Switchgear air chamber based on integrated main switch circuit without wear and low impedance

Abstract

The present invention relates to the field of switch cabinet technology, and specifically to a switch cabinet air chamber based on the integration of the main switch circuit, which is wear-free and low-impedance, and includes an air chamber shell, the left side, right side and upper side of which are respectively sealed and fixedly installed with a reference flange, a second outer cone sleeve and a first outer cone sleeve, the right side of the air chamber shell is fixedly installed with a sealed pole and a grounded static contact, the upper end of the sealed pole is fixedly installed with an isolating three-way static contact and an isolating static contact, the isolating three-way static contact is penetrated by a screw rod, and one end of the screw rod is sleeved with an isolating moving contact; the left side of the reference flange is fixedly installed with an isolating switch mechanism and a circuit breaker mechanism, the isolating static contact is electrically connected to the first outer cone sleeve, the sealed pole is electrically connected to the second outer cone sleeve, and the outer side of the reference flange is grounded. Compared with the prior art, the structural design and assembly method of the air chamber are simplified, and the problems of high impedance, troublesome disassembly and maintenance, and switch refusal to move in the past are solved.

Description

Technical Field

[0001] The invention relates to the technical field of switch cabinets, and in particular to a switch cabinet air chamber with no wear and low impedance based on the integration of a main switch circuit. Background Art

[0002] Traditional medium-voltage switchgear generally adopts air insulation technology. In order to ensure the safe operation of the switchgear, a sufficiently large air clearance is required. The size of this type of switchgear will be relatively large, especially in harsh environments such as high salt fog, high humidity, and high altitude. The requirements for the air clearance of the switchgear are further increased, resulting in a further increase in the size of the switchgear. In order to solve the problem of excessive size, some switchgears use composite insulation technology, that is, adding insulating partitions in the air gap to form an air chamber. This type of structure can reduce the overall size of the switchgear while meeting the air clearance.

[0003] Although the medium-voltage switchgear mentioned above solves the problem of the excessive size of the air-insulated switchgear, it still has some defects. Since the air chamber is formed by setting up an insulating partition, in order to ensure the stability of the installation of components, all components are scattered and welded inside the air chamber, which increases the process difficulty of the remanufacturing link and increases the process steps. Therefore, the medium-voltage switchgear in the prior art has the following problems: First, it cannot be repaired on-site during the operation link, and it is difficult or impossible to repair a fault; second, since the air chamber and the components need to be welded, the structural integrity of the air chamber is destroyed, and the internal pressure easily causes the outer wall of the air chamber to deform. The deformed air chamber will affect the internal components, resulting in the problem of switch refusal to operate; third, the grounding circuit has a high circuit resistance due to the blocking of the air chamber, and the metal powder generated after the switch is operated for a long time causes insulation damage and other thorny problems.

[0004] Therefore, how to design a switch cabinet air chamber with no wear and low impedance based on the integration of the main switch circuit has become an urgent problem to be solved. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a medium-pressure inflatable switch cabinet air chamber that can be quickly replaced as a whole based on the main circuit.

[0006] The purpose of the present invention is achieved through the following technical solutions: The present application provides a switch cabinet air chamber based on the integration of the main switch circuit, which is wear-free and low-impedance, including an air chamber shell, the left side, right side and upper side of the air chamber shell are respectively sealed and fixedly installed with a reference flange, a second outer cone sleeve and a first outer cone sleeve, the right side of the reference flange is located in the air chamber shell and is fixedly installed with a sealed pole and a grounding static contact located above the sealed pole, the upper end of the sealed pole is fixedly installed with an isolating three-way static contact and an isolating static contact in sequence along its axial direction, and the isolating three-way static contact A screw rod is passed through the head, and one end of the screw rod is sleeved with an isolating moving contact that is in contact with the isolating static contact, and the isolating moving contact can slide back and forth along the axial direction of the screw rod; the left side of the reference flange is located outside the air chamber shell and is fixedly installed with an isolating switch mechanism and a circuit breaker mechanism, the insulating pull rod in the sealed pole is connected to the circuit breaker mechanism, and the other end of the screw rod passes through the grounding static contact and is connected to the isolating switch mechanism through the shaft seal assembly; the isolating static contact is electrically connected to the first outer cone sleeve, the end electrode of the sealed pole is electrically connected to the second outer cone sleeve, and the outer side of the reference flange is grounded.

