A ring main unit

Abstract

The present application relates to the field of switch device, specifically relates to a ring main unit, the present application is used to solve the problem that the existing ring main unit is too large to be difficult to enter and exit the tower cylinder, the ring main unit includes cabinet frame, a primary loop element is installed in the cabinet frame, the side of the cabinet frame is provided with a cover shell that can be detachably connected with the cabinet frame, the bottom of the cover shell is provided with an incoming line channel for the incoming line cable to pass through, the incoming line cable passes into the cover shell from the incoming line channel and is connected with the primary loop element in the cabinet frame at the position close to the top of the cabinet frame, the bottom of the cabinet frame is provided with an outgoing line channel for the outgoing line cable to pass out, the space for accommodating the incoming line cable is external to the cabinet frame, which reduces the width of the cabinet frame, the incoming line cable enters from the lower part of the ring main unit, which avoids the problem that the ring main unit is too high due to the incoming line cable entering from the top, and such arrangement reduces the height and width of the cabinet frame as a whole, thereby facilitating the operation of the ring main unit into the tower cylinder.

Description

Technical Field

[0001] This invention relates to the field of switchgear, and more specifically to a ring main unit. Background Technology

[0002] A ring main unit is a set of power transmission and distribution equipment. Ring main units have advantages such as simple structure, improved power supply parameters and performance, and power supply safety. They are widely used in urban residential communities, high-rise buildings, large public buildings, and power distribution stations.

[0003] Existing environmentally friendly ring main units typically consist of a cabinet frame, within which primary circuit components such as instrument transformers, surge arresters, disconnect switches, and grounding switches are installed. The cabinet frame usually also has inlet and outlet cable channels. Inlet cables enter the cabinet frame through the inlet channel and connect to the primary circuit components. Some existing ring main units have the inlet cable channel located at the top of the cabinet frame and the outlet cable channel at the bottom. This requires reserving space at the top of the cabinet for the inlet cable, resulting in a relatively tall cabinet frame. Other ring main units have both inlet and outlet cable channels located at the bottom of the cabinet frame, leading to a wider cabinet frame.

[0004] In wind power systems, to improve land utilization, transformers and ring main units need to be installed inside the wind turbine tower. The tower doors of wind turbines are relatively small, while the traditional environmentally friendly ring main units have large frames, either in height or width, making it difficult to access them from the tower. Summary of the Invention

[0005] The purpose of this invention is to provide a ring main unit to solve the problem that existing ring main units are too large and difficult to enter and exit the tower.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution for a ring main unit: A ring main unit includes a cabinet frame, a primary circuit element installed inside the cabinet frame, a cover detachably connected to the cabinet frame on one side, an inlet channel at the bottom of the cover for the inlet cable to pass through, the inlet cable passing through the inlet channel into the cover and connecting to the primary circuit element inside the cabinet frame near the top, and an outlet channel at the bottom of the cabinet frame for the outlet cable to exit.

[0007] Furthermore, the inner wall of the housing is provided with a cable bundle structure for securing the incoming cable laid from bottom to top.

[0008] Furthermore, the cabinet frame is provided with a mounting structure on one side of the cover for installing a through-type current transformer. When the through-type current transformer is installed on the mounting structure, the main body of the through-type current transformer is located inside the internal space of the cover.

[0009] Furthermore, the instrument room for installing secondary circuit components is located at the top of the front side of the cabinet frame and is detachably connected to the cabinet frame.

[0010] Furthermore, the cabinet door includes an upper cabinet door and a lower cabinet door. The top of the lower cabinet door has an L-shaped curved plate. The horizontal side of the L-shaped curved plate extends to the inside of the lower cabinet door, and the vertical side is at the inside end of the horizontal side and extends upward. The vertical side of the L-shaped curved plate is inside the upper cabinet door. It works in conjunction with the upper cabinet door so that the upper cabinet door can only be closed when the lower cabinet door is closed.

