Ring main unit

Abstract

The application belongs to the technical field of ring main units, and particularly relates to a ring main unit, which comprises a gas tank and a load switch arranged in the gas tank, and the gas tank is filled with environment-friendly insulation gas; the load switch is configured to break and arc-extinguish a load current in the environment-friendly insulation gas medium, and the load switch comprises a static end contact, a dynamic end contact assembly and a driving member, the static end contact and the dynamic end contact assembly are arranged at intervals in a first direction, the dynamic end contact assembly is connected with the driving member, and the dynamic end contact assembly is configured to linearly move along the first direction under the driving of the driving member to be connected with or disconnected from the static end contact. The ring main unit in the application has simplified overall mechanical structure and significantly reduced number of parts, so that the manufacturing cost and assembly difficulty are reduced, the operation reliability of the equipment is improved, the use of sulfur hexafluoride SF6 gas is reduced, and the ring main unit is more environment-friendly.

Description

Technical Field

[0001] This application belongs to the field of ring main unit technology, and specifically relates to a ring main unit. Background Technology

[0002] Ring main units (RNBs) are key equipment in power distribution networks, undertaking the core functions of power distribution, control, and protection. They are widely used in urban power grids, industrial and mining enterprises, and renewable energy access points, and their reliability directly affects the continuity and quality of regional power supply. Among them, load switches are the core components for realizing line connection and disconnection, load switching, and grounding protection.

[0003] Currently, under the global consensus on green and low-carbon development, the power equipment sector is actively promoting environmentally friendly transformation. Due to its strong greenhouse effect, the use of sulfur hexafluoride (SF6) gas in gas-insulated equipment is being strictly limited. Therefore, developing ring main units that use environmentally friendly insulating gases such as dry air and nitrogen has become a major development direction for medium-voltage power distribution equipment.

[0004] However, the related technologies use a combination of "vacuum interrupter" and "three-position switch" to achieve arc extinguishing, but the overall structure is complex and the manufacturing cost is high. Utility Model Content

[0005] The purpose of this application is to solve the problems of complex structure and high manufacturing cost of ring main units using environmentally friendly gases in related technologies.

[0006] This application provides a ring main unit, comprising: a gas box filled with an environmentally friendly insulating gas; and a load switch disposed within the gas box, the load switch being configured to interrupt load current and extinguish arc in the environmentally friendly insulating gas medium, the load switch comprising a stationary contact, a moving contact assembly, and a driving element, the stationary contact and the moving contact assembly being spaced apart in a first direction, the moving contact assembly being connected to the driving element, and the moving contact assembly being configured to move linearly along the first direction under the drive of the driving element to connect or disconnect with the stationary contact.

[0007] In one exemplary embodiment of this application, the moving contact assembly includes a moving contact and a bridging member, the bridging member being connected to the moving contact, and the bridging member being configured to move linearly along the first direction when closing or opening; wherein, when closing, the bridging member is inserted into the stationary contact to form an electrical connection between the moving contact and the stationary contact.

[0008] In one exemplary embodiment of this application, the bridging member is a tubular structure, which is mounted on the outside of the moving end contact and can slide relative to the moving end contact.

[0009] In one exemplary embodiment of this application, the load switch further includes a guide rod extending in the first direction and connected to the drive member; the bridging member is movably sleeved on the guide rod and is capable of linear reciprocating motion along the axial direction of the guide rod.

[0010] In one exemplary embodiment of this application, the drive member includes an operating shaft and an operating insulator. The operating shaft is connected to the bridging member via the operating insulator, and the operating insulator is configured to convert the rotational motion of the operating shaft into linear motion of the bridging member along the first direction.

[0011] In one exemplary embodiment of this application, the ring main unit further includes a grounding switch, and the grounding switch and the load switch are spaced apart inside the gas box.

[0012] In one exemplary embodiment of this application, the grounding switch includes a stationary contact and a connecting conductor, the connecting conductor being electrically connected to the moving contact assembly, and the stationary contact being disposed on the side of the connecting conductor away from the moving contact.

[0013] In one exemplary embodiment of this application, the gas box is further provided with a connector, a busbar bushing and an outlet bushing, and the load switch is connected between the busbar bushing and the outlet bushing through the connector to form a conductive circuit.

