Sf6 free gas insulated disconnector with fully closed arcing chamber and spring actuation

Abstract

To confine the arc generated during disconnector switching.SOLUTION: A disconnector (100) for a GIS, in a gas chamber and along an axis (AA'), includes: a pair of permanent contacts (24, 41); an electrically conducting tube (30) movable along the axis, the tube moving from a position in which both permanent contacts are in electrical contact with each other; a pair of arcing contacts (22, 42); a pair of rear contacts (521, 522), one of them being in electrical contact with the movable arcing contact; means for slowing down the movable arcing contact when separating from the fixed arcing contact; and means (6) for moving the electrically conducting tube and the movable arcing contact along the axis, thereby opening the disconnector and for separating the rear contacts from each other before the arcing contacts separate.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] The present invention relates to gas-insulated substations, commonly referred to as Gas-Insulated Substations (GIS). These substations are equipped with disconnectors, circuit breakers, or earthing switches. The switchgear components are typically metal tanks filled with SF6 (sulfur hexafluoride) under pressure. [Background technology]

[0002] Sulfur hexafluoride (SF6) is estimated to contribute to the greenhouse effect, but in recent years it has been replaced by other gases, so-called "g3", which contains heptafluoroisobutyronitrile mixed with diluent gases including carbon dioxide and oxygen, and is being used to replace SF6, paving the way for the next generation of high voltage (HV) electrical transmission equipment. g3 has a significantly reduced environmental impact (the gas global warming potential (GWP) is reduced by more than 99%).

[0003] However, it has been found that powder is generated during the opening of disconnectors in GISs that use this gas. This powder results from the decomposition of the g3 gas used instead of SF6 and is detrimental to the dielectric strength. In fact, the g3 decomposition, when combined with molten metallic lead, results in metal oxide particles that spread on the corona shield surface, exerting the greatest effect.

[0004] Therefore, there is a challenge to limit the generation of this powder and / or to partially or completely contain the powder. Summary of the Invention

[0005] In order to solve the above problems, the present inventors have found a solution for containing the arc that occurs when switching a disconnector.

[0006] The present invention firstly provides: a pair of permanent contacts, for example one permanent contact being fixed and the other permanent contact being movable or both being fixed relative to each other; a pair of arcing contacts, for example, one of the arcing contacts is fixed and the other of the arcing contacts is movable relative to the fixed arcing contact; a pair of rear contacts, one of the rear contacts being in electrical contact with the movable arcing contact; means for slowing (preferably for a short time) or stopping (preferably for a short time) the movable arcing contact as it separates from the fixed arcing contact, and for separating said rear contacts from one another before the arcing contacts separate; This invention relates to a disconnector for a GIS.

[0007] Preferably, the conductive tube is movable along an axis (AA') from a position where the permanent contacts are in electrical contact with each other to a position where the main contacts are electrically isolated from each other, and the movable arcing contact is movable relative to the conductive tube.

[0008] In one embodiment, the means for slowing or stopping the movable arcing contact as it separates from the fixed arcing contact comprises a limit to the movement of the movable arcing contact, for example the disconnector comprises a surface inclined to the axis (AA') at an angle of between 20° and 40°.

[0009] The disconnector according to the present invention may comprise a rod having a first end forming a movable arcing contact and a second end forming or supporting one of the rear contacts, the rod being slidably mounted relative to the conductive tube.

[0010] The disconnector according to the invention may comprise means for pressing the rear contacts towards each other and forcing the possibly movable arcing contacts apart, in one embodiment said means comprising, for example, a compression spring with a first end abutting a part fixed relative to the movable main contacts and a second end abutting one of the rear contacts.

