EP2193528B1 - Electrical line with carbon nanotubes - Google Patents
Electrical line with carbon nanotubes Download PDFInfo
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- EP2193528B1 EP2193528B1 EP07818370.4A EP07818370A EP2193528B1 EP 2193528 B1 EP2193528 B1 EP 2193528B1 EP 07818370 A EP07818370 A EP 07818370A EP 2193528 B1 EP2193528 B1 EP 2193528B1
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- Prior art keywords
- layer
- electrical
- carbon nanotubes
- electrical line
- composite
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/20—Conductive material dispersed in non-conductive organic material
- H01B1/24—Conductive material dispersed in non-conductive organic material the conductive material comprising carbon-silicon compounds, carbon or silicon
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/42—Insulated conductors or cables characterised by their form with arrangements for heat dissipation or conduction
- H01B7/428—Heat conduction
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/0009—Details relating to the conductive cores
Definitions
- the invention relates to a layered electrical conductor with a first layer of a composite with carbon nanotubes.
- Carbon nanotubes also called CNTs (Carbo-Nano-Tube) are microscopic tubular structures made of carbon. Carbon nanotubes are particularly interesting for the electrical and electronics industry due to their extremely high current carrying capacity and thermal conductivity. For example, carbon nanotubes have about a thousand times higher current carrying capacity than copper wires, and their thermal conductivity is about 6,000 W m ⁇ K almost twice that of diamond.
- a conductor made of a composite of a metal and a mixed amount of carbon nanotubes in the range of 0.2 to 2% known.
- the composite layer forms the core of the conductor, which is surrounded by an insulating layer, a shielding layer and a protective layer.
- the electromagnetic shielding layer also contains carbon nanotubes.
- the GB 319,792 describes an electrical conductor with a heat-conducting layer to improve the current carrying capacity of the conductor. Also the GB 1,002,525 one can see an electrical cable which has an increased thermal conductivity using certain materials.
- the invention is therefore based on the object of reducing the material costs of a carbon nanotube-based electrical conductor.
- the conduit has a first layer of a first material with carbon nanotubes and a second layer, wherein the second layer consists of a thermally conductive second material and immediately adjacent to the first layer, wherein one of the two layers at least partially surrounds the other layer at its periphery in that a heat loss generated in the first layer due to a current flowing through the first layer is dissipated substantially to the second layer.
- the first layer completely encloses the second layer at its circumference.
- a material with a specific thermal conductivity of 100 is referred to as a second material referred to as heat-conducting W m ⁇ K or more at room temperature.
- the core idea of the invention is based on the knowledge that the current-carrying capacity of a conductor not only depends on the specific conductivity of the conductive material but also on the cooling conditions under which the current transport takes place. Given the geometry and otherwise unchanged boundary conditions for the temperatures, the current carrying capacity of a conductor only increases with the root of the factor, which increases the specific conductivity. So if a material with a nine times better conductivity is used, this leads only to a tripling of the permissible continuous current, which can be performed with such an electrical line. As a consequence, in many cases good electrical conductivity properties can only be exploited inefficiently, since the heat generated in conductors can not be dissipated in sufficient quantity.
- the heat dissipated by an electrical line per unit of time depends crucially on the effective surface of the conductor, which can make this available for this purpose. Due to the high cost of materials that must be applied to the carbon nanotube-containing material of the first layer, it would be very uneconomical to increase the cross-sectional area and thus the heat-dissipating surface of a conductor constructed from the first material such that the excellent electrical conduction properties of the carbon nanotubes are fully utilized can. According to the invention, the problem of heat dissipation is addressed by a much more favorable solution, in which the second layer of a good heat conductive material such as copper or aluminum is used to increase the cross section of the electrical line and thus their heat dissipating surface. Due to the excellent conductivity of the first layer with the carbon nanotubes, the flow of current will concentrate primarily in the first layer. The heat generated in this case, due to the also still be characterized as good thermal conductivity of the second layer of this led and brought to the surface.
- the electrical line By the second much cheaper layer not only the thermal conductivity and thus the current carrying capacity of the electrical line are increased. Due to the larger cross-section, which results from the addition of the second layer, the electrical line also receives a comparatively higher strength. The resulting larger cross-section also ensures a lower field strength at the surface of the electrical line. Due to the volume introduced by the two layers, the short-circuit current carrying capacity of the electrical line according to the invention can also be increased, since a higher thermal capacitance results compared to an electrical conductor of the same conductivity, which consists only of the first material.
