High-speed earthing switch for interrupting non-short-circuit currents

Abstract

The present invention relates to a high-speed earthing switch (1), comprising two contacts (2), at least one of which is movable relative to the other between a closed position in which the contact (2) is connected and an open position in which the contact (2) is not connected, the contact (2) defining an arc discharge region in which an arc occurs during a current interruption operation and in which an arc-extinguishing medium is present, and a cylindrical guide tube (3) in which the at least one movable contact (2) forming a piston (4) is slidably arranged for linear movement between a closed position and an open position, the guide tube (3) being closed at an upper end (5) and / or at an opposite lower end (6), thereby defining a first compression chamber (9) with an upper end (5) and / or a second compression chamber (10) with a lower end (6), thereby slowing down the movement of the piston (4) when moving to the open and / or closed positions.

Description

Technical Field

[0001] The present invention relates to a high-speed earthing switch for interrupting non-short-circuit current, comprising two contacts, at least one of which is movable relative to the other contact between a closed position in which the contact is connected and an open position in which the contact is not connected, and the contact defines an arc discharge region in which an arc occurs during a current interruption operation and there is an arc extinguishing medium containing an arc extinguishing gas; and a cylindrical guide tube in which at least one movable contact forming a piston is slidably arranged so as to linearly move between the closed position and the open position.

Background Art

[0002] Dielectric insulating media in liquid or gaseous state have conventionally been applied to the insulation of conductive parts in a wide variety of devices, particularly also in GIS or its components. For example, in medium-voltage or high-voltage metal-enclosed switching devices, the conductive parts are arranged within an airtight housing defining an insulating space which contains an insulating gas and separates the housing from the conductive parts so that current cannot pass through the insulating space.

[0003] For example, in order to interrupt the current of a high-voltage switching device, the insulating medium further functions as an arc extinguishing medium or an arc quenching medium. This also applies, for example, to a circuit breaker or an earthing switch in which an arc generated during current interruption is extinguished under free burning conditions, which means that the arc extinguishing medium is not actively blown towards the arc.

[0004] In conventional gas-insulated switchgear, sulfur hexafluoride (SF6) is typically used as both the insulating and / or arc-extinguishing medium. Recently, the use of organofluorine compounds in the insulating medium has been proposed as an alternative to conventional insulating mediums, such as fluoroketones, which possess high insulating capacity, particularly high dielectric strength, and high arc-extinguishing ability. Simultaneously, they exhibit very low global warming potential (GWP) and very low toxicity.

[0005] High-speed earthing switches are typically operated by an operating mechanism that also provides acceleration and deceleration of the moving contacts. An SF6-free solution for such high-speed earthing switches requires an arc blow mechanism. In principle, the required mass flow rate can be determined by some kind of pump mechanism. The piston required to generate the mass flow to the arc requires a linearly moving mass, thus adding kinetic energy, which necessitates a high-performance damping device with a powerful kinetic chain, increasing the cost and technical risk of mechanical life. [Overview of the project] [Problems that the invention aims to solve]

[0006] Summary of the Invention Therefore, an object of the present invention is to provide an improved reduction mechanism for a high-speed earthing switch for interrupting non-short-circuit currents. [Means for solving the problem]

[0007] The object of the present invention is resolved by the features of the independent claim. Preferred embodiments are described in detail in the dependent claims.

[0008] Therefore, the purpose is a high-speed earthing switch, particularly for interrupting non-short-circuit currents and / or for inducing short-circuit currents to earth. Two contacts, where at least one contact is movable relative to the other contact between a closed position in which the contacts are connected and an open position in which the contacts are not connected, and the two contacts define an arc discharge region in which an arc is generated during current interruption and an arc extinguishing medium is present, A cylindrical guide tube is slidably arranged so as to move linearly between a closed position and an open position, and at least one movable contact forming a piston. This is solved by a high-speed earthing switch, which includes a guide tube that is closed at its upper end and / or the lower end on the opposite side, thereby defining a first compression chamber having an upper end and / or a second compression chamber having a lower end, thereby slowing down the movement of the piston as it moves to the open and / or closed positions.

