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EP 2 159 811 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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01.05.2013 Bulletin 2013/18 |
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Date of filing: 01.09.2008 |
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International Patent Classification (IPC):
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High voltage circuit breaker
Hochspannungsschutzschalter
Disjoncteur haute tension
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Designated Contracting States: |
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AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL
PT RO SE SI SK TR |
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Date of publication of application: |
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03.03.2010 Bulletin 2010/09 |
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Proprietor: ABB Technology AG |
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8050 Zürich (CH) |
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Inventor: |
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- Lidholm, Johan
777 51 Smedjebacken (SE)
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Representative: Kock, Ina |
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ABB AB
Intellectual Property
Ingenjör Bååths Gata 11 721 83 Västerås 721 83 Västerås (SE) |
(56) |
References cited: :
EP-A- 0 077 516
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US-A- 3 504 142
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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FIELD OF INVENTION
[0001] The present invention relates to a high voltage live tank circuit breaker.
BACKGROUND OF THE INVENTION
[0002] Electrical power transmission networks are protected and controlled by high voltage
circuit breakers. Such circuit breakers are divided in two classes: live tank circuit
breakers (LTB) where the enclosure that contains the breaking mechanism is at line
potential and the dead tank circuit breakers (DTB) where the enclosures are at earth
potential.
[0003] The live tank circuit breakers at high voltage levels have to handle the high potential
at the terminal electrodes where the tubes or cables are connected to pass the current
through the circuit breaker. The high potential creates high electrical field stress
at the terminal electrodes. Commonly the terminal electrodes are shielded with corona
rings, which purpose is to reduce the local electrical field stress by their smooth
shape and relatively large area compared to the terminals.
[0004] Two different corona ring designs are common. Either the corona rings are placed
as close to the terminal electrode as possible. If capacitors or pre-insertion resistors
are used the same philosophy is used. Alternatively, a circular corona ring is placed
symmetrically around the circuit breaker center axis.
[0005] The live tank circuit breaker external isolation media is air. The external insulation
is verified with dielectric tests following the requirements in applicable standards.
These verifying tests for high voltage circuit breakers include both dry and wet tests
since the high voltage circuit breaker is an out door equipment.
[0006] An example of circuit breaker with corona ring around the treminals is disclosed
in
US-A-3504142.
SUMMARY OF THE INVENTION
[0007] During such wet tests the rain is collected all over the surface of the circuit breaker
and the corona rings. The water is pouring downwards on the surface and collected
at the lowest position on each individual part of the circuit breaker and finally
it is falling of the surface towards ground.
[0008] The water drops will be affected by the high voltage and change shape; they will
be sharper then normal and increase the local electrical field stress.
[0009] The invention is based on the fact that during switching over voltages during wet
conditions the local electrical field at the corona rings lower part will increase
in comparison to dry conditions.
[0010] An object of the present invention is therefore to provide a high voltage live tank
circuit breaker with an improved dielectric withstand capability, in particular during
wet conditions.
[0011] A further object of the invention is to provide such a high voltage circuit breaker,
which is robust, accurate, uncomplicated, space-saving, and inexpensive, and which
has an optimum performance and which fulfills existing safety requirements.
[0012] A yet further object of the invention is to provide a method for preparing a high
voltage circuit breaker which fulfills any of the above objects.
[0013] These objects are attained by high voltage circuit breakers and methods as claimed
in the appended patent claims.
[0014] According to a first aspect of the invention there is provided a high voltage live
tank circuit breaker comprising a support insulator, an elongated current interrupter
provided on the support insulator, terminals connected to the ends of the current
interrupter, and at least one corona ring arranged to at least partly surround at
least one of the terminals.
[0015] The corona ring is provided with a hydrophobic surface layer to thereby obtain a
high voltage live tank circuit breaker with improved dielectric withstand capability
in wet conditions.
[0016] The wet conditions are the most severe and at the same time the hardest to theoretically
calculate and dimension for each circuit breaker design. Different designs have therefore
been experimentally tested in a high voltage laboratory and it has been found that
the critical factor is the number and size of the water drops on the surface of the
corona rings. A considerable improvement is obtained by the using the invention. The
number and size of the water drops are considerably reduced.