[0011] Furthermore, a grounding switch interlocking mechanism is provided between the upper cabinet door and the grounding switch, and an isolation switch interlocking mechanism is provided between the upper cabinet door and the isolation switch. The grounding switch interlocking mechanism includes a first movable plate provided in front of the operating hole of the grounding switch, and the isolation switch interlocking mechanism includes a second movable plate provided in front of the operating hole of the isolation switch. Each movable plate has a blocking position for blocking the corresponding operating hole and a clearance position for avoiding the corresponding operating hole in its movement stroke. The upper cabinet door is provided with a first mating structure and a second mating structure that cooperate with the first movable plate and the second movable plate, respectively. When the cabinet door is closed, each mating structure cooperates with the corresponding movable plate to make the corresponding movable plate position the clearance position, so that the grounding opening operation can be performed by rotating the operating shaft of the grounding switch or the isolation closing operation can be performed by rotating the operating shaft of the isolation switch.

[0012] Furthermore, the first movable plate is rotatably assembled inside the cabinet around a horizontal axis extending front and rear. The first movable plate rotates to block or avoid the grounding switch operating hole. The first mating structure includes a push structure perpendicular to the upper cabinet door design. The upper part of the push structure is provided with a sliding surface. When the upper cabinet door is closed, the sliding surface on the upper part of the push structure pushes the first movable plate, causing the first movable plate to rotate and thus avoid the grounding switch operating hole. When the upper cabinet door is opened, the push structure disengages from the first movable plate, and the first movable plate rotates to the blocking position to block the grounding switch operating hole under the action of gravity.

[0013] Furthermore, the grounding switch interlocking mechanism also includes a grounding locking mechanism between the upper cabinet door and the grounding switch operating shaft. The grounding locking mechanism includes a rotating plate fixedly connected to the grounding switch operating shaft and a first locking plate with a locking groove on the upper cabinet door. When the grounding switch is open, the rotating plate can rotate into the locking groove so that the upper cabinet door cannot be opened; when the grounding switch is closed, the rotating plate can exit the locking groove to release the interlock on the upper cabinet door.

[0014] Furthermore, the second movable plate is guided to move in a vertical plane perpendicular to the front-back direction to avoid or block the operating hole of the disconnect switch. The second movable plate is connected to a transmission lever. A pressure plate that cooperates with the transmission lever is provided on the upper cabinet door. When the upper cabinet door is closed, the pressure plate can push the end of the transmission lever away from the second movable plate, thereby causing the other end of the transmission lever to drive the second movable plate to move in a guided manner to avoid the operating hole of the disconnect switch. A reset structure is provided on the second movable plate or the transmission lever. When the upper cabinet door is opened, the pressure plate releases the push on the transmission lever, and the second movable plate moves to the blocking position to block the operating hole of the disconnect switch under the action of the reset structure.

[0015] Furthermore, the isolation switch interlocking mechanism also includes an isolation locking mechanism between the upper cabinet door and the operating shaft of the isolation switch. The isolation locking mechanism includes a direct-acting rod that is drivenly connected to the operating shaft of the isolation switch, and a second locking plate with a locking hole on the upper cabinet door. When the isolation switch is closed, the direct-acting rod can be inserted into the locking hole to prevent the upper cabinet door from being opened; when the isolation switch is opened, the direct-acting rod can be withdrawn from the locking hole to release the interlock to the upper cabinet door.

[0016] This invention proposes a novel technical solution: a cover detachably connected to the cabinet frame is installed on one side of the cabinet frame, and the inlet channel is located at the bottom of the cover. The inlet cable passes through the bottom of the cover and connects to the primary circuit element inside the cabinet, while the outlet cable exits through the outlet channel at the bottom of the cabinet frame. In this way, the space for accommodating the inlet cable is external to the cabinet frame, eliminating the need to reserve space within the cabinet frame for this purpose, thus reducing the width of the cabinet frame. Furthermore, the inlet cable enters from the bottom of the ring main unit, and the outlet cable exits from the bottom, avoiding the problem of the ring main unit being too tall due to the inlet cable entering from the top. This design reduces the overall height and width of the cabinet frame, facilitating the transport of the ring main unit into the tower. Attached Figure Description

[0017] Figure 1 A top view showing the transformer and ring main unit placed inside the wind turbine tower; Figure 2 This is a schematic diagram of the internal structure of a ring main unit from the front view according to the present invention; Figure 3 This is a schematic diagram of the internal structure of a ring main unit from the left side view of the present invention; Figure 4 A schematic diagram of the structure for installing an L-shaped curved plate on the lower cabinet door and cooperating with the upper cabinet door; Figure 5 This is a schematic diagram of the grounding interlocking device and the isolation interlocking device.

