Compact environment-friendly gas insulation ring main unit

Abstract

The invention discloses a compact type environment-friendly gas insulation ring main unit. A gas tank is arranged in a cabinet body, a circuit breaker switch unit is arranged at the upper part in the gas tank, an isolation switch unit is arranged at the lower part, a bus side expansion sleeve is arranged at the top, and a lower incoming and outgoing line sleeve is arranged at the bottom. A main shaft of the circuit breaker switch unit is connected with a pole through a transmission connecting lever and other parts, the main shaft is provided with an umbrella skirt insulating part, and an insulating partition plate is arranged between static contacts and integrally cast with the pole. A main shaft of the disconnecting switch unit is sleeved with a moving contact and works cooperatively with other parts through an insulating connecting piece and the like, and a bus side expansion sleeve and a lower incoming and outgoing line sleeve are provided with C-shaped protective covers. The environment-friendly gas is adopted, and the environment-friendly requirement is met; by optimizing the structure and layout of each component, the size of the ring main unit is obviously reduced, and the old network transformation requirement is met; the unique insulation design effectively improves the insulation performance, reduces the fault risk, and guarantees the safe and stable operation of a power system.

Description

Technical Field

[0001] The invention relates to the field of power switches, and in particular to a compact environmentally friendly gas-insulated ring network cabinet. Background Art

[0002] With the continuous rise in global electricity demand and the increasingly stringent requirements for power supply reliability and safety, the ring main unit plays an increasingly critical role in the power distribution system. It undertakes the important mission of power distribution, control and protection, and is an indispensable device to ensure the stable operation of the power network. Traditional ring main units mostly use SF6 gas as an insulating medium. Although SF6 gas has excellent insulation and arc extinguishing properties and can meet the operating requirements of the ring main unit to a certain extent, it is a strong greenhouse gas with an extremely high global warming potential (GWP). With the continuous enhancement of people's environmental awareness and the gradual tightening of international environmental regulations on greenhouse gas emissions, the application of SF6 gas in ring main units faces severe environmental challenges. This has prompted the power equipment industry to actively explore and develop environmentally friendly alternatives, and environmentally friendly gas insulated ring main units have emerged.

[0003] In the process of upgrading and renovating the power system, especially the old network renovation project, there are many practical problems. On the one hand, the infrastructure layout of the old network has been fixed, including the bearing capacity of the foundation, the laying position and path of the incoming and outgoing cables, etc. This requires that the newly replaced environmentally friendly gas insulated ring network cabinet must be highly compatible with the original equipment in terms of size and structure, otherwise it will involve large-scale infrastructure reconstruction, which is not only costly, but also has a great impact on the surrounding environment and the continuity of power supply. On the other hand, the existing environmentally friendly gas insulated ring network cabinet still has some technical deficiencies. For example, the core component of many ring network cabinets, the circuit breaker isolation integrated switch, often adopts an open structure. In this structural mode, key components such as the moving and static contacts, vacuum interrupter and connectors of the circuit breaker and the isolation switch are directly exposed to the air. In order to ensure the insulation level inside the gas box and avoid faults such as phase-to-phase short circuit and ground breakdown, the safety distance between phases and relative to the ground has to be increased. This directly leads to a significant increase in the size of the switch, which in turn increases the size of the gas box accordingly, increases the amount of sheet metal, and significantly increases the manufacturing cost. At the same time, traditional ring main units have defects in insulation protection design. For example, the insulation protection measures at the joints between the busbar and the static contacts of the circuit breaker and the outgoing lines are not perfect. The insulation performance may be easily degraded due to factors such as electric field concentration, dust accumulation, and moisture intrusion, increasing the risk of equipment failure and threatening the safe and stable operation of the power system.

