Three-phase common-cylinder gas insulated metal-enclosed switchgear

Abstract

The technical scheme of the present application discloses a three-phase common-cylinder gas insulated metal enclosed switch cabinet, which comprises, from front to back, a control room containing an operation panel, an operation mechanism and a secondary control circuit, a mounting part and a channel for pressure relief collection and overall hollow; the mounting part is respectively provided with a connecting chamber, a circuit breaker chamber and a three-position switch chamber from bottom to top, and the circuit breaker chamber is a double-cylinder gas chamber with two cross orthogonal cylinder structures. The present application can meet the requirement of wide working pressure, is suitable for SF6 and other insulating gases, meets the requirement of insulation level of different voltage grades, and can be combined and optimized to obtain better cost performance and applicability; the heat dissipation efficiency of the gas chamber can be improved, the rated current can be improved, and the other functions and parameter requirements of the switch cabinet can be met through modular combination, so that the reliability, safety and standardization and serialization of the components and elements are improved, and the green development of environmental protection gas insulation is realized with better cost performance.

Description

Technical Field

[0001] This invention relates to the field of metal-enclosed switchgear technology, and in particular to a three-phase common-cylinder gas-insulated metal-enclosed switchgear. Background Technology

[0002] According to GB3906 and IEC62271-200 standards, 3.6KV-52KV switchgear is a complete set of equipment that is factory-assembled and type-tested, installed indoors or outdoors, and includes A, B, and C three-phase switching devices and related control, measurement, protection, regulation, and intelligent and digital equipment, as well as related accessories, enclosures, support components and their internal connections. It can be classified according to the main insulation medium as follows: air-insulated switchgear (AIS) with atmospheric air as the main insulation medium, and gas-insulated switchgear (C-GIS or gas-filled switchgear) with gas (such as sulfur hexafluoride (SF6) or other gases) as the main insulation medium.

[0003] Because AIS uses atmospheric air as the insulating medium, it is not only large in size and occupies a lot of space, but the insulation reliability of high-voltage live parts is also easily affected by environmental factors such as atmosphere, altitude, humidity, salt spray, dust, and small animals. Therefore, the long-term reliability of operation is affected by the environment and must be maintained, repaired or replaced. Not only are the maintenance and repair costs high, but the risk of equipment and personal injury accidents caused by maintenance and repair also increases.

[0004] C-GIS seals all high-voltage components (such as circuit breakers or load switches, three-position switches, etc.), busbars, and other devices and their interconnections within a chamber filled with insulating gas (such as SF6 gas). These are then electrically connected to the outside via sealed bushings. This protects the insulation of all high-voltage live parts from environmental influences and eliminates the need for maintenance, thus improving operational reliability. Furthermore, by using a gas with superior insulation and heat dissipation properties compared to air (such as SF6 gas), the structure can be more compact, reducing its size and footprint. Therefore, C-GIS is widely used in substation and distribution fields with high reliability requirements, difficult maintenance, heavy environmental pollution, limited space or land, and in coastal and high-altitude areas, serving as an effective supplement and replacement for AIS (Automatic Information System).

[0005] However, on the one hand, current C-GIS still mainly uses SF6 gas. Although SF6 is an excellent insulating and arc-quenching gas, it is also a high-equivalent greenhouse gas with limited emissions. According to data released by the United Nations, the greenhouse effect of SF6 is 23,900 times that of carbon dioxide (CO2), and its natural decomposition time in the atmosphere is as long as 3,200 years, which is difficult to meet the needs of green energy and sustainable development. Moreover, no ideal alternative gas has been found so far. Even new gases such as G3, C4, and C5 still need extensive verification regarding their applicability, decomposition products, and toxicity. On the other hand, using environmentally friendly gases such as nitrogen, dry air, or CO2 only provides about one-third the insulation performance of SF6, and their heat dissipation performance is also poor. All of these factors limit the development of C-GIS.

