A pneumatically operated isolating earthing switch device

Abstract

The utility model relates to high pressure switch technical field especially relates to a kind of pneumatic isolating grounding switch device.The device includes shell, sets up grounding switch static contact and isolating switch static contact on shell, sets up cylinder and piston rod in shell, the inner chamber of cylinder is divided into two gas chambers;The piston rod both ends are respectively equipped with isolating switch moving contact and grounding switch moving contact, and piston rod both ends are from the both ends of cylinder, respectively with the isolating switch static contact, the grounding switch static contact face-to-face setting of shell, two gas chambers are connected with the reversing valve and air pump outside shell, by filling and discharging to two gas chambers, the air pressure of two gas chambers is adjusted to form pressure difference, to push piston rod and moving contact reciprocating sliding.The utility model sets a set of pneumatic structure, can realize the closing of isolating switch, can also realize the closing of grounding switch, greatly simplifies the structure of isolating grounding switch device, makes it more miniaturization, improves the flexibility of equipment arrangement.

Description

Technical Field

[0001] This utility model relates to the field of high voltage switch technology, and in particular to a pneumatic isolation grounding switch device. Background Technology

[0002] Gas-insulated metal-enclosed switchgear (GIS) is widely used in power systems. Disconnect switches / grounding switches, as important components of GIS equipment, play a crucial role in substation operation. One function of a disconnect switch is to isolate circuits or equipment when de-energized, ensuring safe maintenance. Another function is to work with circuit breakers to switch circuit operation modes in double busbar or bypass systems. One function of a grounding switch is to fix the equipment potential to zero during line maintenance, preventing electric shock accidents caused by accidental power surges or induced voltages. Another function of a grounding switch is that, when used in conjunction with a disconnect switch, it performs a grounding operation after isolation, creating a clear disconnection point and further ensuring maintenance safety.

[0003] Currently, there are some GIS disconnecting ground switches on the market, mainly including gear and rack driven disconnecting ground switches and linkage driven disconnecting ground switches. Among them, gear and rack driven disconnecting ground switches have high installation accuracy requirements, complex structure, and non-compact size structure; linkage driven disconnecting ground switches mostly require two separate power mechanisms for the disconnecting switch and the grounding switch, which leads to high cost and complex structure. Summary of the Invention

[0004] To solve the above problems, this utility model provides a pneumatic isolating and grounding switch device, which only requires one power mechanism. By adjusting the pressure difference, the moving contact is moved to realize the closing / opening of the isolating switch and the grounding switch respectively.

[0005] The specific technical solution of this utility model is as follows: A pneumatic isolating grounding switch device includes a housing. One end of the housing has a stationary grounding switch contact, and the other end has a stationary isolating switch contact. A conductive cylinder is housed inside the housing, through which a conductive piston rod passes. A conductive partition is wound around the center of the piston rod, and the edge of the partition is tightly fitted against the inner wall of the cylinder, dividing the cylinder's internal cavity into two chambers. Moving contacts for the isolating switch and grounding switch are respectively located at both ends of the piston rod, which extend from both end faces of the cylinder, allowing the two moving contacts to respectively interact with the stationary isolating switch contact and the grounding switch contact on the housing. The stationary contacts of the switches are arranged face-to-face. When the piston rod slides back and forth along the cylinder under the pressure difference between the two air chambers, the moving contact of the isolating switch alternately engages with the stationary contact of the isolating switch, and the moving contact of the grounding switch alternately engages with the stationary contact of the grounding switch, thereby achieving their respective closing / opening. Two air supply pipes are connected to the side wall of the cylinder. One end of each air supply pipe is connected to one of the two air chambers, and the other end is connected to an air pump outside the housing via a reversing valve. This pump is used to alternately fill or exhaust the two air chambers, thereby changing the pressure in the two air chambers. The side wall of the cylinder is connected to the electrical equipment outside the cylinder via a conductive connector. This invention, by setting up a cylinder and a piston rod, and dividing the cylinder into two air chambers along the piston rod axis, allows the piston rod to reciprocate by adjusting the pressure difference between the two air chambers. This enables the piston rod to close or open with the stationary contacts of the isolating switch or the grounding switch at both ends of the piston rod, achieving isolation or grounding of the electrical equipment.