- an embodiment of the invention is advantageous in which the first material is designed as a composite.
- CNTs may be included to some extent to produce the desired conductive properties.
- the thermal conductivity and the electrical conductivity can be further increased in an advantageous embodiment of the invention, when the heat-conducting material is an electrical conductor, in particular a metallic conductor.
- the heat-conducting material is an electrical conductor, in particular a metallic conductor.
- part of the current to be conducted from the electric wire is also passed through the second layer, thereby relieving the first layer.
- an embodiment of the invention is advantageous in which one of the two layers completely surrounds the other layer at its periphery. This is especially true when the heat transfer resistance between the layers is less than the heat transfer resistance of the first layer to the environment.
- a further advantageous embodiment of the invention is characterized in that the two layers are arranged coaxially to each other and one of the two layers forms an axially extending core of the conduit.
- the surface available for heat removal is determined by the outer layer in such an embodiment.
- a large surface available for heat dissipation can be achieved by the second layer completely enclosing the first layer at its circumference.
- the heat generated in the first layer by the current transport can be transmitted to the second layer, which finally emits this heat to the environment over a comparatively large surface area.
- an embodiment of the invention may be expedient in which the first layer completely encloses the second layer at its periphery.
- the second layer made of the cheaper material forms the core of the coaxial assembly. This core only has to be covered with a comparatively thin layer of the first, more expensive material.
- Such a tubular conductor is particularly advantageous if the current to be supplied has high-frequency components. Due to the high frequencies, there is a current displacement, which leads in this embodiment to the fact that the current components displaced to the surface of the electrical line flow in the area of the extremely conductive first material. Thus, the frequency-dependent increase in resistance of such a conductor is relatively small compared to conventional conductors, which consist only of a conductive layer.
- Electrical leads according to one of the embodiments described above can advantageously be combined into a stranded wire.
- additional insulation such as, for example, a lacquer can be dispensed with.
- the electrical conductivity of the first material is so high that even a copper or aluminum layer enclosing the core acts approximately like electrical isolation between the individual wires because conductivity difference of the layers is very high, although both materials the group of electrical conductors are assigned.
- the fact that in such a stranded wire can be dispensed with an additional paint or plastic insulation also increases the internal electrical and thermal conductivity of the strand and thus the current carrying capacity. The result is a higher filling factor, that is a relatively higher volume fraction, which is filled with electrically and thermally conductive material, as is the case with conventionally insulated stranded wires.
- FIG. 1 shows the cross section of a first electrical line with a core made of a composite with carbon nanotubes.
- the illustrated electrical line is constructed in a layered manner.
- a first layer 1 of the electrical line is formed by the composite material in which the extremely conductive carbon nanotubes are located. Due to the cost of this material, the cross-sectional area and thus the circumference of the first layer 1 is comparatively small. Since the electrical conductivity of the composite material is very high, the given cross-sectional area is sufficient for the transport of very high currents, if it is ensured that the resulting heat is dissipated sufficiently to the outside.
- a second layer 2 around the first layer 1 coaxially with the first layer 1, which consists of a material of very good conductivity.
- the first layer 1 which consists of a material of very good conductivity.
- a metal such as copper or aluminum in question.
- the use of a conductive metal in addition to the good thermal conductivity also has the advantage that a part of the current transport can also be taken over by the second layer 2.
- the electrical line is finally surrounded by a plastic insulation.
- FIG. 2 shows the cross section of a second electrical line with a core made of a composite with carbon nanotubes.
- the arrangement shown essentially corresponds to in FIG. 1 shown arrangement.
- plastic insulation 3 is provided here a resist layer 4 for electrical insulation of the entire electrical line to the outside.
- FIG. 3 shows the cross section of a third electrical line with a tubular layer of a composite with carbon nanotubes.
- the first layer 1 of the electrical line is located on a core formed by the second layer 2.
- the first layer 1 itself has a very large surface through which it can emit the heat, without having to use large amounts of the composite material for this purpose.
