A fast grounding switch with arc extinguishing device

Abstract

A fast grounding switch with an arc extinguishing device belongs to the technical field of fast grounding switches. The fast grounding switch with an arc extinguishing device includes a static contact, a moving contact, an operating mechanism, and an arc extinguishing device disposed in a sealed cylinder. The arc extinguishing device includes a pressure cylinder, a piston plate disposed in the pressure cylinder, and an air inlet chamber formed between the piston plate and the side of the pressure cylinder near the static contact. The air inlet chamber is connected to the interior of the moving contact through a plurality of first air holes, and the air inlet chamber is connected to the exterior of the static contact through a plurality of air ducts. The end of the air duct near the static contact is smoothly and reliably connected to the outer wall of the moving contact, one end of the moving contact cooperates with the static contact, and the other end of the moving contact is connected to the piston plate. The side of the piston plate away from the moving contact is connected to the operating mechanism. The fast grounding switch with an arc extinguishing device optimizes the structure of the fast grounding switch, enhances the arc extinguishing capability, and improves the ability of the fast grounding switch to interrupt induced current, thereby improving the operating reliability of the fast grounding switch.

Description

Technical Field

[0001] The present invention relates to the technical field of fast grounding switches, and in particular to a fast grounding switch with an arc extinguishing device. Background Art

[0002] Class B fast-acting earthing switches are designed for use on lines with extremely long or strong coupling to adjacent energized lines. Their superior ability to extinguish arcs (compared to conventional fast-acting earthing switches) makes them suitable for use on UHV transmission lines requiring automatic reclosing. Installed on GIL pipelines, these fast-acting earthing switches, operated by a spring mechanism, rapidly divert induced currents from the line to the ground, protecting line equipment and maintenance personnel. Compared to UHV transmission lines, UHV lines feature higher voltages, larger transmission capacities, taller towers, and longer insulator strings. Existing grounding switches suitable for UHV GIL pipelines are not yet available to ensure successful interruption of arc currents. Summary of the Invention

[0003] In order to solve the technical problems existing in the prior art, the present invention provides a fast grounding switch with an arc extinguishing device, which optimizes the structure of the fast grounding switch, enhances the arc extinguishing capability, improves the ability of the fast grounding switch to break the induced current, and thus improves the working reliability of the fast grounding switch.

[0004] In order to achieve the above object, the technical solution of the present invention is:

[0005] A fast grounding switch with an arc extinguishing device, comprising a static contact, a moving contact, an operating mechanism and an arc extinguishing device arranged in a sealing cylinder;

[0006] The arc extinguishing device includes a pressure cylinder, a piston plate is provided in the pressure cylinder, the piston plate and the pressure cylinder near the static contact side form an air inlet chamber, the air inlet chamber is connected to the interior of the moving contact through a plurality of first air holes, the air inlet chamber is connected to the outside of the static contact through a plurality of air guide tubes, and the end of the air guide tube near the static contact is smoothly and reliably connected to the outer wall of the moving contact;

[0007] One end of the moving contact cooperates with the static contact, and the other end of the moving contact is connected to the piston plate. The side of the piston plate away from the moving contact is connected to the operating mechanism, and the operating mechanism drives the moving contact to reciprocate to connect or disconnect it with the static contact;

[0008] The static contact is a hollow static contact, and the central conductor is provided with a through hole corresponding to the hollow static contact, so as to connect the static contact with the GIL pipe.

[0009] The air pressure cylinder is a cylindrical cavity, the top of which is connected to the GIL pipeline, and the bottom of which is provided with an opening.

[0010] The piston plate is connected to the inner wall of the air pressure cylinder smoothly and reliably.

[0011] The piston plate is made of conductive material, preferably aluminum sheet.

[0012] The moving contact is located at the axis of the pressure cylinder and moves along the axis of the pressure cylinder. The first air holes are located on a side of the moving contact close to the piston plate.

[0013] The movable contact housing is provided with a movable end shielding cover, a side of the movable end shielding cover close to the movable contact is provided with a circumferential groove, and a guide ring is installed in the circumferential groove.

[0014] The static contact is provided with a static end shielding cover.

[0015] A plurality of second air holes are provided between the air inlet chamber and the GIL pipe, and one end of the air guide pipe close to the air inlet chamber is connected to the second air holes.

