EP2472533A1 - Transformer coil with cooling channel - Google Patents

Transformer coil with cooling channel Download PDF

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Publication number
EP2472533A1
EP2472533A1 EP11000018A EP11000018A EP2472533A1 EP 2472533 A1 EP2472533 A1 EP 2472533A1 EP 11000018 A EP11000018 A EP 11000018A EP 11000018 A EP11000018 A EP 11000018A EP 2472533 A1 EP2472533 A1 EP 2472533A1
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EP
European Patent Office
Prior art keywords
winding
transformer
insulating strips
transformer winding
cooling channel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP11000018A
Other languages
German (de)
French (fr)
Inventor
Jens Tepper
Marcos Bockholt
Benjamin Weber
Bhavesh Patel
Burak Esenlik
Frank Cornelius
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ABB Technology AG
Original Assignee
ABB Technology AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ABB Technology AG filed Critical ABB Technology AG
Priority to EP11000018A priority Critical patent/EP2472533A1/en
Priority to PCT/EP2011/005969 priority patent/WO2012092941A1/en
Priority to CN201180064188.0A priority patent/CN103270560B/en
Priority to EP11790876.4A priority patent/EP2661756A1/en
Publication of EP2472533A1 publication Critical patent/EP2472533A1/en
Priority to US13/934,750 priority patent/US9208939B2/en
Withdrawn legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/2876—Cooling
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/08—Cooling; Ventilating
    • H01F27/085—Cooling by ambient air
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/32—Insulating of coils, windings, or parts thereof
    • H01F27/322—Insulating of coils, windings, or parts thereof the insulation forming channels for circulation of the fluid
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F27/00—Details of transformers or inductances, in general
    • H01F27/28—Coils; Windings; Conductive connections
    • H01F27/32—Insulating of coils, windings, or parts thereof
    • H01F27/327—Encapsulating or impregnating
    • H01F2027/328—Dry-type transformer with encapsulated foil winding, e.g. windings coaxially arranged on core legs with spacers for cooling and with three phases