- the outer insulation layer shows FIG. 4 the same structural design of the electric wire as FIG. 3 ,
- the in the FIGS. 3 and 4 illustrated embodiments of the electrical line have advantages, especially at high frequencies of the current to be transported.
- FIG. 5 shows a groove 5 with electrical lines having a layer of a composite with carbon nanotubes.
- FIG. 5 illustrated can be constructed using the two-layered electrical wires and winding packages for electrical machines, which are characterized by a very low resistivity. Therefore, much higher magnetic field strengths can be generated within these machines with the electrical leads according to the invention than is the case with conventional conductors.
- FIG. 6 shows a stranded wire with electrical leads having a layer of composite with carbon nanotubes.
- the individual lines each have a first layer 1 of the composite material, which forms the core of the lines, and a second layer 2 of a good thermal conductivity material such as copper or aluminum.
- a good thermal conductivity material such as copper or aluminum.
- copper and aluminum are known as good electrical conductors, their specific electrical conductivity is much lower than that of the composite material.
- the second layer 2 acts as an insulating layer which sufficiently insulates the individual electrical leads of the strand from one another.
- the thermal conductivity of the second layer 2 is very high, so that the heat between the individual wires of the Litz wire can be exchanged.
- the current carrying capacity of the stranded wire compared to conventional stranded wire can be significantly increased.
Description
Die Erfindung betrifft eine schichtartig aufgebaute elektrische Leitung mit einer ersten Schicht aus einem Komposit mit Kohlenstoffnanoröhren.The invention relates to a layered electrical conductor with a first layer of a composite with carbon nanotubes.
Kohlenstoffnanoröhren, auch mit CNT (Carbo-Nano-Tube) abkürzend bezeichnet, sind mikroskopisch kleine röhrenförmige Gebilde aus Kohlstoff. Insbesondere für die Elektro- und Elektronikindustrie sind Kohlenstoffnanoröhren aufgrund ihrer extrem hohen Strombelastbarkeit und Wärmeleitfähigkeit interessant. So besitzen Kohlenstoffnanoröhren eine ca. tausendmal höhere Strombelastbarkeit als Kupferdrähte, und ihre Wärmeleitfähigkeit liegt mit ca. 6.000
Reine Kohlenstoffnanoröhren sind heute lediglich in geringen Mengen erhältlich. Somit ist es zurzeit noch schwer vorstellbar, industriell eingesetzte, ausgedehnte elektrische Leiter rein aus Kohlenstoffnanoröhren herzustellen.Pure carbon nanotubes are currently only available in small quantities. Thus, it is currently difficult to imagine using industrially used, extended electrical conductors purely from carbon nanotubes.
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Die Verbreitung von Kompositmaterialien auf Basis von Kohlenstoffnanoröhren wird zurzeit durch die erheblichen Kosten gebremst, die für diese Materialien im Verhältnis zu herkömmlichen Leitermaterialien wie Kupfer und Aluminium aufgebracht werden müssen.The spread of carbon nanotube-based composite materials is currently being curbed by the significant cost that must be borne by these materials relative to conventional conductor materials such as copper and aluminum.
Der Erfindung liegt daher die Aufgabe zugrunde, die Materialkosten eines auf Kohlenstoffnanoröhren basierenden elektrischen Leiters zu reduzieren.The invention is therefore based on the object of reducing the material costs of a carbon nanotube-based electrical conductor.
Diese Aufgabe wird durch eine schichtartig aufgebaute elektrische Leitung gelöst gemäß den Merkmalen des unabhängigen Patentanspruchs 1.