[0018] In the diagram: 1. Side wall; 2. Integrated load switch and fuse combination appliance; 3. Fully insulated surge arrester; 4. Through-type instrument transformer; 5. Display support column; 6. Housing; 7. Rear wall; 8. Instrument room; 9. Emergency trip; 10. Cabinet frame; 101. Top channel steel; 102. Bottom channel steel; 103. Column channel steel; 11. Upper cabinet door; 12. Lower cabinet door; 13. L-shaped bend plate; 14. High negative voltage fuse; 15. Tower; 1501. Tower door; 16. Grounding switch operating shaft; 17. Disconnecting switch operating shaft; 18. Interlocking mechanism; 1801. First movable plate; 1802. U-shaped plate; 1803. First L-shaped plate; 1804. Bending plate; 1805. Turning plate; 1806. Pressure plate; 1807. Second L-shaped plate; 1809. Flat plate; 1810. Straight-acting rod; 19. Grounding switch in load switch-fuse combination electrical appliance; 20. Transformer; 21. Incoming cable; 22. Grounding switch operating hole; 23. Disconnecting switch operating hole; 24. Cable bundle structure. Detailed Implementation

[0019] This invention proposes a novel technical solution to address the problems existing in the aforementioned technical solutions. The core concept of this invention is: a cover detachably connected to the cabinet frame is provided on one side of the cabinet frame, and the inlet channel is located at the bottom of the cover. The inlet cable passes through the bottom of the cover and connects to the primary circuit element inside the cabinet. The outlet cable exits through the outlet channel at the bottom of the cabinet frame. In this way, the space for accommodating the inlet cable is external to the cabinet frame, eliminating the need to reserve space within the cabinet frame for accommodating the inlet cable, thus reducing the width of the cabinet frame. The inlet cable enters from the bottom of the ring main unit, and the outlet cable exits from the bottom of the ring main unit, avoiding the problem of the ring main unit being too tall due to the inlet cable entering from the top. This arrangement reduces the overall height and width of the cabinet frame, thereby facilitating the transport of the ring main unit into the tower.

[0020] In view of the above-mentioned inventive concept, a ring main unit of the present invention includes a cabinet frame 10, and a primary circuit element is installed inside the cabinet frame 10. The cabinet frame 10 is composed of, as shown in the figure below. Figure 2The cabinet frame 10 is composed of a top channel steel 15, a bottom channel steel 16, and a column channel steel 17. Two layers of crossbeams divide the cabinet frame 10 into upper, middle, and lower sections. The upper section corresponds to the grounding switch 19 in the load switch-fuse combination appliance inside the cabinet; the middle section corresponds to the interlocking mechanism 18, the high negative voltage fuse 14, and the integrated load switch-fuse combination appliance 2; and the lower section corresponds to the fully insulated surge arrester 3. The three-phase load switches of the load switch-fuse combination appliance are arranged in the front-to-back direction, with the operating mechanism located at the front. The front of the cabinet frame 10 has a cabinet door, including an upper cabinet door 11 and a lower cabinet door 12. The rear of the cabinet frame 10 has a rear wall 7, the left side of the cabinet frame 10 has a side wall 1, and the top and bottom have top and bottom walls, respectively. In this embodiment, the side wall 1 and the rear wall 7 are detachably connected to the cabinet frame 10. Thus, when the primary circuit components inside the cabinet are damaged, the side wall 1 and the rear wall 7 can be removed for subsequent repairs, which facilitates the repair and replacement of the primary circuit components inside the ring main unit.

