Gas-insulated switchgear equipped with SF6 circuit breaker

Abstract

The utility model relates to a gas-insulated switchgear equipped with an SF6 circuit breaker, and is applied to the field of gas-insulated switchgears. The three-position switch cabinet comprises a cabinet body, a circuit breaker mechanism, a bus sleeve and a three-position switch mechanism, wherein the cabinet body comprises a fixed plate; the circuit breaker mechanism comprises a main body part and a pole, the main body part is arranged at the bottom of the cabinet body, and the pole is arranged at the top of the main body part; the bus sleeve is arranged at the top of the cabinet body and used for connecting an external bus; the three-position switch mechanism comprises a switch-on contact, an isolation contact, a grounding contact and a moving contact, the switch-on contact is electrically connected to the bus sleeve, the isolation contact is installed and electrically connected to the pole, and the grounding contact is installed on the fixing plate; the moving contact can move among the connection contact, the isolation contact and the grounding contact along a first direction. The isolation contact is directly installed at the upper end of the pole of the circuit breaker mechanism, the integrated structural design of the isolation contact and the pole is achieved, copper bars can be saved, the size of a connecting structure in a switch can be reduced, and therefore the overall size of the gas insulated switchgear can be reduced.

Description

Technical Field

[0001] This application relates to the technical field of gas-insulated switchgear, and in particular to a gas-insulated switchgear equipped with an SF6 circuit breaker. Background Technology

[0002] With the development of the power industry, gas-insulated switchgear has been widely used due to its compact structure and small footprint. Gas-insulated switchgear improves its insulation and safety performance by filling a sealed metal casing with an insulating gas, such as SF6.

[0003] However, conventional gas-insulated switchgear is equipped with vacuum circuit breakers. Although vacuum circuit breakers have the ability to quickly extinguish arcs, their performance in interrupting capacitive currents is relatively poor. This means that when faced with large capacitive currents, vacuum circuit breakers may not be able to effectively interrupt the current, affecting the stability and safety of the power system. Utility Model Content

[0004] Therefore, it is necessary to provide a gas-insulated switchgear equipped with an SF6 circuit breaker to address the issue that conventional gas-insulated switchgear is equipped with vacuum circuit breakers, which has a certain impact on the stability and safety of the power system.

[0005] This application provides a gas-filled switchgear equipped with an SF6 circuit breaker, using the following technical solution:

[0006] An SF6 circuit breaker-equipped gas-insulated switchgear includes a cabinet, a circuit breaker mechanism, a busbar bushing, and a three-position switch mechanism. The cabinet includes a fixed plate. The circuit breaker mechanism includes a main body and a pole. The main body is installed at the bottom of the cabinet, and the pole is installed at the top of the main body. The busbar bushing is installed at the top of the cabinet and is used to connect to an external busbar. The three-position switch mechanism includes a closing contact, an isolating contact, a grounding contact, and a moving contact. The closing contact is electrically connected to the busbar bushing, the isolating contact is installed and electrically connected to the pole, and the grounding contact is installed on the fixed plate. The moving contact is configured to move along a first direction between the closing contact, the isolating contact, and the grounding contact.

[0007] In one embodiment, the three-position switch mechanism further includes a drive member and a transmission rod. The drive member is mounted on the fixed plate, and the transmission rod drives the moving contact to the drive member. Under the drive of the drive member, the moving contact can move between the contact, the isolation contact, and the ground contact.

[0008] In one embodiment, the moving contact is threaded to the transmission rod, and the moving contact is at least partially housed within the isolating contact, which is located between the grounding contact and the closing contact.

[0009] In one embodiment, the isolation contact is provided with a mating hole for the moving contact to pass through, and in the first direction, both ends of the mating hole are provided with contact fingers for abutting the moving contact.

[0010] In one embodiment, the transmission rod is made of insulating material.

[0011] In one embodiment, the gas-filled cabinet further includes an interlocking plate disposed between the main body and the driving member to fix the driving member to the main body.

[0012] In one embodiment, the circuit breaker mechanism is an SF6 circuit breaker, and the pole is an SF6 pole.

[0013] In one embodiment, the gas-insulated switchgear further includes a monitoring mechanism electrically connected to the circuit breaker mechanism. The monitoring mechanism includes a surge arrester, a current transformer, and a controller installed inside the switchgear. The surge arrester and the current transformer are both electrically connected to the controller.