[0006] On the other hand, the current sealed gas chambers of C-GIS are designed based on the excellent insulation and heat dissipation properties of SF6. Their working gas pressure is slightly positive (i.e., the filling pressure inside the chamber is slightly higher than atmospheric pressure, such as 0.02-0.06 MPa relative pressure). Therefore, they mainly use box-type gas chambers welded from stainless steel plates. This is not conducive to improving gas insulation capacity by increasing gas pressure (such as 0.3 MPa relative pressure and below), thus increasing the difficulty of developing environmentally friendly gases for higher voltage levels (such as 40.5 KV and above); furthermore, due to the poor thermal conductivity of stainless steel plates, it is not conducive to heat dissipation in the switchgear. The need for heat increases the difficulty of developing C-GIS to larger current levels (such as 2500A and above); it also hinders the vacuuming required for factory production and on-site maintenance and repair (such as -0.1MPa); resulting in different products from different manufacturers, different insulating gases, different voltage levels, different current levels, different C-GIS structural forms, external dimensions, and even different installation, operation and maintenance requirements, causing inconvenience to users in design, construction, installation and maintenance, as well as expansion and renovation, and also causing inconvenience to the manufacturers' own production, and limiting the standardization and serialization development of C-GIS.

[0007] On the other hand, although some C-GIS systems use a cylindrical sealed gas chamber structure, the three phases are either separate, i.e., three aluminum cylindrical gas chambers are arranged one after the other to form a three-phase C-GIS, or although the three phases are in the same steel cylinder, not only are the internal components (such as circuit breakers, three-position switches, etc.) arranged in a vertical triangle and installed separately, making it difficult to adopt the currently mature three-phase horizontal integrated type, but all components are in one chamber and cannot be separated, which reduces the reliability of the switchgear. Furthermore, when connecting the busbars between cabinets at the installation site, it is necessary to open the busbar gas chamber of each switchgear, connect the busbars, and then seal the gas chamber and treat the gas (vacuuming and filling with insulating gas). Therefore, the busbar gas chambers of each switchgear are not independent but several or all connected. If there is a problem with one busbar gas chamber, it will affect the others, which not only increases the installation requirements and costs, but also reduces the reliability of the switchgear busbars.

[0008] Meanwhile, switchgear is required to withstand internal arcing for a certain current (usually the rated short-circuit breaking current, such as 25KA or 31.5KA) and a certain time (such as 0.5 seconds or 1 second) to ensure the safety of personnel, systems and equipment in case of failure. However, when aluminum or aluminum alloy is used as the sealing chamber material, its poor arc resistance limits its application, especially when a three-phase short circuit occurs. Summary of the Invention

[0009] The purpose of this invention is to provide a three-phase common-cylinder medium-voltage gas-insulated switchgear that can operate under a wide range of working gas pressures (e.g., -0.1MPa to 0.3MPa relative pressure), making it suitable for both SF6 and other insulating gases. It can be adjusted to meet the insulation level requirements of different voltage levels through different combinations of insulating gases and rated gas pressures, and can be optimized to achieve better cost-effectiveness and applicability. Furthermore, it can improve and enhance the heat dissipation efficiency of the sealed gas chamber to increase the rated current. Modular combinations can also achieve other functions and parameter requirements of the switchgear. Thus, while improving the reliability, safety, standardization, and serialization of 3.6KV-52KV C-GIS and its components, it achieves a green development towards environmentally friendly gas insulation with better cost-effectiveness.

[0010] To solve the above-mentioned technical problems, the present invention provides a three-phase common-cylinder gas-insulated metal-enclosed switchgear, wherein the switchgear includes:

[0011] The control room, which includes the operation panel, operation mechanism and its secondary control circuit, the installation part, and the hollow channel for pressure relief collection are arranged from front to back.

[0012] The installation section, from bottom to top, includes a connection chamber, a circuit breaker chamber, and a three-position switch chamber.

[0013] The circuit breaker compartment is a double-cylinder air chamber with a structure of two orthogonal cross-shaped cylinders.

[0014] The top of the busbar of the three-position switch chamber is extended into a double-cylinder air chamber with two cross-shaped orthogonal cylindrical structures, or the side of the busbar is extended into a triple-cylinder air chamber with three cross-shaped orthogonal cylindrical structures.