[0021] Meanwhile, both side wall 1 and rear wall 7 are composed of three sealing plates: upper, middle, and lower. The upper, middle, and lower sealing plates correspond to the upper, middle, and lower sections of the cabinet frame, respectively. The lower sealing plate has a portion that covers the middle sealing plate, and the middle sealing plate has a portion that covers the upper sealing plate, so as to ensure that the three sealing plates are removed in the order of lower, middle, and upper, thus ensuring the safety of disassembly and assembly.

[0022] A cover 6, detachably connected to the cabinet frame 10, is provided on the right side of the cabinet frame 10. The bottom of the cover 6 has an inlet channel for the incoming cable 21 to pass through. The incoming cable 21 enters the cover 6 through the inlet channel and connects to the primary circuit component inside the cabinet frame 10 near the top. Inlet terminals for connecting the incoming cable 21 are located on the cabinet frame, and these terminals on the cabinet frame 10 facilitate wiring of the ring main unit. An outlet channel is provided at the bottom of the cabinet frame 10 for the outgoing cable 21 to exit. The incoming cable 21 enters from the bottom of the ring main unit, and the outgoing cable exits from the bottom of the ring main unit, avoiding the problem of the ring main unit being too tall if the incoming cable 21 enters from the top. Simultaneously, placing the space for accommodating the incoming cable 21 (i.e., the space inside the casing 6) outside the cabinet frame 10 reduces the width of the cabinet frame 10. This arrangement reduces the overall height and width of the cabinet frame 10, facilitating the transport of the ring main unit into the tower 15. Figure 1 As shown, the tower door 1501 of the tower 15 is relatively small. When the ring main unit is placed into the tower 15, the cabinet frame 10, the cover 6 and the incoming cable 21 can be transported into the tower 6 one after another, and the ring main unit can be assembled inside the tower.

[0023] In a preferred embodiment, the inner wall of the housing 6 is provided with a means for fixing the incoming cable 21 laid from bottom to top. Figure 2 The cable bundle structure 24 is shown. On the one hand, the cable bundle structure 24 provides support for the incoming cable 21, preventing the connection between the incoming cable 21 and the primary circuit components from becoming loose due to its own weight. On the other hand, it facilitates the neat laying of the incoming cable 21, avoiding the problem of the incoming cable 21 being messy.

[0024] In a preferred embodiment, the cabinet frame 10 is further provided with a mounting structure for installing the through-type current transformer 4 on one side of the housing 6. After the through-type current transformer 4 is installed in the cabinet frame 10, its main body is located inside the housing 6. The incoming cable 21 enters from the bottom of the housing 6, passes through the through-type current transformer 4, and connects to the primary circuit element inside the cabinet frame 10 near the top. In this way, the space of the housing can be used to accommodate the through-type current transformer 4, and there is no need to reserve space inside the cabinet frame 10 to accommodate the through-type current transformer 4, further reducing the volume of the cabinet frame 10. In addition, in another embodiment, the through-type current transformer can also be installed inside the cabinet frame, as long as the cabinet frame can pass through the tower door in this case.

[0025] In one embodiment, the instrument compartment is integrated within the cabinet frame and located near the front. To reduce the depth of the cabinet frame, in this embodiment, as... Figure 3 As shown, the instrument compartment 8, used for installing secondary circuit components, is externally located at the top front of the cabinet frame 10 and is detachably connected to the cabinet frame 10. If the instrument compartment 8 were built inside the cabinet frame, space would need to be reserved within the cabinet frame 10, increasing the depth of the cabinet frame 10 and consequently increasing the length of the output shaft of the operating mechanism. Therefore, in this embodiment, the instrument compartment 8 is externally located within the cabinet frame 10, further reducing the volume of the cabinet frame 10 and making it easier for the cabinet frame 10 to enter the tower 15. In this embodiment, the instrument compartment is installed on the front side of the cabinet frame 10, i.e., on the cabinet door side, and is positioned corresponding to the upper plate of the cabinet frame 10.

[0026] In this embodiment, the cabinet door includes an upper cabinet door 11 and a lower cabinet door 12, and the top of the lower cabinet door 12 has the following features: Figure 4 The L-shaped curved plate 13 shown has a horizontal side extending inward to the lower cabinet door, and a vertical side located at the inner end of the horizontal side and extending upward. The vertical side of the L-shaped curved plate 13 is located inward to the upper cabinet door, and cooperates with the upper cabinet door 11 so that the upper cabinet door 11 can only be closed when the lower cabinet door 12 is closed. This ensures the safety of the cabinet door when it is closed.