[0007] The reference flange is fixedly mounted on the outer side of the air chamber housing by means of bolts, and a first sealing ring is arranged between the reference flange and the air chamber housing.

[0008] The isolating static contact is connected to the first outer cone sleeve through a flexible conductor, and the end electrode of the sealed pole is connected to the second outer cone sleeve through a flexible conductor.

[0009] It also includes a flange, which is sleeved on the outer peripheral side of the insulating pull rod and located on the left side of the reference flange. The flange is fixed to the left side of the reference flange by bolts, and a second sealing ring is provided between the reference flange and the flange.

[0010] Among them, the shaft seal assembly includes a left positioning flange, a right positioning flange, a shaft seal body and a rotating shaft which is inserted into the shaft seal body and can rotate relative to the shaft seal body. An end head is formed at the end of the screw rod facing the shaft seal body. The outer diameter of the end head is larger than the outer diameter of the screw rod. One end of the rotating shaft is inserted into the end head. The rotating shaft is fixedly connected to the end head through a positioning pin. The left positioning flange is sleeved on the outer peripheral side of the rotating shaft and is located on the left side of the end head. The right positioning flange is sleeved on the outer peripheral side of the screw rod and is located on the right side of the end head.

[0011] Among them, the left positioning flange and the right positioning flange are both axially installed in the grounding static contact, the shaft seal body is located on the left side of the reference flange, the shaft seal body is fixed to the reference flange by bolts, and a third sealing ring is provided between the shaft seal body and the reference flange, and the shaft seal body and the left positioning flange clamp the reference flange.

[0012] Among them, the left positioning flange, the right positioning flange and the screw rod are all made of polyetheretherketone material.

[0013] Among them, a maintenance flange is also sealed and fixedly installed on the left side of the air chamber shell, and an explosion-proof pressure relief valve is fixedly installed on the maintenance flange.

[0014] The thickness of the air chamber shell is 3 mm, and the air chamber shell is a stainless steel structure.

[0015] Among them, the reference flange is made of aluminum alloy.

[0016] Beneficial effects of the present invention: Compared with the prior art, the switch cabinet air chamber based on the integrated wear-free and low-impedance main switch circuit of the present application has the following advantages: 1) By integrating the main switch circuit electrical components such as the sealed pole, isolating switch mechanism and circuit breaker mechanism on the reference flange, the structural design and assembly method of the air chamber are simplified, and standardized and modular design is achieved. Different types of integrated reference flanges can be replaced according to the different functions of the product, thereby realizing the replacement of the overall main circuit device, reducing the assembly workload, improving production efficiency, shortening the production cycle, reducing production management costs, and improving the versatility and standardization of parts.

[0017] 2) During maintenance or overhaul, after disassembling the entire reference flange, the electrical components of the main switch circuit can be maintained or overhauled, providing a maintenance or overhaul method that is less time-consuming and more efficient, reduces the probability of accidents, and ensures power supply reliability.

[0018] 3) All electrical components of the main switch circuit are integrated on the reference flange, and each electrical component is independent of the gas chamber shell and has no direct contact with the gas chamber shell, thus retaining the structural integrity of the gas chamber shell and ensuring the structural strength of the gas chamber shell. The sealed pole is connected to each outer cone sleeve through a flexible conductor, which has a certain ductility. After the gas chamber shell is inflated, even if the gas chamber shell is deformed, it will not affect the main circuit, thus avoiding the occurrence of refusal to move.

[0019] 4) The grounding static contact is connected to the reference flange, and the reference flange is grounded, which changes the traditional grounding method and realizes low resistance of the grounding loop. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0021] Figure 1 This is a diagram of the internal structure of the switch cabinet air chamber in this embodiment.