[0015] Optionally, the circuit breaker compartment is a double-cylinder air chamber with two cylindrical axes orthogonally arranged, and the cylinder openings are respectively provided with a first front sealing plate, a first rear sealing plate, a middle sealing plate and a lower sealing plate shared with the three-position switch compartment.

[0016] Optionally, the lower sealing plate is equipped with an inlet / outlet bushing fixed to the bottom, a circuit breaker pole installed on the inner surface of the first front sealing plate and connected to the inlet / outlet bushing, a first operating mechanism for operating the circuit breaker pole installed on the outside of the first front sealing plate, a first pressure relief valve installed on the outside of the first rear sealing plate, a first arc-resistant device provided on the lower sealing plate and located outside the inlet / outlet bushing, and the three-phase circuit breaker poles located in the circuit breaker compartment are arranged horizontally in a straight line.

[0017] Optionally, the three-position switch chamber is a double-cylinder gas chamber with two cylindrical axes orthogonally arranged in a cross shape. A second front sealing plate, a second rear sealing plate, a middle sealing plate shared with the circuit breaker chamber, and an upper sealing plate are respectively installed at the cylinder openings. A connecting sleeve and a second arc-resistant device are installed outside the connecting sleeve on the middle sealing plate. The inner surface of the second front sealing plate is installed with the front end of the three-position switch. The middle end of the three-position switch is connected to the connecting sleeve via an intermediate moving contact seat. The rear end of the three-position switch is connected to the busbar outer conical sleeve installed on the inner surface of the upper sealing plate via a supporting insulator bracket installed on the second rear sealing plate. A second pressure relief valve is installed outside the second rear sealing plate. A second operating mechanism for controlling the three-position switch is installed outside the second front sealing plate. The front, middle, and rear ends of the three-phase three-position switches located within the three-position switch chamber are arranged horizontally in a straight line.

[0018] Optionally, the first pressure relief valve, the second pressure relief valve, the connecting chamber, and the channel are connected.

[0019] Optionally, the three-position switch chamber is a three-cylinder gas chamber with three cylindrical axes in an orthogonal cross structure. A second front sealing plate, a middle sealing plate shared with the circuit breaker chamber, and a second rear sealing plate are respectively installed at the cylinder openings. A connecting sleeve and a second arc-resistant device are installed outside the connecting sleeve on the middle sealing plate. The inner surface of the second front sealing plate is installed with the front end of the three-position switch. The middle end of the three-position switch is connected to the connecting sleeve via an intermediate moving contact seat. The rear end of the three-position switch is connected to the busbar and inner conical sleeve installed in the upper cylindrical gas chamber of the three-position switch chamber via a supporting insulator bracket installed on the second rear sealing plate. A second pressure relief valve is installed outside the second rear sealing plate, and a second operating mechanism for controlling the three-position switch is installed outside the second front sealing plate. The front, middle, and rear ends of the three-phase three-position switches located within the three-position switch chamber are arranged horizontally in a straight line.

[0020] Optionally, the first pressure relief valve, the second pressure relief valve, the connecting chamber, and the channel are connected.

[0021] The beneficial effects of the technical solution of this invention are:

[0022] This invention discloses a three-phase common-cylinder medium-voltage gas-insulated switchgear that can meet a wide range of operating gas pressure requirements (e.g., -0.1MPa to 0.3MPa relative gas pressure). It is suitable for both SF6 and other insulating gases. With a relatively small external size, it can meet the insulation level requirements of different voltage levels by adjusting the combination of different insulating gases and rated gas pressures. Furthermore, it can be optimized to achieve better cost-effectiveness and applicability. It can also improve and enhance the heat dissipation efficiency of the gas chamber, thereby increasing the rated current. Modular combinations can also meet other functional and parameter requirements of the switchgear. Thus, while improving the reliability, safety, standardization, and serialization of 3.6KV-52KV C-GIS and its components, it achieves a green development towards environmentally friendly gas insulation with better cost-effectiveness. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the top-expanded three-phase common-cylinder gas-insulated metal-enclosed switchgear of the present invention;

[0024] Figure 2 This is a schematic diagram of the internal structure of the top-expanded three-phase common-cylinder gas-insulated metal-enclosed switchgear of the present invention;

[0025] Figure 3 This is a schematic diagram of the top-expanded circuit breaker compartment and three-position switch compartment of the present invention;

[0026] Figure 4 This is a perspective view of the double-cylinder type circuit breaker compartment and three-position switch compartment with top expansion of the present invention.