[0014] In one embodiment, the gas-filled cabinet further includes a connecting copper busbar, one end of which is connected to the busbar bushing and the other end of which is connected to the contact.

[0015] In one embodiment, the gas-insulated cabinet further includes a cable terminal for connecting an external load, the cable terminal being configured to be pluggable.

[0016] The aforementioned gas-filled switchgear equipped with SF6 circuit breakers, by directly mounting the isolating contacts on the upper end of the pole of the circuit breaker mechanism, compared with the prior art's technical solution of using copper busbars to achieve electrical connection between the isolating contacts and the pole, constructs the isolating contacts and poles into an integrated structure design in this application, which helps to save copper busbars and reduce the volume of the connection structure in the switch, thereby achieving a reduction in the overall volume of the gas-filled switchgear. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the gas-filled cabinet in the on-state according to one embodiment of this application.

[0018] Figure 2 This is a schematic diagram of the gas-filled cabinet in an isolated state in one embodiment of this application.

[0019] Figure 3 This is a schematic diagram of the gas-filled cabinet in a grounded state in one embodiment of this application.

[0020] Figure 4 for Figure 1 Enlarged view of part A in the middle.

[0021] Attached image annotations:

[0022] 1. Cabinet; 11. Fixing plate; 2. Circuit breaker mechanism; 21. Main body; 22. Pole post; 3. Busbar bushing; 4. Three-position switch mechanism; 41. Connecting contact; 42. Isolating contact; 421. Mating hole; 43. Grounding contact; 44. Moving contact; 45. Drive component; 46. Transmission rod; 5. Interlocking plate; 6. Surge arrester; 7. Instrument transformer; 8. Instrument compartment; 9. Connecting copper busbar; 10. Cable terminal; F1. First direction. Detailed Implementation

[0023] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0024] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0025] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0026] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0027] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0028] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0029] With the rapid development of the power industry, gas-insulated switchgear has been widely used in power systems due to its compact structure and small footprint. The gas environment inside the gas-insulated switchgear effectively isolates external humidity and pollution, improving the insulation performance and reliability of the equipment. However, traditional gas-insulated switchgear is usually equipped with vacuum circuit breakers as its switching devices. Although vacuum circuit breakers have good breaking capacity, their performance when breaking capacitive current is relatively poor, which limits their use in certain specific applications.

[0030] SF6 circuit breakers are widely used due to their excellent capacitive current breaking capacity. SF6 gas possesses superior insulation and arc-extinguishing properties, enabling SF6 circuit breakers to perform exceptionally well when breaking large currents. SF6 circuit breakers have a large breaking current, short arcing time, do not generate reignition overvoltage, and allow for a high number of consecutive interruptions, making them suitable for frequent operation. Furthermore, SF6 circuit breakers have a long electrical life, with maintenance cycles ranging from 10 to 20 years, resulting in high reliability and economy in power systems.

[0031] Therefore, this application combines the miniaturization advantages of gas-insulated switchgear with the high-performance characteristics of SF6 circuit breakers, proposing a gas-insulated switchgear equipped with SF6 circuit breakers. This solution not only achieves excellent breaking capacitive current performance but also maintains the miniaturization of the switchgear, thereby improving power system performance while reducing production costs and space occupation.

[0032] The following is in conjunction with the appendix Figure 1-4 The embodiments of this application will be described in further detail.

[0033] See Figure 1 , Figure 1 This diagram illustrates a gas-filled switchgear in an on-state according to one embodiment of this application. One embodiment of this application provides a gas-filled switchgear, specifically a gas-filled switchgear equipped with an SF6 circuit breaker. The switchgear includes a cabinet 1 with an internal sealed space, and the cabinet 1 is filled with an insulating medium. In this embodiment, the insulating medium can specifically be SF6 gas filled within the cabinet 1. SF6 gas has extremely high insulation strength and can withstand high voltage in a small space, thereby reducing the volume of the gas-filled switchgear.

[0034] Furthermore, SF6 gas has high insulating strength, providing reliable electrical insulation in high-voltage electrical equipment to improve the safety of gas-insulated switchgear. Moreover, SF6 gas is not only an excellent insulating medium but also possesses superior arc-extinguishing capabilities, which is crucial for controlling and protecting the stable operation of power systems.

