Sf6 free gas insulated disconnector with fully closed arcing chamber actuated by rod mechanism

Abstract

To provide a disconnector for a GIS.SOLUTION: A disconnector for a GIS, in a gas chamber and along an axis, includes: a pair of permanent contacts (24, 41), both being fixed; 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 to a position in which both main contacts are electrically separated; a pair of arcing contacts (22, 42), one of them being fixed and the other being movable together with the electrically conducting tube; a pair of rear contacts (521, 522), one of them being in electrical contact with the movable arcing contact (42); 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). This type of substation includes 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[0002] Sulfur hexafluoride (SF6), which contributes to the greenhouse effect, has in recent years been replaced by another gas, the so-called "g3" gas, which contains heptafluoroisobutyronitrile mixed with diluent gases including carbon dioxide and oxygen, and is being used to replace SF6, paving the way for a new generation of high-voltage (HV) power transmission equipment. This g3 gas has a significantly reduced environmental impact (more than 98% less global warming potential (GWP)).

[0003] However, it has been noted that powder is generated during the opening of disconnectors in GIS systems that use this gas. This powder, resulting from the decomposition of the G3 gas used in replacing SF6, is detrimental to the dielectric strength. In fact, the decomposition of G3, combined with the molten metal, results in metal oxide particles spreading on the corona shield surface, resulting in a peaking effect.

[0004] Therefore, there is a challenge to limit the production 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 generated when switching a disconnector.

[0006] The present invention first provides: a pair of permanent contacts, one of which is fixed and the other of which is movable, or both of which are fixed relative to each other, said permanent contacts being, for example, spring contacts; a pair of arcing contacts, one of which is fixed and the other of which is movable; a pair of rear contacts, one of which is in electrical contact with said movable arcing contact; means for separating said rear contacts from one another before the arcing contacts separate; This document relates to a disconnector for a GIS, including:

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

[0008] In one embodiment, the means for separating the rear contacts from one another comprises a lever, e.g. a two-armed lever, one of the rear contacts being fixed to an end of the lever, the lever being capable of rotating, e.g. around an axis fixed relative to the movable permanent contact.

[0009] Each contact of the pair of rear contacts may include, for example, at least one blade, and the rear contacts slide relative to each other when they are separated. In a more particular embodiment, each contact of the pair of rear contacts includes two blades that are parallel to each other.

[0010] Preferably, at least one rear contact in electrical contact with said movable arc contact is also in electrical contact with said movable main contact.

[0011] In certain embodiments, at least one contact of the pair of rear contacts is movable in a plane that may include axes along which the movable main and arcing contacts may move, for example, along an axis that is preferably perpendicular to the axes along which the movable main and arcing contacts may move.

[0012] The present invention also provides a metal tank filled with gas; a disconnector according to the invention as described above or disclosed in the present application; GIS related topics, including:

[0013] 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 relative to the fixed arc contact and the fixed main contact, thereby closing the pair of arc contacts and separating the pair of permanent contacts from each other; separating the pair of rear contacts from each other before the arcing contacts separate, thereby inducing an arc between the rear contacts; - separating said movable arcing contact relative to a fixed arcing contact; The present invention relates to a method comprising:

[0014] The present invention also provides a method for closing a disconnector of a GIS according to the present invention, comprising: - closing the pair of rear contacts before the arcing contacts close; - moving the movable arcing contact and the tube relative to the fixed arcing contact and the main contact, thereby closing the pair of arcing contacts; -closing the main contacts; -Opening the arcing contacts The present invention relates to a method comprising: [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram illustrating an example of a gas-insulated substation. [Figure 2A] 1 is a diagram showing an example of a disconnector according to the present invention; [Figure 2B] 1 is a diagram showing an example of a disconnector according to the present invention; [Figure 2C] 1 is a diagram showing an example of a disconnector according to the present invention; [Figure 2D] 1 is a diagram showing an example of a disconnector according to the present invention; [Figure 3]FIG. 1 shows an enlarged view of a back or rear arcing contact according to the present invention. [Figure 4] 1 illustrates one embodiment of a back or rear arcing contact according to the present invention. [Figure 5A] 1A and 1B are side views of an embodiment of a disconnector and its actuation mechanism according to the present invention; [Figure 5B] 1A and 1B show a top view of an embodiment of a disconnector and its actuation mechanism according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0016] An example of a metal tank 1 or interruption chamber containing a disconnector is shown 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.