[0027] Figure 5 This is a schematic diagram of the structure of the side-expanded three-phase common-cylinder gas-insulated metal-enclosed switchgear of the present invention;

[0028] Figure 6 This is a schematic diagram of the internal structure of the side-expanded three-phase common-cylinder gas-insulated metal-enclosed switchgear of the present invention;

[0029] Figure 7 This is a schematic diagram of the side-expanded circuit breaker compartment and three-position switch compartment of the present invention;

[0030] Figure 8 This is a three-cylinder perspective view of the side-expanded three-position switch chamber of the present invention. Detailed implementation method:

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0032] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0033] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, an embodiment of a three-phase common-cylinder gas-insulated metal-enclosed switchgear is illustrated, wherein the switchgear includes:

[0036] The control room 1, which includes the operation panel, operation mechanism and its secondary control circuit, the installation part and the hollow channel 29 for pressure relief collection are arranged from front to back.

[0037] The installation section, from bottom to top, includes a connection compartment 2, a circuit breaker compartment 5, and a three-position switch compartment 3 / 4.

[0038] Circuit breaker compartment 5 is a double-cylinder air chamber with a structure of two cross-shaped orthogonal cylinders;

[0039] The top extension of the busbar in the three-position switch chamber is a double-cylinder air chamber with a structure of two orthogonal cross cylinders (such as...). Figure 1 and Figure 4 (As shown) or, the side extension of the busbar is 4, forming a three-cylinder air chamber with a three-cross orthogonal cylindrical structure (as shown) Figure 5 and Figure 8 (As shown).

[0040] like Figure 2 , Figure 3 In this embodiment, the circuit breaker chamber 5 is a cylindrical air chamber with two cylindrical axes of orthogonal cross structure. A first front sealing plate 13, a first rear sealing plate 15, a middle sealing plate 16 shared with the three-position switch chamber 3, and a lower sealing plate 17 are respectively provided at the cylinder opening. An inlet / outlet bushing 19 fixed to the bottom is installed on the lower sealing plate 17. A circuit breaker pole 10 is installed inside the first front sealing plate 13 and connected to the inlet / outlet bushing 19. A first operating mechanism 20 for operating the circuit breaker pole 10 is installed outside the first front sealing plate 13. A first pressure relief valve 33 is installed outside the first rear sealing plate 15. A first arc-resistant device 21 is provided on the lower sealing plate 17 outside the inlet / outlet bushing 19. The three-phase circuit breaker poles 10 inside the circuit breaker chamber 5 are arranged horizontally in a straight line.

[0041] In this embodiment, the three-position switch chamber 3 is a double-cylinder air chamber with two cylindrical axes orthogonally arranged, and a second front sealing plate 12, a second rear sealing plate 14, a middle sealing plate 16 shared with the circuit breaker chamber 5, and an upper sealing plate 161 are respectively provided at the cylinder opening positions; a connecting sleeve 18 and a second arc-resistant device 211 disposed outside the connecting sleeve 18 are installed on the middle sealing plate 16; the inner surface of the second front sealing plate 12 is installed with the front end of the three-position switch 9; the middle end of the three-position switch 9 is connected to the connecting sleeve through the intermediate moving contact 11. Pipe 18 is connected, and the rear end of the three-position switch 9 is connected to the busbar outer cone sleeve 23 installed on the inner surface of the upper sealing plate 161 through the support insulator bracket 25 set on the second rear sealing plate 14. The second pressure relief valve 331 is installed on the outside of the second rear sealing plate 14, and the second operating mechanism 22 for controlling the three-position switch 9 is installed on the outside of the second front sealing plate 12. The front end, middle end and rear end of the three-phase (including phase A, phase B and phase C) three-position switch 9 located in the three-position switch chamber 3 are arranged horizontally in a row.

[0042] In this embodiment, the first pressure relief valve 33, the second pressure relief valve 331, the connecting chamber 2, and the channel 29 are connected.