Definitions

  • the invention relates to a transformer winding with at least two hollow cylindrical nested around a common winding axis extending winding modules, which are radially spaced from each other within at least one interposed hollow cylindrical cooling channel by means of insulating strips.
  • power transformers for example, with a rated power of a few MVA and in a voltage range of, for example, 5kV to 30kV or 110kV, sometimes even up to 170kV, are also designed as dry-type transformers, wherein in the latter voltage range well rated power of 50MVA and are possible about it.
  • a loss of heat arises in its electrical windings, which is dissipated to the environment. Therefore, for cooling purposes of such a dry transformer usually at least one guided along the axial extent of the winding cooling channel is pronounced to lead out the heat loss preferably by means of natural air cooling from the winding interior.
  • the usually radially inwardly located lower voltage winding is divided into a plurality of radially spaced and electrically connected in series hollow cylindrical winding segments, between which a likewise hollow cylindrical cooling channel is arranged. But also between low and high voltage winding a cooling channel is usually provided.
  • a radial spacing of adjacent winding modules, through which ultimately a cooling channel is formed, takes place here via electrically insulating rectangular profiles or via so-called "dog-bone" - bars.
  • This object is achieved by a transformer winding of the aforementioned type.
  • This is characterized in that the insulating strips have a cross-sectional shape which avoids a surface profile radially to the winding axis predominantly.
  • the insulating ability of an insulator is determined on the one hand by its material and on the other hand by its outer surface. Longitudinal surface discharges can occur along these lines, insofar as the voltage stress is correspondingly high, for example a few 100 V / cm and higher. Surface discharges are favored when the electric field lines are tangent to the surface of an insulator, so that the stress stress along the surface is highest.
  • the insulating strips are made of a fiber-reinforced epoxy or polyester resin.
  • this has a high insulating ability.
  • the shape of such an insulating strip could be produced for example by milling or by pultrusion.
  • thermoplastic materials such as polyamides.
  • polyamides are suitable, which also have a correspondingly high stability at least 130 ° C.
  • the particular advantage of polyamides lies in their particularly simple formability.
  • the at least one cooling channel has a radially inner and a radially outer wall, which are then spaced by the insulating strips.
  • the walls can also be segmented.
  • the insulating strips have a diamond-like or a round cross-section. These are standard geometric shapes which are easy to manufacture and yet which are suitable for improved insulation. From weight and material savings, it may prove advantageous if the insulation strips are designed with an inner cavity.
  • the insulating strips have an S, X, V, or Y-shaped cross-section.
  • radially extending outer surface portions are advantageously largely avoided, so that an improved insulating ability is achieved.
  • the X, V and Y variants prove to be particularly stable due to their carrier-like structure.
  • a Torsionsbe screwung between the adjacent and spaced winding modules is here to highlight the X and V shape with their slanted support areas as particularly preferred.
  • insulation strips which have a cross-section with sawtooth-like outer edges, are suitable according to the invention to achieve an improved insulating ability.
  • This can mean both an additionally corrugated surface shape of an insulation strip according to the invention and, for example, a rib-like surface or outer surface shape of an insulation strip having a conventional rectangular cross-section.
  • the insulating strips have at their radially inner and / or radially outer end a flattened shape, which is ideally designed such that an insulating strip arranged in a cooling channel adjoins the flattened areas as flat as possible to the regions to be supported.
  • This can be either a winding module itself or a separate wall of a cooling channel.
  • the flattened shape is cylinder-spherical, that is adapted to the cylindrical shape of the adjacent winding modules.
  • cylindrical shape or “hollow cylindrical” is not to be understood as strictly geometrical with a round base, but rather includes a rectangle approximated basic shape with round To understand edge areas. Namely, this allows a particularly high utilization of a volume available in a transformer core by transformer windings.
  • the winding modules are galvanically connected to each other.
  • a cooling channel with inventive spacing is possible both between galvanically isolated upper and lower-voltage windings and between winding modules or also winding segments of a divided transformer winding. This is particularly useful in dry transformers greater power, where in operation correspondingly much waste heat to dissipate from the interior, which is simplified by several cooling channels accordingly.
  • a transformer winding according to the invention is also apparent for a transformer comprising at least one transformer core and a transformer winding according to the invention. This is namely smaller than a conventional transformer winding and thus advantageously allows a smaller construction volume of a transformer according to the invention.
  • Fig. 1 shows a section through an exemplary first transformer winding 10.
  • a first hollow cylindrical winding module 12 Around a winding axis are concentrically arranged a first hollow cylindrical winding module 12 and a second hollow cylindrical winding module 14, wherein between these a likewise hollow cylindrical cooling channel 18 is formed.
  • the two winding modules 12, 14 may, for example, comprise a strip conductor, wherein a winding layer is just as wide as the strip conductor. This is particularly useful in a low-voltage winding, since there is a high conductor cross section is required because of the high current flow in relation to the high-voltage winding during operation of the winding.
  • a conductor layer has a multiplicity of individual turns, as a result of which a more complex potential distribution along the cooling channel is established during operation of the transformer winding.
  • the diameter of such a transformer winding is for example 0.5m to 2.5m, depending on the voltage level and rated power.
  • a plurality of insulating strips 20, 22, 24, 26, 28, 30, 32 are shown by way of example with their cross-sectional shapes, by which the two winding modules 12, 14 are spaced apart in the radial direction 34.
  • the diamond-like insulating strip 20 is just like the round insulating strip 24 provided with an inner cavity 36 and 38, which serves in particular the weight savings.
  • the insulating strips 20, 22, 24, 26, 28, 30, 32 have a cross-sectional shape with a surface course radially 34 to the winding axis 16, which avoids a surface profile radially to the winding axis predominantly. As a result, the insulation resistance of the cooling channel 18 is increased in an advantageous manner.
  • insulating strips 20, 22, 24, 26, 28, 30, 32 are provided in a real cooling channel, for example 4 pieces at a respective angle of 90 °.
  • An insulating strip 20, 22, 24, 26, 28, 30, 32 does not necessarily have to extend over the entire axial length of a transformer winding, for example 1.5 m to 3.5 m, it can also be divided several times.
  • Fig. 2 shows a section through an exemplary second transformer winding 40 in a detailed view.
  • a first winding module 42 and a second winding module 44 are spaced by an insulating strip 48, which has approximately the shape of a double-Y. Radially inwardly and radially outwardly provided contact areas 56, 58 to the adjacent winding modules 42, 44 are flattened, wherein they are also adapted to the cylindrical shape of the winding modules. On In this way, the risk of electrical discharges in the area of the contact surfaces is largely reduced.
  • the insulating strip 48 has a first inclined surface area 50, a second radially extending surface area 52 and a third inclined surface area 54. An increase in the dielectric strength with respect to a rectangular profile is achieved in the inclined regions 50, 54. This can also be illustrated by the extended creepage path 60 along the surface.

Abstract

The winding (10) has a common winding axis (16) that is extended through the winding modules (12,14). A hollow-cylindrical cooling channel (18) is formed between the winding modules and spaced apart from the winding modules by insulating strips (20,22,24,26,28,30,32). The insulating strips are radially arranged in the cooling channel and comprised with a cross-sectional shape having a surface profile which is spaced apart from the winding axis. An independent claim is included for transformer.

Description

Die Erfindung betrifft eine Transformatorwicklung mit wenigstens zwei hohlzylindrisch ineinandergeschachtelten sich um eine gemeinsame Wickelachse erstreckenden Wicklungsmodulen, wobei diese innerhalb wenigstens eines dazwischen angeordneten hohlzylindrischen Kühlkanals mittels Isolationsleisten radial voneinander beabstandet sind.The invention relates to a transformer winding with at least two hollow cylindrical nested around a common winding axis extending winding modules, which are radially spaced from each other within at least one interposed hollow cylindrical cooling channel by means of insulating strips.

