according to the invention, in particular manufactured in a hybrid manner 20Conductor core area, solid, Roebeled individual conductors 10 21Conductor braiding area, in particular manufactured additively, with individual conductors of reduced height 12 as conductor filling area 3Multi-element electrical conductor according to the invention, in particular manufactured in a hybrid manner 30Conductor core area, area in which no change in conductor position occurs (even if the individual conductors do not run parallel to the outer geometry here, we from the conductor core area,since the individual conductors run continuously, in particular solid, conventionally manufactured conductors, at least all with a constant conductor cross-sectional area, in particular also a constant conductor cross-sectional shape in the conductor core area) 31 Conductor braiding area, in particular additively manufactured, with shape-adapted, in particular widened individual conductors 13 and solid, Roebeled individual conductors 10 (conductor braiding area, can be two-part, but can also be a pure filler area; continuous conductor cross-sectional shape for "continuous conductors") 4 Multi-element electrical conductor according to the invention 40 Conductor core area, straight individual conductors 10 41 Conductor braiding area, in particular additively manufactured, with shape-adapted individual conductors 14 and position-changing continuous individual conductors 10 with consistently the same conductor cross-sectional area and shape 5 Multi-element electrical conductor according to the invention 50 Conductor core area, straight individual conductors 10 51Ladder braiding area,in particular additively manufactured, with shape-adapted, position-changing individual conductors 15 with consistently the same conductor cross-sectional area,

Claims

1. Multi-element electrical conductor (2, 3, 4, 5), having conductor core regions (20, 30, 40, 50) comprising a plurality of individual conductors (10) and having conductor braiding regions (21, 31, 41), which conductor braiding regions (21, 31, 41, 51) are designed to form a predeterminable outer geometry (h, b) of the multi-element conductor (2, 3, 4, 5) by means of at least one conductor filling region.

2. Multi-element electrical conductor (2, 3, 4, 5) according to claim 1, wherein the conductor braiding regions (21, 31, 41, 51) comprise individual conductors (10) and conductor filling regions.

3. Multi-element electrical conductor (2, 3, 4, 5) according to claim 1 or 2, wherein the conductor filling region is additively manufactured.

4. Multi-element electrical conductor (2, 3, 4, 5) according to one of the preceding claims, wherein the conductor filling region has a single conductor of reduced height (12), has widened single conductors (13) and / or has shape-adapted single conductors (14, 15).

5. Multi-element electrical conductor (2, 3, 4, 5) according to one of the preceding claims, wherein the individual conductors (10, 12, 13, 14, 15) comprise copper or are made of copper.

6. Multi-element electrical conductor (2, 3, 4, 5) according to one of the preceding claims, wherein the individual conductors (10, 14, 15) are solid individual conductors with a material purity of at least 99.96%, in particular conventionally manufactured conductors.

7. Multi-element electrical conductor (2, 3, 4, 5) according to one of the preceding claims, which is designed as a Roebel conductor or whose conductor core regions (20, 30, 40, 50) are designed as Roebel conductors.

8. Multi-element electrical conductor (2, 3, 4, 5) according to one of the preceding claims, wherein the individual conductors (10, 14, 15) have the same cross-sectional area over the length of the conductor (2, 3, 4, 5).

9. Multi-element electrical conductor (2, 3, 4, 5) according to one of the preceding claims, wherein the individual conductors (10) have the same cross-sectional shape over the length of a conductor core region (20, 30, 40, 50).

10. Multi-element electrical conductor (2, 3, 4, 5) according to one of the preceding claims, comprising a conductor connection region in which the individual conductors (10) are connected.

11. Multi-element electrical conductor (2, 3, 4, 5) according to one of the preceding claims, arranged in a groove of an electrical machine.

12. Use of a multi-element electrical conductor (2, 3, 4, 5) according to one of the preceding claims in a winding, in particular of a transformer.

13. A method for producing a multi-element conductor (2, 3, 4, 5) according to one of the preceding claims 1 to 11, comprising at least one step for producing the conductor core regions (20, 30, 40, 50) and one step for producing the conductor braiding regions (21, 31, 41), in particular the conductor filling regions.

14. The method according to claim 13, further comprising a step for producing a conductor connection region, in which conductor connection region the interconnection of the individual conductors (10) takes place, in particular by means of additive manufacturing.

15. Method according to one of the preceding claims 13 to 14, wherein the conductor filling region is manufactured by means of an additive manufacturing process, in particular an upper and a lower conductor filling region are manufactured additively.

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