Die Leitung hat eine erste Schicht aus einem ersten Material mit Kohlenstoffnanoröhren und eine zweite Schicht, wobei die zweite Schicht aus einem wärmeleitenden zweiten Material besteht und an die erste Schicht unmittelbar angrenzt, wobei eine der beiden Schichten die andere Schicht an deren Umfang zumindest teilweise derart umschließt, dass eine in der ersten Schicht aufgrund eines durch die erste Schicht fließenden Stromes erzeugte Verlustwärme zu wesentlichen Teilen an die zweite Schicht abgegeben wird. Die erste Schicht umschließt dabei die zweite Schicht an deren Umfang vollständig. Unter dem als wärmeleitend bezeichneten zweiten Material ist in diesem Zusammenhang ein Material mit einer spezifischen Wärmeleitfähigkeit von 100
The conduit has a first layer of a first material with carbon nanotubes and a second layer, wherein the second layer consists of a thermally conductive second material and immediately adjacent to the first layer, wherein one of the two layers at least partially surrounds the other layer at its periphery in that a heat loss generated in the first layer due to a current flowing through the first layer is dissipated substantially to the second layer. The first layer completely encloses the second layer at its circumference. In this context, a material with a specific thermal conductivity of 100 is referred to as a second material referred to as heat-conducting
Der Kerngedanke der Erfindung basiert auf der Erkenntnis, dass die Stromtragfähigkeit eines Leiters nicht nur von der spezifischen Leitfähigkeit des leitenden Materials abhängt sondern auch von den Kühlbedingungen, unter denen der Stromtransport stattfindet. Bei gegebener Geometrie und ansonsten unveränderten Randbedingungen für die Temperaturen steigt die Stromtragfähigkeit eines Leiters lediglich mit der Wurzel des Faktors, mit dem die spezifische Leitfähigkeit erhöht wird. Wird also ein Material mit einer neunfach besseren Leitfähigkeit eingesetzt, so führt dies nur zu einer Verdreifachung des zulässigen Dauerstroms, der mit einer derartigen elektrischen Leitung geführt werden kann. In der Konsequenz führt dies dazu, dass in vielen Fällen gute elektrische Leitungseigenschaften nur ineffizient ausgenutzt werden können, da die in Leitern erzeugte Wärme nicht in ausreichender Menge abgeführt werden kann.The core idea of the invention is based on the knowledge that the current-carrying capacity of a conductor not only depends on the specific conductivity of the conductive material but also on the cooling conditions under which the current transport takes place. Given the geometry and otherwise unchanged boundary conditions for the temperatures, the current carrying capacity of a conductor only increases with the root of the factor, which increases the specific conductivity. So if a material with a nine times better conductivity is used, this leads only to a tripling of the permissible continuous current, which can be performed with such an electrical line. As a consequence, in many cases good electrical conductivity properties can only be exploited inefficiently, since the heat generated in conductors can not be dissipated in sufficient quantity.
Die von einer elektrischen Leitung abführbare Wärme pro Zeiteinheit hängt entscheidend von der effektiven Oberfläche des Leiters ab, die dieser zu diesem Zweck zur Verfügung stellen kann. Aufgrund der hohen Materialkosten, die für das kohlenstoffnanoröhrenhaltige Material der ersten Schicht aufgebracht werden müssen, wäre es sehr unwirtschaftlich, die Querschnittsfläche und damit die wärmeabführende Oberfläche eines aus dem ersten Material aufgebauten Leiters derart zu erhöhen, dass die hervorragenden elektrischen Leiteigenschaften der Kohlenstoffnanoröhren voll ausgenutzt werden können. Erfindungsgemäß wird das Problem der Wärmeabfuhr durch eine wesentlich günstigere Lösung angegangen, bei der die zweite Schicht aus einem gut wärmeleitfähigen Material wie beispielsweise Kupfer oder Aluminium dazu verwendet wird, den Querschnitt der elektrischen Leitung und damit deren wärmeabführende Oberfläche zu vergrößern. Aufgrund der hervorragenden Leiteigenschaften der ersten Schicht mit den Kohlenstoffnanoröhren wird sich der Stromfluss in erster Linie in der ersten Schicht konzentrieren. Die hierbei erzeugte Wärme kann aufgrund der ebenfalls noch als gut zu bezeichnenden Wärmeleitfähigkeit der zweiten Schicht von dieser geleitet und an die Oberfläche gebracht werden.The heat dissipated by an electrical line per unit of time depends crucially on the effective surface of the conductor, which can make this available for this purpose. Due to the high cost of materials that must be applied to the carbon nanotube-containing material of the first layer, it would be very uneconomical to increase the cross-sectional area and thus the heat-dissipating surface of a conductor constructed from the first material such that the excellent electrical conduction properties of the carbon nanotubes are fully utilized can. According to the invention, the problem of heat dissipation is addressed by a much more favorable solution, in which the second layer of a good heat conductive material such as copper or aluminum is used to increase the cross section of the electrical line and thus their heat dissipating surface. Due to the excellent conductivity of the first layer with the carbon nanotubes, the flow of current will concentrate primarily in the first layer. The heat generated in this case, due to the also still be characterized as good thermal conductivity of the second layer of this led and brought to the surface.