[0014] In one exemplary embodiment of this application, the ring main unit further includes a low-pressure chamber, which is arranged sequentially with the gas box in the first direction to accommodate control elements.

[0015] In one exemplary embodiment of this application, the ring main unit further includes a cable compartment located below or on the side of the gas box for connecting external cables.

[0016] The ring main unit proposed in this application has at least the following beneficial effects: The ring main unit of this application includes a gas box and a load switch located inside the gas box. The gas box is filled with environmentally friendly insulating gas. The load switch is configured to interrupt the load current and extinguish the arc in the environmentally friendly gas medium. The load switch includes a stationary contact, a moving contact assembly, and a driving element. The stationary contact and the moving contact assembly are spaced apart in a first direction. The moving contact assembly is connected to the driving element and is configured to move linearly along the first direction under the drive of the driving element to connect or disconnect with the stationary contact. By using a driving element to drive the moving contact assembly to move linearly along the first direction, the load switch can complete current interruption and arc extinguishing in the environmentally friendly gas insulating medium. This eliminates the need for the complex "vacuum interrupter" and "three-position switch" combination required in related technologies to achieve the same function. This simplifies the overall mechanical structure of the ring main unit, significantly reduces the number of parts, thereby reducing manufacturing costs and assembly difficulty. It also improves the reliability of equipment operation and reduces the use of sulfur hexafluoride (SF6) gas, making the ring main unit more environmentally friendly.

[0017] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0020] Figure 1 Schematic diagrams of ring main units in some embodiments are shown.

[0021] Figure 2 A schematic diagram of a structure in some embodiments, showing a load switch and a grounding switch inside the gas box, is shown.

[0022] Figure 3 A schematic diagram of the load switch in the open state is shown in some embodiments.

[0023] Figure 4 Schematic diagrams of load switches and grounding switches in some embodiments are shown.

[0024] Explanation of reference numerals in the attached figures: 10. Ring main unit; 100. Gas box; 200. Low-voltage compartment; 300. Mechanism compartment; 400. Cable compartment; 500. Load switch; 510. Stationary contact; 520. Moving contact assembly; 521. Moving contact; 522. Bridging component; 530. Drive component; 531. Operating shaft; 532. Operating insulator; 540. First fixed plate; 550. Second fixed plate; 560. Crossarm; 600. Grounding switch; 610. Moving contact; 620. Stationary contact; 630. Connecting conductor; 700. Connecting component; 800. Busbar bushing; 900. Outgoing bushing. Detailed Implementation

[0025] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0026] In this application, the terms "first" and "second" are used 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 as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0027] In this application, unless otherwise expressly specified and limited, the terms "assembly," "connection," 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0028] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0029] See Figure 1 and Figure 2As shown in the figure, this application provides an environmentally friendly gas-insulated ring main unit 10 suitable for 12kV voltage level, which can be applied to medium-voltage power distribution scenarios such as urban power distribution networks and industrial park power supply systems. The ring main unit 10 can adopt a modular design, which may include a gas box 100, a low-voltage compartment 200, a mechanism compartment 300, and a cable compartment 400. Each module is independent yet closely coordinated to form a complete power distribution unit.

[0030] In some embodiments, the gas box 100 can be made of stainless steel plate by high-precision welding using an automated welding process with welding robots and rotating tooling, to ensure airtightness and structural strength, and reduce insulation failure caused by leakage of environmentally friendly gases.

[0031] In some embodiments, the gas box 100 may be filled with environmentally friendly insulating gas, such as dry air or nitrogen, which does not contain sulfur hexafluoride (SF6) gas at all, so that the ring main unit 10 meets environmental protection requirements.

[0032] In some embodiments, a complete conductive circuit system may be provided within the gas box 100. See also Figure 2 and Figure 3 As shown, the gas box 100 may be equipped with a load switch 500, which is configured to interrupt the composite current and complete the arc extinguishing in an environmentally friendly gas medium such as dry air, without relying on a vacuum arc extinguishing chamber.

[0033] In some embodiments, see Figure 2 and Figure 4 As shown, the load switch 500 may include a stationary contact 510, a moving contact assembly 520, and a drive element 530. The stationary contact 510 may be made of copper-tungsten alloy, which has good resistance to arc erosion. The stationary contact 510 and the moving contact assembly 520 are arranged at intervals in a first direction (vertical direction), and the spacing can be selected according to actual needs, for example, 85mm. The moving contact assembly 520 is connected to the drive element 530. Under the drive of the drive element 530, the moving contact assembly 520 moves linearly along the first direction to connect or disconnect with the stationary contact 510, thereby realizing the closing and opening of the load switch 500.

