EP0167641B1 - Method of constructing a vacuum tight and oil-tight seal for a transformer structure, and seal made in this way - Google Patents

Method of constructing a vacuum tight and oil-tight seal for a transformer structure, and seal made in this way Download PDF

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Publication number
EP0167641B1
EP0167641B1 EP84107720A EP84107720A EP0167641B1 EP 0167641 B1 EP0167641 B1 EP 0167641B1 EP 84107720 A EP84107720 A EP 84107720A EP 84107720 A EP84107720 A EP 84107720A EP 0167641 B1 EP0167641 B1 EP 0167641B1
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EP
European Patent Office
Prior art keywords
insulating material
layer
impregnated
oil
transformer board
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.)
Expired
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EP84107720A
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German (de)
French (fr)
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EP0167641A1 (en
Inventor
Hermann Hummel
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H Weidmann AG
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H Weidmann AG
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Priority to AT84107720T priority Critical patent/ATE27075T1/en
Priority to DE8484107720T priority patent/DE3463585D1/en
Priority to EP84107720A priority patent/EP0167641B1/en
Priority to FR8510183A priority patent/FR2567313B1/en
Publication of EP0167641A1 publication Critical patent/EP0167641A1/en
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Publication of EP0167641B1 publication Critical patent/EP0167641B1/en
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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
    • H01F27/02—Casings
    • H01F27/04—Leading of conductors or axles through casings, e.g. for tap-changing arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B17/00—Insulators or insulating bodies characterised by their form
    • H01B17/26—Lead-in insulators; Lead-through insulators
    • H01B17/28—Capacitor type

Definitions

  • Terminals in transformer construction are used to create a conductor connection and to shield this connection in the field. They generally consist of a shield electrode and an insulating holding element corresponding to the end form.
  • the insulating holding element carrying the shielding electrode and corresponding to the termination form consists of a transformer board.
  • the manufacture, the electrical and mechanical properties as well as the possible applications of Transformerboard are described in detail in Scientia electrica, volume 25, number 3, pages 1 to 120, year 1979.
  • a method according to the preamble of claim 1 can also be gathered from this literature reference.
  • the prior art also includes terminations made of synthetic resin, which, however, can only be produced in one standardized termination type per voltage series for manufacturing reasons, while variations in the dimensions and in the installation position cannot be made due to cost reasons. Furthermore, since it is also difficult to completely avoid gas bubble formation in vacuum casting technology, synthetic resin terminations for very high voltages pose great problems for electrical reasons. Another disadvantage is the limited electrical surface resilience of synthetic resins in oil due to the high dielectric constant.
  • the invention has for its object to develop a cost-effective method that allows the production of a vacuum-tight, oil-tight termination for transformer construction and that also makes it possible, in particular, to produce closures for a wide variety of dimensions and installation positions without great manufacturing outlay.
  • the transformer board-impregnated insulating material layers bring about a vacuum-tight and oil-tight separation of the spaces located on different sides of the seal.
  • the additional layers of insulating material provided on the exposed outer sides of the impregnated layer, together with the impregnated layer, ensure the required mechanical and electrical strength.
  • the closures produced by the method according to the invention maintain a pressure difference of at least 1.5 bar from the inside to the outside and from the outside to the inside. This has the advantage that now only the feedthrough or cable connection space for the oil filling has to be evacuated, which is possible with a relatively small pump set.
  • the closures form a very good barrier against oil and gas exchange between the oil-filled rooms to be separated.
  • the terminations produced by the method according to the invention can also be impregnated with oil and can therefore also be used at very high voltages below the permissible partial discharge level.
  • the resin-impregnated layers of insulating material from the transformer board can also be impregnated with oil, since only the cavities between the fibers of the transformer board are closed by the resin and thereby prevent gas and oil penetration, while the fibers themselves are not impregnated with resin, but instead soak up with oil.
  • the low dielectric constant of the resin used for the impregnation results in similar properties of the mixed dielectric transformer board / resin as transformer board / oil.
  • terminations up to very high voltages can be produced, and optimal solutions can be offered for many dimensions and installation positions without great additional technical outlay.
  • FIG. 1 illustrates the use of a termination 1 produced by the method according to the invention in a transformer 2 with winding 3.
  • the termination the details of which are explained in detail with reference to FIG. 1, is used to connect the winding end 4 to a bushing 5
  • Bushing 5 is carried by a bushing dome 6 which encloses bushing space 7.
  • a further insulating material layer 14 consisting of a transformer board which, however, is not impregnated.
  • a non-impregnated insulating material layer 15 made of transformer board is also provided on the exposed outside of the insulating material layer 11, likewise enveloping the shield electrode 9.
  • a funnel-shaped insulating material layer 16 is provided on the exposed inside of the impregnated insulating material layer 12.
  • a flange ring 17 or 18 is provided in the flange area 13 on the inside and outside.
  • the wall thickness of the funnel-shaped insulating material layer 16 is expediently between 4 and 8 mm.
  • the flange rings 17, 18 can have a thickness between 3 and 8 mm (the latter dimensions apply to a closure with an outer diameter of the flange of 420 mm and a total length of the closure of approximately 400 mm).
  • the part is flooded in a vacuum impregnation kettle (at a temperature below 20 ° C) with a special, low to medium viscosity, oil-resistant resin that cures at low temperature and impregnated for at least 12 hours at normal pressure.
  • a vacuum impregnation kettle at a temperature below 20 ° C
  • a special, low to medium viscosity, oil-resistant resin that cures at low temperature and impregnated for at least 12 hours at normal pressure.
  • the curing takes place in a convection oven at 130 ° C.
  • the impregnated layer consisting of the insulating layers 11 and 12
  • insulating layers 14 and 15 is again formed with a transformer board (insulating layers 14 and 15) to achieve greater mechanical and electrical strength.
  • the funnel-shaped insulating layer 16 is also attached, which is additionally supported by the flange.
  • the flange section is then impregnated with resin in the manner explained above, in order to prevent oil and gas penetration in this area as well.
  • Low- to medium-viscosity resins such as those used for high-voltage insulating parts, for example bushings or switch parts, are suitable as the resin for impregnating the transformer board.
  • Suitable for example, is the cast resin sold by Ciba-Geigy under the type designation CY225 with hardener HY225 (without fillers).
  • CY225 is a modified, solvent-free, medium-viscosity epoxy resin based on bisphenol A at room temperature.
  • terminations can be produced in a wide variety of forms in the sandwich construction explained.
  • 6 to 6 show some variants, for the sake of simplicity only the shield electrode 9a to 9d and the holding element 10a to 10d are shown, without illustrating the individual structure of the holding element from the different layers.
  • the exemplary embodiments according to FIGS. 6 to 6 correspond to the exemplary embodiment according to FIG. 2 in terms of structure and manufacture.
  • zone II there are two resin-impregnated layers of insulating material 11 and 12 made of transformer board one above the other; this is followed by a non-impregnated layer of insulating material 12 made of transformer board.
  • zone 111 there is a sandwich construction in which a resin-impregnated insulating material layer 12 is arranged between an inner insulating material layer 16 and an outer, likewise non-impregnated insulating material layer 14 made of transformer board.
  • the V-shape of the termination shown in FIG. 3 is particularly suitable for voltages up to 110 kV.
  • the short V-shape shown in Fig. 4 is suitable for voltages up to 220 kV.
  • the long U-shape (left, fully extended) or the long V-shape (right, fully extended) shown in FIG. 5 in two variants is suitable for voltages up to 750 kV.
  • the W-shape shown in FIG. 6 can be used up to the highest operating voltages (over 1,000 kV).