[0017] In one embodiment the high voltage live tank circuit breaker comprises a horizontally
arranged elongated current interrupter, and a horizontally arranged elongated capacitor
and/or resistor connected between the terminals in parallel with the current interrupter,
wherein the parts are so arranged that the vertical distance between the inner surface
of the lower end of the corona ring and a center axis of the current interrupter,
the capacitor, if present, or the resistor, if present, whichever being located lowest,
is between about 1.5 and about 4 times shorter than the distance between the inner
surface of the upper end of the corona ring and the center axis.
[0018] Hereby, a more evenly distributed electrical field around the corona ring is obtained
in presence of water, and as a result, the dielectric withstand capability in wet
conditions is further improved.
[0019] According to a second aspect of the invention there is provided a method for preparing
a high voltage live tank circuit breaker comprising a support insulator, an elongated
current interrupter provided on the support insulator, terminals connected to the
ends of the current interrupter, and at least one corona ring arranged to at least
partly surround at least one of the terminals. According to the method, the corona
ring is provided with a hydrophobic surface layer.
[0020] Preferably, the hydrophobic surface layer is provided by means of spraying or coating
the corona ring with hydrophobic material such as silicone rubber or a resin such
as a fluorine or silicone resin.
[0021] Further characteristics of the invention and advantages thereof, will be evident
from the following detailed description of preferred embodiments of the present invention
given hereinafter and the accompanying Figs. 1-2, which are given by way of illustration
only and are thus not limitative of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022]
Fig. 1 illustrates schematically in a side elevation view a high voltage circuit breaker
according to an embodiment of the invention.
Fig. 2 illustrates schematically in an end view a current interrupter and a corona
ring as being comprised in the high voltage circuit breaker of Fig. 1.
DETAILED DESCRIPTION OF EMBODIMENTS
[0023] In the following a detailed description of preferred embodiments of the present invention
will be given. In this description, the term
high voltage will be used for voltages of 1 kV and higher. It shall, however, be noted that the
present invention is primarily intended for high voltage circuit breakers with much
higher voltage ratings, such as 245 kV and above.
[0024] Fig. 1 illustrates schematically in a side elevation view a one-phase high voltage
live tank circuit breaker, which comprises two horizontally arranged and serially
connected elongated current interrupters 10 arranged on a support insulator 20. The
current interrupters 10 may be referred to as breaker or extinguishing chambers and
the assembly of two current interrupters 10 may be referred to as a breaking unit.
Each of the current interrupters 10 is connected to a terminal 30 at its far end and
to a connection flange 32 at its inner end.
[0025] Further, the circuit breaker comprises a respective corona ring 40 arranged to at
least partly surround the terminal 30 connected to the far ends of the serially interconnected
current interrupters 10, that is, typically no corona rings are arranged around the
connection flanges 32, which interconnects the current interrupters 10.
[0026] Fig. 2 illustrates schematically in an end view one of the current interrupters 10
and one of the corona rings 40 of the high voltage circuit breaker of Fig. 1. The
supports 41 holding the corona ring 40 are illustrated.
[0027] According to the invention one or preferably each of the corona rings 40 is provided
with a hydrophobic surface layer 42.
[0028] Preferably, the hydrophobic surface layer 42 is applied by means of spraying or coating
the corona ring(s) 42 with hydrophobic material such as a rubber or a resin material,
e.g. a silicone rubber or a fluorine or silicone resin.
[0029] The hydrophobic surface layer 42 may cover essentially the entire surface of the
corona ring(s) 40 or only portions of the surface of the corona ring(s) 40, preferably
lower portions of the surface of the corona ring(s) 42.
[0030] For illustrative purposes the thickness of the layer 42 is highly exaggerated in
Figs. 1-2.
[0031] It shall be appreciated that the corona rings 40 may be closed or open-ended and
they can have different shapes, though the corona rings 40 in Figs. 1-2 are torus
shaped.
[0032] Provided that the corona rings are arranged symmetrically around the current interrupters
10 in the lateral plane the sum of distances d1 and d2 corresponds to the inner diameter
of the corona rings 40.