[0017] 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 CO2 and / or O2 and / or N2 and / or oxygenated compounds, -or at least CO2 and / or O2 and / or N2 and / or oxygenated compounds and / or water vapor may include:

[0018] The metal tank may be surrounded, or intended to be surrounded, by an atmosphere containing some water and / or water vapor.

[0019] The disconnector includes a pair of electrodes (corona shields) 2, 4 extending along an axis AA' (parallel to axis X) and mounted in contact with each other along said axis AA' with the aid of actuation systems 6, 8 for moving a conductive tube 30 (see Figures 1 and 2A) which 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 current is interrupted, and vice versa.

[0020] 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 perform the function of properly breaking and making contact. The term "movable contacts" is used to refer to the movable arcing contacts and tubes, both of which are connected to the actuating system 6, 8.

[0021] The disconnector is a first movable contact 4, consisting for example of an arcing contact 42 in the form of a number of fingers, and of the main contacts 30, 41 (the arcing contact 42 is movable relative to the contact 41, the tube 30 moving from a position where the two main contacts are in contact to a position where the two main contacts are separated); a second contact 22, which is stationary in this example, and which is composed of an arcing contact 22 and a main contact 24; Includes:

[0022] The main contacts 24, 41 may be fixed relative to one another and the tube 30 moves from a closed position in which the main contacts 24, 41 are in electrical contact with one another to a position in which they are not in electrical contact.

[0023] These two elements cooperate between an open position in which the two electrodes 2, 4 are separated from each other, and a closed position (not shown in Figure 1) which allows current to pass between them (by translation of the tube 30).

[0024] During the breaking procedure, the two main contacts 30, 24 separate and then the arcing contacts 42, 22 take over (FIGS. 2B and 2C).

[0025] The actuation system 6, 8 (forming the means for opening the disconnector) comprises, for example, a rod 6 actuated at one of its ends 62 by a lever 8 (see FIGS. 1, 5A, 5B) mounted to pivot about an axis 14 (perpendicular to the axis AA′ of the disconnector). The rod 6 is also mounted to rotate about an axis 16 (in the XZ plane, see FIGS. 1, 5A, 5B) to move the cylinder 30 along the axis AA′. In other words, the actuation system converts the rotation of the axis 14 (driven by a mechanism not described in detail) into a translation of the cylinder along the axis AA′. As explained below, the rod 6 is extended by a sliding contact inside a totally enclosed arc chamber. In one embodiment, the rod 6 forms a two-arm lever, one arm extending between the end 62 and the axis 16 and the other arm extending between said axis 16 and the other end 52 of the rod, the end 52 supporting at least one electrical contact. In a variant, the means 6 for separating the rear contacts (521, 522) from each other may comprise a one-arm lever instead of a two-arm lever.

[0026] An example of a disconnector according to the invention is shown more precisely in Figures 2A to 2D and 3. The disconnector extends along a longitudinal axis AA'.

[0027] The movable electrode 4 includes a main contact 41 (eg, a non-movable spring contact), a movable tube 30, and an arc contact .

[0028] The movable tube 30 can be moved along an axis AA' between a closed position (Fig. 2A) and an open position (Fig. 2D) with the aid of actuation systems 6, 8.

[0029] The movable arcing contact 42 is formed at the end of a rod or tube 44 which is preferably made from the same conductive material as the contact 42 .

[0030] The arcing contact 42 has, for example, the form of a bulb with 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 end 42 includes, for example, at least two fingers 421, 422 which have a certain degree of elasticity so that they can be pressed against the fixed arcing contact 22. They are separated by a central duct 43 which gives the fingers some freedom to be pressed in the direction of the axis AA', especially when the arcing contact 42 enters the fixed arcing contact 22.

[0031] A wall 46 separates the gas chamber into two parts: a rear gas chamber 302 and an entire gas volume 301 (including the entire disconnector gas chamber). This wall 46 supports the movable arcing contact 42 and is electrically insulated so that the arcing contact 42 can be electrically isolated from the conductive tube 30.