[0004] To sum up, developing an environmentally friendly gas insulated ring main unit that can meet environmental protection requirements, overcome the adaptability problem of old network transformation, and have a compact structure and good insulation performance has become an important issue that needs to be urgently solved in the current power equipment field. Summary of the invention

[0005] 1. Technical issues to be solved

[0006] In view of the deficiencies of the prior art, the present invention aims to provide a compact environmentally friendly gas-insulated ring network cabinet, which solves the problems existing in the prior art. By sealing the vacuum arc extinguishing chamber and its connectors inside the epoxy resin, the lateral size is greatly reduced. The three-phase static contacts of the circuit breaker are separated by insulating partitions and integrally cast with the poles, which not only reduces the space occupied but also enhances the phase-to-phase insulation. The movable contact of the isolating switch is sleeved inside the insulating main shaft. No matter what position the movable contact is in, it can meet the insulation requirements in a limited space, effectively reducing the longitudinal size.

[0007] The lower static contact adopts a T-shaped structure and cooperates with the bowl-shaped structure at the bottom of the pole to form a synergistic combination mode. The lateral part of the T-shaped lower static contact ensures a stable and sufficient current conduction contact area to achieve efficient power transmission, while the longitudinal extension part significantly increases the phase-to-phase distance in the form of a longitudinal facade, effectively reducing the electric field strength between phases and the risk of phase-to-phase short circuit. At the same time, the bowl-shaped structure at the bottom of the pole is connected to the lower static contact. Its unique curved surface shape can accurately guide and evenly disperse the electric field, making the distribution of the electric field near the contact more reasonable, avoiding the local discharge phenomenon caused by the concentration of the electric field. This combination not only optimizes the electric field distribution, greatly improves the insulation performance of the entire contact system, and effectively prevents gas breakdown and arc generation, but also adapts to each other in mechanical structure, enhances the stability and reliability of the contact system during the opening and closing process, reduces mechanical vibration and wear, and extends the service life of the equipment, laying a solid foundation for the safe, stable and efficient operation of electrical equipment.

[0008] Three sets of umbrella skirt insulators are evenly arranged on the main shaft of the circuit breaker switch, which increases the creepage distance, improves the electric field distribution, effectively prevents phase-to-phase short circuit and leakage, and provides mechanical support and protection for the main shaft. A C-shaped protective cover is arranged on the busbar side expansion bushing and the lower inlet and outlet bushing, which can evenly distribute the electric field, increase the creepage distance, and effectively prevent the occurrence of flashover. The insulation design of the above-mentioned components cooperates with each other, such as the integrated casting of the insulating partition and the pole to enhance the insulation reliability of the circuit breaker part, the coordination of the isolating switch moving contact with the insulating main shaft and related insulating connectors to ensure the insulation stability of the isolating switch unit, and improves the insulation performance of the ring network cabinet as a whole, ensuring that the equipment can operate safely and stably in a high-voltage environment, and effectively solving the problem of insufficient insulation protection of traditional ring network cabinets.

[0009] (II) Technical solution

[0010] To achieve the above object, the present invention provides the following technical solution: A compact environmentally friendly gas-insulated ring main unit comprises a cabinet body, a gas box is arranged in the cabinet body, and a switch drive unit is connected to the left side of the gas box;

[0011] A circuit breaker switch unit is arranged at the upper end of the gas box, and an isolating switch unit is arranged at the lower end, and the circuit breaker switch unit is connected to the isolating switch unit; a busbar side expansion bushing is arranged at the top of the gas box, and a lower inlet and outlet bushing is arranged at the bottom;

[0012] The circuit breaker switch unit includes a circuit breaker switch main shaft, which is evenly provided with transmission crank arms and connecting pieces, a pole is fixed at the lower end of the connecting piece, vacuum arc chambers are evenly distributed laterally on the poles, an upper static contact is provided at the upper end of the vacuum arc chamber, and a lower static contact is provided at the lower end of the vacuum arc chamber.

[0013] Preferably, the lower static contact is designed in a T-shaped structure, in which the lateral part of the T-shape constitutes the main current conduction and contact area, and the longitudinally extending part adopts a longitudinal facade form, which extends vertically in space, effectively increasing the phase-to-phase distance, optimizing the electric field distribution characteristics, and enhancing the phase-to-phase insulation performance, thereby improving the stability and safety of the overall electrical device, while providing a more stable support structure and positioning reference for the contact system in terms of mechanical structure, ensuring reliable operation and precise movement under complex working conditions.