[0009] The proposed solution performs deceleration by gas dampers provided at the upper and / or lower ends of the guide tube by the piston and guide tube, respectively, thereby reducing wear and high mechanical load on the operating mechanism of conventional high-speed grounding switches, which are typically under maximum load when deceleration occurs. In other words, the piston necessary to generate mass flow to the arc is used as a gas damper at its end position, thereby enabling deceleration at both ends of the stroke. Furthermore, since the kinetic energy absorbed during closing, i.e., moving to the closed position, is much higher than the kinetic energy during opening, i.e., moving to the open position, the proposed solution allows for the definition of specific damping characteristics for each direction of movement. These damping characteristics can be defined, for example, by dimensioning the piston and / or guide tube at the ends of the guide tube, respectively, or by the gas leak limiting device described below. Moreover, since the gas dampers have 100% efficiency, especially compared to tailor-made oil and rubber dampers with a maximum damping efficiency of 50%, the proposed solution does not have the fatal back-bouncing in the case of make-proof switches.

[0010] High-speed earthing switches, in particular for interrupting non-short-circuit currents, are preferably provided as devices designed to interrupt only non-short-circuit currents, in particular as disconnectors, more specifically as high-voltage disconnectors, or as earthing switches, more specifically as make-proof earthing switches, or as medium-voltage or high-voltage gas-insulated switchgear (GIS) comprising such devices. The term "short-circuit current" can be understood as the current established in the first transient phase, up to approximately 3 seconds after the point at which a component operating under high voltage is connected to earth from a grid operating under high voltage. According to this definition, the term "non-short-circuit current" preferably refers to currents that do not fall under the definition of "short-circuit current" above.

[0011] A short circuit is preferably understood as an electrical circuit that allows current to travel along an unintended path, often encountering essentially no electrical impedance or very low electrical impedance. Generally, such short-circuit currents are preferably interrupted within 5 seconds of occurrence to prevent damage to the electrical network, and more preferably, within 3 seconds. Thus, currents flowing from an electrical network, particularly a high-voltage or medium-voltage network, to ground via an unintended or intended path and lasting longer than 3 seconds or longer than 5 seconds can be considered “non-short-circuit currents.” This definition of non-short-circuit currents is preferably based solely on their duration and is independent of their magnitude or the intent or unintended nature of their occurrence. In particular, this definition of non-short-circuit currents may include nominal currents and exclude short-circuit currents lasting less than 5 seconds. For example, such a non-short-circuit current could be a current induced between two parallel overhead lines, one line connected to ground on both sides and the other line supplying current to a load. Non-short-circuit currents induced in grounded overhead lines can be interrupted by the proposed grounding switch.

[0012] The arc extinguishing medium may include air, or at least one air component, particularly selected from the group consisting of oxygen (O2) and nitrogen (N2), carbon dioxide (CO2), and mixtures thereof. The air or air component may function as a carrier gas or background gas additionally present in the organofluorine compounds of the arc extinguishing medium. The ratio of carbon dioxide to oxygen is particularly preferably in the range of 50:50 to 100:1. The ratio of carbon dioxide to oxygen is 80:20 to 95:5, more preferably 85:15 to 92:8, even more preferably 87:13 to less than 90:10, and particularly more preferably about 89:11. In this regard, it has been found that the presence of oxygen at a mole fraction of at least 5% makes it possible to prevent soot formation even after repeated current interruption events with relatively high current arc discharges. On the other hand, the presence of oxygen at a mole fraction of up to 20% (i.e., 20% or less), more specifically up to 15% (i.e., 15% or less), reduces the risk of device material degradation due to oxidation. The organofluorine compounds can be selected from the group consisting of fluoroethers (including oxiranes), especially hydrofluoromonoethers, fluoroketones, especially perfluoroketones, fluoroolefins, especially hydrofluoroolefins, fluoronitriles, especially perfluoronitriles, and mixtures thereof. The proposed grounding switch achieves safe operation despite the relatively low cooling efficiency of the carrier gas.

[0013] At least one movable contact is preferably axially movable relative to the guide tube. The guide tube is preferably provided as a cylinder, particularly an airtight cylinder, which is fluidly connected to the arc discharge region. The upper end may constitute the upper radially extending base region of the cylinder, and / or the lower end may constitute the lower radially extending base region of the cylinder. The upper end of the movable contact is preferably provided as a piston, particularly integrally with the movable contact. The piston and the movable contact each preferably extend perpendicularly through the lower end, particularly through the center of the lower end.