[0006] Furthermore, the inner wall of the cylinder is provided with a raised ridge parallel to the piston rod, and the partition in the middle of the piston rod has a notch at a position corresponding to the raised ridge. The shape and size of the notch match the raised ridge, and the inner surface of the notch is in close contact with the outer surface of the raised ridge. Through the cooperation between the raised ridge and the notch, the reciprocating motion of the piston rod can be guided, preventing deviation.

[0007] Furthermore, the protruding ridge contains a main air passage aligned with its extending direction. This main air passage is divided into two parts: one part connects to an air supply pipe and an air chamber, while the other part connects to another air supply pipe and another air chamber. By providing a main air passage within the protruding ridge to connect the air supply pipe and the air chamber, the space within the cylinder wall can be fully utilized, eliminating the need for a separate gas connection device.

[0008] Preferably, the cylinder has an insulated air supply rod on the side with the protruding ridge. The outer end of the insulated air supply rod is connected to the housing. Two air supply pipes are arranged axially inside the insulated air supply rod, and their two ends are respectively connected to the air pump and the main air passage inside the protruding ridge. The insulated air supply rod and air supply pipes inside the cylinder facilitate fixing and supporting the air supply pipes; at the same time, the air supply rod is made of insulating material to prevent electrical conductivity between the cylinder and the housing.

[0009] Preferably, the cylinder is open at both ends and sealed by an end cap assembly. The end cap assembly has an auxiliary air passage that connects the main air passage and the air chamber. An opening is made at the center of the end cap assembly for the piston rod end to pass through. Lubricating grease is provided between the hole wall and the piston rod for lubrication and sealing.

[0010] Preferably, the housing is equipped with a disconnecting switch stationary contact and a connecting body via a basin-type insulator for conductive connection with external electrical equipment; the grounding switch stationary contact is connected to an external grounding plate via an insulator and fixed to the housing via a flange.

[0011] Furthermore, the air pump is equipped with a pressure sensor to monitor the pressure difference between the air pump's intake and exhaust sides, and to determine whether the isolating switch and grounding switch are properly closed / opened.

[0012] Furthermore, a shielding cover is provided around the piston rod end on both sides of the cylinder to prevent the sharp corners of the end cap and the fixing screws from worsening the electric field and causing partial discharge or tip discharge.

[0013] Furthermore, the housing has openings at the two gas pipe extension positions and is provided with a removable cover, and the air pump and reversing valve are installed on the outside of the cover.

[0014] Furthermore, the housing is provided with a foreign object collection groove below the corresponding isolating switch stationary contact and grounding switch stationary contact to collect foreign objects that fall when the contacts open or close, effectively reducing the risk of discharge.

[0015] The beneficial effects of this utility model are: 1. This utility model flexibly utilizes a pneumatic structure composed of a cylinder, piston rod, and air pump. The pressure difference formed by the inflation and deflation of air drives the piston rod to move, causing the moving contact to close / open with the stationary contact. The operation is simple, convenient, and easy to implement.

[0016] 2. This utility model is equipped with a pneumatic structure, with the moving contact of the isolating switch and the moving contact of the grounding switch integrated at both ends of the piston rod. By cooperating with the air pump and the reversing valve, the air pressure in the two air chambers of the cylinder is changed. When the piston rod is pushed to move back and forth under the action of pressure difference, both the isolating switch and the grounding switch can be closed. This greatly simplifies the structure of the isolating and grounding switch device, makes it more compact, and improves the flexibility of equipment layout. Attached Figure Description