Durch die zweite sehr viel preiswertere Schicht werden nicht nur die Wärmeleitfähigkeit und damit die Stromtragfähigkeit der elektrischen Leitung erhöht. Durch den größeren Querschnitt, der sich durch Hinzufügen der zweiten Schicht ergibt, erhält die elektrische Leitung auch eine vergleichsweise höhere Festigkeit. Der resultierende größere Querschnitt sorgt darüber hinaus für eine geringere Feldstärke an der Oberfläche der elektrischen Leitung. Aufgrund des durch die beiden Schichten eingebrachten Volumens kann auch die Kurzschlussstrombelastbarkeit der erfindungsgemäßen elektrischen Leitung erhöht werden, da sich eine höhere thermische Kapazität im Vergleich zu einem elektrischen Leiter gleicher Leitfähigkeit ergibt, der nur aus dem ersten Material besteht.By the second much cheaper layer not only the thermal conductivity and thus the current carrying capacity of the electrical line are increased. Due to the larger cross-section, which results from the addition of the second layer, the electrical line also receives a comparatively higher strength. The resulting larger cross-section also ensures a lower field strength at the surface of the electrical line. Due to the volume introduced by the two layers, the short-circuit current carrying capacity of the electrical line according to the invention can also be increased, since a higher thermal capacitance results compared to an electrical conductor of the same conductivity, which consists only of the first material.
Aufgrund der technologischen Schwierigkeiten und der damit verbundenen Herstellungskosten bei der Erzeugung eines Materials aus reinen Kohlenstoffnanoröhren, die mit zunehmender Leitungslänge ebenfalls signifikanter werden, ist eine Ausgestaltung der Erfindung vorteilhaft, bei der das erste Material als Komposit ausgeführt ist. In diesem Komposit können die CNT zu einem gewissen Prozentsatz enthalten sein, um die gewünschten Leiteigenschaften zu erzeugen.Due to the technological difficulties and the associated manufacturing costs in the production of a material made of pure carbon nanotubes, which also become more significant with increasing line length, an embodiment of the invention is advantageous in which the first material is designed as a composite. In this composite, CNTs may be included to some extent to produce the desired conductive properties.
Nicht nur die Wärmeleitfähigkeit auch die elektrische Leitfähigkeit kann in vorteilhafter Ausgestaltung der Erfindung weiter erhöht werden, wenn das wärmeleitende Material ein elektrischer Leiter, insbesondere ein metallischer Leiter, ist. In dem Fall wird auch ein Teil des von der elektrischen Leitung zu führenden Stromes über die zweite Schicht geführt, wodurch die erste Schicht entlastet wird.Not only the thermal conductivity and the electrical conductivity can be further increased in an advantageous embodiment of the invention, when the heat-conducting material is an electrical conductor, in particular a metallic conductor. In that case, part of the current to be conducted from the electric wire is also passed through the second layer, thereby relieving the first layer.
Insbesondere dann, wenn durch die Wahl des ersten und zweiten Materials eine geringer Wärmeübergangswiderstand zwischen den beiden Schichten erzielt wird, ist eine Ausführung der Erfindung vorteilhaft, bei der eine der beiden Schichten die andere Schicht an deren Umfang vollständig umschließt. Dies gilt insbesondere dann, wenn der Wärmeübergangswiderstand zwischen den Schichten geringer ist als der Wärmeübergangswiderstand der ersten Schicht zur Umgebung.In particular, if a low heat transfer resistance between the two layers is achieved by the choice of the first and second material, an embodiment of the invention is advantageous in which one of the two layers completely surrounds the other layer at its periphery. This is especially true when the heat transfer resistance between the layers is less than the heat transfer resistance of the first layer to the environment.
Eine weitere vorteilhafte Ausführungsform der Erfindung ist dadurch gekennzeichnet, dass die beiden Schichten koaxial zueinander angeordnet sind und eine der beiden Schichten einen axial verlaufenden Kern der Leitung bildet. Die der Wärmeabfuhr zur Verfügung stehende Oberfläche ist bei einer derartigen Ausführungsform durch die außen liegende Schicht bestimmt.A further advantageous embodiment of the invention is characterized in that the two layers are arranged coaxially to each other and one of the two layers forms an axially extending core of the conduit. The surface available for heat removal is determined by the outer layer in such an embodiment.