[0014] Preferably, the isolating switch unit comprises an isolating switch main shaft, a moving contact is sleeved inside the isolating switch main shaft, and an insulating connector is provided at the lower end of the isolating switch main shaft.

[0015] Preferably, three groups of shed insulation members are evenly arranged on the main shaft of the circuit breaker switch.

[0016] Preferably, the bottom of the pole is a bowl-shaped structure and is connected to the upper static contact.

[0017] Preferably, an insulating partition is provided between the upper static contacts, and the insulating partition is integrally cast with the pole.

[0018] Preferably, the moving contact comprises a connecting rod portion and a contact portion which are symmetrically arranged, and the contact portion is fixed inside the insulating connector.

[0019] Preferably, the contact part is connected to the lower inlet and outlet bushing via a guide rod.

[0020] Preferably, the main shaft of the isolating switch is cylindrical, and transmission insulating parts are evenly arranged on the upper end, and the transmission insulating parts are clamped with the guide rod.

[0021] Furthermore, the gas box busbar adopts an optimized design structure with large thickness and small width, which effectively reduces the lateral space occupied by the busbar in the gas box while ensuring the current carrying capacity and mechanical strength. By adding a C-type protective cover to the expansion bushing on the busbar side, the protective cover can effectively evenly distribute the electric field and significantly increase the creepage distance due to its unique structural shape and insulation characteristics, thereby effectively ensuring the insulation level of the busbar inside the entire gas box, greatly reducing the risk of insulation breakdown caused by factors such as electric field distortion, dust accumulation, and humid environment, and effectively improving the electrical insulation reliability and stability of the ring network cabinet under complex operating conditions, providing a solid guarantee for the safe and stable operation of the power system.

[0022] Furthermore, a C-type protective cover is also added to the lower inlet and outlet bushings, which plays a key role in insulation enhancement at the outlet end. It effectively ensures the insulation safety of the outlet part through multiple insulation strengthening mechanisms such as optimizing the electric field distribution and increasing the creepage distance. In the connection link between the switch and the outlet insulator, a special copper rod is used as a connecting component. This special copper rod is precisely designed and manufactured according to the current carrying capacity requirements and has excellent conductivity. While ensuring the stable transmission of large currents, it can better coordinate with the C-type protective cover and other insulation components with its structural characteristics and surface treatment process to build a reliable insulation system, thereby comprehensively improving the insulation performance of the entire connection path, effectively preventing the occurrence of electrical faults such as leakage and flashover, and providing strong support for the efficient and safe operation of the power system.

[0023] (III) Beneficial effects

[0024] The present invention has significant beneficial effects in many aspects. In terms of environmental protection, environmentally friendly gases are used to replace traditional SF6 gas with strong greenhouse effect, actively responding to the requirements of international environmental regulations on greenhouse gas emission restrictions, and vigorously promoting the green and sustainable development of the power industry. In terms of structural compactness, through innovative designs of circuit breaker switch units and disconnector units, such as the sealed layout of vacuum arc chambers and connectors, integrated casting of insulating partitions and poles, nested design of disconnector moving contacts, and special shape of static contact structure, the volume of the ring network cabinet is greatly reduced, so that it can be easily adapted to the original foundation and the position of incoming and outgoing cables in the transformation of old networks, avoiding large-scale infrastructure reconstruction, significantly reducing costs and reducing the impact on the surrounding environment and power supply continuity. In terms of insulation performance, insulation designs such as the umbrella skirt insulators on the main shaft of the circuit breaker switch, the C-shaped protective covers on the busbar and the lower inlet and outlet bushings, effectively increase the creepage distance, optimize the electric field distribution, prevent flashover and resist interference from external environmental factors, greatly improve the insulation reliability of the ring network cabinet, reduce the probability of faults such as phase-to-phase short circuit and ground breakdown, effectively ensure the safe and stable operation of the power system, and provide a high-efficiency, environmentally friendly and reliable equipment solution for the power distribution field, with broad application prospects and significant social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the whole of the compact environmentally friendly gas insulated ring main unit of the present invention;

[0026] Figure 2 It is a schematic diagram of a gas box in a compact environmentally friendly gas-insulated ring main unit of the present invention;