[0033] It shall further be appreciated that there can be arranged more corona rings around
each terminal. Commonly, the corona rings are provided in pairs with a short fixed
distance in between.
[0034] Further, in one version of the invention, one or each of the corona rings is located
such that the vertical distance d1 between the inner surface of the lower end of the
corona ring 40 and a center axis 10a of the current interrupter 10 is between about
1.5 and about 4 times shorter than the distance d2 between the inner surface of the
upper end of the corona ring 40 and the center axis 10a.
[0035] If the circuit breaker, for each current interrupter, comprises a horizontally arranged
elongated capacitor and/or resistor connected between the terminals in parallel with
the current interrupter, each corona ring is preferably arranged such that the vertical
distance between the inner surface of the lower end of the corona ring 40 and a center
axis of the current interrupter 10, of the elongated capacitor, or of the resistor,
whichever being located lowest, is between about 1.5 and about 4 times shorter than
the distance between the inner surface of the upper end of the corona ring and that
center axis.
[0036] By using the new design a higher dielectric withstand capability to withstand both
the switching and lightning impulse voltage is obtained, especially during wet conditions.
[0037] A three-phase high voltage live tank circuit breaker comprises three of the circuit
breaker as disclosed above.
1. A high voltage live tank circuit breaker comprising:
- a support insulator (20);
- at least one elongated current interrupter (10) provided on said support insulator
(20);
- terminals (30) connected to the ends of said current interrupter; and
- at least one corona ring (40) arranged to at least partly surround one of the terminals,
characterised in that
- said corona ring (40) is provided with a hydrophobic surface layer (42).
2. The circuit breaker of claim 1 wherein said hydrophobic surface layer (42) is made
of any of a rubber or a resin material such as e.g. a silicone rubber or a fluorine
or silicone resin.
3. The circuit breaker of claim 1 or 2 wherein said hydrophobic surface layer (42) covers
essentially the entire surface of said corona ring.
4. The circuit breaker of claim 1 or 2 wherein said hydrophobic surface layer (42) covers
only portions of the surface of said corona ring, preferably lower portions of the
surface of said corona ring.
5. The circuit breaker of any of claims 1-4 wherein the corona ring is open-ended.
6. The circuit breaker of any of claims 1-5 comprising a further corona ring arranged
to at least partly surround said one of the terminals, the corona rings being arranged
concentrically with respect to one another.
7. The circuit breaker of any of claims 1-6 comprising a corona ring arranged to at least
partly surround another one of the terminals, the corona rings being arranged concentrically
with respect to one another.
8. The circuit breaker of any of claims 1-7 comprising a further elongated current interrupter
(10) and terminals (30) connected to the ends of the current interrupter, the current
interrupters being arranged concentrically with respect to one another and being serially
connected, wherein said one of the terminals, which is at least partly surrounded
by the corona ring (40), is an outer terminal of said serially connected current interrupters;
and further comprising a corona ring (40) arranged to at least partly surround the
other outer terminal of said serially connected current interrupters and being provided
with a hydrophobic surface layer (42), the corona rings being arranged concentrically
with respect to one another.
9. The circuit breaker of any of claims 1-7 wherein said elongated current interrupter
is arranged essentially horizontally and said corona ring is arranged such that the
vertical distance (d1) between the inner surface of the lower end of said corona ring
and a center axis (10a) of said essentially horizontally arranged elongated current
interrupter (10) is between about 1.5 and about 4 times shorter than the distance
(d2) between the inner surface of the upper end of said corona ring and said center
axis.
10. The circuit breaker of any of claims 1-7 comprising an essentially horizontally arranged
elongated capacitor (50) and/or resistor (60) connected between the terminals in parallel
with the current interrupter (10), which is essentially horizontally arranged, wherein
said corona ring (40) is arranged such that the vertical distance (d1) between the
inner surface of the lower end of said corona ring and a center axis (10a) of said
essentially horizontally arranged elongated current interrupter (10), of said essentially
horizontally arranged elongated capacitor (50), or of said essentially horizontally
arranged elongated resistor (60), whichever being located lowest, is between about
1.5 and about 4 times shorter than the distance (d2) between the inner surface of
the upper end of said corona ring and said center axis.