Beispielsweise kann in weiterer vorteilhafter Ausgestaltung der Erfindung eine große zur Wärmeabfuhr zur Verfügung stehende Oberfläche dadurch erzielt werden, dass die zweite Schicht die erste Schicht an deren Umfang vollständig umschließt. Hierbei kann die in der ersten Schicht durch den Stromtransport erzeugte Wärme an die zweite Schicht übertragen werden, die diese Wärme schließlich an die Umgebung über eine vergleichsweise große Oberfläche abgibt.For example, in a further advantageous embodiment of the invention, a large surface available for heat dissipation can be achieved by the second layer completely enclosing the first layer at its circumference. Here, the heat generated in the first layer by the current transport can be transmitted to the second layer, which finally emits this heat to the environment over a comparatively large surface area.
Umgekehrt kann aber auch eine Ausführungsform der Erfindung zweckmäßig sein, bei der die erste Schicht die zweite Schicht an deren Umfang vollständig umschließt. Bei dieser Ausführungsform bildet die zweite, aus dem preiswerteren Material hergestellte Schicht den Kern der koaxialen Anordnung. Dieser Kern muss nur mit einer vergleichsweise dünnen Schicht des ersten, teureren Materials umhüllt werden.Conversely, however, an embodiment of the invention may be expedient in which the first layer completely encloses the second layer at its periphery. In this embodiment, the second layer made of the cheaper material forms the core of the coaxial assembly. This core only has to be covered with a comparatively thin layer of the first, more expensive material.
Ein derartiger rohrförmig ausgebildeter Leiter ist besonders dann vorteilhaft, wenn der zu führende Strom hochfrequente Anteile besitzt. Aufgrund der hohen Frequenzen kommt es zu einer Stromverdrängung, die bei dieser Ausführungsform dazu führt, dass die an die Oberfläche der elektrischen Leitung verdrängten Stromanteile im Bereich des extrem leitfähigen ersten Materials fließen. Somit ist die frequenzabhängige Widerstandserhöhung eines solchen Leiters relativ gering im Vergleich zu herkömmlichen Leitern, die nur aus einer leitfähigen Schicht bestehen.Such a tubular conductor is particularly advantageous if the current to be supplied has high-frequency components. Due to the high frequencies, there is a current displacement, which leads in this embodiment to the fact that the current components displaced to the surface of the electrical line flow in the area of the extremely conductive first material. Thus, the frequency-dependent increase in resistance of such a conductor is relatively small compared to conventional conductors, which consist only of a conductive layer.
Elektrische Leitungen gemäß einer der zuvor beschriebenen Ausführungsformen können in vorteilhafter Weise zu einem Litzendraht kombiniert werden. Wird für die elektrische Leitung eine Ausführungsform gewählt, bei der die zweite Schicht die erste Schicht an deren kompletten Umfang umschließt, so kann auf eine zusätzlich Isolierung wie beispielsweise einen Lack verzichtet werden. Dies ist darauf zurückzuführen, dass die elektrische Leitfähigkeit des ersten Materials derart hoch ist, dass sogar eine Kupfer- oder Aluminiumschicht, die den Kern umschließt, annähernd wie eine elektrische Isolation zwischen den Einzeldrähten wirken, da Leitwertunterschied der Schichten sehr hoch ist, obwohl beide Materialien der Gruppe der elektrischen Leiter zuzuordnen sind. Dadurch, dass bei einem solchen Litzendraht auf eine zusätzliche Lack- oder Kunststoffisolation verzichtet werden kann, erhöht sich auch die innere elektrische und thermische Leitfähigkeit der Litze und damit die Stromtragfähigkeit. Es ergibt sich ein höherer Füllfaktor, dass heißt ein relativ höherer Volumenanteil, der mit elektrisch und thermisch leitendem Material gefüllt ist, als es bei konventionell isolierten Litzendrähten der Fall ist.Electrical leads according to one of the embodiments described above can advantageously be combined into a stranded wire. If an embodiment is selected for the electrical conduction in which the second layer surrounds the first layer at its entire circumference, additional insulation such as, for example, a lacquer can be dispensed with. This is because the electrical conductivity of the first material is so high that even a copper or aluminum layer enclosing the core acts approximately like electrical isolation between the individual wires because conductivity difference of the layers is very high, although both materials the group of electrical conductors are assigned. The fact that in such a stranded wire can be dispensed with an additional paint or plastic insulation, also increases the internal electrical and thermal conductivity of the strand and thus the current carrying capacity. The result is a higher filling factor, that is a relatively higher volume fraction, which is filled with electrically and thermally conductive material, as is the case with conventionally insulated stranded wires.
