Double-fracture isolation grounding switch with position indication and expansion installation mode

Abstract

The invention relates to a double-fracture isolation grounding switch with position indication, which comprises a shell, a three-phase switch body is arranged in the shell, any switch body comprises a first static contact seat, a first moving contact, a second static contact seat and a second moving contact, the first moving contact is electrically connected with the second moving contact, and the second moving contact is electrically connected with the first static contact seat. A driving device is also arranged in the shell, the driving device respectively drives the first static contact seat and the first moving contact as well as the second static contact seat and the second moving contact to be electrically connected or separated to form two fractures, and the switch body also comprises a grounding switch which is driven by the driving device to open and close; the invention further comprises an extension installation mode, the bus is connected in series with the double-fracture isolation grounding switch with the position indication during installation and testing, the three-phase switch bodies are all disconnected, and the grounding switch is grounded. The device has the effect that the situation that the whole bus is powered off due to the fact that an isolation fracture or an isolation switch is broken down when the bus end is expanded or in a voltage withstand test after expansion is completed is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of isolating earthing switches, and in particular to a double-break isolating earthing switch with position indication and an expansion installation method. Background Art

[0002] With the progress of power technology and the booming development of the national economy, the power transmission capacity has been continuously climbing. Gas Insulated Switchgear (GIS) has been increasingly widely used due to its advantages such as small floor area, high reliability, and maintenance-free. Due to various considerations such as project design planning and engineering budget, GIS substations often cannot be fully installed in the first-phase project, which gives rise to the concept of reserved intervals. In GIS equipment, arranging the reserved intervals within the intervals between complete intervals belongs to interval expansion, and arranging the reserved intervals at the ends of GIS equipment belongs to end expansion.

[0003] In the related art, the isolating switch has only one break. Whether it is in the expansion of the busbar end interval or the interval expansion, or during the withstand voltage test after the expansion equipment is installed, if the test voltage cannot be kept in the same frequency and phase as the operating voltage, there will be a dangerous condition where the test voltage and the operating voltage amplitudes at both ends of the isolating break are reversely superimposed, and there is a risk of breakdown of the isolating break, which will endanger the safety of the operating equipment and the power grid.

[0004] In order to prevent the isolating switch from breaking down and discharging, the entire busbar needs to be powered off, or even the entire power station needs to be powered off. And powering off the entire GIS busbar will inevitably lead to a decline in power grid quality and an increase in operating costs. Summary of the Invention

[0005] In order to reduce the occurrence of the situation where the isolating break or the isolating switch is broken down during the expansion of the busbar end or the withstand voltage test after the expansion is completed, resulting in the power failure of the entire busbar, the present application provides a double-break isolating earthing switch with position indication and an expansion installation method.

[0006] The double-break isolating earthing switch with position indication and the expansion installation method provided by the present application adopt the following technical solutions: A double-break isolating and grounding switch with position indication, comprising a shell, a switch body arranged in the shell, the switch body being horizontally arranged, the switch body comprising a first static contact seat and a first moving contact, and a second static contact seat and a second moving contact, which respectively cooperate with each other, the first moving contact and the second moving contact being electrically connected, and an inlay electrically connected to the outer side of the shell being respectively provided on the side of the first static contact seat and the second static contact seat facing away from each other, a driving device being further provided in the shell, the driving device driving the first static contact seat and the first moving contact, and the second static contact seat and the second moving contact to electrically connect or separate each other, when the first static contact seat and the first moving contact are separated, and the second static contact seat and the second moving contact are separated, two breaks are formed; the switch body also comprises a grounding static contact seat and a grounding moving contact, and the driving device drives the grounding static contact seat and the grounding moving contact to open and close the switch; three groups of the switch body are arranged in the shell to form a three-phase switch, and the interior of the shell is a sealed pressure air chamber.