[0022] Figure 2 Schematic diagram of the structure of the switch cabinet air chamber in this embodiment.

[0023] Figure 3This is a schematic diagram of the structure of the switch cabinet air chamber after the air chamber shell is hidden in the air chamber shell in this embodiment.

[0024] Figure 4 Schematic diagram of the structure of the shaft seal assembly in this embodiment.

[0025] Figure numerals: air chamber casing 1, pressure gauge 2, first outer cone sleeve 4, flexible conductor 5, explosion-proof pressure relief valve 6, inspection flange 7, second outer cone sleeve 9, isolating static contact 10, isolating moving contact 11, isolating three-way static contact 12, sealed pole 13, shaft seal assembly 14, flange 15, grounding static contact 16, reference flange 17, isolating switch mechanism 18, circuit breaker mechanism 19, shaft seal body 20, left positioning flange 21, positioning pin 22, right positioning flange 23, screw 24, rotating shaft 25, end 26. DETAILED DESCRIPTION

[0026] The present invention is further described in conjunction with the following examples.

[0027] For a specific implementation of the switch cabinet air chamber based on the main switch circuit integration without wear and low impedance of the present invention, please see Figure 1 The air chamber includes an air chamber shell 1, and the left side, right side and upper side of the air chamber shell 1 are respectively sealed and fixedly installed with a reference flange 17, a second outer cone sleeve 9 and a first outer cone sleeve 4. It should be noted that the side of the air chamber shell 1 where the reference flange 17 is installed is provided with an opening for inserting the flange of the reference flange 17, and the skirt of the reference flange 17 is fixedly installed on the outer side of the air chamber shell 1 by bolts, and the locking force of the bolts is used to make the reference flange 17 close to the left side of the air chamber shell 1. In order to ensure an effective seal between the reference flange 17 and the air chamber shell 1, a first sealing ring is provided between the reference flange 17 and the air chamber shell 1. Specifically, the first sealing ring is an EPDM rubber sealing ring. The EPDM rubber sealing ring has the characteristics of long service life, high temperature resistance, uniform density and good sealing performance. It can ensure the airtightness between the air chamber shell 1 and the reference flange 17 and meet the requirements of sealing insulation safety. In order to facilitate the observation of the air pressure value in the air chamber shell 1, a barometer 2 is installed on the left side of the air chamber shell 1. In addition, combined with Figure 2 The number of the second outer cone sleeve 9 and the number of the first outer cone sleeve 4 are both three, and the sealing and fixing installation method of each second outer cone sleeve 9 and the first outer cone sleeve 4 can adopt the installation method in the prior art, and can also be sealed and fixed by flange sealing.

[0028] As an improvement, combined with Figure 4The left side surface of the reference flange 17 is located outside the gas chamber shell 1 and is fixedly installed with an isolating switch mechanism 18 and a circuit breaker mechanism 19, while the right side surface of the reference flange 17 is located inside the gas chamber shell 1 and is fixedly installed with a sealed pole 13 and a grounding static contact 16 located above the sealed pole 13. Similarly, there are three sealed poles 13 and three grounding static contacts 16, and the upper end of each sealed pole 13 is fixedly installed with an isolating three-way static contact 12 and an isolating static contact 10 in sequence along its axial direction. It should be noted that the sealed pole 13 is a conventional sealed pole 13 in the prior art, and a circuit-breaking mechanism is provided inside the sealed pole 13, and the circuit-breaking mechanism includes an insulating pull rod located inside the sealed pole 13, and the insulating pull rods in each sealed pole 13 are connected to the transmission connecting rod of the circuit breaker operating mechanism through a bellows assembly, wherein the bellows assembly includes a flange 15, and the flange 15 is sleeved on the outer peripheral side of the insulating pull rod and is located on the left side of the reference flange 17, and the flange 15 is fixedly installed on the left side of the reference flange 17 by bolts, and a second sealing ring is provided between the reference flange 17 and the flange 15 to form an effective seal between the two, and similarly, the second sealing ring is an EPDM rubber sealing ring, which has the characteristics of long service life, high temperature resistance, uniform density and good sealing.