[0027] Figure 3 A schematic diagram of a circuit breaker switch unit and an isolating switch unit in a compact environmentally friendly gas-insulated ring main unit of the present invention;

[0028] Figure 4 It is a front cross-sectional view of a circuit breaker switch unit and an isolating switch unit in a compact environmentally friendly gas-insulated ring main unit of the present invention;

[0029] Figure 5 A side cross-sectional view of a circuit breaker switch unit and an isolating switch unit in a compact environmentally friendly gas-insulated ring main unit of the present invention;

[0030] Figure 6 It is an enlarged view of point A in the compact environmentally friendly gas-insulated ring main unit of the present invention;

[0031] Figure 7 It is a schematic diagram of a circuit breaker switch unit and an isolating switch unit in an insulated ring main unit in a compact environmentally friendly gas insulated ring main unit of the present invention after removing the isolating switch main shaft;

[0032] Figure 8 It is a schematic diagram of the main shaft of the isolating switch in the compact environmentally friendly gas-insulated ring main unit of the present invention;

[0033] Fig. 9 It is a schematic diagram of the lower static contact in the compact environmentally friendly gas-insulated ring main unit of the present invention;

[0034] In the figure: 1-cabinet, 2-gas box, 3-switch drive unit, 21-circuit breaker switch unit, 22-isolating switch unit, 23-busbar side expansion bushing, 24-lower inlet and outlet bushing, 211-circuit breaker switch main shaft, 212-transmission crank arm, 213-connecting piece, 214-pole, 215-vacuum interrupter, 216-upper static contact, 217-lower static contact, 218-insulating partition, 221-isolating switch main shaft, 222-moving contact, 223-insulating connecting piece, 2111-umbrella skirt insulating piece, 2211-transmission insulating piece, 2221-connecting rod part, 2222-contact part, 2223-guide rod. DETAILED DESCRIPTION

[0035] The following will be combined with the attached examples of the present invention Figure 1-Figure 9A clear and complete description is given to the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0036] The present invention provides a technical solution: a compact environmentally friendly gas-insulated ring main unit, comprising a cabinet 1, a gas box 2 is arranged inside the cabinet 1, and a switch drive unit 3 is connected to the left side of the gas box 2; the cabinet 1 plays a role in protecting the internal electrical components, providing physical support and protection for the entire ring main unit, and preventing the external environment from affecting the internal equipment. The gas box 2 is one of the core parts of the ring main unit, and is filled with environmentally friendly gas to provide insulation and arc extinguishing environment for the electrical components to ensure the safe operation of the equipment. The switch drive unit 3 is used to drive the switch action in the gas box 2 to realize the connection and disconnection of the circuit and control the transmission and distribution of power.

[0037] A circuit breaker switch unit 21 is provided at the upper end of the gas box 2, and an isolating switch unit 22 is provided at the lower end, and the circuit breaker switch unit 21 is connected to the isolating switch unit 22; a busbar side expansion sleeve 23 is provided at the top of the gas box 2, and a lower inlet and outlet sleeve 24 is provided at the bottom; the circuit breaker switch unit 21 is mainly used to quickly cut off the circuit when overload, short circuit and other fault protection are performed in the circuit to ensure the safe and stable operation of the power system. The isolating switch unit 22 is used to isolate the circuit and provide an obvious disconnection point during equipment inspection or maintenance to ensure the safety of the maintenance personnel. The busbar side expansion sleeve 23 is used to support and fix the busbar, and at the same time plays an insulating role to prevent leakage or short circuit and other faults between the busbar and the cabinet. The lower inlet and outlet sleeve 24 is used to support and insulate the lower outlet to ensure the electrical safety of the outlet part.

[0038] C-shaped protective covers are provided on the busbar side expansion sleeve 23 and the lower inlet and outlet sleeve 24. Under high voltage conditions, electric field concentration will appear on the surface of the insulator, causing the air to be ionized and forming a flashover phenomenon. The C-shaped protective cover can change the electric field distribution around the insulator to make it more uniform, thereby reducing the electric field strength and reducing the probability of flashover. The shape of the C-shaped protective cover increases the creepage distance on the surface of the insulator. The creepage distance refers to the shortest distance along the surface of the insulating material between two conductive parts on the surface of the insulating material. Increasing the creepage distance can effectively prevent the occurrence of leakage and improve the insulation reliability of the equipment.