11. a three-phase high voltage live tank circuit breaker comprising three of the circuit
breaker of any of claims 1-10, one for each phase.
12. A method for preparing a high voltage live tank circuit breaker comprising a support
insulator (20); at least one elongated current interrupter (10) provided on said support
insulator (20); terminals (30) connected to the ends of said current interrupter;
and at least one corona ring (40) arranged to at least partly surround one of the
terminals, said method being
characterised by the step of
- providing said at least one corona ring (40) with a hydrophobic surface layer (42).
13. The method of claim 12 wherein the step of providing comprises spraying or coating
said at least one corona ring with hydrophobic material.
14. The method of claim 12 or 13 wherein said hydrophobic surface layer (42) is made of
any of a rubber or a resin material such as e.g. a silicone rubber or a fluorine or
silicone resin.
1. Hochspannungs-Schaltkammerleistungsschalter, umfassend:
- einen Stützisolator (20);
- mindestens einen gestreckten Stromunterbrecher (10), der an dem Stützisolator (20)
zur Verfügung gestellt ist;
- Anschlüsse (30), die mit den Enden des Stromunterbrechers verbunden sind; und
- mindestens ein Koronaring (40), der zum zumindest teilweise Umgeben eines der Anschlüsse
ausgelegt ist,
dadurch gekennzeichnet, dass
- der Koronaring (40) mit einer hydrophoben Oberflächenschicht (42) versehen ist.
2. Leistungsschalter nach Anspruch 1, wobei die hydrophobe Oberflächenschicht (42) aus
einem Gummi- oder einem Harzmaterial hergestellt ist, wie zum Beispiel einem Silikongummi
oder einem Fluor- oder Silikonharz.
3. Leistungsschalter nach Anspruch 1 oder 2, wobei die hydrophobe Oberflächenschicht
(42) im Wesentlichen die ganze Oberfläche des Koronarings bedeckt.
4. Leistungsschalter nach Anspruch 1 oder 2, wobei die hydrophobe Oberflächenschicht
(42) nur Abschnitte der Oberfläche des Koronarings bedeckt, vorzugsweise untere Abschnitte
der Oberfläche des Koronarings.
5. Leistungsschalter nach einem der Ansprüche 1-4, wobei der Koronaring offen ist.
6. Leistungsschalter nach einem der Ansprüche 1-5, der einen weiteren Koronaring umfasst,
welcher zum zumindest teilweisen Umgeben eines der Anschlüsse ausgelegt ist, wobei
die Koronaringe konzentrisch zueinander angeordnet sind.
7. Leistungsschalter nach einem der Ansprüche 1-6, der einen Koronaring umfasst, welcher
zum zumindest teilweisen Umgeben eines Weitern der Anschlüsse ausgelegt ist, wobei
die Koronaringe konzentrisch zueinander angeordnet sind.
8. Leistungsschalter nach einem der Ansprüche 1-7, der einen weiteren gestreckten Stromunterbrecher
(10) und Anschlüsse (30) umfasst, die mit den Enden des Stromunterbrechers verbunden
sind, wobei die Stromunterbrecher konzentrisch zueinander angeordnet sind und in Reihe
geschaltet sind, wobei einer der Anschlüsse, der zumindest teilweise vom Koronaring
(40) umgeben ist, ein äußerer Anschluss der in Reihe geschalteten Stromunterbrecher
ist; und der ferner einen Koronaring (40) umfasst, welcher zum zumindest teilweisen
Umgeben des anderen äußeren Anschlusses der in Reihe geschalteten Stromunterbrecher
angeordnet ist und der mit einer hydrophoben Oberflächenschicht (42) versehen ist,
wobei die Koronaringe konzentrisch zueinander angeordnet sind.
9. Leistungsschalter nach einem der Ansprüche 1-7, wobei der gestreckte Stromunterbrecher
im Wesentlichen horizontal angeordnet ist und der Koronaring so angeordnet ist, dass
der vertikale Abstand (d1) zwischen der Innenfläche des unteren Endes des Koronarings
und einer Mittelachse (10a) des im Wesentlichen horizontal angeordneten gestreckten
Stromunterbrechers (10) zwischen etwa 1,5-mal und etwa 4-mal kürzer als der Abstand
(d2) zwischen der Innenfläche des oberen Endes des Koronarings und der Mittelachse
ist.