[0016] Beneficial effects of the present invention:

[0017] 1) The present invention is applicable to UHV GIL pipelines, can ensure the successful interruption of the submerged current, enhance the arc extinguishing capability, and improve the ability of the fast grounding switch to interrupt the induced current and its working reliability;

[0018] 2) When the moving contact and the static contact just separate, the air flow channel formed between the static contact and the moving contact is extremely narrow, resulting in a high flow rate of the insulating gas in the channel. At this time, due to the low pressure in the air inlet chamber, the air duct introduces the gas near the air duct opening into the air inlet chamber, accelerating the gas flow rate between the static contact and the moving contact, thereby achieving a rapid arc extinguishing effect. At the same time, the gas at one end of the moving contact is also introduced into the air inlet chamber through the first air hole, further accelerating the gas flow rate between the static contact and the moving contact, thereby enhancing the rapid arc extinguishing effect.

[0019] 3) When the piston plate moves downward, it moves to the position of the opening of the pressure cylinder, the air inlet chamber opens, and the gas in the air inlet chamber quickly flows into the sealing cylinder, playing the role of balancing the pressure;

[0020] 4) The sealing cylinder can effectively prevent the leakage of insulating gas, ensuring that the insulating gas inside the GIL pipeline is not contaminated and achieving the effect of rapid arc extinguishing;

[0021] 5) The static contact uses a hollow static contact. When the fast earthing switch is in the open state, an arc is generated between the moving contact and the static contact. At this time, the pressure at the end of the static contact is low and the temperature is high. The insulating gas flows quickly from the hollow part of the static contact through the GIL pipe to the end of the static contact, accelerating the gas flow rate and achieving the purpose of rapid arc extinguishing.

[0022] 6) The technical solution of the present invention can be obtained by modifying the existing super-class B fast earthing switch. Compared with the fast earthing switch in the existing technology, an arc extinguishing device is added, which saves costs.

[0023] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A structural front view of a fast earthing switch with an arc extinguishing device provided in an embodiment of the present invention;

[0025] Figure 2 A structural side view of a fast earthing switch with an arc extinguishing device provided in an embodiment of the present invention;

[0026] Figure 3 A schematic diagram of a movable contact and a stationary contact provided in an embodiment of the present invention when in communication;

[0027] Figure 4 A schematic diagram of a movable contact and a stationary contact provided in an embodiment of the present invention when disconnected.

[0028] The reference numerals in the drawings of the specification include:

[0029] 1. Static contact, 2. Static end shield, 3. Air guide tube, 4. Center conductor, 5. Moving contact, 6. Moving end shield, 7. Second air hole, 8. Piston plate, 9. First air hole, 10. Air inlet chamber, 11. Connecting rod, 12. Operating mechanism, 13. Sealing cylinder. DETAILED DESCRIPTION

[0030] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention, in conjunction with the accompanying drawings. Obviously, the described embodiments represent only a portion of the embodiments of the present invention, and not all of them. In the description of the present invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," "the other end," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplification of the present invention. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation, and are therefore not to be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Unless otherwise expressly specified or limited, the terms "mounted," "provided with," and "connected" should be understood broadly. For example, "connected" can mean fixed, removable, or integral; mechanical or electrical; direct or indirect through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention.

[0031] In order to solve the problems existing in the prior art, such as Figure 1-4 As shown, an embodiment of the present invention provides a fast grounding switch with an arc extinguishing device, which optimizes the structure of the fast grounding switch, enhances the arc extinguishing capability, improves the ability of the fast grounding switch to interrupt the induced current, and thus improves the working reliability of the fast grounding switch.