[0027] A grounding switch interlocking mechanism is provided between the upper cabinet door 11 and the grounding switch, and an isolation switch interlocking mechanism is provided between the upper cabinet door 11 and the isolation switch. Figure 5As shown, the grounding switch interlocking mechanism includes a first movable plate 1801 disposed in front of the grounding switch operating hole 16, and the isolating switch interlocking mechanism includes a second movable plate disposed in front of the isolating switch operating hole 17. Each movable plate has a blocking position for blocking the corresponding operating hole and a clearance position for avoiding the corresponding operating hole during its movement stroke. The upper cabinet door 11 is respectively provided with a first mating structure and a second mating structure that cooperate with the first movable plate 1801 and the second movable plate. When the cabinet door is closed, each mating structure cooperates with the corresponding movable plate to make the corresponding movable plate position the clearance position, so that the grounding switch operating shaft 16 can be rotated to perform a grounding tripping operation or the isolating switch operating shaft 17 can be rotated to perform an isolating closing operation. The isolating switch interlocking mechanism and the grounding switch interlocking mechanism ensure the safety of the ring main unit operation, prevent staff misoperation, and ensure the personal safety of the staff.

[0028] The first movable plate 1801 is rotatably assembled inside the cabinet around a horizontal axis extending front and rear. The first movable plate 1801 rotates to block or avoid the grounding switch operating hole 16. The first mating structure includes a push structure perpendicular to the upper cabinet door design. The upper part of the push structure is provided with a sliding surface. When the upper cabinet door 11 is closed, the sliding surface on the upper part of the push structure pushes the first movable plate, causing the first movable plate 1801 to rotate and thus avoid the grounding switch operating hole 16. When the upper cabinet door 11 is opened, the push structure disengages from the first movable plate 1801, and the first movable plate 1801 rotates to the blocking position to block the grounding switch operating hole 16 under the action of gravity. The push-pushing structure in this embodiment is a U-shaped plate 1802 as shown in Figure 5. One surface of the U-shaped plate 1802 has an upper slope, and the other surface has mounting holes. A first L-shaped plate 1803 is installed on the upper cabinet door, and the U-shaped plate 1802 is mounted on the first L-shaped plate 1803 through its mounting holes. At this time, the upper slope of the other surface of the U-shaped plate 1802 can serve as a sliding surface to cooperate with the first movable plate 1801. Furthermore, in other embodiments, the push-pushing structure can also be a three-dimensional structure with a sliding surface at its upper part. When installing the three-dimensional structure on the upper cabinet door, it is only necessary to ensure that the sliding surface at the top of the push-pushing structure can push the first movable plate, causing the first movable plate to rotate and thus avoid the grounding switch operating hole.

[0029] In this embodiment, the grounding switch interlocking mechanism further includes a grounding locking mechanism disposed between the upper cabinet door 11 and the grounding switch operating shaft 16. The grounding locking mechanism includes a rotating plate 1805 fixedly connected to the grounding switch operating shaft 16, and a first locking plate with a locking groove disposed on the upper cabinet door 11. When the grounding switch is open, the rotating plate 1805 can rotate into the locking groove to prevent the upper cabinet door 11 from opening. When the grounding switch is closed, the rotating plate 1805 can exit the locking groove to release the interlock on the upper cabinet door 11. This ensures that the upper cabinet door 11 cannot be opened when the grounding switch is open. In this embodiment, the first locking plate is a first L-shaped plate 1803 installed on the upper cabinet door. Two round holes are opened on one side of the first L-shaped plate 1803 and it is installed on the upper cabinet door by bolts. An emergency unlocking point 9 is set on the outside of the cabinet corresponding to the bolt position. In case of emergency, the bolts can be directly unscrewed at the emergency unlocking point 9 on the outside of the cabinet. The locking groove is a rectangular groove set on the first L-shaped plate 1803. When the grounding switch operating shaft 16 rotates, it can drive the rotating plate 1805 to rotate into the rectangular groove. The rotating plate 1805 can cooperate with the rectangular groove to block the opening of the upper cabinet door 11.