[0034] Understandably, the load switch 500 adopts a direct-acting structural design, which eliminates the combination of "vacuum interrupter" and "three-position switch" in related technologies, thus simplifying the structure, reducing the number of parts, thereby reducing manufacturing costs and assembly difficulty, and improving the reliability of equipment operation.

[0035] In some embodiments, see Figure 4As shown, the moving contact assembly 520 includes a fixed moving contact 521 and a movable bridging member 522. The bridging member 522 can be connected to the moving contact 521 by a sliding fit and can slide linearly on the moving contact 521. When closing, the bridging member 522 moves upward linearly and inserts into the stationary contact 510 to form an electrical connection between the moving contact 521 and the stationary contact 510; when opening, the bridging member 522 moves downward and disengages from the stationary contact 510 to separate the moving contact 521 from the stationary contact 510.

[0036] In some embodiments, see Figure 3 and Figure 4 As shown, the load switch 500 may further include a first fixing plate 540 and a second fixing plate 550. Both the first fixing plate 540 and the second fixing plate 550 can be made of the same material and have the same structure. They are parallel to each other and spaced apart, with the spacing determined according to the size of the conductive components and insulation requirements, for example, 30mm, 40mm, or 50mm. The two fixing plates can be connected by reinforcing ribs to form a stable frame structure.

[0037] The stationary contact 510 and the moving contact 521 are clamped and fixed between the first fixing plate 540 and the second fixing plate 550 by fasteners. This sandwich structure ensures that the conductive components are subjected to uniform clamping force, avoiding stress concentration that may occur with unilateral fixing.

[0038] Understandably, the first fixing plate 540 and the second fixing plate 550 are provided with mounting flanges around their perimeters to facilitate the installation of the entire load switch 500 onto the switch cabinet frame. The mounting flanges are provided with multiple mounting holes, which can be designed as elongated holes to facilitate position adjustment during installation.

[0039] Furthermore, this sandwich structure makes the installation of conductive components more secure and able to withstand greater electrodynamic impacts. At the same time, the structure itself increases the complexity of the insulation path and extends the creepage distance, providing a strong guarantee for the long-term reliable operation of the switch.

[0040] In some embodiments, a guide groove may be provided on the inner wall of the bridging member 522, and a guide key may be provided on the moving end contact 521. The guide groove and the guide key are precisely matched to form a sliding pair, so that the bridging member 522 can slide relative to the moving end contact 521. The sliding fit design ensures the precise movement of the bridging member 522, and the insertion connection ensures the reliability of electrical contact.

[0041] In some embodiments, the bridging member 522 may be made of a highly conductive copper alloy material, and its structure is cylindrical with a precision-machined inner wall to ensure good contact with the stationary contact 510. Under the drive of the driving member 530, the bridging member 522 moves precisely in a first direction X, so that it has a first position (i.e., closed state) to contact the stationary contact 510 to connect the circuit, and a second position (i.e., open state) to separate from the stationary contact 510 to disconnect the circuit.

[0042] Understandably, adopting a direct-acting switching scheme in a single direction offers advantages such as a short transmission path, precise operation, and no lateral force interference. This design effectively reduces contact wear during closing and opening processes, extending electrical life. Furthermore, the direct-acting structure is more compact than the rotary structure in related technologies.

[0043] Furthermore, during the circuit breaker tripping process, dry air or nitrogen can effectively extinguish the arc through a self-powered air-blowing principle. The extremely high energy of the electric arc instantly heats and ionizes the surrounding environmentally friendly gas, causing it to rapidly expand and form high pressure within the sealed arc chamber. This high pressure drives a high-speed airflow to be directionally ejected along a direct-acting "tube-casing" structure, powerfully cooling, elongating, and dispersing the arc plasma, while simultaneously introducing a cold medium to promote deionization. This synergistic effect of combining arc energy utilization with mechanical structure enhancement enables ordinary environmentally friendly gases to reliably extinguish arcs generated by load currents, successfully replacing sulfur hexafluoride (SF6) gas.