[0039] The circuit breaker switch unit 21 includes a circuit breaker switch main shaft 211, and the circuit breaker switch main shaft 211 is evenly provided with a transmission crank arm 212 and a connecting piece 213, a vacuum interrupter 214 is fixed at the lower end of the connecting piece 213, and an upper static contact 215 is provided at the upper end of the vacuum interrupter 214; a pole 216 is provided inside the vacuum interrupter 214, and a lower static contact 217 is provided at the lower end of the vacuum interrupter 214;

[0040] The circuit breaker switch main shaft 211 receives the operating force from the switch drive unit and controls the opening and closing operation of the entire circuit breaker through its own rotational movement. Its evenly arranged structure ensures that power can be transmitted smoothly during operation, making the operation of the circuit breaker more reliable. The transmission crank arm 212 converts the rotational movement of the circuit breaker switch main shaft 211 into linear motion, transmits it to the connector 213, and then controls the movement of the vacuum interrupter 214. The function of the connector 213 is to connect the vacuum interrupter 214 with the circuit breaker switch main shaft 211, and play a role of fixing and supporting. At the same time, in order to ensure the insulation performance, the connector 213 is made of insulating material to prevent current leakage between different components and ensure the safe and reliable operation of the circuit breaker.

[0041] The pole 214 provides physical support for the vacuum arc chamber 215, so that it can be stably fixed in a specific position. In addition, the pole 214 itself has certain insulation properties, which can effectively prevent current leakage and ensure that the current is conducted within the specified path. It is an important structural part to ensure electrical insulation safety. The vacuum arc chamber 215 is a component that realizes the arc extinguishing function during the circuit breaking process. When the circuit needs to be disconnected, the arc generated at the moment of contact separation will be quickly extinguished in the high vacuum environment of the vacuum arc chamber 215, avoiding the continuous burning of the arc and causing damage to the equipment, thereby ensuring the safe disconnection of the circuit and the normal operation of the equipment. The upper static contact 216 and the lower static contact 217 are respectively located at the upper and lower ends of the vacuum arc chamber 215. When the circuit is closed, the two are in close contact, forming a current conduction path, so that the electric energy can pass smoothly, and when the circuit is disconnected, they are quickly separated, cooperating with the vacuum arc chamber 215 to complete the circuit cutting action, and their contact performance and structural design directly affect the reliability and stability of the circuit.

[0042] The lower static contact 217 is a T-shaped structure, and its extended part is in the form of a longitudinal facade. The T-shaped structure and its longitudinal facade extended part can effectively increase the distance between the lower static contacts of different phases. In the ring network cabinet, phase-to-phase insulation is very important, and sufficient phase-to-phase distance can prevent faults such as phase-to-phase short circuit. This structure helps to optimize the electric field distribution. The geometric shape of the T-shaped structure can make the electric field more evenly distributed around the contact, reducing the situation where the local electric field strength is too high. This is very critical for maintaining the insulation performance of the insulating gas, because local high electric field strength may cause gas ionization and reduce the insulation effect. The T-shaped structure of the lower static contact can provide a more stable contact surface. When combined with the moving contact, the T-shaped structure can ensure that there is sufficient contact area between the contacts during the closing operation, thereby reducing the contact resistance. This is very important for reducing heat generation and improving conductivity, ensuring that the current can pass through the contacts smoothly. At the same time, this structure has certain advantages in mechanical strength. The T-shaped structure can usually better withstand the mechanical impact force during the closing and opening process, reducing the possibility of deformation or damage to the contacts. During long-term operation, it can maintain its shape and performance, thus improving the reliability and service life of the ring main unit.