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Insulating Of Coils (AREA)
  • Pressure Vessels And Lids Thereof (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)

Abstract

1. Method of producing a vacuum-sealed and oil-tight closure for transformer construction, in which a shield electrode (9) is provided with an insulating retaining element (10) which is produced using transformer board, characterised by the following steps : a) at least in the main part of its length the shield electrode (9) is shaped around with a first layer of insulating material (11) made from transformer board ; b) then a second layer of insulating material (12) which corresponds to the desired shape of the retaining element (10) and is made from transformer board is applied so that it partially overlaps the first layer of insulating material (11) ; c) after vacuum drying the two layers of insulating material (11, 12) made from transformer board are impregnated in a vacuum with an oil-resistant resin of low or medium viscosity which hardens at low temperature ; d) after the resin has hardened, the film formed by the two layers of impregnated insulating material (11, 12) is provided on each of the free outer faces with at least one further layer of insulating material (14, 15, 16).

Description

Abschlüsse im Transformatorbau dienen zur Herstellung einer Leiterverbindung und zur feldgerechten Abschirmung dieser Verbindung. Sie bestehen im allgemeinen aus einer Schirmelektrode und einem der Abschlußform entsprechenden, isolierenden Halteelement.Terminals in transformer construction are used to create a conductor connection and to shield this connection in the field. They generally consist of a shield electrode and an insulating holding element corresponding to the end form.