Es ist allgemein bekannt, dass Leistungstransformatoren, beispielsweise mit einer Nennleistung von einigen MVA und in einem Spannungsbereich von beispielsweise 5kV bis 30kV oder 110kV, teilweise sogar bis 170kV, auch als Trockentransformatoren ausgeführt werden, wobei in dem zuletzt genannten Spannungsbereich durchaus auch Nennleistungen von 50MVA und darüber möglich sind. Beim Betrieb eines Transformators entsteht in dessen elektrischen Wicklungen eine Verlustwärme, die an die Umgebung abzuführen ist. Daher ist zu Kühlzwecken eines derartigen Trockentransformators zumeist wenigstens ein längs der axialen Erstreckung der Wicklung geführter Kühlkanal ausgeprägt, um die Verlustwärme vorzugsweise mittels natürlicher Luftkühlung aus dem Wicklungsinneren herauszuführen. Um die Kühlwirkung zu vergrößern, ist insbesondere die üblicherweise radial innen liegende Unterspannungswicklung in mehrere radial beabstandete und elektrisch in Reihe geschaltete hohlzylindrische Wicklungssegmente geteilt, zwischen denen ein ebenfalls hohlzylindrischer Kühlkanal angeordnet ist. Aber auch zwischen Unter- und Oberspannungswicklung ist zumeist ein Kühlkanal vorgesehen. Eine radiale Beabstandung von benachbarten Wicklungsmodulen, durch welche letztendlich ein Kühlkanal ausgebildet ist, erfolgt hierbei über elektrisch isolierende Rechteckprofile oder auch über sogenannte "Dog-Bone"- Leisten.It is well known that power transformers, for example, with a rated power of a few MVA and in a voltage range of, for example, 5kV to 30kV or 110kV, sometimes even up to 170kV, are also designed as dry-type transformers, wherein in the latter voltage range well rated power of 50MVA and are possible about it. During operation of a transformer, a loss of heat arises in its electrical windings, which is dissipated to the environment. Therefore, for cooling purposes of such a dry transformer usually at least one guided along the axial extent of the winding cooling channel is pronounced to lead out the heat loss preferably by means of natural air cooling from the winding interior. In order to increase the cooling effect, in particular the usually radially inwardly located lower voltage winding is divided into a plurality of radially spaced and electrically connected in series hollow cylindrical winding segments, between which a likewise hollow cylindrical cooling channel is arranged. But also between low and high voltage winding a cooling channel is usually provided. A radial spacing of adjacent winding modules, through which ultimately a cooling channel is formed, takes place here via electrically insulating rectangular profiles or via so-called "dog-bone" - bars.

Nachteilig hierbei ist jedoch, dass der Kühlkanal - je nach elektrischen Randbedingungen - teilweise breiter ausgeführt werden muss als vom Kühlquerschnitt notwendig wäre, weil bedarfsweise noch eine elektrische Mindestisolationswirkung zwischen benachbarten Wicklungsmodulen benötigt wird, welche durch entsprechend dickere Isolationsleisten erreicht wird. Hierdurch wird die Transformatorwicklung unnötig groß und die Leistungsdichte eines Transformators entsprechend reduziert.The disadvantage here, however, is that the cooling channel - depending on the electrical boundary conditions - must be made partially wider than would be necessary from the cooling cross section, because, if necessary, still a minimum electrical insulation effect between adjacent winding modules is required, which is achieved by correspondingly thicker insulation strips. As a result, the transformer winding is unnecessarily large and the power density of a transformer is reduced accordingly.

Ausgehend von diesem Stand der Technik ist es Aufgabe der Erfindung, eine Transformatorwicklung mit einem Kühlkanal bereitzustellen, welcher eine verbesserte Isolationsfähigkeit aufweist.Based on this prior art, it is an object of the invention to provide a transformer winding with a cooling channel, which has an improved insulation capability.

Diese Aufgabe wird gelöst durch eine Transformatorwicklung der eingangs genannten Art. Diese ist dadurch gekennzeichnet, dass die Isolationsleisten eine Querschnittsform aufweisen, welche einen Oberflächenverlauf radial zur Wickelachse überwiegend vermeidet.This object is achieved by a transformer winding of the aforementioned type. This is characterized in that the insulating strips have a cross-sectional shape which avoids a surface profile radially to the winding axis predominantly.