[0030] In this embodiment, the second movable plate moves in a vertical plane perpendicular to the front-to-back direction to avoid or block the operating hole 23 of the disconnect switch. The second movable plate is connected to a transmission lever. A pressure plate 1806 cooperating with the transmission lever is provided on the upper cabinet door 11. When the upper cabinet door 11 is closed, the pressure plate 1806 can push the end of the transmission lever away from the second movable plate, thereby causing the other end of the transmission lever to drive the second movable plate to move in a guided manner to avoid the operating hole 23 of the disconnect switch. A reset structure is also provided on the second rotating plate or the transmission lever (such as a reset tension spring installed on the second movable plate and the cabinet frame 10; or a reset torsion spring installed at the rotating assembly of the transmission lever), so that when the upper cabinet door 11 is opened, the pressure plate 1806 releases its push on the transmission lever, and the second movable plate moves to the blocking position to block the operating hole 23 of the disconnect switch under the action of the reset structure. The transmission lever in this embodiment is as follows: Figure 5 The bent plate 1804 shown is rotatably assembled inside the cabinet via a vertical pin installed at its bend. The bent plate 1804 has an adjusting elongated hole, and a stop pin is provided on the first movable plate. Displacement compensation between the stop pin and the adjusting elongated hole is achieved. In this embodiment, the transmission lever is rotatably assembled inside the cabinet about a vertical axis, and the second movable plate connected to the transmission lever moves horizontally as a guide. In another embodiment, the transmission lever can also be rotatably assembled inside the cabinet about a horizontal axis; in this case, the second movable plate connected to the transmission lever moves vertically as a guide.

[0031] In this embodiment, the isolation switch interlocking mechanism further includes an isolation locking mechanism disposed between the upper cabinet door 11 and the operating shaft 17 of the isolation switch. The isolation locking mechanism includes a linear actuator 1810 driven by the operating shaft 17 of the isolation switch, and a second locking plate with a locking hole disposed on the upper cabinet door. When the isolation switch is closed, the linear actuator 1810 can be inserted into the locking hole to prevent the upper cabinet door 11 from opening. When the isolation switch is opened, the linear actuator 1810 can be disengaged from the locking hole to release the interlock on the upper cabinet door. The second locking plate in this embodiment is as follows: Figure 5 The second L-shaped plate 1807 shown has a flat plate 1809 on it. Both the flat plate 1809 and the second locking plate have corresponding locking holes. The rotation of the disconnector operating shaft 17 is converted into the linear motion of the direct-acting rod 1810 via a transmission mechanism. The transmission structure can be a cam mounted on the disconnector operating shaft, which cooperates with the direct-acting rod to drive the rod to linear motion when the cam rotates. Alternatively, the transmission mechanism can be a gear mounted on the disconnector operating shaft, or a rack mounted on the direct-acting rod that can cooperate with the gear.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present invention shall also be included within the scope of protection of the present invention.

Claims

1. A ring main unit, characterized in that: The system includes a cabinet frame, inside which a primary circuit component is installed. One side of the cabinet frame has a cover that can be detachably connected to the cabinet frame. The bottom of the cover has an inlet channel for the incoming cable to pass through. The incoming cable passes through the inlet channel into the cover and connects to the primary circuit component inside the cabinet frame near the top. The bottom of the cabinet frame has an outlet channel for the outgoing cable to pass through.

2. The ring main unit according to claim 1, characterized in that: The inner wall of the enclosure is provided with a cable bundle structure for securing the incoming cables laid from bottom to top.

3. The ring main unit according to claim 1, characterized in that: The cabinet frame is also provided with a mounting structure on one side of the cover for installing the through-type current transformer. When the through-type current transformer is installed on the mounting structure, the main body of the through-type current transformer is located in the internal space of the cover.

4. The ring main unit according to any one of claims 1-3, characterized in that: The instrument panel for installing secondary circuit components is located at the top of the front side of the cabinet frame and is detachably connected to the cabinet frame.