[0043] The bottom of the pole 214 is a bowl-shaped structure, and is connected to the lower static contact 217. The bowl-shaped structure at the bottom of the pole 214 is a structure with a specific geometric shape. This shape plays a role similar to a "voltage equalizing ring" in the electric field. When a voltage is applied, the bowl-shaped structure can guide the distribution of electric lines (electric field lines). Due to its curved surface shape, the distribution of electric lines on the surface of the bowl-shaped structure is more uniform. For the area where the upper static contact 215 is connected to the bowl-shaped structure, the bowl-shaped structure can "disperse" the electric field strength. For example, assuming there is no bowl-shaped structure, the edge of the upper static contact 215 will have dense electric field lines, resulting in excessive local electric field strength. The bowl-shaped structure disperses the electric field lines originally concentrated on the edge of the contact to a larger area through its curved surface. From the perspective of potential distribution, the bowl-shaped structure can make the potential change more smoothly on its surface, avoiding sudden changes in electric field strength caused by sharp changes in potential. By optimizing the electric field distribution, the bowl-shaped structure can ensure that the electric field strength near the contact does not exceed the breakdown electric field strength of the insulating medium. In the vacuum interrupter, the interior is a high vacuum environment, and the breakdown electric field strength is relatively high, but it is still necessary to avoid the situation where the local electric field strength is too high. When the electric field is evenly distributed, it can effectively prevent the gas (if there is a trace amount of gas) from being broken down to form an arc under high voltage, thereby ensuring the insulation performance and normal operation of the vacuum interrupter.

[0044] The bowl-shaped structure at the bottom of the pole 214 cooperates with the lower static contact 217 to provide a stable and large contact area. The bowl-shaped structure can be well matched with the lower static contact to ensure that the contact between the contacts is tighter and more sufficient when the switch is closed. A larger contact area can reduce contact resistance, reduce the heat generated when current passes through, improve the conductive efficiency of the equipment, and ensure the stability and reliability of the ring main unit during normal operation.

[0045] Three groups of umbrella skirt insulators 2111 are evenly arranged on the main shaft 211 of the circuit breaker switch. The umbrella skirt insulator 2111 is in the shape of a skirt and has a smooth surface, which can effectively increase the creepage distance. In a high voltage environment, when there is a small current leakage, the current needs to crawl along the surface of the insulator. The structure of the umbrella skirt insulator 2111 can change the distribution of the electric field. In the electric field, the power lines will preferentially distribute along paths with relatively weak insulation performance. The shape of the umbrella skirt makes the electric field lines more evenly distributed on its surface, avoiding the concentration of the electric field in certain areas. This helps to reduce the local electric field strength and prevent insulation breakdown caused by excessive electric field strength.

[0046] An insulating partition 218 is provided between the upper static contacts 215, and the insulating partition 218 is integrally cast with the pole 214. The insulating partition 218 separates the upper static contacts 215, effectively increasing the insulation distance between phases. In a high voltage environment, phase-to-phase insulation is one of the key factors to ensure the safe operation of equipment. When an electrical device fails, such as an overvoltage in one phase, the insulating partition 218 can prevent the voltage from breaking through the air, avoiding the occurrence of phase-to-phase short circuits, thereby protecting the stable operation of the entire ring network cabinet system. The insulating partition 218 and the pole 216 are integrally cast to make the entire structure more compact. In the design of the ring network cabinet, space is limited, and this compact structural design helps to reduce the size of the equipment and improve space utilization.

[0047] The isolating switch unit 22 includes an isolating switch main shaft 221, a moving contact 222 is sleeved inside the isolating switch main shaft 221, and an insulating connector 223 is provided at the lower end of the isolating switch main shaft 221. The isolating switch main shaft 221 receives the operating force from the external operating mechanism and transmits it to the moving contact 222 to realize the opening and closing actions of the moving contact 222.

[0048] The moving contact 222 is a component in the isolating switch unit that directly participates in the circuit opening and closing. In the closed state, the moving contact 222 is in close contact with the corresponding static contact to form a conductive path so that the current can pass; in the open state, the moving contact 222 is separated from the static contact to cut off the circuit. The moving contact 222 is sleeved inside the isolating switch main shaft 221. This structural design enables the moving contact 222 to accurately perform the opening and closing actions as the isolating switch main shaft 221 rotates.

[0049] The main function of the insulating connector 223 is to fix the isolating static contact and realize the insulation isolation between the isolating static contact and other components. It prevents the current from leaking between the isolating switch main shaft 221 and other conductive components, and ensures the insulation performance of the isolating switch.