[0044] In some embodiments, the load switch 500 may also include a guide rod. The guide rod may be made of stainless steel and its surface is precision ground to ensure straightness and surface finish.

[0045] In some embodiments, the guide rod (not shown) extends in the first direction X (vertical direction), and its length can be precisely designed according to the travel requirements of the switch, for example, 100mm, 120mm, or 150mm. The bridging member 522 can be movably fitted onto the guide rod by a bearing or a self-lubricating bushing so that it can reciprocate linearly along the axial direction of the guide rod.

[0046] In some embodiments, the installation position of the guide rod needs to ensure that the bridging member 522 remains aligned with the stationary contact 510 during movement. The diameter of the guide rod can be designed according to the stress conditions, for example, it can be 8mm, 10mm, 12mm or 15mm, thus ensuring sufficient rigidity while avoiding excessive movement resistance.

[0047] Understandably, the guide rod provides precise guidance and support for the bridging component 522, ensuring its straightness and stability during closing and opening. The guide rod effectively prevents the bridging component 522 from skewing or jamming during movement, thus guaranteeing the accuracy and reliability of its contact with the stationary contact 510. Furthermore, this guide rod significantly improves contact quality, avoiding excessive temperature rise or arc erosion caused by poor contact, and extending the switch's service life.

[0048] In some embodiments, see Figure 3 and Figure 4 As shown, the drive unit 530 may include an operating shaft 531 and an operating insulator 532. The operating shaft 531 may be made of alloy structural steel and its surface is hardened to improve wear resistance. The operating shaft 531 extends along a second direction Y (i.e., the front-to-back direction), which intersects perpendicularly with the first direction X (i.e., the up-down direction). This orthogonal arrangement makes full use of three-dimensional space and optimizes the overall structural layout of the switch.

[0049] In some embodiments, the operating shaft 531 is connected to the bridging member 522 via the operating insulator 532, which can take various forms such as a linkage mechanism, a gear and rack mechanism, or a cam mechanism.

[0050] For example, the operating insulator 532 can employ a rocker arm linkage mechanism. The operating insulator 532 includes a rocker arm fixedly connected to the operating shaft 531 and a push rod connected to the bridging member 522. The length and angle design of the rocker arm ensures that the rotational motion of the operating shaft 531 is efficiently converted into the linear motion of the bridging member 522.

[0051] In some embodiments, see Figure 2 As shown, the end of the operating shaft 531 is provided with an operating interface, which can be connected to a manual operating mechanism or an electric operating mechanism.

[0052] For example, in manual operation, the operating shaft 531 is driven to rotate by rotating the handle. In electric operation, the operating shaft 531 is driven to rotate by a motor reduction mechanism. The rotation angle of the operating shaft 531 is typically designed to be 90° or 180°, corresponding to the fully open and closed positions of the bridging component 522.

[0053] By decoupling the power input direction from the movement direction (first direction X) of the bridging component 522 through the operating shaft 531 and the operating insulator 532, the drive mechanism can be flexibly arranged in the optimal position of the switch, optimizing the internal space utilization of the switch. This arrangement is particularly beneficial for achieving lateral arrangement within the narrow-body ring main unit 10, further supporting the miniaturization design of the equipment. Simultaneously, the conversion of rotary motion into linear motion results in a smoother operating torque, lower operating force, and improved controllability and reliability of operation.

[0054] In some embodiments, see Figure 3 and Figure 4 As shown, the load switch 500 may also include a crossarm 560. The crossarm 560 may be made of the same insulating material as the mounting plate and integrally molded using a molding process. The crossarm 560 may extend along a second direction Y (i.e., the front-to-back direction), and its length is determined according to the overall width of the switch, for example, 200mm, 260mm, or 300mm. Both ends of the crossarm 560 are fixed to the support frame of the switch using high-strength insulating bolts, forming a stable support structure.

[0055] In some embodiments, the guide rod can be fixed to the crossarm 560 by clamps or fasteners. The clamps are designed to prevent loosening, ensuring that they will not loosen under long-term vibration. The crossarm 560 has multiple mounting holes to facilitate adjustment of the guide rod's mounting position according to different switch specifications. The crossarm 560 can have an I-beam or box-shaped cross-section to minimize weight while ensuring sufficient rigidity.