[0043] like Figure 5 , Figure 6 , Figure 7 and Figure 8As shown, in this embodiment, the three-position switch chamber 4 is a three-cylinder air chamber with a cross-shaped orthogonal structure of three cylindrical axes. A second front sealing plate 12, a middle sealing plate 16 shared with the circuit breaker chamber 5, and a second rear sealing plate 14 are respectively installed at the cylinder openings. A connecting sleeve 18 and a second arc-resistant device 211 are installed on the middle sealing plate 16 outside the connecting sleeve 18. The inner surface of the second front sealing plate 12 is installed with the front end of the three-position switch 9. The middle end of the three-position switch 9 is connected to the connecting sleeve 18 through an intermediate moving contact 11. The rear end of the three-position switch 9 is connected to the inner conical sleeve 24 of the busbar in the upper cylindrical air chamber 7 of the three-position switch chamber 4 via a support insulator bracket 25 set on the second rear sealing plate 14. A second pressure relief valve 331 is installed on the outside of the second rear sealing plate 14. A second operating mechanism 22 for controlling the three-position switch 9 is installed on the outside of the second front sealing plate 12. The front end, middle end and rear end of the three-phase (including phase A, phase B and phase C) three-position switch 9 in the three-position switch chamber 4 are arranged horizontally in a row.

[0044] In this embodiment, the first pressure relief valve 33, the second pressure relief valve 331, the connecting chamber 2, and the channel 29 are connected.

[0045] The features and functions of the present invention will be further understood through the following description.

[0046] A three-phase common-cylinder medium-voltage gas-insulated switchgear is classified into two structures according to its busbar extension method. The first type is the busbar top extension structure (e.g., Figures 1-4 The structure includes: a control room 1 containing the front operating panel, operating mechanism and its secondary control circuit; a connection room (such as a cable or busbar, also called a cable room) located in the lower middle for connecting incoming and outgoing lines; a three-position switch room 3 located in the upper middle containing a three-position switch (or busbar) and sealed in a cylindrical gas chamber filled with insulating gas; a circuit breaker room 5 located in the middle containing a circuit breaker (or load switch) and sealed in a cylindrical gas chamber filled with insulating gas; and a channel 29 located at the rear for pressure relief collection, etc.; the second type is a busbar side extension structure (such as... Figures 5-8 The structure is the same as the first type, except that the three-position switch chamber 4 located in the upper middle part is different.

[0047] like Figures 1-8As shown, the three-position switch compartments 3 and 4 are connected to the circuit breaker compartment 5 from the top and bottom, respectively, to form the main circuit of the top and side expansion structures of the switchgear. They can be separated by metal plates, and the gas systems are independent and modularly designed. The three-position switch compartments 3 and 4 and the circuit breaker compartment 5 all adopt a three-phase common cylinder structure, that is, the three phases A, B, and C are in the same cylindrical gas chamber. Cylindrical gas chambers 6, 7, and 8 (the internal gas chamber of the top-expanded three-position switch compartment is cylindrical gas chamber 6, and the internal gas chamber of the side-expanded three-position switch compartment is cylindrical gas chamber 8) are cylindrical gas chambers 6, 7, and 8. The internal air chamber of the circuit breaker compartment is a cylindrical air chamber 8. It adopts a cross-shaped orthogonal combination structure of two or three cylindrical axes and is made of aluminum, aluminum alloy or steel. The three-position switch 9 installed in the three-position switch compartment 3 and 4 and the circuit breaker (or load switch) pole 10 installed in the circuit breaker compartment 5 are arranged horizontally in a straight line in the three-phase A, B and C of the cylindrical air chambers 6, 7 and 8 and are connected to the operating mechanisms 22 and 20 respectively to form a whole. The top extension and side extension of the busbar adopt the plug-in extension connection method.