5. The ring main unit according to any one of claims 1-3, characterized in that: The cabinet door includes an upper cabinet door and a lower cabinet door. The lower cabinet door has an L-shaped curved plate at the top. The horizontal side of the L-shaped curved plate extends to the inside of the lower cabinet door, and the vertical side is at the inside end of the horizontal side and extends upward. The vertical side of the L-shaped curved plate is inside the upper cabinet door. It works with the upper cabinet door so that the upper cabinet door can only be closed when the lower cabinet door is closed.

6. The ring main unit according to claim 5, characterized in that: A grounding switch interlocking mechanism is provided between the upper cabinet door and the grounding switch, and an isolating switch interlocking mechanism is provided between the upper cabinet door and the isolating switch. The grounding switch interlocking mechanism includes a first movable plate provided in front of the operating hole of the grounding switch, and the isolating switch interlocking mechanism includes a second movable plate provided in front of the operating hole of the isolating switch. Each movable plate has a blocking position that blocks the corresponding operating hole and an abdicating position that avoids the corresponding operating hole during its movement stroke. The upper cabinet door is provided with a first mating structure and a second mating structure that cooperate with the first movable plate and the second movable plate, respectively. When the cabinet door is closed, each mating structure cooperates with the corresponding movable plate to make the corresponding movable plate position the abdicating position, so that the grounding switch operating shaft can be rotated to perform a grounding tripping operation or the isolating switch operating shaft can be rotated to perform an isolating closing operation.

7. The ring main unit according to claim 6, characterized in that: The first movable plate is rotatably assembled inside the cabinet around a horizontal axis extending front and rear. The first movable plate rotates to block or avoid the grounding switch operating hole. The first mating structure includes a push structure designed perpendicular to the upper cabinet door. The upper part of the push structure is provided with a sliding surface. When the upper cabinet door is closed, the sliding surface on the upper part of the push structure pushes the first movable plate, causing the first movable plate to rotate and thus avoid the grounding switch operating hole. When the upper cabinet door is opened, the push structure disengages from the first movable plate, and the first movable plate rotates to the blocking position to block the grounding switch operating hole under the action of gravity.

8. The ring main unit according to claim 7, characterized in that: The grounding switch interlocking mechanism also includes a grounding locking mechanism between the upper cabinet door and the grounding switch operating shaft. The grounding locking mechanism includes a rotating plate fixedly connected to the grounding switch operating shaft and a first locking plate with a locking groove on the upper cabinet door. When the grounding switch is open, the rotating plate can rotate into the locking groove so that the upper cabinet door cannot be opened; when the grounding switch is closed, the rotating plate can exit the locking groove to release the interlock on the upper cabinet door.

9. The ring main unit according to claim 6, characterized in that: The second movable plate moves in a vertical plane perpendicular to the front-to-back direction to avoid or block the operating hole of the disconnect switch. The second movable plate is connected to a transmission lever. A pressure plate that cooperates with the transmission lever is provided on the upper cabinet door. When the upper cabinet door is closed, the pressure plate can push the end of the transmission lever away from the second movable plate, thereby causing the other end of the transmission lever to drive the second movable plate to move in a guided manner to avoid the operating hole of the disconnect switch. A reset structure is provided on the second movable plate or the transmission lever. When the upper cabinet door is opened, the pressure plate releases the push on the transmission lever, and the second movable plate moves to the blocking position to block the operating hole of the disconnect switch under the action of the reset structure.

10. The ring main unit according to claim 9, characterized in that: The isolation switch interlocking mechanism also includes an isolation locking mechanism between the upper cabinet door and the operating shaft of the isolation switch. The isolation locking mechanism includes a linear actuator that is drivenly connected to the operating shaft of the isolation switch, and a second locking plate with a locking hole on the upper cabinet door. When the isolation switch is closed, the linear actuator can be inserted into the locking hole to prevent the upper cabinet door from being opened; when the isolation switch is opened, the linear actuator can be withdrawn from the locking hole to release the interlock to the upper cabinet door.

Images