[0007] This technical solution employs three horizontally arranged switch bodies within the housing, each equipped with two opposing static and dynamic contact assemblies (forming a double break), achieving dual-breakpoint isolation per phase. Electrical connection is achieved by connecting the dynamic contact in series with the static contact, while grounding is accomplished by an independent pair of grounding contacts. This dual-break simultaneous grounding reduces the risk of power outages caused by accidental busbar breakdown, thereby protecting the busbar and equipment along the line.

[0008] Preferably, the driving device includes an operating mechanism and a rotating shaft arranged in a shell, the outer shell of the operating mechanism is fixed to the outside of the shell, the rotating shaft in the shell rotates synchronously with the first output shaft in the operating mechanism, and insulating transmission shafts are respectively arranged between the three switch bodies. The operating mechanism drives each insulating transmission shaft to rotate synchronously around mutually parallel axes through the rotating shaft.

[0009] By adopting the above technical solution, the operating mechanism is connected to the internal rotating shaft through the housing, and then drives the three-phase insulated transmission shaft to realize three-phase synchronous operation, thereby ensuring three-phase synchronous opening and closing operations, improving system coordination and synchronicity, and reducing false operations or arc faults caused by phase asynchrony.

[0010] Preferably, the first moving contact and the second moving contact in any one of the switch bodies are connected to each other through a transmission mechanism, and the insulating transmission shaft drives the transmission mechanism to make the first moving contact and the second moving contact approach or move away from each other. When the first moving contact and the second moving contact move in directions away from each other, they will gradually insert into the corresponding first static contact seat or the second static contact seat, so that the two ends of the switch body are conductive; when the first moving contact and the second moving contact move in a direction approaching each other, they will gradually disconnect from the first static contact seat and the second static contact seat, forming two fractures.

[0011] By adopting the above technical solutions, the two disconnection ports operate synchronously, avoiding the failure of a single disconnection port, improving the overall isolation reliability, and facilitating remote or automatic control.

[0012] Preferably, the transmission mechanism includes a gear. The insulating transmission shaft drives the gear to rotate. On both sides in the radial direction of the gear, a first rack and a second rack are respectively arranged. The first rack and the second rack are respectively meshed with the gear. The first rack is fixedly connected to the first moving contact, and the second rack is fixedly connected to the second moving contact.

[0013] By adopting the above technical solutions, the transmission mode of the gear meshing with the rack realizes the conversion from rotational motion to linear sliding, which can ensure the synchronization of the two groups of racks and moving contacts, thereby realizing the synchronization between the two disconnection ports of the same phase.

[0014] Preferably, the switch body further includes a moving contact mounting seat. Both the first moving contact and the second moving contact are arranged within the moving contact mounting seat. An insulating support column is fixedly arranged under the moving contact mounting seat, and the insulating support column is detachably fixed to the housing.

[0015] By adopting the above technical solutions, the moving contact is installed on the supporting insulating column through the fixed seat and then installed in the housing, realizing the electrical insulation between the moving contact and the housing.

[0016] Preferably, the grounding static contact seat is communicatively arranged on the moving contact mounting seat. The grounding moving contact can be communicatively arranged with the outer ground wire. The switch body further includes a grounding transmission shaft. The driving device drives the transmission shaft to rotate around its own axis direction. A crank arm is arranged on the grounding transmission shaft. One end of the crank arm is fixed to the grounding transmission shaft, and the other end is rotatably connected with a grounding moving rod. The grounding moving rod is in sliding fit with the grounding moving contact and is communicatively arranged. The rotation of the crank arm drives the grounding moving rod to be inserted into the grounding static contact seat, making the grounding static contact seat and the grounding moving contact closed.

[0017] By adopting the above technical solutions, the grounding moving contact is driven by the crank arm - moving rod combined structure to be inserted into the grounding static contact seat to form a grounding closure. The driving device drives the grounding transmission shaft to complete the action in linkage, making the two moving contacts reliably grounded, preventing the residual voltage or induced current from causing harm to the person or equipment, and improving the grounding reliability and operation convenience. Preferably, both ends of the housing are respectively arranged to be open. First flanges are installed at both ends of the housing. A pot - type insulator is fixed on any one of the first flanges. Any one of the inserts is correspondingly embedded in the resin layer of the pot - type insulator and is conducted with the outside of the housing.