[0011] The present invention also provides A metal tank filled with gas, A disconnector according to the present invention as disclosed above or in this application; This relates to a GIS that includes:

[0012] The present invention also provides a method for opening a disconnector of a GIS according to the present invention, comprising the steps of: moving the movable arc contact and the movable main contact to close the pair of arc contacts and separate the pair of permanent contacts from each other; slowing (preferably for a short time) or stopping (preferably for a short time) the movement of the movable arcing contact relative to the fixed arcing contact; separating the pair of rear contacts from each other before separating the arcing contacts, thereby inducing an arc between the rear contacts; The present invention relates to a method, including:

[0013] The present invention also provides a method for closing a disconnector of a GIS according to the present invention, comprising the steps of: closing the pair of arcing contacts by moving the movable arcing contact and the conductive tube relative to the fixed arcing contact and the main contact; closing the main contacts; Opening the arcing contacts The present invention relates to a method, including: [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating an example of a gas-insulated substation. [Figure 2A] FIG. 1 is a diagram showing an example of a disconnector according to the present invention. [Figure 2B] FIG. 1 is a diagram showing an example of a disconnector according to the present invention. [Figure 2C] FIG. 1 is a diagram showing an example of a disconnector according to the present invention. [Figure 2D] FIG. 1 is a diagram showing an example of a disconnector according to the present invention. [Figure 2E] FIG. 1 is a diagram showing an example of a disconnector according to the present invention. [Figure 3A] 1 illustrates an embodiment of an arcing contact according to the present invention. [Figure 3B] 1 illustrates an embodiment of an arcing contact according to the present invention. [Figure 4] FIG. 4 shows a displacement-stress curve for a finger of an arcing contact of a disconnector according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] An example of a metal tank 1 or interrupter chamber that can be equipped with a disconnector according to the present invention is illustrated in Figure 1. The metal tank 1 is filled with a gas, for example "g3" gas comprising heptafluoroisobutyronitrile mixed with a diluent gas comprising carbon dioxide and oxygen.

[0016] For example, the gas is Heptafluoroisobutyronitrile and / or heptafluoroisopropyl trifluoromethyl ketone (also called 2-butanone, 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-(CAS No. 756-12-7)), optionally mixed with a gas or diluent gas containing at least CO and / or O and / or N and / or an oxygenated compound, Or it may contain at least CO2 and / or O2 and / or N2 and / or oxygenated compounds and / or water vapor.

[0017] The metal tank may be surrounded by, or intended to be surrounded by, an atmosphere containing some water and / or water vapor.

[0018] The disconnector extends along an axis AA' (parallel to axis X) and comprises a pair of contacts 2, 4 (see Figures 1 and 2A) mounted to move at least partially relative to one another along said axis AA' with the aid of actuation systems 6, 8 for moving, for example, a conductive tube 30. This conductive tube 30 can be moved along said axis AA' from a closed position, in which current can flow through the contacts, to an open position, in which the current is interrupted, and vice versa.

[0019] By convention, the term "main contacts" is used to refer to the electrical contacts through which the rated current passes. The main contacts are associated with "arcing contacts" which function to break and make the contact themselves. The term "movable contact" is used to refer to the movable arcing contact and the conductive tube, both of which are connected to the actuating system 6, 8.

[0020] The disconnector is a first movable contact 4, consisting of an arcing contact 42, for example in the form of a plurality of fingers, and main contacts 24, 41 (the main contact 41 being stationary relative to the arcing contact 42); The second contact 2, which is stationary in this example, is composed of an arcing contact 22 and a main contact 24. It is equipped with:

[0021] These two elements cooperate between an open position in which the two contacts 2, 4 are electrically isolated from each other, and a closed position (not shown in Figure 1), thereby allowing current to flow between them (by translation of the conductive tube 30).

[0022] During the disconnection procedure, the two main contacts 24, 41 separate and then the arcing contacts 42, 22 take over (FIGS. 2C and 2D).

[0023] An example of a circuit disconnector according to the invention is more precisely illustrated in Figures 2A to 2E. The disconnector extends along a longitudinal axis AA'.

[0024] The movable electrode 4 comprises a main contact 41 (eg, a non-movable spring contact), a movable conductive tube 30 and an arc contact 42 .

[0025] The movable conductive tube 30 is movable along an axis AA' between a closed position (FIG. 2A) and an open position (FIG. 2E) with the aid of actuation systems 6,8.

[0026] The movable arcing contact 42 is formed at the end of a rod or tube 44 which is preferably made of the same conductive material as the arcing contact 42 .