10. Leistungsschalter nach einem der Ansprüche 1-7, der einen im Wesentlichen horizontal
angeordneten gestreckten Kondensator (50) und/oder Widerstand (60) umfasst, welcher
zwischen den Anschlüssen parallel zum Stromunterbrecher (10) liegt, der im Wesentlichen
horizontal angeordnet ist, wobei der Koronaring (40) derart angeordnet ist, dass der
vertikale Abstand (d1) zwischen der Innenfläche des unteren Endes des Koronarings
und einer Mittelachse (10a) des im Wesentlichen horizontal angeordneten gestreckten
Stromunterbrechers (10), des im Wesentlichen horizontal angeordneten gestreckten Kondensators
(50) oder des im Wesentlichen horizontal angeordneten gestreckten Widerstandes (60),
je nachdem, welcher am tiefsten angeordnet ist, etwa 1,5-mal bis etwa 4-mal kürzer
als der Abstand (d2) zwischen der Innenfläche des oberen Endes des Koronarings und
der Mittelachse ist.
11. Dreiphasen-Hochspannungs-Schaltkammerleistungsschalter, der drei der Leistungsschalter
nach einem der Ansprüche 1-10 umfasst, einer für jede Phase.
12. Verfahren zum Bereitstellen eines Hochspannungs-Schaltkammerleistungsschalters, der
einen Stützisolator (20); mindestens einen gestreckten Stromunterbrecher (10), der
an dem Stützisolator (20) zur Verfügung gestellt ist; Anschlüsse (30), die mit den
Enden des Stromunterbrechers verbunden sind; und mindestens einen Koronaring (40)
umfasst, der zum zumindest teilweise Umgeben eines der Anschlüsse ausgelegt ist, wobei
das Verfahren durch den folgenden Schritt gekennzeichnet ist:
- Bereitstellen des mindestens einen Koronarings (40) mit einer hydrophoben Oberflächenschicht
(42).
13. Verfahren nach Anspruch 12, wobei der Schritt des Bereitstellens das Besprühen oder
Beschichten des mindestens einen Koronarings mit hydrophobem Material umfasst.
14. Verfahren nach Anspruch 12 oder 13, wobei die hydrophobe Oberflächenschicht (42) aus
einem Gummi- oder einem Harzmaterial hergestellt ist, wie zum Beispiel einem Silikongummi
oder einem Fluor- oder Silikonharz.
1. Disjoncteur à haute tension à réservoir vivant, comprenant :
- un isolateur (20) de support ;
- au moins un interrupteur allongé (10) de courant, prévu sur ledit isolateur (20)
de support ;
- des bornes (30), reliées aux extrémités dudit interrupteur de courant et
- au moins une bague (40) à effet de couronne, agencée pour entourer, au moins partiellement,
l'une des bornes,
caractérisé en ce que
- ladite bague (40) à effet de couronne est munie d'une couche superficielle hydrophobe
(42).
2. Disjoncteur selon la revendication 1, dans lequel ladite couche superficielle hydrophobe
(42) est faite de l'un quelconque des matériaux parmi un caoutchouc ou une résine,
tel que, par ex., un caoutchouc silicone ou une résine fluorée ou silicone.
3. Disjoncteur selon la revendication 1 ou 2, dans lequel ladite couche superficielle
hydrophobe (42) couvre essentiellement l'intégralité de la surface de ladite bague
à effet de couronne.
4. Disjoncteur selon la revendication 1 ou 2, dans lequel ladite couche superficielle
hydrophobe (42) couvre uniquement des parties de la surface de ladite bague à effet
de couronne, de préférence des parties inférieures de la surface de ladite bague à
effet de couronne.
5. Disjoncteur selon l'une quelconque des revendications 1 à 4, dans lequel la bague
à effet de couronne est ouverte.
6. Disjoncteur selon l'une quelconque des revendications 1 à 5 comprenant une autre bague
à effet de couronne, agencée pour entourer, au moins partiellement, l'une des bornes,
les bagues à effet de couronne étant agencées de manière concentrique l'une par rapport
à l'autre.