[0035] Specifically, the gas-insulated switchgear includes a circuit breaker mechanism 2, a three-position switch mechanism 4, and a busbar bushing 3, all installed in the cabinet 1. The circuit breaker mechanism 2 includes a main body 21 and poles 22. The main body 21 is installed at the bottom of the cabinet 1, and the poles 22 are located at the top of the main body 21. In this embodiment, the circuit breaker mechanism 2 is specifically an SF6 circuit breaker, and the poles 22 can specifically be SF6 poles 22. SF6 circuit breakers perform well when interrupting large currents.

[0036] SF6 circuit breakers have a large breaking current, short arcing time, and do not generate reignition overvoltage. They also allow for a high number of consecutive interruptions, making them suitable for frequent operation. Furthermore, the long electrical life of SF6 circuit breakers helps improve the reliability and economy of gas-insulated switchgear.

[0037] Combination Figure 2 and Figure 3 As shown, Figure 2 This diagram illustrates a gas-filled cabinet in an isolated state according to one embodiment of this application. Figure 3 A schematic diagram of the gas-filled cabinet in a grounded state is shown in one embodiment of this application.

[0038] In some embodiments, the busbar bushing 3 is installed on the top of the cabinet 1. One end of the busbar bushing 3 is used to connect to the aforementioned three-position switch mechanism 4, and the other end is used to connect to an external busbar. In this embodiment, the cabinet 1 also includes a fixing plate 11 for providing an installation position. The three-position switch mechanism 4 is specifically a direct-acting three-position disconnect switch, which includes a connecting contact 41, an isolating contact 42, a grounding contact 43, and a moving contact 44. The grounding contact 43 is installed on the fixing plate 11. Along the first direction F1, the isolating contact 42 and the connecting contact 41 are sequentially arranged on the side of the grounding contact 43 away from the fixing plate 11.

[0039] Compared to another common type of disconnect switch in the prior art, the knife-switch type disconnect switch has higher requirements for concentricity and its overall assembly is more complex. The direct-acting three-position disconnect switch shown in this application has fewer components, resulting in a simpler structure and higher reliability. Furthermore, the direct-acting three-position disconnect switch ensures a uniform electric field distribution and effectively guarantees coaxiality, thus ensuring the electrical performance of the product and improving the reliability of the entire power supply system.

[0040] Specifically, the connecting contact 41 is electrically connected to the bus bushing 3 mentioned above, and the isolating contact 42 is installed on the top of the pole post 22 and electrically connected to the pole post 22. In this embodiment, the isolating contact 42 and the pole post 22 are constructed as an integral structure, and in actual production, it is directly installed on the top of the pole post 22.

[0041] In some embodiments, the gas-insulated switchgear also includes a connecting copper busbar 9, one end of which is connected to the contact 41 and the other end to the busbar bushing 3, to achieve connection with the external busbar. In this embodiment, because the three-position switch mechanism 4 is a direct-acting three-position disconnect switch and the disconnecting contact 42 is installed at the top of the pole post 22, the positions of the three stationary contacts—the contact 41, the disconnecting contact 42, and the grounding contact 43—are moved upward in the height direction, thereby reducing the distance between the contact 41 and the busbar, and thus saving the connecting copper busbar 9. This reduces the space occupied by the connecting copper busbar 9 and lowers the overall production cost of the gas-insulated switchgear.

[0042] Furthermore, in this application, by directly installing the isolating contact 42 on the upper end of the pole 22 in the circuit breaker mechanism 2, compared with the prior art's technical solution of using copper busbars to achieve electrical connection between the pole 22 and the isolating contact 42, this application directly eliminates the copper busbar connection between the isolating contact 42 and the pole 22. On the one hand, it can save copper busbars and further reduce production costs; on the other hand, the elimination of copper busbars can also effectively save internal space in the cabinet 1. The integrated structural design of the isolating contact 42 and the pole 22 helps to reduce the volume of the connection structure in the switch, thereby reducing the overall volume of the gas-insulated switchgear.