[0014] In a preferred embodiment, at least one pressure relief valve is provided at the upper and / or lower end of the guide tube. The pressure relief valve can be provided as a gas leak limiting device, thereby enabling the generation of specific damping characteristics. Preferably, the pressure relief valve is provided as a through pin in the guide tube.

[0015] In a more preferred embodiment, the piston is provided as a disc-shaped piston having a piston rod that slides on the inner surface of the guide tube and is positioned perpendicular to it, extending linearly in the direction of movement within the guide tube. The disc-shaped piston preferably extends radially and / or slides airtightly on the inner surface of the guide tube. In the internal view, the piston may have a T-shape. The piston rod preferably extends axially together with the guide tube.

[0016] In another preferred embodiment, the piston rod is hollow, and the damper element comprises a damper element whose upper end faces the hollow piston rod, and which becomes surrounded by the hollow piston rod when the piston reaches the open position. The damper element preferably has a cylindrical shape and / or extends from the upper end to the lower end. The damper element is preferably sized such that its outer diameter is slightly smaller than the inner diameter of the hollow piston rod. The hollow piston rod is preferably fluid-connected to the arc discharge region.

[0017] In a more preferred embodiment, the piston rod is provided as a tube, and the damper element has a tubular shape with a diameter smaller than the diameter of the piston rod. The diameter is preferably 0, 5, 1, 2, 3, 5, or 10% smaller. The damper element preferably extends within the guide tube for 5, 10, 15, or 20 cm from the upper end.

[0018] According to another preferred embodiment, the disc-shaped piston comprises at least one piston bar-shaped element extending linearly from the disc-shaped piston toward the upper and / or lower ends, the upper and / or lower ends having respective piston bar-shaped openings through which the piston bar-shaped element passes when the piston reaches the open and / or closed positions. The piston bar-shaped element preferably extends axially, preferably over 5, 10, 15, or 20 cm, and / or is provided as a rod. The outer diameter of the piston bar-shaped element is preferably 0, 5, 1, 2, 3, 5, or 10% smaller than the inner diameter of the piston bar-shaped opening. Multiple parallel-extending piston bar-shaped elements can be provided. Such piston bar-shaped elements allow for individual adjustment of damping characteristics.

[0019] In a more preferred embodiment, the lower end comprises at least one lower bar-shaped element extending linearly from the lower end to the upper end, and the disc-shaped piston comprises lower bar-shaped openings through which the lower bar-shaped elements pass when the piston reaches the closed position. The lower bar-shaped elements preferably extend axially, preferably over 5, 10, 15, or 20 cm, and / or are provided as rods. The outer diameter of the lower bar-shaped elements is preferably 0, 5, 1, 2, 3, 5, or 10% smaller than the inner diameter of the lower bar-shaped openings. Multiple parallel-extending lower bar-shaped elements can be provided. Such lower bar-shaped elements allow for individual adjustment of the damping characteristics.

[0020] In another preferred embodiment, the lower end is provided in the shape of a disc surrounding the piston rod. Preferably, the lower end is airtightly connected to a guide cube, and / or the piston rod has an outer diameter that is 1, 2, 5, or 10% smaller than the opening of the lower end surrounding the piston rod.

[0021] In a more preferred embodiment, the grounding switch includes an operating mechanism for the movable contact. The operating mechanism may include an operating spring for operating the closing movement of the movable contact from the open position to the closed position, and / or at least a drive lever attached to an operating shaft for operating the opening movement of the movable contact from the closed position to the open position. The drive lever may also partially reload the operating spring during the opening movement. Furthermore, the operating mechanism may further include coupling means for operably coupling the drive lever to the movable contact.

[0022] According to another preferred embodiment, the upper end of the guide tube is equipped with a gas refill valve. Such a gas refill valve is advantageous in avoiding loss of velocity generation when low pressure occurs. The same spring can be used for the opening and closing operation. In such a case, the same amount of energy is available for both operations. The velocity can be controlled by utilizing the gas resistance from the piston. In this way, the contact may open slightly slower than it closes, but not significantly.

[0023] This objective is further addressed by a three-pole high-voltage (HV) substation equipped with high-speed earthing switches on each pole, and in particular, a motor on each pole for operating the high-speed earthing switch on the corresponding pole. In such a three-pole HV substation, the high-speed earthing switches can be configured in three-pole operation, with a single motor and mechanical connection to operate all the high-speed earthing switch devices, or in single-pole operation, with a motor on each pole for operating the high-speed earthing switch device on the corresponding pole.