Um Großtransformatoren transportieren zu können, ist es erforderlich, die Durchführungen oder Hochspannungskabelanschlüsse (die mit den erwähnten Abschlüssen verbunden sind) zu demontieren. Oft müssen ferner Durchführungen oder Kabelanschlüsse bei Änderungen oder Defekten ausgewechselt werden. Um nun eine derartige Demontage oder Auswechslung ohne Ablassen des Öles im Kesselraum vornehmen zu können, wurden sog. tropfdichte Abschlüsse entwickelt. Sie trennen das Öl zwischen Transformator und Durchführung (bzw. Kabelanschluß), so daß bei Demontage- und Auswechslungsarbeiten an den Durchführungen und Kabelanschlüssen das Öl im Kessel verbleiben kann.In order to be able to transport large transformers, it is necessary to dismantle the bushings or high-voltage cable connections (which are connected to the terminations mentioned). In addition, bushings or cable connections often have to be replaced in the event of changes or defects. In order to be able to carry out such a disassembly or replacement without draining the oil in the boiler room, so-called drip-tight seals have been developed. They separate the oil between the transformer and bushing (or cable connection) so that the oil can remain in the boiler during dismantling and replacement work on the bushings and cable connections.

Bei den bisher bekannten tropfdichten Abschlüssen besteht das die Schirmelektrode tragende, der Abschlußform entsprechende isolierende Halteelement aus Transformerboard. Die Herstellung, die elektrischen und mechanischen Eigenschaften sowie die Anwendungsmöglichkeiten von Transformerboard sind in Scientia electrica, Band 25, Heft 3, Seiten 1 bis 120, Jahrgang 1979 eingehend beschrieben. Aus dieser Literaturstelle läßt sich auch ein Verfahren entsprechend dem Oberbegriff des Anspruches 1 entnehmen.In the drip-tight terminations known to date, the insulating holding element carrying the shielding electrode and corresponding to the termination form consists of a transformer board. The manufacture, the electrical and mechanical properties as well as the possible applications of Transformerboard are described in detail in Scientia electrica, volume 25, number 3, pages 1 to 120, year 1979. A method according to the preamble of claim 1 can also be gathered from this literature reference.

Beim Anlegen von Vakuum im Durchführungsraum tritt bei tropfdichten Abschlüssen ein kleiner Öldurchfluß durch die Poren des Transformerboards von der Kesselseite zur Außenseite auf. Ebenso wirkt sich die Gasdurchlässigkeit von Transformerboard insofern ungünstig aus, als sich im Durchführungsraum des tropfdichten Abschlusses bei der Betriebstemperatur des Transformators entsprechend hohe Gaskonzentrationen bilden können, die die Betriebssicherheit gefährden können. Außerdem halten sie der mechanischen Beanspruchung nicht stand.When applying a vacuum in the lead-through space, there is a small oil flow through the pores of the transformer board from the boiler side to the outside with drip-tight seals. Likewise, the gas permeability of Transformerboard has an unfavorable effect in that high gas concentrations can form in the lead-through area of the drip-tight seal at the operating temperature of the transformer, which can endanger operational safety. In addition, they do not withstand the mechanical stress.

Zum Stand der Technik gehören weiterhin Abschlüsse aus Kunstharz, die jedoch aus fertigungstechnischen Gründen nur in einem genormten Abschlußtyp pro Spannungsreihe hergestellt werden können, während Variationen in den Abmessungen und in der Einbaulage aus Kostengründen nicht gefertigt werden können. Da es ferner auch bei der Vakuumgießtechnik schwierig ist, eine Gasblasenbildung völlig zu vermeiden, werfen Kunstharzabschlüsse für sehr hohe Spannungen aus elektrischen Gründen große Probleme auf. Nachteilig ist ferner die durch die hohe Dielektrizitätskonstante bedingte begrenzte elektrische Oberflächenbelastbarkeit von Kunstharzen in Öl.The prior art also includes terminations made of synthetic resin, which, however, can only be produced in one standardized termination type per voltage series for manufacturing reasons, while variations in the dimensions and in the installation position cannot be made due to cost reasons. Furthermore, since it is also difficult to completely avoid gas bubble formation in vacuum casting technology, synthetic resin terminations for very high voltages pose great problems for electrical reasons. Another disadvantage is the limited electrical surface resilience of synthetic resins in oil due to the high dielectric constant.

Der Erfindung liegt die Aufgabe zugrunde, ein kostengünstiges Verfahren zu entwickeln, das die Herstellung eines vakuumfesten, öldichten Abschlusses für den Transformatorbau gestattet und das es insbesondere auch ermöglicht, ohne großen herstellungstechnischen Aufwand Abschlüsse für die unterschiedlichsten Abmessungen und Einbaulagen zu fertigen.The invention has for its object to develop a cost-effective method that allows the production of a vacuum-tight, oil-tight termination for transformer construction and that also makes it possible, in particular, to produce closures for a wide variety of dimensions and installation positions without great manufacturing outlay.

Diese Aufgabe wird erfindungsgemäß durch die kennzeichnenden Merkmale des Anspruches 1 gelöst.This object is achieved by the characterizing features of claim 1.