7. Disjoncteur selon l'une quelconque des revendications 1 à 6, comprenant une bague
à effet de couronne, agencée pour entourer, au moins partiellement, une autre borne,
les bagues à effet de couronne étant agencées de manière concentrique l'une par rapport
à l'autre.
8. Disjoncteur selon l'une quelconque des revendications 1 à 7, comprenant un autre interrupteur
allongé (10) de courant et des bornes (30), reliées aux extrémités de l'interrupteur
de courant, les interrupteurs de courant étant agencés de manière concentrique l'un
par rapport à l'autre et étant reliés en série, dans lequel l'une des bornes, qui
est entourée, au moins partiellement, par la bague (40) à effet de couronne, est une
borne extérieure desdits interrupteurs de courant, reliés en série et comprenant,
en outre, une bague (40) à effet de couronne, agencée pour entourer, au moins partiellement,
l'autre borne extérieure desdits interrupteurs de courant, reliés en série et étant
munie d'une couche superficielle hydrophobe (42), les bagues à effet de couronne étant
agencées de manière concentrique l'une par rapport à l'autre.
9. Disjoncteur selon l'une quelconque des revendications 1 à 7, dans lequel ledit interrupteur
allongé de courant est agencé essentiellement horizontalement et ladite bague à effet
de couronne est agencée, de sorte que la distance verticale (d1), entre la surface
intérieure de l'extrémité inférieure de ladite bague à effet de couronne et un axe
central (10a) dudit interrupteur allongé (10) de courant, agencé essentiellement horizontalement,
est entre environ 1,5 et environ 4 fois plus courte que la distance (d2) entre la
surface intérieure de l'extrémité supérieure de ladite bague à effet de couronne et
dudit axe central.
10. Disjoncteur selon l'une quelconque des revendications 1 à 7, comprenant un condensateur
allongé (50), agencé essentiellement horizontalement et / ou une résistance (60),
connectée entre les bornes, en parallèle avec l'interrupteur (10) de courant, qui
est agencé essentiellement horizontalement, dans lequel ladite bague (40) à effet
de couronne est agencée, de sorte que la distance verticale (d1), entre la surface
intérieure de l'extrémité inférieure de ladite bague à effet de couronne et un axe
central (10a) dudit interrupteur allongé (10) de courant, agencé essentiellement horizontalement,
dudit condensateur allongé (50), agencé essentiellement horizontalement ou de ladite
résistance allongée (60), agencée essentiellement horizontalement, quelque soit l'élément
qui est situé le plus bas, est entre environ 1,5 et environ 4 fois plus courte que
la distance (d2) entre la surface intérieure de l'extrémité supérieure de ladite bague
à effet de couronne et dudit axe central.
11. Disjoncteur triphasé à réservoir vivant à haute tension selon l'une quelconque des
revendications 1 à 10, comprenant trois disjoncteurs, un pour chaque phase.
12. Procédé, destiné à préparer un disjoncteur à réservoir vivant à haute tension, comprenant
un isolateur (20) de support, au moins un interrupteur allongé (10) de courant, prévu
sur ledit isolateur (20) de support, des bornes (30), connectées aux extrémités dudit
interrupteur de courant et au moins une bague (40) à effet de couronne, agencée pour
entourer, au moins partiellement, l'une des bornes, ledit procédé étant
caractérisé par l'opération, consistant à
- munir ladite au moins une bague (40) à effet de couronne d'une couche superficielle
hydrophobe (42).
13. Procédé selon la revendication 12, dans lequel l'opération de fourniture comprend
l'opération, consistant à pulvériser ou à revêtir ladite au moins une bague à effet
de couronne avec un matériau hydrophobe.
14. Procédé selon la revendication 12 ou 13, dans lequel ladite couche superficielle hydrophobe
(42) est faite d'un matériau quelconque parmi un caoutchouc ou une résine, tel que,
par ex, un caoutchouc silicone ou une résine fluorée ou silicone.
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only.
It does not form part of the European patent document. Even though great care has
been taken in compiling the references, errors or omissions cannot be excluded and
the EPO disclaims all liability in this regard.
Patent documents cited in the description