[0017] Figure 1 This is a perspective view of the present invention; Figure 2 This is a cross-sectional view of the present invention; Figure 3 This is a side view of the cylinder and connecting body described in this utility model; Figure 4 yes Figure 3AA section view; Figure 5 This is a perspective view of the piston rod described in this utility model; Figure 6 It is a three-dimensional representation of the outer end cap described in this utility model. Figure 1 ; Figure 7 It is a three-dimensional representation of the outer end cap described in this utility model. Figure 2 ; Figure 8 It is a three-dimensional representation of the inner end cap described in this utility model. Figure 1 ; Figure 9 It is a three-dimensional representation of the inner end cap described in this utility model. Figure 2 ; In the diagram, 1. Shell, 2. Basin-type insulator, 3. Grounding plate, 4. Insulator, 5. Flange, 6. Air pump, 7. Reversing valve, 8. Top cover, 9. Insulating air supply rod, 10. Stationary contact of disconnecting switch, 11. Stationary contact of grounding switch, 12. Cylinder, 13. Shielding cover, 14. Moving contact of grounding switch, 15. Outer end cover, 16. Inner end cover, 17. Piston rod, 18. Partition plate, 19. Foreign object collection trough, 20. Air supply pipe, 21. Main air passage, 22. Auxiliary air passage, 23. Moving contact of disconnecting switch, 24. Connector, 25. Air chamber, 26. Protruding ridge, 27. Baffle plate, 28. Notch, 29. Arc-shaped groove, 30. Annular groove, 31. First through hole, 32. Second through hole. Detailed Implementation

[0018] The structure of this utility model will be described in detail below with reference to the accompanying drawings and embodiments.

[0019] A pneumatic isolating grounding switch device, such as Figure 1 , 2As shown, the device includes a four-way housing 1. The left and bottom openings of the housing 1 are larger, each housing a basin-type insulator 2 with a conductive base. A disconnector stationary contact 10 is installed on the conductive base of the left basin-type insulator 2. The right opening of the housing 1 is smaller, used to install a grounding switch stationary contact 11. The grounding switch stationary contact 11 is electrically connected to a grounding plate 3 via an insulator 4. A flange 5 is installed at the right opening of the housing. After the grounding switch stationary contact is inserted into the housing, it is fixed by connecting the insulator to the flange. The centerlines of the disconnector stationary contact 10 and the grounding switch stationary contact 11 are on the same straight line. The housing 1 has a foreign matter collection groove 19 below each of the disconnector and grounding switch stationary contacts to collect debris falling during contact opening and closing, preventing discharge. A top cover 8 is bolted to the top opening of the housing 1. An air pump 6 and a reversing valve 7 are installed on the outside of the top cover 8. The air pump 6 is equipped with a pressure sensor (not shown in the figure) to monitor the pressure difference between the air pump's intake and exhaust sides. Through multiple tests, the maximum pressure difference corresponding to the closed and open positions on both sides can be measured, and a threshold can be set based on this. During operation, when the pressure difference detected by the pressure sensor reaches the set threshold, it is considered that the closed or open position is reached. Thus, by monitoring the pressure difference, it is determined whether the closed or open position is reached.

[0020] like Figure 2-4 As shown, a cylindrical cylinder 12 is provided inside the housing 1, and the cylinder 12 is made of conductive material. A conductive connector 24 is provided at the bottom of the cylinder 12, corresponding to the conductive seat of the basin-type insulator at the bottom of the housing. The connector 24 is connected to the conductive seat, and the cylinder is electrically connected to external electrical equipment through the basin-type insulator. The top sidewall of the cylinder protrudes into the cylinder, forming a convex ridge 26 extending along the cylinder's axial direction. The surface of the convex ridge 26 is arc-shaped. A main air passage 21 is provided axially inside the convex ridge 26. An insulating air supply rod 9 is fixedly connected to the cylinder at the position where it aligns with the top cover. Two air supply pipes 20 are provided inside the insulating air supply rod 9, and the top ends of the two air supply pipes extend from the top cover and connect to the reversing valve 7 and the air pump 6 on the top cover. A baffle 27 is provided at the position where the insulating air supply rod is located in the main air passage 21, dividing the main air passage into left and right parts. The left part of the main air passage is connected to the left air supply pipe, and the right part of the main air passage is connected to the right air supply pipe.