Die Isolationsfähigkeit eines Isolators ist einerseits bestimmt durch dessen Material und andererseits durch dessen Außenfläche. Längs derer kann es nämlich zu Oberflächenentladungen kommen, insofern die Spannungsbeanspruchung entsprechend hoch ist, beispielsweise einige 100V/cm und höher. Oberflächenentladungen werden begünstigt, wenn die die elektrischen Feldlinien tangential zur Oberfläche eines Isolators stehen, so dass die Spannungsbeanspruchung längs der Oberfläche am höchsten ist. Innerhalb eines hohlzylindrischen Kühlkanals verlaufen die Feldlinien oder auch Äquipotentiallinien - je nach konkretem Aufbau des Transformators - in etwa konzentrisch um eine Mittelachse des Kühlkanals, welche auch der Wickelachse der Wicklung entspricht. Daher ist bei Verwendung der üblichen Rechteckprofile oder auch der Doppel-T ähnlichen "Dog-Bone" Profilleisten als Isolationsleisten innerhalb eines Kühlkanals die Spannungsbelastung längs deren Außenflächen maximal, weil diese zu einem sehr hohen Anteil radial zur Wickelachse verlaufen. Hintergrund für eine derartige Anordnung ist, dass die mechanischen Kräfte zum Beabstanden der benachbarten Wicklungssegmente ebenfalls radial ausgerichtet sind. Die Querschnittsform der Isolationsleisten entsprechend dem Stand der Technik richtet sich daher nach einer möglichst einfachen mechanisch geeigneten Form. Die Grundidee der Erfindung besteht nunmehr darin, die Isolationsfähigkeit der Isolationsleisten durch eine entsprechend Gestaltung von deren Querschnitt beziehungsweise Außenflächen so zu gestalten, dass deren Spannungsbeanspruchung reduziert wird, wobei andererseits dennoch eine entsprechend hohe mechanische Stabilität gewährleistet ist.The insulating ability of an insulator is determined on the one hand by its material and on the other hand by its outer surface. Longitudinal surface discharges can occur along these lines, insofar as the voltage stress is correspondingly high, for example a few 100 V / cm and higher. Surface discharges are favored when the electric field lines are tangent to the surface of an insulator, so that the stress stress along the surface is highest. Within a hollow-cylindrical cooling channel, the field lines or also equipotential lines-depending on the concrete structure of the transformer-extend approximately concentrically about a central axis of the cooling channel, which also corresponds to the winding axis of the winding. Therefore, when using the usual rectangular profiles or the double-T similar "Dog-Bone" profile strips as insulation strips within a cooling channel, the stress along their outer surfaces maximum, because they extend to a very high proportion radially to the winding axis. The background for such an arrangement is that the mechanical forces for spacing the adjacent winding segments are also radially aligned. The cross-sectional shape of the insulating strips according to the prior art therefore depends on the simplest possible mechanically suitable form. The basic idea of the invention is now to design the insulating capability of the insulating strips by a corresponding design of their cross-section or outer surfaces so that their voltage stress is reduced, on the other hand nevertheless a correspondingly high mechanical stability is ensured.

Entsprechend einer bevorzugten Ausgestaltung der Erfindung sind die Isolationsleisten aus einem faserverstärkten Epoxid- oder Polyesterharz gefertigt. Dies weist einerseits eine hohe Isolationsfähigkeit auf. Andererseits ist es durch die Faserverstärkung möglich, eine hohe Variantenvielfalt an Querschnittsformen zu realisieren, welche sich dennoch durch eine hohe mechanische Stabilität auszeichnen. Die Form einer derartigen Isolationsleiste könnte beispielsweise durch Fräsen oder durch Pultrusionsverfahren hergestellt werden. Eine weitere Voraussetzung für den Einsatz in einer Transformatorwicklung, nämlich eine Temperaturbeständigkeit bis 150°C und darüber hinaus, wie sie bei Trockentransformatoren durchaus gefordert sein kann, ist ebenfalls in vorteilhafter Weise gegeben.According to a preferred embodiment of the invention, the insulating strips are made of a fiber-reinforced epoxy or polyester resin. On the one hand, this has a high insulating ability. On the other hand, it is possible by the fiber reinforcement to realize a high variety of variants of cross-sectional shapes, which are still characterized by a high mechanical stability. The shape of such an insulating strip could be produced for example by milling or by pultrusion. Another prerequisite for use in a transformer winding, namely a temperature resistance up to 150 ° C and beyond, as may well be required in dry-type transformers, is also given in an advantageous manner.

Selbstverständlich ist es auch möglich, weitere Isolationswerkstoffe zu verwenden, beispielsweise unverstärkte thermoplastische Materialien wie Polyamide. Selbstverständlich sind nur die Polyamide geeignet, welche auch über eine entsprechend hohe Stabilität bei mindestens 130°C verfügen. Der besondere Vorteil an Polyamiden liegt in deren besonders einfacher Formbarkeit.Of course, it is also possible to use other insulation materials, such as unreinforced thermoplastic materials such as polyamides. Of course, only the polyamides are suitable, which also have a correspondingly high stability at least 130 ° C. The particular advantage of polyamides lies in their particularly simple formability.

Erfindungsgemäß ist es entsprechend einer weiteren Variante vorgesehen, dass der wenigstens eine Kühlkanal eine radial innere und eine radial äußere Wandung aufweist, welche dann durch die Isolationsleisten beabstandet sind. Die Wandungen können durchaus auch segmentiert sein. Somit ist in vorteilhafter Weise eine vereinfachte Montage von dann schalenähnlichen Kühlkanälen ermöglicht, wodurch zudem ein Schutz der angrenzenden Wicklungsflächen ermöglicht ist.According to the invention, it is provided according to a further variant that the at least one cooling channel has a radially inner and a radially outer wall, which are then spaced by the insulating strips. The walls can also be segmented. Thus, a simplified assembly of then shell-like cooling channels is made possible in an advantageous manner, which also allows protection of the adjacent winding surfaces.

Einer weiteren Erfindungsvariante folgend weisen die Isolationsleisten einen rautenähnlichen oder einen runden Querschnitt auf. Dies sind geometrische Standardformen, welche einfach zu fertigen sind und welche dennoch für eine verbesserte Isolation geeignet sind. Aus Gewichts- und Materialersparnis kann es sich als vorteilhaft erweisen, wenn die Isolationsleisten mit einem inneren Hohlraum ausgeführt sind.According to a further variant of the invention, the insulating strips have a diamond-like or a round cross-section. These are standard geometric shapes which are easy to manufacture and yet which are suitable for improved insulation. From weight and material savings, it may prove advantageous if the insulation strips are designed with an inner cavity.