[0024] This objective is further addressed by the use of high-speed earthing switches, as described above, to interrupt non-short-circuit currents and / or to guide short-circuit currents to earth.

[0025] This object is a method for decelerating the movement of a piston in a high-speed earthing switch, especially for interrupting non-short-circuit currents and / or for inducing a short-circuit current to ground, wherein the high-speed earthing switch comprises two contacts, at least one of which is movable relative to the other between a closed position in which the contacts are connected and an open position in which the contacts are not connected, and said contacts define an arc discharge region in which an arc occurs and an arc quenching medium is present during a current interruption operation, a cylinder-shaped guide tube in which at least one movable contact forming a piston is slidably arranged so as to move linearly between the closed position and the open position and the guide tube is closed at its upper end and / or at its opposite lower end, thereby defining a first compression chamber having an upper end and / or a second compression chamber having a lower end for the piston, and the method comprises decelerating the movement of the piston when moving to the open position and / or the closed position and is further solved by the method.

[0026] The proposed method makes it possible to attenuate the piston in both the open and closed positions and to apply individual attenuation characteristics to both positions without the need for expensive damping devices as known from the prior art, thus resulting in a reduction in the cost of the earthing switch and a reduction in the technical risk of mechanical life. [[ID=·16]]

[0027] Further embodiments and advantages of the method are directly and clearly derivable by a person skilled in the art from the earthing switch as described above.

[0028] This object is further solved by the use of a method for decelerating the movement of a piston in a high-speed earthing switch according to the preceding claims, for interrupting non-short-circuit currents and / or for inducing a short-circuit current to ground.

[0029] Brief description of the drawings These and other aspects of the present invention will become apparent and will be described by reference to the embodiments described below. [Brief explanation of the drawing]

[0030] [Figure 1] A cross-sectional view of the upper part of a fast earthing switch for interrupting non-short-circuit currents and / or directing short-circuit currents to earth, according to a preferred embodiment, is shown. [Figure 2] A cross-sectional view shows the upper part of a high-speed earthing switch for interrupting non-short-circuit currents and / or guiding short-circuit currents to earth, according to a more preferred embodiment. [Figure 3] Furthermore, a cross-sectional view of the upper part of a high-speed earthing switch for interrupting non-short-circuit currents and / or guiding short-circuit currents to earth is shown in a further preferred embodiment. [Modes for carrying out the invention]

[0031] Description of the Embodiment Figures 1 to 3 show cross-sectional views of the upper parts of a high-speed earthing switch 1 for interrupting non-short-circuit currents and / or guiding short-circuit currents to earth, according to different preferred embodiments.

[0032] The high-speed earthing switch 1 for interrupting non-short-circuit current comprises two contacts 2, one of which is movable relative to the other contact, which is located below a movable contact 2 (not shown in the figures). The movable contact is movable between a closed position in which contact 2 is electrically connected and an open position in which contact 2 is not connected (as shown in all figures). The movable contact 2 can be provided as a tulip contact, the fixed contact as a plug contact, or vice versa. Both contacts can also be arranged to be movable relative to each other. The two contacts 2 define an arc discharge region in which an arc is generated during current interruption operation and an arc-extinguishing medium containing arc-extinguishing gas is present (not shown in the figures).

[0033] The grounding switch 1 further comprises an airtight cylindrical guide tube 3, specifically a right-circular hollow cylinder. The upper end of the movable contact 2 is formed as a T-shaped piston 4 in the cross-sectional view shown in the figure, thereby allowing the piston 4 to slide so as to move linearly in the vertical direction shown in the figure between a closed position and an open position within the guide tube 3. The guide tube 3 is closed at an upper end 5 and a lower end 6 on the opposite side.

[0034] Specifically, the upper end portion 5 is provided in a disc shape as a closed base region, and the lower end portion 6 is provided in a disc shape surrounding the piston rod 7 of the piston 4. Since the piston 4 is provided as a disc-shaped piston 8 having a disc-shaped head that slides on the inner surface of the guide tube 3, the piston 4 defines a first compression chamber 9 having the upper end portion 5 and a second compression chamber 10 having the lower end portion 6. When the piston 4 is moved between the open position and the closed position, the arc-extinguishing medium present in the guide tube 3 inside the first compression chamber 9 and the second compression chamber 10 is compressed, thereby causing deceleration of the piston 4 when moving to the open position and the closed position, respectively.