[0048] like Figure 3 , Figure 4 As shown, cylindrical air chambers 6 and 8 adopt a structure composed of two cylindrical chambers (e.g., with outer diameters of 400mm, 600mm, 800mm, etc.) whose axes are orthogonally combined. This structure ensures that the insulation distance required for the internally installed three-phase components (e.g., three-position switch 9, circuit breaker pole 10, etc.) and their interconnections is met within a relatively small cylindrical size. To achieve lateral expansion of the busbar, cylindrical air chamber 7 is added above the orthogonally combined air chamber of the two cylindrical chambers in cylindrical air chamber 6, with its axis perpendicular to the orthogonal plane of the two cylindrical axes, forming a three-cylinder orthogonal structure for lateral expansion of the busbar. Cylindrical air chambers 6, 7, and 8 are made of aluminum, aluminum alloy, or steel, which have good corrosion resistance and heat transfer properties, and can be further enhanced by adding prisms to improve heat dissipation. Thermal performance; the front and rear of cylindrical gas chambers 6, 7, and 8 can be equipped with airtight first and second front sealing plates 13 and 12 and first and second rear sealing plates 15 and 14. Cylindrical gas chambers 6 and 8 are equipped with airtight upper sealing plate 161, middle sealing plate 16, and lower sealing plate 17. The upper sealing plate 161 of cylindrical gas chamber 8 can become the lower sealing plate (i.e., middle sealing plate 16) of cylindrical gas chamber 6. Cylindrical gas chamber 7 only has a sealing plate 16 shared with cylindrical gas chamber 8. When constructed or combined in this way, it constitutes the sealing function of three-position switch chambers 3 and 4 and circuit breaker chamber 5, thereby utilizing the characteristics of high pressure resistance and small mechanical deformation of cylindrical structure to meet the working requirements of the filled insulating gas within a certain range (such as -0.1MPa to 0.3MPa relative pressure).

[0049] The circuit breaker compartment 5 contains three-phase circuit breaker poles 10, connecting bushings 18, inlet and outlet bushings 19, pressure relief valves 33, and insulating gas, all sealed within a cylindrical gas chamber 8. Its overall arrangement employs a front-to-back and top-to-bottom configuration to suit the structural characteristics of the cylindrical gas chamber. Specifically, the circuit breaker poles 10 are installed on the inner surface of the first front sealing plate 13 of the cylindrical gas chamber 8; the connecting bushings 18 are located above the circuit breaker poles 10 for direct electrical connection with the three-position switch 9; and the inlet and outlet bushings 19 are located below the circuit breaker poles 10 and installed on the lower sealing plate 17 of the cylindrical gas chamber 8 for connection with external cables, surge arresters, and voltage transformers. The circuit breaker terminals 10 are connected by plug-in insulated electrical connections. The three-phase arrangement utilizes the cross-orthogonal structure of the cylindrical air chamber 8 to achieve a common cylinder and horizontal linear arrangement of the A, B, and C phases of the circuit breaker terminals 10. The operating mechanism 20 of the circuit breaker terminals 10 is installed on the outer surface of the first front sealing plate 13 of the cylindrical air chamber 8, and drives the circuit breaker terminals 10 inside the cylindrical air chamber 8 through a sealed transmission method, so that the circuit breaker is integrated into a whole. The first pressure relief valve 33 is installed on the first rear sealing plate 15 of the cylindrical air chamber 8. The first arc-resistant device 21 is installed on the lower sealing plate 17 inside the cylindrical air chamber 8 and around the inlet and outlet bushings 19 to improve the internal arc resistance.

[0050] When the three-position switch chamber 3 is used for top expansion, it includes a three-phase three-position switch 9 (isolation and grounding) sealed in a cylindrical gas chamber 6, a busbar outer cone bushing 23, a second pressure relief valve 331, and insulating gas, etc.

[0051] When the three-position switch chamber 4 is used for side expansion, it includes a three-phase three-position switch 9 (isolation and grounding) sealed in a cylindrical gas chamber 7, a busbar and its inner tapered sleeve 24, a second pressure relief valve 331, and insulating gas, etc.