[0027] The arcing contact 42 is, for example, in the form of a bulb having an outer diameter larger than the outer diameter of the rod or tube 44 and slightly larger than the inner diameter of the fixed arcing contact 22. The ends of the arcing contact 42 are, for example, provided with at least two fingers 421, 422 having a certain degree of elasticity so that they can be pressed against the fixed arcing contact 22, the fingers being separated by a central duct 43 which gives the fingers some freedom to be pressed in the direction of the axis AA', particularly when the arcing contact 42 enters the fixed arcing contact 22.

[0028] A movable arcing contact 42 is slidably mounted within the cylinder 30 such that it can slide relative to the conductive tube 30 along the axis AA'. For example, the arcing contact is guided within a wall 46 that separates the internal volume of the cylinder 30 from the overall disconnector gas compartment. The cylinder 30 thus comprises two chambers: a front chamber 301 and a rear chamber 302.

[0029] The wall 46 supports the movable arcing contact 42 via insulating bearings so that the arcing contact 42 can be electrically isolated from the conductive tube 30 .

[0030] One end of the spring or compression spring 50 abuts against the wall 46 or a portion fixed relative to said wall or a portion fixed relative to the conductive tube 30, and the other end abuts against a metallic end (or rear) contact 521 located at the end of the rod 44. The end contact 521 faces another metallic end (or rear) contact 522 maintained by the cylinder 30. Both contacts 521 and 522 can be in contact (see, for example, Figures 2A-2C) or separated from each other (see, for example, Figure 2D) and move relative to each other along the axis AA'.

[0031] 3A shows a portion of the fixed arcing contact 22, which has an inner cylindrical surface 23 provided with a limiting portion 25 against which the movable arcing contact 42 abuts when driven along the axis AA′ during the opening phase. The limiting portion may extend over the entire circumference of the inner cylindrical surface 23 (around the axis AA′) or over only a portion thereof. In this way, the movable arcing contact is slowed down or stopped for a short period during the opening phase, so that the arc between contacts 521 and 522 is extinguished and the contacts are separated from each other by a distance of, for example, 1 mm. The period and / or the distance depend on the characteristics of the compression spring 50.

[0032] 3B shows details of one embodiment of the limiting portion 25. The limiting portion comprises a shoulder 27 against which the movable arcing contact 42 makes contact after sliding against the inner cylindrical surface 23, and flexible fingers 421, 422 of the arcing contact 42 are slightly curved towards the axis AA' but maintain contact with the surface of the limiting portion 25 of the arcing contact 22. The shoulder preferably has a flat surface inclined to the axis AA' at an angle of about 30°, for example between 20° and 40°. This is followed by the end faces of the fixed arcing contacts, which are in contact with one or more surfaces 221, 222, for example a first (dielectric) surface 221, which preferably ensures smooth finger compression during closing; optionally a second dielectric surface 222 and It can be equipped with:

[0033] Other shapes of the limiter 25 are possible to ensure that the compression spring 50 compresses and briefly slows or stops the arcing contacts 42 so that the contacts 521 and 522 separate from one another. For example, the limiter may be in the form of teeth or may comprise a trigger with a spring.

[0034] The flexible fingers 421, 422 of the arcing contact 42 have a larger outer diameter than the inner cylindrical surface 23 to ensure good electrical contact with the inner cylindrical surface 23. The restriction 25 presses the fingers in the direction of the axis AA'.

[0035] 2A to 2E show the different steps of the opening phase of the disconnector according to the invention, which is controlled by a mechanism driving the insulating rod 6 translationally and rotationally about the axis of rotation 16.

[0036] FIG. 2A shows a first position, where both electrodes 2 and 4 are in contact via main contacts 24, 41 (which in this example are both spring contacts) and conductive tube 30, as well as rear contacts 521 and 522.

[0037] After the opening phase begins, the conductive tube 30 slides against the main contact 24 (FIG. 2B) until they are separated (FIG. 2C), and the arcing contact 42 slides against the arcing contact 22. Current flows through the arcing contacts 42, 22, the tube 44, the rear contacts 521, 522 (which are still connected to each other), and the cylinder 30.

[0038] After a period of time, the movable arcing contact 42 contacts the surface of the restriction 25 (FIGS. 3A and 3B), slowing or stopping the movement of the movable arcing contact 42. This causes the rear contacts 521 and 522 to open (FIG. 2D), thus initiating an arc between these two contacts 521 and 522 in the rear chamber 302 where decomposition of the gas will not harm the compressed compression spring 50.