[0029] In this embodiment, a screw rod 24 is passed through the isolating three-way static contact 12, and one end of the screw rod 24 is sleeved with an isolating moving contact 11 which is in contact and conductive with the isolating static contact 10. The other end of the screw rod 24 passes through the grounding static contact 16 and is connected to the isolating switch mechanism 18 through the shaft seal assembly 14. The isolating switch mechanism 18 and the screw rod 24 of the sealed pole 13 are a clamping structure. The isolating switch mechanism 18 is provided with a driving device for driving the screw rod 24 to rotate, and the isolating moving contact 11 can be understood as a ball sleeve sleeved on the screw rod 24. The isolating switch mechanism 18 drives the screw rod 24 to rotate forward or reverse, so that the sleeve (isolating moving contact 11) slides back and forth along the axial direction of the screw rod 24, thereby controlling the conduction or disconnection between the isolating moving contact 11 and the isolating static contact 10.

[0030] In this embodiment, each isolating static contact 10 is connected to the first outer cone sleeve 4 through a flexible conductor 5, the end electrode of the sealed pole 13 is connected to the second outer cone sleeve 9 through a flexible conductor 5, and the outer side of the reference flange 17 is grounded. It should be noted that the flexible conductor 5 can be made of soft copper material, soft aluminum material or other conductive materials with lower hardness, or a conventional soft conductor on the market.

[0031] The switch cabinet air chamber of this embodiment integrates the main switch circuit electrical components such as the sealed pole 13, the isolating switch mechanism 18 and the circuit breaker mechanism 19 on the reference flange 17, simplifies the structural design and assembly method of the air chamber, realizes standardized and modular design, and can replace different types of integrated reference flanges 17 according to the different functions of the product, thereby realizing the replacement of the overall main circuit device, reducing the assembly workload, improving production efficiency, shortening the production cycle, reducing production management costs, and improving the versatility and standardization of parts. In addition, since all the main switch circuit electrical components are integrated on the reference flange 17, and each electrical component is independent of the air chamber shell 1 and does not directly contact the air chamber shell 1, the structural integrity of the air chamber shell 1 is retained, the structural strength of the air chamber shell 1 is ensured, and the sealed pole 13 is connected to each first outer cone sleeve 4 and the second outer cone sleeve 9 through the flexible conductor 5, and has a certain ductility. After the air chamber shell 1 is inflated, even if the air chamber shell 1 is deformed, it will not affect the main circuit, further avoiding the occurrence of the refusal to move phenomenon.

[0032] In actual applications, since the isolating switch mechanism 18 is used for a long time or works frequently, the isolating switch mechanism 18 will drive the screw rod 24 to rotate when it is working. The rotation of the screw rod 24 causes the isolating movable contact 11 sleeved on the screw rod 24 to slide back and forth. The isolating movable contact 11 will generate a reverse axial force on the screw rod 24. If the axial force is not eliminated, when the screw rod 24 is not fully limited, it will cause wear between the isolating movable contact 11 and the screw rod 24. The wear will produce metal powder and cause insulation damage. In order to solve the above problems, the air chamber of this embodiment is provided with a shaft seal assembly 14 between the screw rod 24 and the reference flange 17. Specifically, in combination with Figure 4 The shaft seal assembly 14 includes a left positioning flange 21, a right positioning flange 23, a shaft seal body 20, and a rotating shaft 25 that is inserted into the shaft seal body 20 and can rotate relative to the shaft seal body 20. The end of the screw rod 24 facing the shaft seal body 20 is formed with a terminal head 26, and the outer diameter of the terminal head 26 is larger than the outer diameter of the screw rod 24, so that the end of the screw rod 24 forms a "convex" structure, one end of the rotating shaft 25 is inserted into the terminal head 26, and the rotating shaft 25 is fixedly connected to the terminal head 26 through the positioning pin 22, and the rotating shaft 25 and the shaft seal body 20 are clearance-matched. The left positioning flange 21 is sleeved on the outer peripheral side of the rotating shaft 25 and is located on the left side of the end head 26, so as to limit the left side of the end head 26. The right positioning flange 23 is sleeved on the outer peripheral side of the screw rod 24 and is located on the right side of the end head 26, so as to limit the right side of the end head 26. In order to ensure the smoothness of the rotation of the screw rod 24, the left positioning flange 21, the right positioning flange 23 and the screw rod 24 can all be made of high-strength, self-lubricating polyetheretherketone material.