Gemäß weiteren Ausführungsformen der Isolationsleisten weisen diese einen S-, X-, V-, oder Y- förmigen Querschnitt auf. Hier sind radial verlaufende Außenflächenanteile in vorteilhafter Weise weitgehend vermieden, so dass eine verbesserte Isolationsfähigkeit erreicht ist. Zudem erweisen sich insbesondere die X-, V- und Y- Varianten aufgrund ihres trägerartigen Aufbaus als besonders stabil. Gerade auch in Hinblick auf eine Torsionsbeanspruchung zwischen den benachbarten und beabstandeten Wicklungsmodulen ist hier die X- und V- Form mit ihren schräggestellten Trägerbereichen als besonders bevorzugt hervorzuheben.According to further embodiments of the insulating strips, these have an S, X, V, or Y-shaped cross-section. Here radially extending outer surface portions are advantageously largely avoided, so that an improved insulating ability is achieved. In addition, in particular the X, V and Y variants prove to be particularly stable due to their carrier-like structure. Especially with regard to a Torsionsbeanspruchung between the adjacent and spaced winding modules is here to highlight the X and V shape with their slanted support areas as particularly preferred.

Aber auch Isolationsleisten, welche einen Querschnitt mit sägezahnähnlichen Aussenkanten aufweisen, sind erfindungsgemäß geeignet, um eine verbesserte Isolationsfähigkeit zu erzielen. Dies kann sowohl eine zusätzlich geriffelte Oberflächenform einer bereits erfindungsgemäßen Isolationsleiste als auch beispielsweise eine rippenähnlich ausgeführte Oberflächen- oder Außenflächenform einer Isolationsleiste mit einem herkömmlichen rechteckförmigen Querschnitt bedeuten.But also insulation strips, which have a cross-section with sawtooth-like outer edges, are suitable according to the invention to achieve an improved insulating ability. This can mean both an additionally corrugated surface shape of an insulation strip according to the invention and, for example, a rib-like surface or outer surface shape of an insulation strip having a conventional rectangular cross-section.

Gemäß einer bevorzugten Variante der Erfindung weisen die Isolationsleisten an ihrem radial inneren und/oder radial äußeren Ende eine abgeplattete Form auf, welche idealerweise derart ausgestaltet ist, dass eine in einem Kühlkanal angeordnete Isolationsleiste an den abgeplatteten Bereichen möglichst plan an die abzustützenden Bereiche angrenzt. Dies kann entweder ein Wicklungsmodul selbst oder auch eine separate Wandung eines Kühlkanals sein. In einer besonders bevorzugten Variante ist die abgeplattete Form zylindersphärisch, also angepasst auf die Zylinderform der angrenzenden Wicklungsmodule, ausgestaltet. Hierdurch werden elektrische Entladungen an den Kontaktbereichen in vorteilhafter Weise vermieden. Je nach Ausgestaltungsform der Transformatorwicklung ist der Begriff ,Zylinderform' oder auch ,hohlzylindrisch' nicht als streng geometrisch mit runder Grundfläche zu verstehen, vielmehr ist darunter auch eine einem Rechteck angenäherte Grundform mit runden Kantenbereichen zu verstehen. Dies ermöglicht nämliche eine besonders hohe Ausnutzung eines in einem Transformatorkern zur Verfügung stehenden Volumens durch Transformatorwicklungen.According to a preferred variant of the invention, the insulating strips have at their radially inner and / or radially outer end a flattened shape, which is ideally designed such that an insulating strip arranged in a cooling channel adjoins the flattened areas as flat as possible to the regions to be supported. This can be either a winding module itself or a separate wall of a cooling channel. In a particularly preferred variant, the flattened shape is cylinder-spherical, that is adapted to the cylindrical shape of the adjacent winding modules. As a result, electrical discharges are avoided at the contact areas in an advantageous manner. Depending on the embodiment of the transformer winding, the term "cylindrical shape" or "hollow cylindrical" is not to be understood as strictly geometrical with a round base, but rather includes a rectangle approximated basic shape with round To understand edge areas. Namely, this allows a particularly high utilization of a volume available in a transformer core by transformer windings.

Entsprechend einer weiteren Ausgestaltungsform der Erfindung sind die Wicklungsmodule galvanisch miteinander verbunden. Damit ist ein Kühlkanal mit erfindungsgemäßer Beabstandung sowohl zwischen galvanisch getrennten Ober- und Unterspannungswicklungen als auch zwischen Wicklungsmodulen oder auch Wicklungssegmenten einer geteilten Transformatorwicklung möglich. Dies ist insbesondere bei Trockentransformatoren größerer Leistung sinnvoll, wo im Betrieb entsprechend viel Abwärme aus deren Inneren abzuführen ist, was durch mehrere Kühlkanäle entsprechend vereinfacht ist.According to a further embodiment of the invention, the winding modules are galvanically connected to each other. Thus, a cooling channel with inventive spacing is possible both between galvanically isolated upper and lower-voltage windings and between winding modules or also winding segments of a divided transformer winding. This is particularly useful in dry transformers greater power, where in operation correspondingly much waste heat to dissipate from the interior, which is simplified by several cooling channels accordingly.