[0032] like Figure 1-4As shown, a rapid earthing switch with an arc extinguishing device includes a static contact 1, a movable contact 5, an operating mechanism 12, and an arc extinguishing device disposed within a sealed cylinder 13. The arc extinguishing device makes this a Class B rapid earthing switch suitable for ultra-high voltage (UHV) GIL (Geared Inductive Loop) pipelines, providing enhanced breaking capacity and ensuring successful interruption of submerged current. The arc extinguishing device includes a pressure cylinder, which is a cylindrical cavity with a top connected to the GIL pipeline and an opening at the bottom. An unsealed opening is provided on one side of the pressure cylinder below the piston plate 8 to facilitate connection between the connecting rod 11 of the operating mechanism 12 and the other end of the movable contact 5. The sealed cylinder 13 contains insulating gas to ensure its stability. Furthermore, when the piston plate 8 moves downward and reaches the position of the pressure cylinder opening, the air inlet chamber 10 opens, allowing the gas in the air inlet chamber 10 to rapidly flow into the sealed cylinder 13, thereby balancing the pressure. A piston plate 8 is provided in the air cylinder. The piston plate 8 is smoothly and reliably connected to the inner wall of the air cylinder so that the outer periphery of the piston plate 8 contacts the inner wall of the air cylinder to ensure the sealing of the air chamber and the friction between the piston plate 8 and the inner wall of the air cylinder is very small, which is convenient for the reciprocating motion of the piston plate 8 and improves efficiency. The piston plate 8 is made of conductive material, preferably aluminum sheet. The piston plate 8 and the side of the air cylinder close to the static contact 1 form an air intake chamber 10. The air intake chamber 10 is connected to the inside of the moving contact 5 through a number of first air holes 9. The moving contact 5 is located at the axial position of the air cylinder. The moving contact 5 moves along the axial direction of the air cylinder. The first air holes 9 are located on the side of the moving contact 5 close to the piston plate 8. The outer cover of the moving contact 5 is provided with a moving end shielding cover 6. The side of the moving end shielding cover 6 close to the moving contact 5 is provided with a circumferential groove. A guide ring is installed in the circumferential groove to ensure the stability of the reciprocating motion of the moving contact 5. One end of the moving contact 5 In conjunction with the static contact 1, the other end of the moving contact 5 is connected to a piston plate 8. The side of the piston plate 8 facing away from the moving contact 5 is connected to an operating mechanism 12. The operating mechanism 12 drives the moving contact 5 to reciprocate, connecting and disconnecting it from the static contact 1. The air inlet chamber 10 is connected to the exterior of the static contact 1 via several air ducts 3. The ends of the air ducts 3 closest to the static contact 1 are smoothly and reliably connected to the outer wall of the moving contact 5. Several second air holes 7 are provided between the air inlet chamber 10 and the GIL pipe. The ends of the air ducts 3 closest to the air inlet chamber 10 are connected to the second air holes 7. A static end shield 2 is provided around the static contact 1. This shield 2 balances voltage and suppresses severe field distortion in areas with greater curvature of the static contact 1. The metal vapor, electrons, and ions generated during arcing can diffuse quickly and be adsorbed onto the static end shield 2, where they condense. This forces the arc to extinguish when the current passes through zero, restoring insulation.The static contact 1 is a hollow static contact, that is, a hollow structure is set in the axial direction of the existing static contact 1, and the central conductor 4 is provided with a through hole corresponding to the hollow structure of the hollow static contact, so as to connect the static contact 1 with the GIL pipeline. When the rapid earthing switch is in the open state, an arc is generated between the moving contact 5 and the static contact 1. At this time, the pressure at the end of the static contact 1 is low and the temperature is high. The insulating gas flows rapidly from the hollow part of the static contact 1 to the end of the static contact 1 through the GIL pipeline, thereby accelerating the gas flow rate and achieving the purpose of rapid arc extinguishing.

[0033] In this embodiment, the operating mechanism can adopt the operating mechanism 12 in the fast earthing switch of the prior art, which may include a pivotally connected connecting rod 11 and a mechanism connecting plate, etc. The connecting rod 11 drives the piston plate 8 and the moving contact 5 to move, thereby changing the pressure of the air inlet chamber 10, thereby achieving the function of increasing the gas flow rate. When the operating mechanism 12 drives the moving contact 5 to move downward, before the latent current passes through zero for the first time, the end of the air duct 3 close to the static contact 1 is separated from the outer wall of the moving contact 5, ensuring arc extinction at the first zero crossing. In actual use, the relative position of the air duct 3 and the static contact 1 can be determined according to the peak value of the first zero crossing of the latent current. The sealing cylinder 13 is connected to the GIL pipeline. The moving contact 5 is a hollow moving contact 5 in the prior art. The guide ring acts as a guide sleeve to ensure the stability of the reciprocating motion of the moving contact 5. The moving contact 5 is provided with 6 first air holes 9 to ensure the connection between the air inlet chamber 10 and the inside of the moving contact 5. The topmost first air hole 9 among the 6 first air holes 9 cannot be higher than the guide ring inside the moving end shielding cover 6 when the moving contact 5 and the static contact 1 are combined, so as to ensure the stability of the switch operation. Four second air holes 7 are opened between the air inlet chamber 10 and the GIL pipeline. The diameters of the first air holes 9 and the second air holes 7 are adjusted according to the different breaking voltage levels to achieve the breaking effect. The static contact 1 is surrounded by a static end shield 2, which is installed on the central conductor 4 of the GIL pipe, and a moving end shield 6 is installed on the periphery of the moving contact 5 to uniform the electric field. Both the static end shield 2 and the moving end shield 6 are metal structures with good conductive properties. The mating parts of the static contact 1 and the moving contact 5 are both made of high-temperature resistant tungsten-copper alloy, and the air guide tube 3 is made of high-temperature resistant ceramic.