[0033] In this embodiment, the left positioning flange 21 and the right positioning flange 23 are both axially installed in the grounding static contact 16, the end 26 of the screw rod 24 is confined between the left positioning flange 21 and the right positioning flange 23, and the shaft seal body 20 is located on the left side of the reference flange 17. The shaft seal body 20 is fixed to the reference flange 17 by bolts, and a third sealing ring is provided between the shaft seal body 20 and the reference flange 17. The third sealing ring is an EPDM rubber sealing ring, and the shaft seal body 20 and the left positioning flange 21 clamp the reference flange 17. When the screw rod 24 rotates around its own central axis, the screw rod 24 drives the isolating movable contact 11 to slide back and forth along the axial direction of the screw rod 24. Since there is pressure on the isolating movable contact 11, the isolating movable contact 11 will generate reverse axial stress on the screw rod 24 while moving. The left positioning flange 21, the right positioning flange 23 and the end 26 of the screw rod 24 are matched to prevent the end 26 of the screw rod 24 from jumping and deviating, thereby eliminating the axial stress and protecting the shaft seal body 20 from being disturbed by the axial force, thereby avoiding wear caused by the operation of the isolating switch mechanism 18 and avoiding the problem of insulation damage caused by the production of metal powder, thereby further improving the safety of the air chamber and extending the service life of the air chamber.

[0034] In this embodiment, a maintenance flange 7 is also sealed and fixedly installed on the left side of the gas chamber housing 1. Specifically, the maintenance flange 7 is crimped to the outer side of the gas chamber housing 1 by bolts and is further sealed by an EPDM rubber sealing ring. During assembly, insulating gas can be filled into the maintenance flange 7 to ensure that the gas chamber achieves gas insulation that reduces the phase-to-phase and relative safety distance. In addition, an explosion-proof pressure relief valve 6 is arranged on the maintenance flange 7 to release excess pressure when a fault occurs inside the gas chamber housing 1 and causes a sharp increase in pressure.

[0035] As a preferred solution, the air chamber shell 1 is made of 3mm thick high-strength stainless steel plate that is bent and sealed, and a 35mm thick reinforcing rib plate can be welded inside it, so that it can withstand an internal and external pressure difference of 0.8MPa without obvious deformation.

[0036] In this embodiment, since the grounding static contact 16 is fixedly mounted on the left side of the reference flange 17, the reference flange 17 is externally grounded, which changes the traditional grounding method, realizes a complete grounding loop, effectively reduces the loop resistance, and ensures grounding continuity and reliability. The reference flange 17, as an installation reference of electrical components and a component of the grounding loop, can be made of aluminum alloy material with high hardness, high yield strength, and high conductivity.