[0035] Various possibilities exist for adjusting the damping characteristics of the first compression chamber 9 and the second compression chamber 10, which can be described separately or combined below. As a first measure, a gas leak limiting device formed by a pressure relief valve 11 can be provided, which can be positioned to extend axially through the upper end 5 and / or lower end 6 of the guide tube 3.

[0036] In a further embodiment, the piston rod 7 is hollow and tubular in shape so that the arc-extinguishing medium can flow from the arc discharge region into the guide tube 3. In this respect, a damper element 12 in the form of a mass cylinder is positioned at the upper end 5 so as to extend toward the lower end 6 and can be aligned with the piston rod 7. The outer diameter of the damper element 12 is 2, 5, or 10% smaller than the inner diameter of the piston rod 7.

[0037] In this way, when the piston rod 7 reaches the open position, it surrounds the damper element 12. This means that while the piston 4 moves to the open position, the arc-extinguishing medium is compressed in the first compression chamber 9 and then attempts to leak out through the entire diameter of the hollow piston rod 7. However, once the hollow piston rod 7 surrounds the damper element 12, the free diameter of the system rod 7 becomes much smaller for the arc-extinguishing medium to leak out, and the damping at the end of the piston 7's movement becomes greater.

[0038] Similarly, the free diameter of the lower end 6 relative to the outer diameter of the piston rod 7 defines the damper characteristics of the second compression chamber 10 when the piston 4 moves to the closed position.

[0039] Figure 2 shows a further embodiment of the grounding switch 1, in which the disc-shaped piston 8 comprises two piston rod bar-shaped elements 13 extending in the axial direction, each piston rod bar-shaped element 13 being provided as a rod, each extending linearly in the direction of movement from the disc-shaped piston 13, one toward the upper end 5 and the other toward the lower end 6 by extension thereof. The upper end 5 and the lower end 6 each have piston bar-shaped openings 14 through which the piston bar-shaped elements 13 pass when the piston 4 reaches the open position and the closed position, respectively.

[0040] The outer diameter of the piston bar-shaped element 13 is slightly smaller than the inner diameter of the piston bar-shaped opening 14. The length of the piston bar-shaped element 13 is sized so that it can move freely between the open and closed positions without penetrating each piston bar-shaped opening 14, while simultaneously penetrating each piston bar-shaped opening 14 in its vicinity, thereby increasing the damping force near the end of its movement.

[0041] Figure 3 shows a further embodiment of the grounding switch 1, wherein the lower end 6 is provided with a lower bar-shaped element 15 on each side of the piston rod 7, which extends linearly axially from the lower end 6 to the upper end 5 as a rod. The disc-shaped piston 8 is provided with lower bar-shaped openings 16 through which each lower bar-shaped element 15 passes when the piston 4 reaches the closed position. Here again, the outer diameter of the lower bar-shaped element 15 is slightly smaller than the inner diameter of the lower bar-shaped opening 16.

[0042] The grounding switch further comprises an operating mechanism 17 for operating the movable contact 2, as can be seen in Figure 1. The operating mechanism 17 may comprise an operating spring for operating the closing movement of the movable contact 2 from the open position to the closed position, and / or at least a drive lever attached to an operating shaft for operating the opening movement of the movable contact from the closed position to the open position. The described grounding switch can be used in a three-pole high-voltage substation, which has a high-speed grounding switch at each pole and a motor at each pole for operating the high-speed grounding switch of the corresponding pole.

[0043] Although the present invention is illustrated and described in detail in the drawings and the foregoing description, such illustrations and descriptions should be considered descriptive or illustrative and not restrictive. The present invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments can be understood and achieved by those skilled in the art in carrying out the claimed invention from a study of the drawings, disclosure and the appended claims. In the claims, the words “comprising” do not exclude other elements or steps, and the indefinite articles “a” or “an” do not exclude plurals. The mere fact that certain means are described in different dependent claims does not imply that combinations of these means cannot be used advantageously. No reference numeral in the claims should be construed as restrictive. [Explanation of Symbols]

[0044] Reference Code List 1 Earthing switch 2 Movable contact 3 Guide tubes 4 pistons 5 Upper end 6 Lower end 7 Piston rod 8. Disc-shaped piston 9. First compression chamber 10 Second compression chamber 11 Pressure relief valve 12 Damper elements 13 Piston bar-shaped element 14 Piston bar-shaped opening 15 Lower bar-shaped element 16 Lower bar-shaped opening 17 Operating mechanism