[0056] The crossarm 560 provides a stable mounting base for the guide rod, enhancing the structural rigidity and stability of the entire moving-side actuator assembly. This design allows the switch to maintain structural integrity and prevent component deformation or damage when subjected to the enormous electrodynamic impact of short-circuit currents. The insulating properties of the crossarm 560 also provide an inter-phase insulation barrier, further enhancing the switch's insulation performance.

[0057] In some embodiments, see Figure 2 and Figure 4 As shown, the ring main unit 10 may also include a grounding switch 600. The grounding switch 600 and the load switch 500 are spaced apart inside the gas box 100. The grounding switch 600 and the load switch 500 are set independently of each other, making inspection and maintenance more convenient.

[0058] In some embodiments, the grounding switch 600 may be a knife switch type. See also Figure 4 As shown, it may include a moving contact 610, a stationary contact 620, and a connecting conductor 630. The moving contact 610 is rotatably mounted on a drive shaft via a rotating shaft, and its structure is a rotary knife switch. The stationary contact 620 is connected to the end of the connecting conductor 630 away from the moving contact 521 of the load switch 500 by bolts. The connecting conductor 630 may be a connecting copper busbar, which can be connected to the crossarm 560 by fasteners to further enhance the stability of the connecting conductor 630.

[0059] It should be noted that the grounding switch 600 has an independent operating mechanism, which is connected to the operating mechanism of the load switch 500 through a mechanical interlocking device. This ensures that the grounding switch 600 can only be operated when the load switch 500 is open, preventing accidental operation of closing the grounding wire while it is energized.

[0060] By integrating the load switch 500 and the grounding switch 600 into the ring main unit 10, a complete, fully functional, and environmentally friendly switchgear is formed. This design ensures reliable and safe grounding through the grounding switch 600 after the load switch 500 is tripped, fully meeting the safety operation specifications of the power distribution system. This ring main unit 10 has advantages such as small size, good insulation performance, reliable operation, and convenient maintenance. Moreover, the ring main unit 10 can reduce the use of sulfur hexafluoride (SF6) gas, thereby reducing greenhouse gas emissions and achieving significant environmental benefits. At the same time, the compact design reduces the footprint of the ring main unit 10, greatly saving installation space.

[0061] Understandably, this ring main unit 10 also has an operating mechanism connected to the grounding switch 600, which is independently set up from the operating mechanism of the load switch 500. When closing, the operating mechanism of the grounding switch 600 drives the moving contact 610 to rotate around the drive shaft until the moving contact 610 is tightly fitted with the stationary contact 620, which is fixed and connected to the conductor 630, forming a grounding circuit. At this time, the load switch 500 is in the open state, preventing live grounding. When opening, the operating mechanism drives the moving contact 610 to rotate in the opposite direction, completely separating it from the stationary contact 620, switching the grounding circuit, and the equipment can return to normal operation preparation state. The knife switch structure has a clear opening and closing angle, a large contact area, and strong current carrying capacity. After opening, it has a clear isolation gap, meeting the requirements for the disconnection point in the composite ionization safety specifications, thus improving the safety of maintenance operations.

[0062] In some embodiments, see Figure 2 and Figure 3 As shown, the gas box 100 also includes a connector 700, a busbar bushing 800, and an outgoing bushing 900. The connector 700 can be a connecting copper rod with a silver-plated surface. The load switch 500 is connected between the busbar bushing 800 and the outgoing bushing 900 via the connector 700 to form a conductive circuit. Both the busbar bushing 800 and the outgoing bushing 900 are made of epoxy resin. This makes the modular conductive circuit easy to install, provides strong current carrying capacity, and ensures a uniform electric field distribution.

[0063] In some embodiments, see Figure 2As shown, the low-pressure compartment 200 of the ring main unit 10 is located outside the gas box 100. The low-pressure compartment 200 houses relays, instrument transformers, or measurement and control modules, primarily used for signal acquisition, status detection, and remote control of the equipment, providing maintenance personnel with operational data. The ring main unit 10 is equipped with on / off buttons, status indicator lights, and a human-machine interface. The location of the low-pressure compartment 200 outside the gas box 100 ensures high and low pressure isolation, safe operation, and convenient maintenance.