Zweckmäßige Ausgestaltungen der Erfindung sind Gegenstand der Unteransprüche.Appropriate embodiments of the invention are the subject of the dependent claims.

Bei dem nach dem erfindungsgemäßen Verfahren hergestellten vakuumfesten, öldichten Abschluß bewirken die mit Harz imprägnierten Isolierstofflagen Transformerboard eine vakuumfeste und öldichte Trennung der auf unterschiedlichen Seiten des Abschlusses befindlichen Räume. Die auf den freiliegenden Außenseiten der imprägnierten Schicht vorgesehenen weiteren Isolierstofflagen gewährleisten zusammen mit der imprägnierten Schicht die erforderliche mechanische und elektrische Festigkeit.In the case of the vacuum-tight, oil-tight seal produced by the method according to the invention, the transformer board-impregnated insulating material layers bring about a vacuum-tight and oil-tight separation of the spaces located on different sides of the seal. The additional layers of insulating material provided on the exposed outer sides of the impregnated layer, together with the impregnated layer, ensure the required mechanical and electrical strength.

Die nach dem erfindungsgemäßen Verfahren hergestellten Abschlüsse halten eine Druckdifferenz von mindestens 1,5 bar von innen nach außen sowie von außen nach innen. Dadurch ergibt sich der Vorteil, daß nunmehr nur noch der Durchführungs- oder Kabelanschlußraum für die Ölfüllung evakuiert werden muß, was mit einem relativ kleinen Pumpsatz möglich ist.The closures produced by the method according to the invention maintain a pressure difference of at least 1.5 bar from the inside to the outside and from the outside to the inside. This has the advantage that now only the feedthrough or cable connection space for the oil filling has to be evacuated, which is possible with a relatively small pump set.

Die Abschlüsse bilden dabei eine sehr gute Barriere gegen einen ÖI- und Gasaustausch zwischen den zu trennenden, ölgefüllten Räumen.The closures form a very good barrier against oil and gas exchange between the oil-filled rooms to be separated.

Die nach dem erfindungsgemäßen Verfahren hergestellten Abschlüsse sind ferner mit Öl imprägnierbar und können daher auch bei sehr hohen Spannungen unter dem zulässigen Teilentladungspegel eingesetzt werden. Auch die mit Harz imprägnierten Isolierstofflagen aus Transformerboard lassen sich dabei mit Öl imprägnieren, da nur die Hohlräume zwischen den Fasern des Transformerboards durch das Harz verschlossen werden und dadurch den Gas- und Öldurchtritt verhindern, während die Fasern selbst nicht mit Harz imprägniert werden, sondern sich mit Öl vollsaugen.The terminations produced by the method according to the invention can also be impregnated with oil and can therefore also be used at very high voltages below the permissible partial discharge level. The resin-impregnated layers of insulating material from the transformer board can also be impregnated with oil, since only the cavities between the fibers of the transformer board are closed by the resin and thereby prevent gas and oil penetration, while the fibers themselves are not impregnated with resin, but instead soak up with oil.

Die niedrige Dielektrizitätskonstante des für die Imprägnierung verwendeten Harzes ergibt ähnliche Eigenschaften des Mischdielektrikums Transformerboard/Harz wie Transformerboard/Öl.The low dielectric constant of the resin used for the impregnation results in similar properties of the mixed dielectric transformer board / resin as transformer board / oil.

Nach dem erfindungsgemäßen Verfahren lassen sich Abschlüsse bis zu sehr hohen Spannungen herstellen, wobei ohne großen technischen Mehraufwand für viele Abmessungen und Einbaulagen optimale Lösungen angeboten werden können.With the method according to the invention, terminations up to very high voltages can be produced, and optimal solutions can be offered for many dimensions and installation positions without great additional technical outlay.

Die Erfindung wird im folgenden anhand einiger Ausführungsbeispiele näher erläutert. Es zeigen

  • Figur 1 eine Schemadarstellung, die den Einbau eines nach dem erfindungsgemäßen Verfahren hergestellten Abschlusses veranschaulicht.
  • Figur 2 einen Schnitt durch einen erfindungsgemäßen Abschluß,
  • Figuren 3-6 Schemadarstellungen einiger unterschiedlicher Abschlüsse.
The invention is explained in more detail below with the aid of a few exemplary embodiments. Show it
  • Figure 1 is a schematic diagram illustrating the installation of a closure manufactured by the method according to the invention.
  • FIG. 2 shows a section through a closure according to the invention,
  • Figures 3-6 Schematic representations of some different degrees.