[0043] Combination Figures 1 to 3 As shown, the moving contact 44 can move along the first direction F1 between the moving contact 44, the isolating contact 42, and the grounding contact 43, thereby realizing the isolation, connection, and grounding of the three-position switch mechanism 4. Specifically, the three-position switch mechanism 4 also includes a driving member 45 and a transmission rod 46. The driving member 45 is mounted on the aforementioned fixed plate 11, and the transmission rod 46 extends along the first direction F1 and drives the moving contact 44 to the driving member 45. Under the drive of the driving member 45, the moving contact 44 can move along the first direction F1 between the connecting contact 41, the isolating contact 42, and the grounding contact 43 to realize the connection, isolation, and grounding of the three-position switch mechanism 4, respectively.

[0044] In some embodiments, the drive unit 45 includes a motor mounted on the fixed plate 11, and the motor and the transmission rod 46 are connected by a transmission system combining gears and chains. Specifically, a rotating gear is coaxially fixed on the output shaft of the motor, which can drive the main shaft to rotate. The rotation of the main shaft can drive the chain to rotate, thereby driving the magnetohydrodynamic fluid on which the transmission rod 46 is mounted to rotate, so as to realize the driving operation of the moving contact 44.

[0045] In this embodiment, the main function of the magnetic fluid is sealing, which prevents the SF6 gas, which plays an insulating role, from leaking out of the cabinet 1, thereby ensuring the operational safety of the gas-filled cabinet.

[0046] Specifically, as shown in this application, the moving contact 44 is threadedly connected to the transmission rod 46, and the moving contact 44 is at least partially housed within the isolating contact 42, which is located between the grounding contact 43 and the closing contact 41. The moving contact 44 is configured to move along the arrangement direction (first direction F1) of the grounding contact 43 and the closing contact 41 during the rotation of the transmission rod 46 of the drive member 45, so as to realize the connection, isolation and grounding of the three-position switch mechanism 4.

[0047] In this embodiment, the transmission rod 46 is specifically a threaded rod made of insulating material, such as a nylon threaded rod or a acetal rod. Nylon threaded rods have better insulation and strength, while acetal rods are more brittle and may break under external impact. Therefore, in this embodiment, a nylon threaded rod is preferred as the transmission rod 46.

[0048] In some embodiments, the moving contact 44 is always at least partially contained within the isolating contact 42, and the moving contact 44 is configured with a non-circular cross-section, so that the moving contact 44 and the isolating contact 42 are always electrically connected, and the rotation of the moving contact 44 in its own axial direction is restricted, so that the isolating contact 42 also serves as a guide.

[0049] When the transmission rod 46 rotates around its own axis under the drive of the driving member 45, it can drive the moving contact 44 to move along the first direction F1 through threaded transmission, thereby enabling the moving contact 44 to move between the connecting contact 41, the isolating contact 42, and the grounding contact 43. This application adopts a direct-acting structure, which ensures a uniform electric field distribution and coaxiality, guaranteeing the electrical performance of the product and thus improving the reliability of the entire power supply system.

[0050] Combination Figure 4 As shown, Figure 4 It shows Figure 1 Enlarged view of part A. In some other embodiments, the isolating contact 42 has a mating hole 421 through which the moving contact 44 passes. In the first direction F1, both ends of the mating hole 421 are provided with contact fingers (not shown) for abutting the moving contact 44. In this embodiment, the contact fingers installed on the inner wall of the mating hole 421 are specifically elastic contact fingers with a certain elasticity. During the movement of the moving contact 44, at least one end of the contact finger abuts against the side wall of the moving contact 44, making the contact between the moving contact 44 and the isolating contact 42 more stable, thereby improving conductivity.

[0051] Furthermore, there is a gap between the outer wall of the moving contact 44 and the wall of the mating hole 421, so that friction can be avoided between the outer wall of the moving contact 44 and the wall of the mating hole 421 during the movement of the moving contact 44 relative to the wall of the mating hole 421 along the first direction F1, thereby improving the stability of the electric field.

[0052] In some other embodiments, the gas-insulated switchgear also includes an interlocking plate 5, which is connected between the main body 21 and the drive member 45 to fix the drive member 45 to the main body 21, thereby enabling the three-position switch mechanism 4 to interlock with the circuit breaker mechanism 2 by means of the interlocking plate 5.