[0021] like Figure 2 , 5As shown, a piston rod 17 made of conductive material runs axially through the cylinder. The diameter of the piston rod is smaller than the inner diameter of the cylinder, and there is a cavity between the piston rod and the cylinder wall. The left end of the piston rod 17 is embedded with a copper-tungsten alloy as a moving contact 23 for a disconnecting switch, meeting the performance requirements of the disconnecting switch contact. The right end of the piston rod 17 directly serves as a moving contact 14 for a grounding switch. A partition 18 of the same conductive material is integrally surrounded in the middle of the piston rod. The partition has an arc-shaped notch 28 at a position corresponding to the protrusion, the size and shape of which match the protrusion. The notch and protrusion provide guidance when the piston rod moves left and right. The edge of the partition fits tightly against the inner wall of the cylinder, dividing the cavity into two chambers 25. The contact surface between the partition and the cylinder is coated with GIS-specific grease to ensure the left and right sliding of the piston rod while ensuring the two chambers are sealed and isolated. An end cap assembly is provided at each of the left and right ends of the cylinder for sealing. The end cap assembly includes an outer end cap 15 and an inner end cap 16. The outer end cap and the inner end cap have an opening in the middle for the two ends of the piston rod to pass through. At the same time, an annular groove 30 is formed in the wall of the opening. The annular groove 30 contains grease, which serves to lubricate and seal the piston rod.

[0022] like Figure 6 , 7 As shown, the outer end cap 15 has an arc-shaped groove 29 on its upper part, and the inner end cap 16 has a matching arc-shaped groove 29 at the corresponding position. When the two are fitted together, they form an auxiliary air passage 22. At the same time, the two arc-shaped grooves extend upward in the middle to ensure that they can be aligned with the main air passage outlet when the two end caps are installed at both ends of the cylinder. The end of the upward extension of the arc-shaped groove of the inner end cap has a first through hole 31, which communicates with the main air passage 21; the two ends of the arc-shaped groove of the inner end cap have second through holes 32, which communicate with the air chamber, thereby realizing the gas transmission from the air supply pipe, the main air passage, the auxiliary air passage to the air chamber. Each end of the cylinder is also provided with a shield 13, which surrounds the two moving contacts. It does not affect the extension of the moving contacts, and at the same time, it can play a shielding role to prevent the sharp corners of the end cap and the fixing screws from deteriorating the electric field and causing partial discharge or tip discharge.

[0023] The working process of this utility model is as follows: When the isolating switch needs to be opened and the grounding switch needs to be closed, the air pump's intake port is connected to the air supply line of the cylinder's grounding switch side chamber via a reversing valve, and the air pump's exhaust port is connected to the air supply line of the cylinder's isolating switch side chamber. When the air pump is started, a low-pressure zone forms in the cylinder's grounding switch side chamber, and a high-pressure zone forms in the cylinder's isolating switch side chamber. The pressure difference across the piston rod partition generates a thrust that pushes the piston rod towards the grounding switch side, causing the moving contacts of the isolating switch and grounding switch to move synchronously with the piston rod. The air pump's built-in pressure sensor monitors the pressure difference between the air pump's intake and exhaust sides. When the pressure difference reaches a set threshold, it indicates that the isolating switch contacts are open and the grounding switch contacts are closed, at which point the air pump stops working, thus achieving the grounding operation of the electrical equipment.

[0024] When the grounding switch needs to be opened and the isolating switch needs to be closed, the air pump's intake port is connected to the air supply line of the isolating switch side chamber of the cylinder via a reversing valve, and the air pump's exhaust port is connected to the air supply line of the grounding switch side chamber of the cylinder. When the air pump is started, a low-pressure zone forms in the isolating switch side chamber and a high-pressure zone forms in the grounding switch side chamber. The pressure difference across the piston rod partition generates a thrust that moves the piston rod towards the isolating switch side. The moving contacts of the isolating switch and the grounding switch move synchronously with the piston rod. The air pump's built-in pressure sensor monitors the pressure difference between the air pump's intake and exhaust sides. When the pressure difference reaches a set threshold, it indicates that the grounding switch contacts are open and the isolating switch contacts are closed, at which point the air pump stops working, achieving the isolation operation of the electrical equipment.