Fig.1 veranschaulicht die Verwendung eines nach dem erfindungsgemäßen Verfahren hergestellten Abschlusses 1 bei einem Transformator 2 mit Wicklung 3. Der Abschluß 1, dessen Einzelheiten anhand von Fig. noch im einzelnen erläutert werden, dient zur Verbindung des Wicklungsendes 4 mit einer Durchführung 5. Die Durchführung 5 wird von einem Durchführungsdom 6 getragen, der den Durchführungsraum 7 umschließt.1 illustrates the use of a termination 1 produced by the method according to the invention in a transformer 2 with winding 3. The termination 1, the details of which are explained in detail with reference to FIG. 1, is used to connect the winding end 4 to a bushing 5 Bushing 5 is carried by a bushing dome 6 which encloses bushing space 7.

Im Kessel 8 herrscht im Betrieb ein Ölsäulendruck von ca. 0,3 bar und im Durchführungsraum 7 ein Ölsäulendruck von maximal 0.2 bar. Wird der Durchführungsraum 7 evakuiert oder wird im Kessel 8 ein Vakuum hergestellt, so erfährt der Abschluß 1 eine zusätzliche Druckbelastung. Unter dieser Belastung soll der Abschluß 1 vakuumfest und öldicht sein.An oil column pressure of approx. 0.3 bar prevails in the boiler 8 and an oil column pressure of a maximum of 0.2 bar in the lead-through space 7. If the lead-through space 7 is evacuated or a vacuum is created in the boiler 8, the closure 1 is subjected to an additional pressure load. Under this load, the closure 1 should be vacuum-tight and oil-tight.

Der in Fig. 2 in seinen Einzelheiten veranschaulichte Abschluß 1 besteht im wesentlichen aus einer Schirmelektrode 9 aus Kupfer und einem isolierenden Halteelement 10, das wie folgt aufgebaut ist :

  • Eine erste Isolierstofflage 11 aus Transformerboard umgibt die Schirmelektrode 9 und erstreckt sich im wesentlichen über die ganze Länge dieser Schirmelektrode. Diese erste Isolierstofflage 11 aus Transformerboard ist harzimprägniert.
The termination 1 illustrated in detail in FIG. 2 essentially consists of a shield electrode 9 made of copper and an insulating holding element 10, which is constructed as follows:
  • A first insulating layer 11 of transformer board surrounds the shield electrode 9 and extends essentially over the entire length of this shield electrode. This first insulating layer 11 made of transformer board is resin-impregnated.

Eine zweite Isolierstofflage 12 aus Transformerboard, die gleichfalls harzimprägniert ist, überdeckt teilweise die erste Isolierstofflage 11 und erstreckt sich im übrigen trichterförmig nach außen bis zu einem Flanschbereich 13. Auf der freiliegenden Außenseite der imprägnierten Isolierstofflage 12 befindet sich eine weitere, aus Transformerboard bestehende Isolierstofflage 14 die jedoch nicht imprägniert ist. Eine nicht imprägnierte Isolierstofflage 15 aus Transformerboard ist ferner auf der freiliegenden Außenseite der Isolierstofflage 11, gleichfalls die Schirmelektrode 9 umhüllend, vorgesehen.A second insulating material layer 12 made of transformer board, which is also resin-impregnated, partially covers the first insulating material layer 11 and also extends outward in a funnel shape to a flange region 13. On the exposed outside of the impregnated insulating material layer 12 there is a further insulating material layer 14 consisting of a transformer board which, however, is not impregnated. A non-impregnated insulating material layer 15 made of transformer board is also provided on the exposed outside of the insulating material layer 11, likewise enveloping the shield electrode 9.

Auf der freiliegenden Innenseite der imprägnierten Isolierstofflage 12 ist eine trichterförmig ausgebildete Isolierstofflage 16 vorgesehen. Schließlich ist noch im Flanschbereich 13 auf der Innen- und Außenseite je ein Flanschring 17 bzw. 18 vorgesehen.A funnel-shaped insulating material layer 16 is provided on the exposed inside of the impregnated insulating material layer 12. Finally, a flange ring 17 or 18 is provided in the flange area 13 on the inside and outside.

Die mit Harz imprägnierten Isolierstofflagen 11 und 12 besitzen ebenso wie die nicht imprägnierten Isolierstofflagen 14 und 15 eine Wandstärke von 3 bis 5 mm. Die Wandstärke der trichterförmigen Isolierstofflage 16 liegt zweckmäßig zwischen 4 und 8 mm. Die Flanschringe 17, 18 können eine Stärke zwischen 3 und 8 mm besitzen (letztgenannte Abmessungen gelten für einen Abschluß mit einem Außendurchmesser des Flansches von 420 mm und einer Gesamtlänge des Abschlusses von ca. 400 mm).The resin-impregnated insulating layers 11 and 12, like the non-impregnated insulating layers 14 and 15, have a wall thickness of 3 to 5 mm. The wall thickness of the funnel-shaped insulating material layer 16 is expediently between 4 and 8 mm. The flange rings 17, 18 can have a thickness between 3 and 8 mm (the latter dimensions apply to a closure with an outer diameter of the flange of 420 mm and a total length of the closure of approximately 400 mm).