[0037] During the manufacturing process of the medium-voltage pneumatic switchgear air chamber, the electrical components are first installed on the reference flange 17 according to functional requirements, and then the whole is encapsulated in the air chamber shell 1, which can improve production efficiency, reduce production management costs, and improve the degree of standardized operation. During the operation of the medium-voltage pneumatic switchgear, the inspection flange 7 can be opened on site for simple maintenance or parts replacement; the connection between the flexible conductor 5 and the sealed pole 13 can also be untied, and then the reference flange 17 can be disassembled as a whole, and the electrical components of the main switch circuit can be maintained or repaired, providing a way for maintenance or repair, which is less time-consuming and more efficient, reduces the probability of accidents, and ensures power supply reliability.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A switch cabinet air chamber based on the integrated wear-free and low-impedance main switch circuit comprises an air chamber shell, wherein the left side, right side and upper side of the air chamber shell are respectively sealed and fixedly mounted with a reference flange, a second outer cone sleeve and a first outer cone sleeve, characterized in that: The right side surface of the reference flange is located in the air chamber housing and is fixedly mounted with a sealed pole and a grounded static contact located above the sealed pole. An isolating three-way static contact and an isolating static contact are sequentially fixedly mounted along the axial direction of the upper end of the sealed pole. A screw rod is passed through the isolating three-way static contact. An isolating moving contact in contact and conduction with the isolating static contact is sleeved on one end of the screw rod. The isolating moving contact can slide back and forth along the axial direction of the screw rod. The left side surface of the reference flange is located outside the air chamber housing and is fixedly mounted with an isolating switch mechanism and a circuit breaker mechanism, the insulating pull rod in the sealed pole is connected to the circuit breaker mechanism, and the other end of the screw rod passes through the grounding static contact and is connected to the isolating switch mechanism through the shaft seal assembly; The isolating static contact is electrically connected to the first outer cone sleeve, the end electrode of the sealed pole is electrically connected to the second outer cone sleeve, and the outer side of the reference flange is grounded; It also includes a flange, which is sleeved on the outer peripheral side of the insulating pull rod and located on the left side of the reference flange. The flange is fixedly installed on the left side of the reference flange by bolts, and a second sealing ring is provided between the reference flange and the flange; A maintenance flange is also sealed and fixedly installed on the left side of the air chamber shell, and an explosion-proof pressure relief valve is fixedly installed on the maintenance flange.

2. The switch cabinet air chamber based on the main switch circuit integration without wear and low impedance according to claim 1 is characterized in that: The reference flange is fixedly mounted on the outer side of the air chamber shell by means of bolts, and a first sealing ring is arranged between the reference flange and the air chamber shell.

3. The switch cabinet air chamber based on the main switch circuit integration without wear and low impedance according to claim 1 is characterized in that: The isolating static contact is connected to the first outer cone sleeve via a flexible conductor, and the end electrode of the sealed pole is connected to the second outer cone sleeve via a flexible conductor.

4. The switch cabinet air chamber based on the main switch circuit integration without wear and low impedance according to claim 1 is characterized in that: The shaft seal assembly includes a left positioning flange, a right positioning flange, a shaft seal body and a rotating shaft which is inserted into the shaft seal body and can rotate relative to the shaft seal body. The end of the screw rod facing the shaft seal body is formed with an end head, the outer diameter of the end head is larger than the outer diameter of the screw rod, one end of the rotating shaft is inserted into the end head, and the rotating shaft is fixedly connected to the end head by a positioning pin. The left positioning flange is sleeved on the outer peripheral side of the rotating shaft and is located on the left side of the end head, and the right positioning flange is sleeved on the outer peripheral side of the screw rod and is located on the right side of the end head.

5. The switch cabinet air chamber based on the main switch circuit integration without wear and low impedance according to claim 4 is characterized in that: The left positioning flange and the right positioning flange are both axially installed in the grounding static contact, the shaft seal body is located on the left side of the reference flange, the shaft seal body is fixed to the reference flange by bolts, and a third sealing ring is provided between the shaft seal body and the reference flange, and the shaft seal body and the left positioning flange clamp the reference flange.

6. The switch cabinet air chamber based on the main switch circuit integration without wear and low impedance according to claim 4 is characterized in that: The left positioning flange, the right positioning flange and the screw rod are all made of polyetheretherketone material.

7. The switch cabinet air chamber based on the main switch circuit integration without wear and low impedance according to claim 1 is characterized in that: The thickness of the air chamber shell is 3 mm, and the air chamber shell is a stainless steel structure.

8. The switch cabinet air chamber based on the main switch circuit integration without wear and low impedance according to claim 1 is characterized in that: The reference flange is an aluminum alloy structure.

Images