[0034] The working principle of the above-mentioned fast grounding switch with arc extinguishing device is as follows:

[0035] When a GIL pipeline fails, Figure 3 As shown, the static contact 1 and the moving contact 5 are in the connected state;

[0036] After troubleshooting the GIL pipeline, Figure 4As shown, the operating mechanism 12 is opened, and the operating mechanism 12 is operated so that its connecting rod 11 pulls the moving contact 5 and the piston plate 8 to move downward together. The gas pressure in the air inlet chamber 10 and the moving contact 5 is reduced, and the gas flows into the air inlet chamber 10 from the second air hole 7 through the air guide pipe 3; when the moving contact 5 and the static contact 1 just move apart, the air flow channel formed between the static contact 1 and the moving contact 5 is extremely narrow, so that the insulating gas flow rate in the channel formed between the static contact 1 and the moving contact 5 is high. Since the pressure in the air inlet chamber 10 is relatively low, the air guide pipe 3 guides the gas near the air guide pipe 3 opening into the air inlet chamber 10, accelerating the gas flow rate between the static contact 1 and the moving contact 5, thereby achieving the effect of rapid arc extinguishing. At the same time, the gas at one end of the moving contact 5 is also introduced into the air inlet chamber 10 through the first air hole 9, further accelerating the gas flow speed between the static contact 1 and the moving contact 5, and enhancing the rapid arc extinguishing effect. At the same time, the static contact 1 uses a hollow static contact. Since the pressure at the end of the static contact 1 is low and the temperature is high, the insulating gas flows rapidly from the GIL pipe to the end of the static contact 1 through the hollow part of the static contact 1, accelerating the gas flow rate and achieving the purpose of rapid arc extinguishing. In this embodiment, when the distance between the static contact 1 and the moving contact 5 is 177 mm, the piston plate 8 moves downward to the position of the pressure cylinder opening, and the gas in the air inlet chamber 10 quickly flows into the sealing cylinder 13, playing a role in balancing the pressure.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fast grounding switch with an arc extinguishing device, characterized in that: It includes a static contact, a moving contact, an operating mechanism and an arc extinguishing device arranged in a sealing cylinder; The arc extinguishing device includes a pressure cylinder, a piston plate is provided in the pressure cylinder, the piston plate and the pressure cylinder near the static contact side form an air inlet chamber, the air inlet chamber is connected to the interior of the moving contact through a plurality of first air holes, the air inlet chamber is connected to the outside of the static contact through a plurality of air guide tubes, and the end of the air guide tube near the static contact is smoothly and reliably connected to the outer wall of the moving contact; One end of the moving contact cooperates with the static contact, and the other end of the moving contact is connected to the piston plate. The side of the piston plate away from the moving contact is connected to the operating mechanism, and the operating mechanism drives the moving contact to reciprocate to connect or disconnect it with the static contact; The static contact is a hollow static contact, and the central conductor is provided with a through hole corresponding to the hollow static contact, so as to connect the static contact with the GIL pipe; The air pressure cylinder is a cylindrical cavity, the top of which is connected to the GIL pipeline and the bottom of which is provided with an opening; The piston plate is connected to the inner wall of the pressure cylinder smoothly and reliably; The piston plate is made of conductive material; The movable contact is located at the axis of the pressure cylinder and moves along the axis of the pressure cylinder. The plurality of first air holes are located on a side of the movable contact close to the piston plate. The movable contact housing is provided with a movable end shielding cover, and a circumferential groove is provided on the side of the movable end shielding cover close to the movable contact, and a guide ring is installed in the circumferential groove; The static contact is provided with a static end shield; A plurality of second air holes are provided between the air inlet chamber and the GIL pipe, and one end of the air guide pipe close to the air inlet chamber is connected to the second air holes.

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