Die Vorteile einer erfindungsgemäßen Transformatorwicklung erschließen sich auch für einen Transformator, umfassend wenigstens einen Transformatorkern und eine erfindungsgemäße Transformatorwicklung. Diese ist nämlich kleiner als eine herkömmliche Transformatorwicklung und ermöglicht so in vorteilhafter Weise ein geringeres Bauvolumen eines erfindungsgemäßen Transformators.The advantages of a transformer winding according to the invention are also apparent for a transformer comprising at least one transformer core and a transformer winding according to the invention. This is namely smaller than a conventional transformer winding and thus advantageously allows a smaller construction volume of a transformer according to the invention.

Weitere vorteilhafte Ausgestaltungsmöglichkeiten sind den weiteren abhängigen Ansprüchen zu entnehmen.Further advantageous embodiment possibilities can be found in the further dependent claims.

Anhand der in den Zeichnungen dargestellten Ausführungsbeispiele sollen die Erfindung, weitere Ausführungsformen und weitere Vorteile näher beschrieben werden.Reference to the embodiments illustrated in the drawings, the invention, further embodiments and other advantages will be described in detail.

Es zeigen:

Fig. 1
einen Schnitt durch eine exemplarische erste Transformatorwicklung sowie
Fig. 2
einen Schnitt durch exemplarische zweite Transformatorwicklung.
Show it:
Fig. 1
a section through an exemplary first transformer winding as well
Fig. 2
a section through exemplary second transformer winding.

Fig. 1 zeigt einen Schnitt durch eine exemplarische erste Transformatorwicklung 10. Um eine Wickelachse sind konzentrisch angeordnet ein erstes hohlzylindrisches Wicklungsmodul 12 und ein zweites hohlzylindrisches Wicklungsmodul 14, wobei zwischen diesen ein ebenfalls hohlzylindrischer Kühlkanal 18 ausgebildet ist. Die beiden Wicklungsmodule 12, 14 können beispielsweise einen Bandleiter aufweisen, wobei eine Wickellage genau so breit ist wie der Bandleiter. Dies ist insbesondere bei einer Unterspannungswicklung sinnvoll, da dort aufgrund des im Verhältnis zur Oberspannungswicklung hohen Stromflusses im Betrieb der Wicklung ein hoher Leiterquerschnitt gefordert ist. Es ist aber auch üblich, insbesondere bei oberspannungsseitigen Wicklungen, dass eine Leiterlage eine Vielzahl an Einzelwindungen aufweist, wodurch sich beim Betrieb der Transformatorwicklung auch eine komplexere Potentialverteilung längs des Kühlkanals einstellt. Der Durchmesser einer solchen Transformatorwicklung beträgt beispielsweise 0,5m bis 2,5m, je nach Spannungsebene und Nennleistung. Fig. 1 shows a section through an exemplary first transformer winding 10. Around a winding axis are concentrically arranged a first hollow cylindrical winding module 12 and a second hollow cylindrical winding module 14, wherein between these a likewise hollow cylindrical cooling channel 18 is formed. The two winding modules 12, 14 may, for example, comprise a strip conductor, wherein a winding layer is just as wide as the strip conductor. This is particularly useful in a low-voltage winding, since there is a high conductor cross section is required because of the high current flow in relation to the high-voltage winding during operation of the winding. But it is also common, especially in the case of high-voltage side windings, that a conductor layer has a multiplicity of individual turns, as a result of which a more complex potential distribution along the cooling channel is established during operation of the transformer winding. The diameter of such a transformer winding is for example 0.5m to 2.5m, depending on the voltage level and rated power.

Im Kühlkanal 18 sind exemplarisch mehrere Isolationsleisten 20, 22, 24, 26, 28, 30, 32 mit ihren Querschnittsformen gezeigt, durch welche die beiden Wicklungsmodule 12, 14 in radialer Richtung 34 voneinander beabstandet sind. Die rautenähnliche Isolationsleiste 20 ist ebenso wie die runde Isolationsleiste 24 mit einem inneren Hohlraum 36 beziehungsweise 38 versehen, welcher insbesondere der Gewichtsersparnis dient. Die Isolationsleisten 20, 22, 24, 26, 28, 30, 32 weisen eine Querschnittsform mit einem Oberflächenverlauf radial 34 zur Wickelachse 16 auf, welche einen Oberflächenverlauf radial zur Wickelachse überwiegend vermeidet. Dadurch ist in vorteilhafter Weise die Isolationsfestigkeit des Kühlkanals 18 erhöht. Selbstverständlich sind in einem realen Kühlkanal vorzugsweise nur eine einzige Art von Isolationsleisten 20, 22, 24, 26, 28, 30, 32 vorzusehen, beispielsweise 4 Stück in einem jeweiligen Winkel von 90°. Eine Isolationsleiste 20, 22, 24, 26, 28, 30, 32 muss sich nicht zwangsläufig über die gesamte axiale Länge einer Transformatorwicklung, beispielsweise 1,5m bis 3,5m, erstrecken, sie kann durchaus auch mehrfach geteilt sein.In the cooling channel 18, a plurality of insulating strips 20, 22, 24, 26, 28, 30, 32 are shown by way of example with their cross-sectional shapes, by which the two winding modules 12, 14 are spaced apart in the radial direction 34. The diamond-like insulating strip 20 is just like the round insulating strip 24 provided with an inner cavity 36 and 38, which serves in particular the weight savings. The insulating strips 20, 22, 24, 26, 28, 30, 32 have a cross-sectional shape with a surface course radially 34 to the winding axis 16, which avoids a surface profile radially to the winding axis predominantly. As a result, the insulation resistance of the cooling channel 18 is increased in an advantageous manner. Of course, preferably only a single type of insulating strips 20, 22, 24, 26, 28, 30, 32 are provided in a real cooling channel, for example 4 pieces at a respective angle of 90 °. An insulating strip 20, 22, 24, 26, 28, 30, 32 does not necessarily have to extend over the entire axial length of a transformer winding, for example 1.5 m to 3.5 m, it can also be divided several times.