Mit der erfindungsgemäßen elektrischen Leitung bzw. einer der zuvor erwähnten Ausführungsformen können verschiedenste Anwendungsfelder erschlossen werden. Eine Anwendung derartiger Leiter ist insbesondere dort interessant, wo sehr hohe Ströme auf begrenztem Raum geführt werden sollen. Daher stellt eine Spulenwicklung insbesondere für eine elektrische Maschine umfassend schichtartig aufgebaute elektrische Leitungen nach einer der bereits erwähnten Ausführungsformen eine beispielhafte vorteilhafte Weiterbildung des erfindungsgemäßen Gedankens dar.With the electrical line according to the invention or one of the aforementioned embodiments, a wide variety of fields of application can be developed. An application of such conductors is particularly interesting where very high currents are to be performed in a limited space. Therefore, a coil winding, in particular for an electrical machine comprising stratified electrical lines according to one of the embodiments already mentioned represents an exemplary advantageous development of the inventive concept.
Im Folgenden wird die Erfindung anhand der in den Figuren dargestellten Ausführungsbeispiele näher beschrieben und erläutert.In the following the invention will be described and explained in more detail with reference to the embodiments illustrated in the figures.
Es zeigen:
- FIG 1
- Den Querschnitt einer ersten elektrischen Leitung mit einem Kern aus einem Komposit mit Kohlenstoffnanoröhren,
- FIG 2
- den Querschnitt einer zweiten elektrischen Leitung mit einem Kern aus einem Komposit mit Kohlenstoffnanröhren,
- FIG 3
- den Querschnitt einer dritten elektrischen Leitung mit einer rohrförmigen Schicht aus einem Komposit mit Kohlenstoffnanoröhren,
- FIG 4
- den Querschnitt einer vierten elektrischen Leitung mit einer rohrförmigen Schicht aus einem Komposit mit Kohlenstoffnanoröhren,
- FIG 5
- eine Nut mit elektrischen Leitungen, die eine Schicht aus einem Komposit mit Kohlenstoffnanoröhren aufweisen und
- FIG 6
- einen Litzendraht mit elektrischen Leitungen, die eine Schicht aus einem Komposit mit Kohlenstoffnanoröhren aufweisen.
- FIG. 1
- The cross section of a first electrical line with a core made of a composite with carbon nanotubes,
- FIG. 2
- the cross section of a second electrical line with a core made of a composite with carbon nanotubes,
- FIG. 3
- FIG. 2 shows the cross section of a third electrical line with a tubular layer made of a composite with carbon nanotubes, FIG.
- FIG. 4
- the cross section of a fourth electrical line with a tubular composite layer with carbon nanotubes,
- FIG. 5
- a groove with electrical leads, which have a layer of a composite with carbon nanotubes and
- FIG. 6
- a stranded wire with electrical leads comprising a layer of composite with carbon nanotubes.
Dies geschieht, in dem um die erste Schicht 1 herum eine zweite Schicht 2 koaxial zur ersten Schicht 1 angeordnet wird, die aus einem sehr gut leitfähigen Material besteht. Hierfür kommt beispielsweise ein Metall wie Kupfer oder Aluminium in Frage. Die Verwendung eines leitfähigen Metalls hat neben der guten Wärmeleitfähigkeit auch noch den Vorteil, dass ein Teil des Stromtransportes auch von der zweiten Schicht 2 übernommen werden kann.This is done by arranging a
Zur elektrischen Isolierung wird die elektrische Leitung schließlich von einer Kunststoffisolation umgeben.For electrical insulation, the electrical line is finally surrounded by a plastic insulation.