[0052] Its overall layout adopts a front-to-back and top-to-bottom arrangement to suit the structural characteristics of cylindrical air chambers 3 and 4. Specifically, the front end (grounding end) of the three-position switch 9 is fixed to the inner surface of the second front sealing plate 12 of cylindrical air chambers 6 and 7. The intermediate moving contact seat 11 is connected to the circuit breaker pole 10 through the connecting sleeve 18 fixed on the middle sealing plate 16. The rear end is connected to the outer conical sleeve 23 of the busbar in the three-position switch chamber 3 and to the busbar formed by the inner conical sleeve 24 in the three-position switch chamber 4. All of these are fixed to the second front sealing plate 12 of cylindrical air chambers 6 and 7 through supporting insulators and brackets 25. Inside the rear sealing plate 14, the three-phase arrangement utilizes the cross-orthogonal structure of the cylindrical gas chambers 6 and 7 to achieve a three-phase common cylinder and a horizontal straight-line arrangement; the operating mechanism 22 of the three-position switch 9 is installed on the outer surface of the second front sealing plate 12 of the cylindrical gas chambers 6 and 7, and drives the three-position switch 9 in the gas chamber through a sealed transmission method and is integrated into a whole; the second pressure relief valve 33 is installed on the second rear sealing plate 14 of the cylindrical gas chambers 6 and 7; a second arc-resistant device 211 is installed on the middle sealing plate 16 inside the cylindrical gas chambers 6 and 7 and around the connecting sleeve 18 to improve the arc-resistant capability.

[0053] The three-position switch compartments 3 and 4 and the circuit breaker compartment 5 can be simplified and combined into one compartment. The compartment contains the main circuit of the switch cabinet and is located in the same sealed gas system in a cylindrical gas chamber. The cylindrical gas chamber can be an integral structure or a combination of the cylindrical gas chambers 6 or 7 and 8 of the three-position switch compartment 3 or 4 and the circuit breaker compartment 5. The three-position switch and the circuit breaker poles are also arranged vertically, horizontally in a line, and integrated into a whole in the cylindrical gas chambers 6, 7, and 8.

[0054] The three-position switch compartments 3 and 4 and the circuit breaker compartment 5 are filled with insulating gas. The insulating gas can be SF6, nitrogen, dry air, or other gases, as well as mixed gases. Furthermore, due to the structural characteristics of the cylindrical gas compartments 6, 7, and 8, through gas-solid composite insulation coordination and optimization of the structure and electric field of energized components, the insulating gas and its rated filling pressure can be flexibly selected to meet the insulation requirements of different voltage levels (such as 12KV / SF6 / 0.1MPa, 12KV / dry air / 0.12MPa, 12KV / C5 / 0.12MPa, 40.5KV / SF6 / 0.12MPa, 40.5KV / N2 / 0.25MPa, etc., selection and combination), suitable for the use of various insulating gases (the filling pressure generally does not exceed 0.3MPa (relative pressure)). Combination optimization can be performed to achieve better cost performance and applicability; it can also improve heat dissipation performance while making the external dimensions (including installation dimensions) and structure of different specifications of C-GIS products as uniform as possible or reducing differences, forming modular design and specialized production of cylindrical air chambers 6, 7, 8 and their internal components (such as three-position switches and circuit breakers, bushings, etc.). For example, 12KV / 1250A and 40.5KV / 1250A, 12KV / 2500A and 40.5KV / 2500A can use cylindrical air chambers 6, 7, 8 or their combinations with the same external dimensions. It is also easy to achieve larger rated currents (such as 3150A, 4000A, etc.), thereby improving the reliability, safety and standardization and serialization of C-GIS and its components, reducing costs and facilitating installation, use and maintenance while achieving green development.

[0055] In summary, the three-phase common-cylinder medium-voltage gas-insulated switchgear of this invention can meet the requirements of a wide range of working gas pressures (such as -0.1MPa to 0.3MPa relative gas pressure), and is suitable for both SF6 and other insulating gases. With a relatively small external size, it can meet the insulation level requirements of different voltage levels by adjusting the combination of different insulating gases and rated gas pressures, and can be optimized to achieve better cost performance and applicability. Furthermore, it can improve and enhance the heat dissipation efficiency of the gas chamber to increase the rated current. Modular combinations can also meet other functional and parameter requirements of the switchgear, thereby improving the reliability, safety, standardization, and serialization of 3.6KV-52KV C-GIS and its components, while achieving a green development towards environmentally friendly gas insulation with better cost performance.