[0039] After the movable arc contact 42 is unlocked from the surface of the restriction 25 and the compression spring 50 is released (FIG. 2E), this The contacts 521 and 522 are pressed against each other, so that the potential of the movable arc contact 42 is maintained after opening, The arcing contacts 22, 42 are forced apart and no arc occurs between them as they separate because the current has already been cut off by the rear contacts 521 and 522.

[0040] 4 indicates the compression of the fingers upon contact with the inner cylindrical surface 23. This is followed by a plateau corresponding to sliding movement along the inner cylindrical surface 23 and a second peak on the right indicating the compression of the fingers on the restriction 25. This results in increased friction, which compresses the compression spring 50 and opens the rear contacts 521 and 522. In this manner, contacts 521 and 522 open when the arcing contact is in physical contact with the restriction 25.

[0041] Arcing between rear contacts 521 and 522 causes gas decomposition in rear chamber 302, avoiding decomposition in the entire disconnector gas chamber. Because the arcing occurs inside rear chamber 302, gas decomposition occurs only within this rear chamber and does not contaminate the entire disconnector gas chamber (where dielectric strength is important).

[0042] The actuation system 6, 8 (formed means for opening the disconnector, i.e. a double-armed lever) comprises, for example, a rod 6 actuated at one of its ends 62 by a lever 8 (see FIG. 1) mounted to pivot about an axis 14 (perpendicular to the axis AA' of the disconnector). The other end 64 of the rod 6 is mounted for rotation about an axis 16 (in the XZ plane, see FIG. 1), causing the cylinder 30 to move along the axis AA'. In other words, the actuation system converts the rotation of the shaft 14 (driven by a mechanism not described in detail) into a translation of the cylinder along the axis AA'.

[0043] Therefore, the disconnector should be opened as follows: closing the arcing contacts 22, 42; separating the conductive tube 30 from one of the main contacts 24; opening the rear contacts by slowing or stopping the movable arcing contacts relative to the conductive tube 30 (FIG. 2D), causing an arc to form between the rear contacts away from the arcing contacts 22, 42; opening the arcing contacts 22, 42; After the opening sequence, the rear contact is closed to eliminate the floating potential (Figure 2E). Includes.

[0044] In this way, the rear contacts 521, 522 separate before the arcing contacts 22, 42 separate.

[0045] The disconnector is closed as follows: closing the arcing contacts 22, 42; closing the main contacts 24, 41; opening the arcing contacts 22, 42 to allow current to flow only through the main contacts; may include: [Industrial Applicability]

[0046] The present invention finds application to GIS operating at relatively low voltages (e.g., 27V, more typically between 10V and 500V) and relatively low currents (e.g., 3000A, more typically between 1000A and 6300A). [Explanation of symbols]

[0047] 1 metal tank 2 Second contact, electrode 4. First movable contact, electrode 6 Actuation system, insulating rod, rod 8 Actuation system, lever 14 axes 16 Rotation axis, axis 22 Arcing Contact 221 first dielectric surface 222 second dielectric surface 23 Internal cylindrical surface 24 Main contacts, permanent contacts 25 Restricted Section 27 Shoulder 30 Conductive tube, cylinder 301 Front Chamber 302 rear chamber 41 Main contacts, permanent contacts 42 Arcing Contact 421 Finger 422 Finger 43 Central Duct 44 Rods, tubes 46 Wall 50 compression spring 521 end contacts, rear contacts, back contacts 522 end contacts, rear contacts, back contacts 62 (rod) end 64 (rod) end 100 Disconnector AA' axis

Claims

1. A disconnector (100) for a gas insulator (GIS) is provided in a gas chamber along an axis (AA'): a pair of permanent contacts (24, 41) fixed together; a conductive tube (30) that is movable along the axis (AA') and that moves from a position where the permanent contacts (24, 41) are in electrical contact with each other to a position where the main contacts (24, 41) are electrically separated from each other; a pair of arc contacts (22, 42), one of which is fixed and the other of which is movable relative to the conductive tube (30); A pair of rear contacts (52 １ , 52 ２ ) and one rear contact (52 ２ A pair of rear contacts (52) are in electrical contact with the movable arc contact (42). １ , 52 ２ )and, means (25) for slowing or stopping the movable arcing contact (42) as it separates from the fixed arcing contact (22); The disconnector (100) is opened by moving the conductive tube (30) and the movable arcing contacts (22, 42) along the axis (AA'), and the rear contact (52) is opened before the arcing contacts (22, 42) separate. １ , 52 ２ means (6) for separating the A disconnector (100).