[0053] In some embodiments, the gas-insulated switchgear also includes a monitoring mechanism installed in the cabinet 1. The monitoring mechanism includes a surge arrester 6, a current transformer 7, and a controller (not shown) installed within the cabinet 1. Specifically, the surge arrester 6 protects the power system from damage caused by lightning surges and transient overvoltages. When a lightning surge traveling along the line into the gas-insulated switchgear exceeds the protection level of the surge arrester 6, the surge arrester 6 first discharges, safely diverting the lightning current to the ground through a good conductor, thereby protecting the equipment from damage. The current transformer 7 includes a current transformer 7 (CT) and a voltage transformer 7 (PT), which are used for measurement and protection in the power system. The current transformer 7 measures the current flowing through the conductors, while the voltage transformer 7 measures the voltage between the conductors. These measurements are crucial for monitoring the operating status, protection, and control of the power system. The current transformer 7 can convert high voltage and large current into low voltage and small current, facilitating the use of measurement and protection devices.

[0054] Both the surge arrester 6 and the instrument transformer 7 are electrically connected to the controller, enabling the controller to control the data in the gas-insulated switchgear based on the signals transmitted by the surge arrester 6 and the instrument transformer 7. The surge arrester 6 and the instrument transformer 7 play a dual role of protection and monitoring in the gas-insulated switchgear, ensuring the safe and stable operation of the power system. In this embodiment, the gas-insulated switchgear also includes an instrument compartment 8, in which the controller is encapsulated for protection.

[0055] In other embodiments, the gas-insulated switchgear also includes a cable terminal 10 for connecting to an external load, the cable terminal 10 being used to connect the gas-insulated switchgear to the external load. In this embodiment, the cable terminal 10 is configured as a pluggable type, which helps to improve the convenience of connecting the gas-insulated switchgear to the external load.

[0056] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0057] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A gas-insulated switchgear equipped with an SF6 circuit breaker, characterized in that, The gas-filled cabinet includes: Cabinet body, including fixed panels; A circuit breaker mechanism includes a main body and a pole, wherein the main body is installed at the bottom of the cabinet and the pole is installed at the top of the main body; Busbar bushings, installed on the top of the cabinet and used for connecting to external busbars; and The three-position switch mechanism includes a connecting contact, an isolating contact, a grounding contact, and a moving contact. The connecting contact is electrically connected to the bus bushing, the isolating contact is installed and electrically connected to the pole post, and the grounding contact is installed on the fixed plate. The moving contact is configured to move along a first direction between the connecting contact, the isolating contact, and the grounding contact.

2. The gas-filled cabinet according to claim 1, characterized in that, The three-position switch mechanism also includes a driving component and a transmission rod. The driving component is mounted on the fixed plate, and the transmission rod drives the moving contact to the driving component. Under the drive of the driving component, the moving contact can move between the connecting contact, the isolating contact, and the grounding contact.

3. The gas-filled cabinet according to claim 2, characterized in that, The moving contact is threaded to the transmission rod, and the moving contact is at least partially housed within the isolating contact, which is located between the grounding contact and the closing contact.

4. The gas-filled cabinet according to any one of claims 2 or 3, characterized in that, The isolation contact is provided with a mating hole for the moving contact to pass through. In the first direction, both ends of the mating hole are provided with contact fingers for abutting the moving contact.

5. The gas-filled cabinet according to claim 2, characterized in that, The transmission rod is made of insulating material.

6. The gas-filled cabinet according to claim 2, characterized in that, The gas-filled cabinet also includes an interlocking plate, which is disposed between the main body and the driving member to fix the driving member to the main body.

7. The gas-filled cabinet according to claim 1, characterized in that, The circuit breaker mechanism is an SF6 circuit breaker, and the pole is an SF6 pole.

8. The gas-filled cabinet according to any one of claims 1-3, characterized in that, The gas-insulated switchgear also includes a monitoring mechanism electrically connected to the circuit breaker mechanism. The monitoring mechanism includes a surge arrester, a current transformer, and a controller installed inside the switchgear. The surge arrester and the current transformer are both electrically connected to the controller.

9. The gas-filled cabinet according to claim 1, characterized in that, The gas-filled cabinet also includes a connecting copper busbar, one end of which is connected to the busbar bushing and the other end is connected to the contact.

10. The gas-filled cabinet according to claim 1, characterized in that, The gas-filled cabinet also includes a cable terminal for connecting to an external load, the cable terminal being pluggable.

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