Claims

1. A pneumatic isolating grounding switch device, comprising a housing, wherein a grounding switch stationary contact is provided at one end of the housing, and an isolating switch stationary contact is provided at the other end; characterized in that: The housing contains a conductive cylinder with a conductive piston rod running through it. A conductive partition surrounds the piston rod, with its edge tightly fitted to the inner wall of the cylinder, dividing the cylinder's internal cavity into two chambers. The piston rod has a moving contact for an isolating switch and a moving contact for a grounding switch at each end, extending from the cylinder's end faces. These moving contacts face-to-face with the stationary contacts of the isolating and grounding switches on the housing. When the piston rod slides back and forth along the cylinder under the pressure difference between the two chambers, the moving contacts alternately engage with the stationary contacts, achieving their respective closing / opening operations. Two air supply pipes connect to the cylinder's sidewall. One end of each pipe connects to one of the two chambers, and the other end connects to an external air pump via a reversing valve. These pipes alternately fill or exhaust the two chambers, thereby changing their pressure. The cylinder's sidewall is connected to external electrical equipment via a conductive connector.

2. The pneumatic isolating grounding switch device according to claim 1, characterized in that: The cylinder inner wall is provided with a convex ridge parallel to the piston rod. The partition in the middle of the piston rod has a notch at the position corresponding to the convex ridge. The shape and size of the notch match the convex ridge, and the inner surface of the notch is in close contact with the outer surface of the convex ridge.

3. The pneumatic isolating grounding switch device according to claim 2, characterized in that: The protruding ridge has a main air passage that extends in the same direction as the ridge. The main air passage is divided into two parts. One part of the main air passage is used to connect an air supply pipe and an air chamber, and the other part of the main air passage is used to connect another air supply pipe and another air chamber.

4. The pneumatic isolating grounding switch device according to claim 3, characterized in that: The cylinder has an insulated air supply rod on the side with the protrusion. The outer end of the insulated air supply rod is connected to the housing. Two air supply pipes are arranged axially inside the insulated air supply rod, and their two ends are respectively connected to the air pump and the main air passage inside the protrusion.

5. The pneumatic isolating grounding switch device according to claim 3, characterized in that: The cylinder is open at both ends and sealed by an end cap assembly. The end cap assembly has an auxiliary air passage that connects the main air passage and the air chamber. An opening is made at the center of the end cap assembly for the piston rod end to pass through. Lubricating grease is provided between the hole wall and the piston rod for lubrication and sealing.

6. The pneumatic isolating grounding switch device according to any one of claims 1-5, characterized in that: The air pump is equipped with a pressure sensor to monitor the pressure difference between the air pump's intake and exhaust sides, and to determine whether the isolating switch and grounding switch are properly closed / opened.

7. The pneumatic isolating grounding switch device according to any one of claims 1-5, characterized in that: The housing is equipped with the stationary contact of the disconnecting switch and the connecting body via a basin-type insulator for conductive connection with external electrical equipment; the stationary contact of the grounding switch is connected to the external grounding plate via an insulator and fixed to one end of the housing via a flange.

8. The pneumatic isolating grounding switch device according to any one of claims 1-5, characterized in that: A shield is provided around the piston rod ends on both sides of the cylinder.

9. The pneumatic isolating grounding switch device according to any one of claims 1-5, characterized in that: The housing has openings at the two gas pipe extension positions and is equipped with a removable cover. The air pump and reversing valve are installed on the outside of the cover.

10. The pneumatic isolating grounding switch device according to any one of claims 1-5, characterized in that: The housing is provided with a foreign object collection groove below the corresponding isolating switch stationary contact and grounding switch stationary contact.

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