Die Herstellung des in Fig. 2 dargestellten Abschlusses 1 erfolgt nach dem erfindungsgemäßen Verfahren wie folgt :

  • Nach der Herstellung der Kupfer- Schirmelektrode 9 und deren Umformung mit einer ersten Isolierstofflage 11 aus Transformerboard wird eine zweite Isolierstofflage 12 aus Transformerboard in einer Form hergestellt, die entsprechend der ermittelten elektrischen Feldverteilung ausgebildet ist. Sodann erfolgt im Umluftofen eine Trocknung, bis die Formstabilität erreicht ist. Dann wird das Teil von der Form befreit.
The closure 1 shown in FIG. 2 is produced as follows using the method according to the invention:
  • After the production of the copper shielding electrode 9 and its reshaping with a first insulating layer 11 from a transformer board, a second insulating layer 12 is made from a transformer board in a form which is designed in accordance with the determined electrical field distribution. Then it is dried in a forced air oven until the shape is stable. Then the part is released from the mold.

Nun erfolgt eine Trocknung im Vakuumschrank bei 105°C. bis die Endfeuchte < 0,1 % beträgt und ein Endvakuum von 0,1 mbar erreicht ist.Now it is dried in a vacuum cabinet at 105 ° C. until the final moisture is <0.1% and a final vacuum of 0.1 mbar is reached.

Nach dieser Trocknung wird das Teil in einem Imprägnierkessel unter Vakuum kalt (bei einer Temperatur unter 20 °C) mit einem speziellen, nieder- bis mittelviskosen, bei niedriger Temperatur aushärtenden ölbeständigen Harz geflutet und mindestens 12 Stunden bei Normaldruck weiter imprägniert. Nach dem Ablassen des Harzes und dem Reinigen des Abschlusses von überschüssigem Harz erfolgt im Umluftofen bei 130 °C die Aushärtung. Sodann wird die imprägnierte Schicht (bestehend aus den Isolierstofflagen 11 und 12) zur Erreichung größerer mechanischer und elektrischer Festigkeit nochmals mit Transformerboard (Isolierstofflagen 14 und 15) umformt.After this drying, the part is flooded in a vacuum impregnation kettle (at a temperature below 20 ° C) with a special, low to medium viscosity, oil-resistant resin that cures at low temperature and impregnated for at least 12 hours at normal pressure. After the resin has been drained and the excess resin has been cleaned, the curing takes place in a convection oven at 130 ° C. Then the impregnated layer (consisting of the insulating layers 11 and 12) is again formed with a transformer board (insulating layers 14 and 15) to achieve greater mechanical and electrical strength.

Vor dem Aufkleben der Flanschringe 17, 18 wird noch die trichterförmige Isolierstofflage 16 angebracht, die durch den Flansch zusätzlich abgestützt wird. Anschließend wird die Flanschpartie in der oben erläuterten Weise mit Harz imprägniert, um auch in diesem Bereich einen ÖI-und Gasdurchtritt zu verhindern.Before the flange rings 17, 18 are glued on, the funnel-shaped insulating layer 16 is also attached, which is additionally supported by the flange. The flange section is then impregnated with resin in the manner explained above, in order to prevent oil and gas penetration in this area as well.

Als Harz zum Imprägnieren des Transformerboard kommen nieder- bis mittelviskose Harze in Betracht, wie sie für Hochspannungsisolierteile, beispielsweise Durchführungen oder Schalterteile, verwendet werden. Geeignet ist beispielsweise das von der Fa. Ciba-Geigy unter der Typenbezeichnung CY225 vertriebene Gießharz mit Härter HY225 (ohne Füllstoffe). CY225 ist ein modifiziertes, lösungsmittelfreies, bei Raumtemperatur mittelviskoses Epoxidharz auf Basis von Bisphenol A.Low- to medium-viscosity resins, such as those used for high-voltage insulating parts, for example bushings or switch parts, are suitable as the resin for impregnating the transformer board. Suitable, for example, is the cast resin sold by Ciba-Geigy under the type designation CY225 with hardener HY225 (without fillers). CY225 is a modified, solvent-free, medium-viscosity epoxy resin based on bisphenol A at room temperature.