Claims

1. Two contacts (2), wherein at least one of the movable contacts (2) is movable relative to the other contact between a closed position to which the contact (2) is connected and an open position to which the contact (2) is not connected, and the two contacts (2) define an arc discharge region in which an arc is generated during current interruption operation and an arc extinguishing medium is present, The piston (4) comprises at least one movable contact (2) slidably arranged to move linearly between the closed position and the open position, The guide tube (3) is closed at its upper end (5), thereby defining the first compression chamber (9) having the upper end (5) for the piston (4), thereby slowing down the movement of the piston (4) when it moves to the open position, and / or The guide tube (3) is closed at its opposite lower end (6), thereby defining a second compression chamber (10) having the lower end (6) of the piston (4), thereby slowing down the movement of the piston (4) when it moves to the closed position. The piston (4) slides on the inner surface of the guide tube (3) and is provided as a disc-shaped piston (8) having a piston rod (7) that is arranged perpendicularly thereto and extends linearly in the direction of movement within the guide tube (3), and The disc-shaped piston (8) comprises at least one piston bar-shaped element (13) extending linearly from the disc-shaped piston (8) toward the upper end (5) and / or the lower end (6), and the upper end (5) and / or the lower end (6) comprises piston bar-shaped openings (14) through which the bar-shaped element of the piston (4) passes when the piston (4) reaches the open position and / or the closed position, or The lower end portion (6) comprises at least one lower bar-shaped element (15) extending linearly from the lower end portion (6) toward the upper end portion (5), and the disc-shaped piston (8) comprises lower bar-shaped openings (16) through which the lower bar-shaped elements (15) pass when the piston (4) reaches the closed position. A high-speed grounding switch (1) is provided with a damper element (12) whose upper end (5) faces the hollow piston rod (7), and which surrounds the piston (4) when it reaches the open position.

2. Two contacts (2), wherein at least one movable contact (2) is movable relative to the other contact between a closed position to which the contact (2) is connected and an open position to which the contact (2) is not connected, and the two contacts (2) define an arc discharge region in which an arc is generated during current interruption operation and an arc extinguishing medium is present, The piston (4) comprises at least one movable contact (2) slidably arranged to move linearly between the closed position and the open position, The guide tube (3) is closed at its upper end (5), thereby defining the first compression chamber (9) having the upper end (5) for the piston (4), thereby slowing down the movement of the piston (4) when it moves to the open position, and / or The guide tube (3) is closed at its opposite lower end (6), thereby defining a second compression chamber (10) having the lower end (6) of the piston (4), thereby slowing down the movement of the piston (4) when it moves to the closed position. The piston (4) slides on the inner surface of the guide tube (3) and is provided as a disc-shaped piston (8) having a piston rod (7) that is arranged perpendicularly thereto and extends linearly in the direction of movement within the guide tube (3), and The disc-shaped piston (8) comprises at least one piston bar-shaped element (13) extending linearly from the disc-shaped piston (8) toward the upper end (5) and / or the lower end (6), and the upper end (5) and / or the lower end (6) comprises piston bar-shaped openings (14) through which the bar-shaped element of the piston (4) passes when the piston (4) reaches the open position and / or the closed position, or The lower end portion (6) comprises at least one lower bar-shaped element (15) extending linearly from the lower end portion (6) toward the upper end portion (5), and the disc-shaped piston (8) comprises lower bar-shaped openings (16) through which the lower bar-shaped elements (15) pass when the piston (4) reaches the closed position. A high-speed grounding switch (1) is provided with a gas refill valve at the upper end (5) of the guide tube (3).

3. The high-speed grounding switch (1) according to claim 1 or 2, wherein at least one pressure relief valve (11) is provided at the upper end (5) and / or the lower end (6) of the guide tube (3).

4. The high-speed earthing switch (1) according to claim 1, wherein the piston rod (7) is provided as a tube, and the damper element (12) has a tubular shape with a diameter smaller than the diameter of the piston rod (7).

5. The high-speed grounding switch (1) according to claim 1 or 2, wherein the lower end portion (6) is provided in a disc shape surrounding the piston rod (7).

6. The high-speed earthing switch (1) according to claim 1 or 2, comprising an operating mechanism (17) for at least one movable contact (2).