[0056] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A three-phase common-cylinder gas-insulated metal-enclosed switchgear, characterized in that, The switchgear includes: The control room, which includes the operation panel, operation mechanism and its secondary control circuit, the installation part, and the hollow channel for pressure relief collection are arranged from front to back. The installation section is equipped with a connection chamber, a circuit breaker chamber and a three-position switch chamber from bottom to top. The circuit breaker chamber is the first cross-shaped air chamber with a structure of two cross-shaped orthogonal cylinders. The cylinder opening is provided with a first front sealing plate, a first rear sealing plate, a middle sealing plate and a lower sealing plate shared with the three-position switch chamber. The three-position switch chamber is selected from one of the following two extended structures: I) The top of the busbar extends into a second cross-shaped air chamber with two orthogonal cross-shaped cylinder structures, and a second front sealing plate, a second rear sealing plate, a middle sealing plate shared with the circuit breaker chamber, and an upper sealing plate are respectively installed at the cylinder opening positions; or II) The side of the busbar is extended into a double cross-shaped air chamber with three cross-shaped orthogonal cylinders, and the cylinder openings are respectively provided with a second front sealing plate, the middle sealing plate shared with the circuit breaker chamber, and a second rear sealing plate. The switchgear can operate under air pressure of -0.1MPa to 0.3MPa.

2. The three-phase common-cylinder gas-insulated metal-enclosed switchgear according to claim 1, characterized in that, The lower sealing plate is equipped with an inlet / outlet bushing fixed to the bottom, a circuit breaker pole installed on the inner surface of the first front sealing plate and connected to the inlet / outlet bushing, a first operating mechanism for operating the circuit breaker pole installed on the outside of the first front sealing plate, a first pressure relief valve installed on the outside of the first rear sealing plate, a first arc-resistant device installed on the lower sealing plate and located outside the inlet / outlet bushing, and three-phase circuit breaker poles arranged horizontally in a row in the circuit breaker compartment.

3. The three-phase common-cylinder gas-insulated metal-enclosed switchgear according to claim 2, characterized in that, The first pressure relief valve is connected to the channel.

4. The three-phase common-cylinder gas-insulated metal-enclosed switchgear according to claim 1, characterized in that, When the top of the busbar is extended, a connecting sleeve and a second arc-resistant device are installed on the middle sealing plate. The inner surface of the second front sealing plate is installed with the front end of the three-position switch. The middle end of the three-position switch is connected to the connecting sleeve through the intermediate moving contact seat. The rear end of the three-position switch is connected to the outer conical sleeve of the busbar installed on the inner surface of the upper sealing plate through the supporting insulator bracket installed on the second rear sealing plate. A second pressure relief valve is installed on the outside of the second rear sealing plate. A second operating mechanism for controlling the three-position switch is installed on the outside of the second front sealing plate. The front, middle and rear ends of the three-phase three-position switches in the three-position switch chamber are arranged horizontally in a straight line.

5. The three-phase common-cylinder gas-insulated metal-enclosed switchgear according to claim 4, characterized in that, The second pressure relief valve is connected to the channel.

6. The three-phase common-cylinder gas-insulated metal-enclosed switchgear according to claim 1, characterized in that, When a busbar side extension structure is adopted, a connecting sleeve and a second arc-resistant device are installed on the middle sealing plate. The inner surface of the second front sealing plate is installed with the front end of the three-position switch. The middle end of the three-position switch is connected to the connecting sleeve through an intermediate moving contact seat. The rear end of the three-position switch is connected to the busbar and inner conical sleeve installed in the upper cylindrical air chamber of the three-position switch chamber through a supporting insulator bracket installed on the second rear sealing plate. A second pressure relief valve is installed on the outside of the second rear sealing plate. A second operating mechanism for controlling the three-position switch is installed on the outside of the second front sealing plate. The front, middle and rear ends of the three-phase three-position switches in the three-position switch chamber are arranged horizontally in a straight line.

7. The three-phase common-cylinder gas-insulated metal-enclosed switchgear according to claim 6, characterized in that, The second pressure relief valve is connected to the channel.

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