[0050] The moving contact 222 includes a symmetrically arranged connecting rod portion 2221 and a T-type contact portion 217, and the contact portion 2222 is fixed inside the insulating connector 223. The gap in the middle of the symmetrically arranged connecting rod portion 2221 plays a key on-off control role. When the connecting rod portion 2221 is engaged with the T-type contact portion 217, the gap is filled, forming a current path, thereby realizing the connection of the circuit. When the connecting rod portion 2221 is not engaged with the T-type contact portion 217, the gap exists, the circuit is cut off, and the disconnection function of the disconnector is realized. The symmetrical arrangement of the connecting rod portion 2221 helps to ensure stability and balance during the connection and disconnection process. During operation, the connecting rod portions on both sides can be evenly stressed, reducing the possibility of stagnation or malfunction caused by uneven stress. At the same time, the structure of the connecting rod portion 2221 ensures that it has sufficient strength and rigidity to withstand the mechanical force during connection and disconnection, and is not easy to deform during long-term operation.

[0051] The contact part 2222 is fixed inside the insulating connector 223. This fixing method ensures that the position of the contact part 2222 is stable during operation. The contact part 2222 is connected to the outlet insulator 24 below through the guide rod 2223, forming a current conduction path. It needs to ensure good conductivity to ensure that the current can be smoothly transmitted from the contact part 2222 to the outlet insulator.

[0052] The isolating switch main shaft 221 is cylindrical, and transmission insulating parts 2211 are evenly arranged on the upper end, and the transmission insulating parts 2211 are clamped with the guide rod 2221. This shape design is conducive to its rotation during operation. The cylindrical structure can evenly distribute the operating force on the main shaft, reduce stress concentration, and increase the service life of the main shaft. The transmission insulating parts 2211 evenly arranged on the upper end are clamped with the guide rod 2221, and their function is to transmit the rotation of the isolating switch main shaft 221 to the moving contact 222. The transmission insulating parts 2211 are made of insulating material, which can effectively prevent the current from being conducted between the isolating switch main shaft 221 and the moving contact 222, thereby ensuring the insulation performance of the isolating switch.

[0053] The working principle is divided into the following stages:

[0054] 1. Circuit connected state:

[0055] Circuit breaker switch unit: When the circuit needs to be connected, the switch drive unit 3 applies power to the circuit breaker switch main shaft 211 to rotate the circuit breaker switch main shaft 211. The rotational motion is converted into linear motion by the transmission crank arm 212 and transmitted to the vacuum interrupter 215 by the connector 213. At this time, the moving contact and the static contact in the vacuum interrupter 215 are in close contact, and the current is conducted through the upper static contact 215, the interrupter and the lower static contact 217. The umbrella skirt insulator 2111 on the circuit breaker switch main shaft 211 plays an insulating role to prevent inter-phase short circuit and leakage, and ensure that the current is conducted in the correct path. The insulating partition 218 between the upper static contacts 215 is integrally cast with the pole 216 to enhance the phase-to-phase insulation performance and avoid inter-phase short circuit.

[0056] Disconnector unit: The disconnector main shaft 221 also rotates under the action of the external operating force. The connecting rod part 2221 of the moving contact 222 sleeved inside the disconnector main shaft 221 is engaged with the T-type contact 217 to connect the circuit. The contact part 2222 of the moving contact 222 is fixed inside the insulating connector 223 and connected to the lower inlet and outlet bushing 24 through the guide rod 2223 to conduct the current to the lower inlet and outlet bushing 24. The transmission insulating part 2211 at the upper end of the disconnector main shaft 221 is engaged with the guide rod 2221 to ensure the transmission and insulation of the action.

[0057] Overall current path: The current is introduced from the busbar side expansion bushing 23, passes through the circuit breaker switch unit 21 and the disconnector unit 22, and finally flows out through the lower inlet and outlet bushing 24 to complete the circuit connection. In this process, the C-shaped protective cover on the busbar side expansion bushing 23 and the lower inlet and outlet bushing 24 prevents flashover, dust and water, and ensures insulation and safety.