Abschließend sei erwähnt, dass die in den Figuren dargestellte runde Leitungsform nur eine von vielen alternativen zur Umsetzung des erfindungsgemäßen Gedankens darstellt. So sind selbstverständlich auch eckige Leitungsformen mit zwei aneinandergrenzenden Schichten oder auch sehr viel komplizierter Geometrien unter Verwendung der erfindungsgemäßen Lehre denkbar und vom Schutzumfang umfasst.Finally, it should be mentioned that the round line shape shown in the figures represents only one of many alternatives for implementing the inventive concept. So, of course, square pipe forms with two adjacent layers or much more complicated Geometries using the teaching of the invention conceivable and encompassed by the scope.
Claims (7)
- Electrical line of layerlike construction comprising a first layer (1) composed of a first material comprising carbon nanotubes and a second layer (2), and
the second layer (2) consists of a thermally conductive second material and directly adjoins the first layer (1), wherein one of the two layers (1, 2) at least partly encloses the other layer (1, 2) at the circumference thereof in such a way that a heat loss generated in the first layer on account of a current flowing through the first layer (1) is substantially designated to the second layer (1), characterized in that
the first layer (1) completely encloses the second layer (2) at the circumference thereof. - Electrical line according to Claim 1,
wherein the first material is embodied as a composite. - Electrical line according to Claim 1 or 2,
wherein the thermally conductive second material is an electrical conductor, in particular a metallic conductor. - Electrical line according to Claim 3,
wherein the two layers (1, 2) are arranged coaxially with respect to one another and one of the two layers (1, 2) forms an axially extending core of the line. - Multiple-stranded wire comprising electrical lines of layerlike construction according to any of Claims 1 to 4.
- Multiple-stranded wire comprising electrical lines of layerlike construction according to Claim 4, wherein the electrical lines are fashioned in such a way that an electrical insulation of the individual electrical lines from one another is effected solely by the second layer (2) .
- Coil winding in particular for an electrical machine comprising electrical lines of layerlike construction according to any of Claims 1 to 4.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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PCT/EP2007/008283 WO2009039872A1 (en) | 2007-09-24 | 2007-09-24 | Electrical line with carbon nanotubes |
Publications (2)
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EP2193528A1 EP2193528A1 (en) | 2010-06-09 |
EP2193528B1 true EP2193528B1 (en) | 2018-12-26 |
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EP07818370.4A Not-in-force EP2193528B1 (en) | 2007-09-24 | 2007-09-24 | Electrical line with carbon nanotubes |
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WO (1) | WO2009039872A1 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
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DE102008064579B4 (en) * | 2008-12-22 | 2012-03-15 | Siemens Aktiengesellschaft | Method and carrier cylinder for producing an electrical winding |
US9449739B2 (en) * | 2012-10-16 | 2016-09-20 | The Boeing Company | High power, high frequency power cable |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
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US1837952A (en) * | 1927-10-31 | 1931-12-22 | Delon Jules | Electric cable |
FR682416A (en) * | 1928-09-28 | 1930-05-27 | Reinforcement for high current cables | |
GB1002525A (en) * | 1963-08-01 | 1965-08-25 | Ass Elect Ind | Improvements in or relating to electrical power cables |
US3798346A (en) * | 1973-04-16 | 1974-03-19 | Midland Ross Corp | Power transmission apparatus, especially cable and cable bus housings |
SE7801543L (en) * | 1978-02-09 | 1979-08-10 | Ssab Svenskt Stal Ab | RORKABEL |
EP0729158B1 (en) * | 1995-02-24 | 2003-04-09 | Sumitomo Wiring Systems, Ltd. | Radiation wire |
JP2005096024A (en) * | 2003-09-24 | 2005-04-14 | Fuji Xerox Co Ltd | Wire, its manufacturing method, and electromagnet using the wire |
JP2006260898A (en) * | 2005-03-16 | 2006-09-28 | Auto Network Gijutsu Kenkyusho:Kk | Shield conductive line and manufacturing method for sheet-like conductive line |
JP2006269201A (en) * | 2005-03-23 | 2006-10-05 | Auto Network Gijutsu Kenkyusho:Kk | Shielded conductive path |
-
2007
- 2007-09-24 EP EP07818370.4A patent/EP2193528B1/en not_active Not-in-force
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WO2009039872A1 (en) | 2009-04-02 |
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