Nach dem erfindungsgemäßen Verfahren lassen sich Abschlüsse in der erläuterten Sandwich-Konstruktion in den unterschiedlichsten Formen herstellen. Die Fig. bis 6 zeigen einige Varianten, wobei der Einfachheit halber jeweils nur die Schirmelektrode 9a bis 9d und das Halteelement 10a bis 10d dargestellt ist, ohne den Einzelaufbau des Halteelementes aus den verschiedenen Lagen zu veranschaulichen. Die Ausführungsbeispiele gemäß den Fig. bis 6 entsprechen insoweit bezüglich Aufbau und Herstellung dem Ausführungsbeispiel gemäß Fig. 2.According to the method according to the invention, terminations can be produced in a wide variety of forms in the sandwich construction explained. 6 to 6 show some variants, for the sake of simplicity only the shield electrode 9a to 9d and the holding element 10a to 10d are shown, without illustrating the individual structure of the holding element from the different layers. In this respect, the exemplary embodiments according to FIGS. 6 to 6 correspond to the exemplary embodiment according to FIG. 2 in terms of structure and manufacture.

Ebenso wie bei der Variante gemäß Fig. 2 sind auch bei den Ausführungsbeispielen der Fig. 3 bis 6 drei unterschiedliche Zonen des Isolationsaufbaues vorhanden :

  • In der Zone I folgt auf eine harzimprägnierte Isolierstofflage 11 aus Transformerboard eine nichtimprägnierte Isolierstofflage 15 aus Transformerboard.
As in the variant according to FIG. 2, three different zones of the insulation structure are also present in the exemplary embodiments in FIGS. 3 to 6:
  • In zone I, a resin-impregnated insulating layer 11 made of transformer board is followed by a non-impregnated insulating layer 15 made of trans formerboard.

In der Zone II liegen zwei harzimprägnierte Isolierstofflagen 11 und 12 aus Transformerboard übereinander; hierauf folgt eine nichtimprägnierte Isolierstofflage 12 aus Transformerboard.In zone II there are two resin-impregnated layers of insulating material 11 and 12 made of transformer board one above the other; this is followed by a non-impregnated layer of insulating material 12 made of transformer board.

In der Zone 111 ist schließlich eine Sandwichkonstruktion vorhanden, in der eine harzimprägnierte Isolierstofflage 12 zwischen einer inneren Isolierstofflage 16 und einer äußeren, gleichfalls nicht imprägnierten Isolierstofflage 14 aus Transformerboard angeordnet ist.Finally, in zone 111 there is a sandwich construction in which a resin-impregnated insulating material layer 12 is arranged between an inner insulating material layer 16 and an outer, likewise non-impregnated insulating material layer 14 made of transformer board.

Die in Fig. 3 dargestellte V-Form des Abschlusses ist vor allem für Spannungen bis 110 kV geeignet. Die in Fig. 4 dargestellte kurze V-Form kommt für Spannungen bis 220 kV in Betracht.The V-shape of the termination shown in FIG. 3 is particularly suitable for voltages up to 110 kV. The short V-shape shown in Fig. 4 is suitable for voltages up to 220 kV.

Die in Fig. 5 in zwei Varianten dargestellte lange U-Form (links, voll ausgezogen) bzw. die lange V-Form (rechts, voll ausgezogen) ist für Spannungen bis 750 kV geeignet. Schließlich kann in Fig. 6 dargestellte W-Form bis zu höchsten Betriebsspannungen (über 1 000 kV) eingesetzt werden.The long U-shape (left, fully extended) or the long V-shape (right, fully extended) shown in FIG. 5 in two variants is suitable for voltages up to 750 kV. Finally, the W-shape shown in FIG. 6 can be used up to the highest operating voltages (over 1,000 kV).

Claims (8)