Fig. 2 zeigt einen Schnitt durch eine exemplarische zweite Transformatorwicklung 40 in einer Detailansicht. Ein erstes Wicklungsmodul 42 und ein zweites Wicklungsmodul 44 sind durch eine Isolationsleiste 48 beabstandet, welche in etwa die Form eines Doppel-Y aufweist. Radial innen und radial außen vorgesehene Kontaktbereiche 56, 58 zu den angrenzenden Wicklungsmodulen 42, 44 sind abgeplattet ausgeführt, wobei sie zudem auf die zylindrische Form der Wicklungsmodule angepasst sind. Auf diese Weise ist das Risiko von elektrischen Entladungen im Bereich der Kontaktflächen weitestgehend reduziert. Die Isolationsleiste 48 weist einen ersten schräg verlaufenden Oberflächenbereich 50, einen zweiten radial 62 verlaufenden Oberflächenbereich 52 und einen dritten schräg verlaufenden Oberflächenbereich 54 auf. Eine Erhöhung der Spannungsfestigkeit gegenüber einem Rechteckprofil wird in den schräg verlaufenden Bereichen 50, 54 erreicht. Dies lässt sich auch anhand des verlängerten Kriechweges 60 längs der Oberfläche verdeutlichen. Fig. 2 shows a section through an exemplary second transformer winding 40 in a detailed view. A first winding module 42 and a second winding module 44 are spaced by an insulating strip 48, which has approximately the shape of a double-Y. Radially inwardly and radially outwardly provided contact areas 56, 58 to the adjacent winding modules 42, 44 are flattened, wherein they are also adapted to the cylindrical shape of the winding modules. On In this way, the risk of electrical discharges in the area of the contact surfaces is largely reduced. The insulating strip 48 has a first inclined surface area 50, a second radially extending surface area 52 and a third inclined surface area 54. An increase in the dielectric strength with respect to a rectangular profile is achieved in the inclined regions 50, 54. This can also be illustrated by the extended creepage path 60 along the surface.

BezugszeichenlisteLIST OF REFERENCE NUMBERS

1010
Schnitt durch eine exemplarische erste TransformatorwicklungSection through an exemplary first transformer winding
1212
erstes Wicklungsmodulfirst winding module
1414
zweites Wicklungsmodulsecond winding module
1616
Wickelachsewinding axis
1818
erster Kühlkanalfirst cooling channel
2020
erste Isolationsleistefirst insulation strip
2222
zweite Isolationsleistesecond insulation strip
2424
dritte Isolationsleistethird insulation strip
2626
vierte Isolationsleistefourth insulation strip
2828
fünfte Isolationsleistefifth insulation strip
3030
sechste Isolationsleistesixth insulation strip
3232
siebte Isolationsleisteseventh insulating strip
3434
erster radialer Vektorfirst radial vector
3636
innerer Hohlraum von erster IsolationsleisteInner cavity of first insulation strip
3838
innerer Hohlraum von dritter IsolationsleisteInner cavity of third insulation strip
4040
Schnitt durch exemplarische zweite TransformatorwicklungSection through exemplary second transformer winding
4242
erstes Wicklungsmodulfirst winding module
4444
zweites Wicklungsmodulsecond winding module
4646
zweiter Kühlkanalsecond cooling channel
4848
siebte Isolationsleisteseventh insulating strip
5050
erster schräg verlaufender Oberflächenbereichfirst inclined surface area
5252
zweiter radial verlaufender Oberflächenbereichsecond radially extending surface area
5454
dritter schräg verlaufender Oberflächenbereichthird oblique surface area
5656
abgeplattete Form an radial innerem Ende der IsolationsleisteFlattened shape at the radially inner end of the insulating strip
5858
abgeplattete Form an radial äußerem Ende der IsolationsleisteFlattened shape at the radially outer end of the insulating strip
6060
Kriechweg längs der OberflächeCreepage along the surface
6262
zweiter radialer Vektorsecond radial vector

Claims (11)