2. 2. The disconnector (100) of claim 1, wherein the means (25) for slowing or stopping the movable arcing contact (42) when separating from the fixed arcing contact (22) comprises a limiting portion (25) of the fixed arcing contact (22).

3. The disconnector (100) according to claim 2, wherein the restriction (25) of the fixed arcing contact (22) comprises a surface that is inclined relative to the axis (AA').

4. The disconnector (100) of claim 3, wherein said surface is inclined with respect to said axis (AA') at an angle between 20° and 40°.

5. A first end forming the movable arc contact (42) and a rear contact (52) １ , 52 ２ ) one rear contact (52 １ and a second end forming or supporting a first end of the first rod.

6. The disconnector (100) of claim 5, wherein the rod (44) is slidably mounted relative to the conductive tube (30).

7. The rear contact (52 １ , 52 ２ 7. The disconnector (100) of claim 6, comprising means (50) for pressing the first and second terminals (12) toward each other.

8. The rear contact (52 １ , 52 ２ 8. The disconnector (100) of claim 7, wherein the means (50) for urging the springs (100) toward each other comprises a compression spring (50).

9. The compression spring (50) has a first end that abuts against a wall (46) fixed to the conductive tube (30) and a rear contact (52). １ , 52 ２ ) one rear contact (52 １ 9. The disconnector (100) of claim 8, further comprising a second end abutting the first end.

10. The wall (46) separates the gas chamber from the rear contact (52 １ , 52 ２ a rear chamber (30) containing ２ ) and a front chamber (30) that houses the arc contacts (22, 42) when the arc contacts (22, 42) are closed. １ 10. The disconnector (100) of claim 9,

11. The rear contact (52 １ , 52 ２ ) one rear contact (52 ２ 11. The disconnector (100) of claim 10, wherein a movable conductive tube (30) is electrically coupled to and fixed to the movable conductive tube (30).

12. a metal tank (1) filled with gas; A disconnector (100) according to any one of claims 1 to 11; GIS equipped with.

13. The gas is containing heptafluoroisobutyronitrile and / or heptafluoroisopropyl trifluoromethyl ketone (also called 2-butanone, 1,1,1,3,4,4,4-heptafluoro-3-(trifluoromethyl)-(CAS No 756-12-7)), optionally mixed with a gas or diluent gas containing at least CO2 and / or O2 and / or N2 and / or an oxygenated compound, or at least CO2 and / or O2 and / or N2 and / or oxygenated compounds and / or water vapor; The GIS of claim 11.

14. 14. A method for opening a disconnector of a GIS according to claim 12 or 13, comprising the steps of: moving the movable arc contact (42) and the conductive tube (30) relative to the fixed arc contact (22) and the main contact (24, 41) to close the pair of arc contacts (22, 42) and electrically separate the pair of permanent contacts (24, 41); slowing or stopping the movement of the movable arcing contact (42) relative to the conductive tube (30); Before the arc contacts (22, 42) separate, the pair of rear contacts (52) １ , 52 ２ ) from each other, thereby separating said rear contacts (52 １ , 52 ２ ) inducing an arc between the Separating the movable arcing contact (42) from or relative to the fixed arcing contact (22) and separating the pair of rear contacts (52) １ , 52 ２ ) and A method comprising:

15. 14. A method for closing a disconnector of a GIS according to claim 12 or 13, comprising: closing the pair of arcing contacts (22, 42) by moving the movable arcing contact (42) and the conductive tube (30) relative to the fixed arcing contact (22) and the main contacts (24, 41); closing the main contacts (24, 41); opening said arcing contacts (22, 42); A method comprising:

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