7. A three-pole high-voltage substation, each pole having a high-speed earthing switch (1) according to claim 1 or 2, and each pole having a motor for operating the high-speed earthing switch (1) of the corresponding pole.

8. Use of the high-speed earthing switch (1) according to claim 1 or 2 for interrupting non-short-circuit currents and / or for inducing short-circuit currents to earth.

9. A method for decelerating the movement of a piston (4) in a high-speed earthing switch (1), wherein the high-speed earthing switch (1) Two contacts (2), wherein at least one of the movable contacts (2) is movable relative to the other contact between a closed position to which the contact (2) is connected and an open position to which the contact (2) is not connected, and the two contacts (2) define an arc discharge region in which an arc is generated during current interruption operation and an arc extinguishing medium is present, The piston (4) comprises at least one movable contact (2) which is slidably arranged to move linearly between the closed position and the open position, The guide tube (3) is closed at its upper end (5), thereby defining the first compression chamber (9) having the upper end (5) of the piston (4), and / or The guide tube (3) is closed at its opposite lower end (6), thereby defining the second compression chamber (10) having the piston (4) at its lower end (6), and The piston (4) slides on the inner surface of the guide tube (3) and is provided as a disc-shaped piston (8) having a piston rod (7) that is arranged perpendicularly thereto and extends linearly in the direction of movement within the guide tube (3), and the method is, This includes decelerating the movement of the piston (4) when it moves to the open position and / or the closed position, The disc-shaped piston (8) comprises at least one piston bar-shaped element (13) extending linearly from the disc-shaped piston (8) toward the upper end (5) and / or the lower end (6), and the upper end (5) and / or the lower end (6) comprises piston bar-shaped openings (14) through which the bar-shaped element of the piston (4) passes when the piston (4) reaches the open position and / or the closed position, or The lower end portion (6) comprises at least one lower bar-shaped element (15) extending linearly from the lower end portion (6) toward the upper end portion (5), and the disc-shaped piston (8) comprises lower bar-shaped openings (16) through which the lower bar-shaped elements (15) pass when the piston (4) reaches the closed position. A method comprising a damper element (12) wherein the piston rod (7) is hollow, and the upper end (5) of the damper element (12) faces the hollow piston rod (7), and when the piston (4) reaches the open position, the damper element (12) is surrounded by the hollow piston rod (7).

10. A method for decelerating the movement of a piston (4) in a high-speed earthing switch (1), wherein the high-speed earthing switch (1) Two contacts (2), wherein at least one of the movable contacts (2) is movable relative to the other contact between a closed position to which the contact (2) is connected and an open position to which the contact (2) is not connected, and the two contacts (2) define an arc discharge region in which an arc is generated during current interruption operation and an arc extinguishing medium is present, The piston (4) comprises at least one movable contact (2) which is slidably arranged to move linearly between the closed position and the open position, The guide tube (3) is closed at its upper end (5), thereby defining the first compression chamber (9) having the upper end (5) of the piston (4), and / or The guide tube (3) is closed at its opposite lower end (6), thereby defining the second compression chamber (10) having the piston (4) at its lower end (6), and The piston (4) slides on the inner surface of the guide tube (3) and is provided as a disc-shaped piston (8) having a piston rod (7) that is arranged perpendicularly thereto and extends linearly in the direction of movement within the guide tube (3), and the method is, This includes decelerating the movement of the piston (4) when it moves to the open position and / or the closed position, The disc-shaped piston (8) comprises at least one piston bar-shaped element (13) extending linearly from the disc-shaped piston (8) toward the upper end (5) and / or the lower end (6), and the upper end (5) and / or the lower end (6) comprises piston bar-shaped openings (14) through which the bar-shaped element of the piston (4) passes when the piston (4) reaches the open position and / or the closed position, or The lower end portion (6) comprises at least one lower bar-shaped element (15) extending linearly from the lower end portion (6) toward the upper end portion (5), and the disc-shaped piston (8) comprises lower bar-shaped openings (16) through which the lower bar-shaped elements (15) pass when the piston (4) reaches the closed position. A method wherein the upper end (5) of the guide tube (3) is equipped with a gas refilling valve.

11. Use of a method for slowing the movement of a piston (4) in a high-speed earthing switch (1) according to claim 9 or 10, for the purpose of interrupting a non-short-circuit current and / or inducing a short-circuit current to earth.

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