Transformatorwicklung (10, 40) mit wenigstens zwei hohlzylindrisch ineinandergeschachtelten sich um eine gemeinsame Wickelachse (16) erstreckenden Wicklungsmodulen (12, 14, 42, 44), wobei diese innerhalb wenigstens eines dazwischen angeordneten hohlzylindrischen Kühlkanals (18, 46) mittels Isolationsleisten (20, 22, 24, 26, 28, 30, 32, 48) radial (32, 62) voneinander beabstandet sind, dadurch gekennzeichnet,
dass die Isolationsleisten (20, 22, 24, 26, 28, 30, 32, 48) eine Querschnittsform aufweisen, welche einen Oberflächenverlauf (50, 52, 54) radial (32, 62) zur Wickelachse (16) überwiegend vermeidet.Transformator winding (10, 40) with at least two hollow cylindrical nested around a common winding axis (16) extending winding modules (12, 14, 42, 44), said within at least one interposed hollow cylindrical cooling channel (18, 46) by means of insulating strips (20, 22, 24, 26, 28, 30, 32, 48) are radially (32, 62) spaced from each other, characterized
the insulation strips (20, 22, 24, 26, 28, 30, 32, 48) have a cross-sectional shape, which avoids a surface profile (50, 52, 54) radially (32, 62) to the winding axis (16) mainly. Transformatorwicklung nach Anspruch 1, dadurch gekennzeichnet, dass die Isolationsleisten (20, 22, 24, 26, 28, 30, 32, 48) aus einem faserverstärkten Epoxid- oder Polyesterharz gefertigt sind.Transformer winding according to claim 1, characterized in that the insulating strips (20, 22, 24, 26, 28, 30, 32, 48) are made of a fiber-reinforced epoxy or polyester resin. Transformatorwicklung nach Anspruch 1, dadurch gekennzeichnet, dass die Isolationsleisten (20, 22, 24, 26, 28, 30, 32, 48) aus einem unverstärkten thermoplastischen Material gefertigt sind.Transformer winding according to claim 1, characterized in that the insulating strips (20, 22, 24, 26, 28, 30, 32, 48) are made of an unreinforced thermoplastic material. Transformatorwicklung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass der wenigstens eine Kühlkanal (18, 46) eine radial innere und eine radial äußere Wandung aufweist.Transformer winding according to one of the preceding claims, characterized in that the at least one cooling channel (18, 46) has a radially inner and a radially outer wall. Transformatorwicklung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass die Isolationsleisten (20, 22, 24, 26, 28, 30, 32, 48) einen rautenähnlichen (20) oder einen runden (24, 26) Querschnitt aufweisen.Transformer winding according to one of the preceding claims, characterized in that the insulating strips (20, 22, 24, 26, 28, 30, 32, 48) have a diamond-like (20) or a round (24, 26) cross-section. Transformatorwicklung nach Anspruch 5, dadurch gekennzeichnet, dass die Isolationsleisten (20, 22, 24, 26, 28, 30, 32, 48) mit einem innerem Hohlraum (36, 38) ausgeführt sind.Transformer winding according to claim 5, characterized in that the insulating strips (20, 22, 24, 26, 28, 30, 32, 48) with an inner cavity (36, 38) are executed. Transformatorwicklung nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass die lsolationsleisten (20, 22, 24, 26, 28, 30, 32, 48) einen S (22) -, X (30) -, V (28) -, oder Y (34) - förmigen Querschnitt aufweisen.Transformer winding according to one of Claims 1 to 4, characterized in that the insulating strips (20, 22, 24, 26, 28, 30, 32, 48) have an S (22) -, X (30) -, V (28) - , or Y (34) -shaped cross-section. Transformatorwicklung nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass die Isolationsleisten (20, 22, 24, 26, 28, 30, 32, 48) einen Querschnitt mit sägezahnähnlichen Aussenkanten aufweisen.Transformer winding according to one of claims 1 to 4, characterized in that the insulating strips (20, 22, 24, 26, 28, 30, 32, 48) have a cross section with sawtooth-like outer edges. Transformatorwicklung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass die lsolationsleisten (20, 22, 24, 26, 28, 30, 32, 48) an ihrem radial inneren (56) und/oder radial äußeren (58) Ende eine abgeplattete Form aufweisen.Transformer winding according to one of the preceding claims, characterized in that the insulating strips (20, 22, 24, 26, 28, 30, 32, 48) at their radially inner (56) and / or radially outer (58) end have a flattened shape , Transformatorwicklung nach einem der vorherigen Ansprüche, dadurch gekennzeichnet, dass die Wicklungsmodule (12, 14, 42, 44) galvanisch miteinander verbunden sind.Transformer winding according to one of the preceding claims, characterized in that the winding modules (12, 14, 42, 44) are galvanically connected to each other. Transformator, umfassend wenigstens einen Transformatorkern und eine Transformatorwicklung (10, 40) nach einem der Ansprüche 1 bis 9.A transformer comprising at least one transformer core and a transformer winding (10, 40) according to any one of claims 1 to 9.
EP11000018A 2011-01-04 2011-01-04 Transformer coil with cooling channel Withdrawn EP2472533A1 (en)

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EP11000018A EP2472533A1 (en) 2011-01-04 2011-01-04 Transformer coil with cooling channel
PCT/EP2011/005969 WO2012092941A1 (en) 2011-01-04 2011-11-29 Transformer winding with cooling channel
CN201180064188.0A CN103270560B (en) 2011-01-04 2011-11-29 Transformer winding and transformer
EP11790876.4A EP2661756A1 (en) 2011-01-04 2011-11-29 Transformer winding with cooling channel
US13/934,750 US9208939B2 (en) 2011-01-04 2013-07-03 Transformer winding with cooling channel

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US9208939B2 (en) 2015-12-08
EP2661756A1 (en) 2013-11-13

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