[0032] On the side of the rear chamber 302, a metal contact 521 is electrically coupled to the tube 30 and is fixed relative to the tube.

[0033] The actuating rod 6 extends beyond the pivot axis 16 with a metal contact 522 designed to make contact with a back contact 521 (electrically coupled and fixed to the tube 30) at a range of positions on the actuating rod. This metal contact 522 is in constant electrical contact with the movable arc contact 42 by sliding over it (it can be appreciated that parts 48, 44 and 42 can be combined into a single machined part). Additional contacts can be included to avoid floating potentials on the arc contacts.

[0034] Rear contacts 522 (which remain in electrical contact with movable arcing contact 42) and 521 open slightly after main contact 24 and tube 30 have separated from each other, but during the period when arcing contacts 42 and 22 are still in contact. As a result, arc 53 is established between rear contacts 521 and 522, rather than between arcing contacts 42 and 22 (as shown in FIG. 3). Starting from a position where both rear contacts are in contact with each other, when second rear contact 522 is driven by the end of rod 6 in the plane XZ in which rod 6 rotates (see FIG. 5A), rear contact 522 can slide relative to rear contact 521, thus separating the rear contacts.

[0035] The disconnector according to the invention may therefore comprise means 6 for opening said disconnector and for opening said rear or back contacts 521, 522 before the arcing contacts 22, 42 are separated.

[0036] In an exemplary embodiment, each of the rear contacts includes at least one blade or one spring blade that can slide relative to one another in the XZ plane, preferably along an axis that is essentially perpendicular to the AA′ axis. In the embodiment shown in Figures 4 and 5A, each rear contact includes two parallel blades (see, for example, blades 522, 52′2 in Figures 4 and 5B).

[0037] 2A to 2D 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 in translation and rotation about the axis of rotation 16.

[0038] The first position is shown in FIG. 2A, where both electrodes 2 and 4 are in contact via main contacts 24, 41 (which in this example are both spring contacts) and tube 30, and rear contacts 521 and 522.

[0039] After the opening phase begins, the tube slides against main contact 24 until they separate (FIG. 2B), and arcing contact 22 slides against arcing contact 42. Current flows through arcing contacts 42, 22, tube 44, rear contacts 521 and 522 (which are still connected to each other), and cylinder 30.

[0040] After a certain time, rear contacts 521 and 522 separate (FIG. 2C), which induces an arc 53 between these two contacts 521 and 522 in rear chamber 302 where the decomposition of gases is harmless (as shown in FIG. 3).

[0041] An arc 53 is created between rear arcing contacts 521 and 522, causing gas decomposition in the rear chamber 302 and avoiding decomposition in the front chamber 301. Because the arc is created inside the rear chamber 302, gas decomposition occurs only inside this rear chamber and does not contaminate the front chamber 301 (including the entire disconnector gas chamber where dielectric strength is important).

[0042] The arcing contacts 22, 42 then separate (FIG. 2D). Because the current has already been interrupted by the rear contacts 521 and 522, no arc is created when they separate.

[0043] Therefore, opening the disconnector involves the following steps: - closing the arcing contacts 22, 42; - opening the main contacts 24, 41; - opening the rear contacts, thereby inducing an arc 53 between the rear contacts away from the arcing contacts 22, 42; - opening the arcing contacts 22, 42; - Closing the rear contact so that it has no floating potential after the opening sequence (Fig. 2D) Includes:

[0044] Thus, the rear contacts 521, 522 separate before the arcing contacts 22, 42 separate.

[0045] The length from the contact 522 to the lever 6 and the size of the rear contacts 521, 522 can be dimensioned as required, particularly depending on the expected timing of arcing.