1. Method of producing a vacuum-sealed and oil-tight closure for transformer construction, in which a shield electrode (9) is provided with an insulating retaining element (10) which is produced using transformer board, characterised by the following steps :
a) at least in the main part of its length the shield electrode (9) is shaped around with a first layer of insulating material (11) made from transformer board ;
b) then a second layer of insulating material (12) which corresponds to the desired shape of the retaining element (10) and is made from transformer board is applied so that it partially overlaps the first layer of insulating material (11) ;
c) after vacuum drying the two layers of insulating material (11, 12) made from transformer board are impregnated in a vacuum with an oil-resistant resin of low or medium viscosity which hardens at low temperature ;
d) after the resin has hardened, the film formed by the two layers of impregnated insulating material (11, 12) is provided on each of the free outer faces with at least one further layer of insulating material (14, 15, 16).
2. Method as claimed in Claim 1, characterised in that flange rings (17, 18) are mounted on both sides in the flange region (13) of the retaining element (10) after the application of a layer of insulating material (14, 15. 16) to each of the free outer faces of the film formed by the two layers of impregnated insulating material (11, 12).
3. Method as claimed in claim 2, characterised in that after the flange rings (17, 18) have been mounted the flange region (13) is impregnated with an oil-resistant resin with low to medium viscosity which hardens at low temperature.
4. Method as claimed in claim 1, characterised in that first of all the first and second layers of insulating material (11, 12) made from transformer board are dried in a circulating air oven until natural stability is achieved and then vacuum drying is carried out, preferably at a temperature between 100 and 110°C.
5. Method as claimed in claim 1, characterised in that the two layers of insulating material (11, 12) made from transformer board are flooded with resin under a vacuum at a temperature between 10 and 20 °C and are then further impregnated for at least 12 hours at normal pressure.
6. Method as claimed in claim 1, characterised in that the resin is hardened in a circulating air oven at a temperature between 110 and 150 °C, preferably between 120 and 140 °C.
7. Method as claimed in claim 1, characterised in that transformer board with a layer thickness of 3 to 5 mm is used for each of the first and second layers (11, 12) of insulating material.
8. Method as claimed in claim 7, characterised in that an element made from insulating material, constructed in the shape of a funnel or ring and having a wall thickness between 4 and 8 mm is used as a further layer of insulating material (16) on the free inner surface of the impregnated second layer of insulating material (12).
EP84107720A 1984-07-03 1984-07-03 Method of constructing a vacuum tight and oil-tight seal for a transformer structure, and seal made in this way Expired EP0167641B1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
AT84107720T ATE27075T1 (en) 1984-07-03 1984-07-03 PROCESS FOR MAKING A VACUUM-TIGHT, OIL-TIGHT SEAL FOR TRANSFORMER CONSTRUCTION AND SEAL MANUFACTURED BY THIS METHOD.
DE8484107720T DE3463585D1 (en) 1984-07-03 1984-07-03 Method of constructing a vacuum tight and oil-tight seal for a transformer structure, and seal made in this way
EP84107720A EP0167641B1 (en) 1984-07-03 1984-07-03 Method of constructing a vacuum tight and oil-tight seal for a transformer structure, and seal made in this way
FR8510183A FR2567313B1 (en) 1984-07-03 1985-07-03 PROCESS FOR PRODUCING A VACUUM AND OIL SEALED BLANKET IN CONSTRUCTION OF TRANSFORMERS AS WELL AS A SHUTTER PRODUCED ACCORDING TO THIS PROCESS

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP84107720A EP0167641B1 (en) 1984-07-03 1984-07-03 Method of constructing a vacuum tight and oil-tight seal for a transformer structure, and seal made in this way

Publications (2)

Publication Number Publication Date
EP0167641A1 EP0167641A1 (en) 1986-01-15
EP0167641B1 true EP0167641B1 (en) 1987-05-06

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EP84107720A Expired EP0167641B1 (en) 1984-07-03 1984-07-03 Method of constructing a vacuum tight and oil-tight seal for a transformer structure, and seal made in this way

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EP (1) EP0167641B1 (en)
AT (1) ATE27075T1 (en)
DE (1) DE3463585D1 (en)
FR (1) FR2567313B1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3540637A1 (en) * 1985-11-15 1987-05-21 Transformatoren Union Ag TRANSFORMER WITH FUSE
DE102008013204A1 (en) * 2008-03-07 2009-09-17 Abb Technology Ag Conductor connection to transformers
CN113096925B (en) * 2021-03-31 2023-03-28 广东电网有限责任公司广州供电局 Power transformer suitable for guide rod type sleeve

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1490056A1 (en) * 1957-03-30 1969-07-03 Moser Glaser & Co Ag Process for the production of wound capacitors and bushings provided with electrically conductive layers
CH387116A (en) * 1961-09-06 1965-01-31 Bbc Brown Boveri & Cie Isolator for pressurized gas-insulated, fully enclosed switchgear
DE1465706A1 (en) * 1963-07-22 1969-06-04 Inst Prueffeld Fuer Elek Sche High voltage bushing for electrical equipment, especially for low-liquid transformers
US3348180A (en) * 1964-06-18 1967-10-17 Westinghouse Electric Corp Electrical inductive apparatus having a multi-conductor bushing
JPS57120317A (en) * 1981-01-17 1982-07-27 Kansai Electric Power Co Inc:The Connecting structure for electric device to wire

Non-Patent Citations (1)

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Title
H. P. MOSER: "TRANSFORMER BOARD", Scientia Electrica, Band 25, Heft 3, Seiten 1-120, Jahrgang 1979 *

Also Published As

Publication number Publication date
ATE27075T1 (en) 1987-05-15
EP0167641A1 (en) 1986-01-15
FR2567313B1 (en) 1987-12-24
FR2567313A1 (en) 1986-01-10
DE3463585D1 (en) 1987-06-11

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