[0058] 2. Circuit disconnection status:

[0059] Circuit breaker switch unit: When the circuit needs to be disconnected, the switch drive unit 3 drives the circuit breaker switch main shaft 211 to rotate in the opposite direction. The transmission crank arm 212 and the connecting piece 213 drive the vacuum interrupter 215 to move, so that the moving contact and the static contact in the interrupter are separated, and the current path is cut off. The vacuum interrupter 215 uses the high vacuum environment inside it to extinguish the arc generated when the contacts are separated.

[0060] Working principle of the isolating switch unit: The isolating switch main shaft 221 rotates in the opposite direction under the action of the external operating force, and the connecting rod 2221 of the moving contact 222 is separated from the T-type contact 217, further ensuring that the circuit is disconnected, forming an obvious disconnection point, and facilitating the inspection and maintenance of the equipment. At this time, the internal circuit of the entire ring network cabinet is in a disconnected state, and each insulating component still plays an insulating role to prevent accidental leakage and short circuit.

[0061] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A compact environmentally friendly gas-insulated ring main unit, comprising a cabinet (1), characterized in that: An air box (2) is provided in the cabinet (1), and a switch drive unit (3) is connected to the left side of the air box (2); A circuit breaker switch unit (21) is arranged at the upper end of the gas box (2), and an isolating switch unit (22) is arranged at the lower end, and the circuit breaker switch unit (21) is connected to the isolating switch unit (22); a busbar side expansion bushing (23) is arranged at the top of the gas box (2), and a lower inlet and outlet bushing (24) is arranged at the bottom; The circuit breaker switch unit (21) comprises a circuit breaker switch main shaft (211), the circuit breaker switch main shaft (211) is evenly provided with a transmission crank arm (212) and a connecting piece (213), a pole (214) is fixed at the lower end of the connecting piece (213), vacuum interrupter chambers (215) are evenly distributed laterally on the pole (214), an upper static contact (216) is provided at the upper end of the vacuum interrupter chamber (215), and a lower static contact (217) is provided at the lower end of the vacuum interrupter chamber (214); The lower static contact (217) is designed in a T-shaped structure, and its longitudinally extending portion is in the form of a longitudinal facade, which extends in a vertical direction in space.

2. The compact environmentally friendly gas insulated ring main unit according to claim 1, characterized in that: The isolating switch unit (22) comprises an isolating switch main shaft (221), a moving contact (222) is sleeved inside the isolating switch main shaft (221), and an insulating connector (223) is provided at the lower end of the isolating switch main shaft (221).

3. The compact environmentally friendly gas insulated ring main unit according to claim 1, characterized in that: Three groups of shed insulation parts (2111) are evenly arranged on the circuit breaker switch main shaft (211).

4. The compact environmentally friendly gas insulated ring main unit according to claim 1, characterized in that: The bottom of the pole (214) is a bowl-shaped structure and is connected to the lower static contact (217).

5. The compact environmentally friendly gas insulated ring main unit according to claim 1, characterized in that: An insulating partition (218) is provided between the upper static contacts (216), and the insulating partition (218) is integrally cast with the pole (214).

6. The compact environmentally friendly gas insulated ring main unit according to claim 2, characterized in that: The movable contact (222) comprises a connecting rod portion (2221) and a contact portion (2222) which are symmetrically arranged, and the contact portion (2222) is fixed inside the insulating connecting piece (223).

7. The compact environmentally friendly gas insulated ring main unit according to claim 6, characterized in that: The contact part (2222) is connected to the lower inlet and outlet bushing (24) via a guide rod (2223).

8. The compact environmentally friendly gas insulated ring main unit according to claim 6, characterized in that: The connecting rod portion (2221) is clamped with the bottom of the lower static contact (217).

9. The compact environmentally friendly gas insulated ring main unit according to claim 2, characterized in that: The isolating switch main shaft (221) is cylindrical, and transmission insulating parts (2211) are evenly arranged on the upper end, and the transmission insulating parts (2211) are clamped with the guide rod (2221).

10. The compact environmentally friendly gas insulated ring main unit according to claim 1, characterized in that: The busbar side expansion sleeve (23) and the lower inlet and outlet sleeve (24) are provided with C-shaped protective covers.

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