[0046] Closing the disconnector involves the following steps: - closing the rear contacts 521, 522, - closing the arcing contacts 22, 42; - closing the main contacts 24, 41; - opening the arcing contacts 22, 42 may include:

[0047] The present invention finds application in GIS operating at relatively low voltages (eg 27V, more typically 10V-500V) and relatively low currents (eg 3000A, more typically 1000A-6300A) between the rear contacts. [Explanation of symbols]

[0048] 1 metal tank 2 electrodes 2. Second Contact Point 4 electrodes 4 First Movable Contact 6. Actuation System 6 rods 6 Lever 8. Actuation System 8 Lever 14 axes 16 axes 22 Arcing Contact 24 Main contact 30 Conductive tube 30 cylinders 30 Main contact 301 total gas volume 302 rear gas chamber 41 Main contact 42 Arcing Contact 42 End 42 parts 44 parts 48 parts 421 Finger 422 Finger 43 Central Duct 44 tube 46 Wall 52 End 521 rear contact 522 Rear contact, blade 52' 2 blades 53 Arc 62 End AA' axis X-axis XZ plane

Claims

1. A disconnector (100) for a gas insulator (GIS) having a gas chamber along an axis (AA'): a pair of permanent contacts (24, 41) both of which are fixed; a conductive tube (30) movable along said axis (AA'), the conductive tube (30) moving from a position where both permanent contacts are in electrical contact to a position where both main contacts are electrically separated; a pair of arc contacts (22, 42), one (22) being fixed and the other (42) being movable together with the conductive tube (30); A pair of rear contacts (52 １ , 52 ２ ), and one of them (52 ２ a pair of rear contacts (52) in electrical contact with the movable arc contact (42); １ , 52 ２ )and, The conductive tube (30) and the movable arcing contacts (22, 42) are moved along the axis (AA'), thereby opening the disconnector (100), and the rear contact (52) is moved before the arcing contacts (22, 42) separate. １ , 52 ２ means (6) for separating the A disconnector (100) comprising:

2. The rear contact (52 １ , 52 ２ 2. The disconnector (100) of claim 1, wherein the means (6) for isolating the movable permanent contacts (41) from one another comprises a one-arm or two-arm lever, one of the rear contacts being fixed to an end (52) of the lever, and the lever rotating about an axis (16) fixed relative to the movable permanent contact (41).

3. A wall (46) separates the gas chamber from the rear contact (52). １ , 52 ２ a rear gas chamber (30) including ２ ) and a front chamber (30) containing said arc contacts when said arc contacts are closed. １ The disconnector (100) of claim 1 .

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

5. The pair of rear contacts (52 １ , 52 ２ 2. The disconnector (100) of claim 1, wherein each of the rear contacts includes at least one blade that slide relative to one another when the rear contacts are separated.

6. A pair of rear contacts (52 １ , 52 ２ Each contact point of the blades (52) is parallel to each other. ２ , 52' ２ The disconnector (100) of claim 5, comprising:

7. The pair of rear contacts (52 １ , 52 ２ 2. The disconnector (100) of claim 1, wherein at least one of the contacts of said movable arc contact is movable in a plane (XZ) containing said axis (AA') along which said movable arc contact can move.

8. The pair of rear contacts (52 １ , 52 ２ 8. The disconnector (100) of claim 7, wherein at least one of the contacts (AA') is movable along an axis perpendicular to the (AA') axis.

9. The rear contact (52 １ , 52 ２ 2. The disconnector (100) of claim 1, wherein a first contact (22, 42) is disposed in a portion of the disconnector (100) remote from the arcing contacts (22, 42).

10. a metal tank (1) filled with gas; A disconnector (100) according to any one of claims 1 to 9. Including GIS.

11. 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 10.

12. 11. A GIS according to claim 10, wherein the metal tank (1) is surrounded or intended to be surrounded by an atmosphere containing some water and / or water vapor.

13. moving the movable arcing contact (42) and the tube (30) relative to the fixed arcing contact (22) and the main contact, thereby closing the pair of arcing contacts and separating the pair of permanent contacts (24, 41); Before the arcing contacts (22, 42) separate, the pair of rear contacts (52) １ , 52 ２ ) from each other, thereby inducing an arc (53) between said rear contacts; separating the movable arcing contact (42) relative to the fixed arcing contact (22); 13. A method for opening a disconnector (100) of a GIS according to any one of claims 10 to 12, comprising:

14. Before the arc contacts (22, 42) close, the pair of rear contacts (52) １ , 52 ２ ) and moving the movable arc contact (42) and the tube (30) relative to the fixed arc contact (22) and the main contacts (24, 41), thereby closing the pair of arc contacts; Closing the main contacts (24, 41); Opening the arcing contacts (22, 42); 13. A method for closing a disconnector (100) of a GIS according to any one of claims 10 to 12, comprising:

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