[0064] In some embodiments, see Figure 2 As shown, the cable compartment 400 of the ring main unit 10 is located below the gas box 100. It contains cable terminals, cable fixing brackets, insulation supports, and other components, and can accommodate three interface power cables. The cable compartment 400 has an observation window on its door panel, allowing observation of the internal condition without opening the door. The cable compartment 400 provides ample wiring space and facilitates installation and maintenance. Furthermore, the cable compartment 400 also provides maintenance space to facilitate cable installation, replacement, and maintenance.

[0065] In some embodiments, see Figure 2 As shown, the mechanism chamber 300 of the ring main unit 10 integrates the operating mechanism (spring operating mechanism) of the load switch 500 and the grounding switch 600, which can drive the load switch 500 and the grounding switch 600 to complete the closing and opening actions through mechanical transmission.

[0066] The working principle of the load switch 500 of this application is as follows: When closing, the spring operating mechanism of the mechanism chamber 300 is activated, which drives the operating insulator 532 to rotate through the operating shaft 531. The rotational motion is converted into the upward linear motion of the bridging member 522. The bridging member 522 smoothly inserts into the stationary contact 510. The load switch 500 is fixedly connected to the connecting member 700 through the connecting conductor 630 to complete the circuit conduction. When opening, the bridging member 522 smoothly moves downward and disengages from the stationary contact 510, forming a strong longitudinal airflow in dry air to achieve reliable arc extinguishing.

[0067] During grounding operation, the grounding switch 600 closes the grounding switch while the load switch 500 is opening. The moving contact 610 and the stationary contact 620 of the grounding switch 600 close to form a safe ground, preventing electric shock to maintenance personnel and ensuring operation and maintenance safety.

[0068] In the description of this specification, references to terms such as "some embodiments," "exemplarily," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. The illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0069] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application. Therefore, any changes or modifications made in accordance with the claims and description of this application should fall within the scope of this patent application.

Claims

1. A ring main unit, characterized in that, include: A gas chamber filled with environmentally friendly insulating gas; and a gas chamber located within the gas chamber. A load switch is configured to interrupt load current and extinguish arc in an environmentally friendly insulating gas medium. The load switch includes a stationary contact, a moving contact assembly, and a drive element. The stationary contact and the moving contact assembly are spaced apart in a first direction. The moving contact assembly is connected to the drive element and is configured to move linearly along the first direction under the drive of the drive element to connect or disconnect with the stationary contact.

2. The ring main unit according to claim 1, characterized in that, The moving end contact assembly includes a moving end contact and a bridging member, the bridging member being connected to the moving end contact, and the bridging member being configured to move linearly along the first direction when closing or opening the circuit breaker; When the circuit is closed, the bridging component is inserted into the stationary contact to form an electrical connection between the moving contact and the stationary contact.

3. The ring main unit according to claim 2, characterized in that, The bridging component is a tubular structure, installed on the outside of the moving end contact, and can slide relative to the moving end contact.

4. The ring main unit according to claim 2 or 3, characterized in that, The load switch further includes a guide rod that extends in the first direction and is connected to the drive member; the bridging member is movably sleeved on the guide rod and is capable of linear reciprocating motion along the axial direction of the guide rod.

5. The ring main unit according to claim 2, characterized in that, The drive unit includes an operating shaft and an operating insulator. The operating shaft is connected to the bridging member via the operating insulator. The operating insulator is configured to convert the rotational motion of the operating shaft into linear motion of the bridging member along the first direction.

6. The ring main unit according to claim 1, characterized in that, The ring main unit also includes a grounding switch, and the grounding switch and the load switch are spaced apart inside the gas box.

7. The ring main unit according to claim 6, characterized in that, The grounding switch includes a stationary contact and a connecting conductor. The connecting conductor is electrically connected to the moving contact assembly. The stationary contact is located on the side of the connecting conductor away from the moving contact.

8. The ring main unit according to claim 1, characterized in that, The gas box is also equipped with a connector, a busbar bushing and an outgoing bushing. The load switch is connected between the busbar bushing and the outgoing bushing through the connector to form a conductive circuit.

9. The ring main unit according to claim 1, characterized in that, The ring main unit also includes a low-pressure chamber, which is arranged sequentially with the gas box in the first direction to accommodate control components.

10. The ring main unit according to claim 9, characterized in that, The ring main unit also includes a cable compartment, which is located below or on the side of the gas box for connecting external cables.

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