[0018] By adopting the above technical solutions, the insert is fixedly installed on the housing flange through the pot - type insulator, realizing the reliable insulating connection between the internal conductive element and the external electrical interface. The structure is compact and meets the requirements of the GIS closed gas chamber.

[0019] Preferably, an opening and closing indicator is further provided on the housing, and the driving device synchronously drives the opening and closing indicator to rotate. When the driving device drives the first moving contact and the first static contact seat in the three switch bodies to separate, the second moving contact and the second static contact seat to separate, and the grounding moving contact to communicate with the grounding static contact seat, the opening and closing indicator indicates the open position; when the driving device drives the first moving contact in the three switch bodies to conduct with the first static contact seat, and the second moving contact and the second static contact seat to conduct, a loop is formed between the first static contact seat and the second static contact seat, and the grounding moving contact is separated from the grounding static contact seat, the opening and closing indicator indicates the closed position.

[0020] By adopting the above technical solution, the operating mechanism and the opening and closing indicator act synchronously, the opening and closing state is visually visible, the accuracy of operation confirmation is improved, misjudgment is prevented, and the safety of operation and maintenance is improved.

[0021] An expansion installation method using a double-break isolating grounding switch with position indication. When it is necessary to expand equipment on the main bus, the double-break isolating grounding switch with position indication is connected in series on the bus. The driving device in the double-break grounding switch with position indication drives the three-phase switch bodies to open separately, forming isolation break 1 and isolation break 2. A grounding switch is formed between the grounding static contact seat and the grounding moving contact in the three-phase switch bodies. The grounding switch is connected to the structure between isolation break 1 and isolation break 2. The driving device drives the grounding switch to close, keeping the main bus energized, and at the same time conducting the grounding switch and the outer ground wire. At this time, the docking of the expanded equipment can be started, and the substation is energized and operating; after the docking of the expanded equipment is completed, a power frequency withstand voltage test is performed on the newly installed equipment alone. At this time, the bus or single bus can still be kept energized. The three-phase switch bodies in the double-break grounding switch with position indication are all opened to form isolation break 1 and isolation break 2, and the grounding switch is grounded; when the on-site test is completed, each switch body and the grounding switch are adjusted to the corresponding state according to the actual working conditions of the substation.

[0022] By adopting the above technical solution, the switch device is connected in series on the main bus. By opening the double-break structure to form two isolation breaks and grounding in the middle, it is ensured that the equipment docking and withstand voltage test are completed under the condition that the bus is energized; the double-break is used to shunt and ground the current path of accidental breakdown, and the expansion construction of the main bus without power outage can be realized, ensuring the personal and equipment safety during the expansion process and the test process, improving the construction efficiency and reducing the economic losses caused by power outage.

[0023] In summary, the present application includes at least one of the following beneficial technical effects: 1. By setting a double-break structure in each phase switch body, the first moving contact and the first static contact seat, and the second moving contact and the second static contact seat can be disconnected respectively, so as to form two independent isolation breaks in the same phase, significantly enhancing the isolation ability and the safety of system operation. At the same time, by controlling the closing of the earthing switch through the linkage drive device, a grounding loop can be quickly constructed under the condition that the two isolation breaks are in the open state, reducing the occurrence of accidental breakdown of the busbar, and further ensuring the safety of operators and the system; 2. Install opening and closing position indicators on the housing and the operating mechanism respectively. Among them, the body indicator is directly linked with the transmission shaft, which can more accurately reflect the true state of the break, avoid the problem of false indication of the mechanism in the traditional structure, and improve the accuracy of operation judgment. At the same time, the modular structure design also facilitates the installation, expansion and maintenance of the equipment; 3. The proposed expansion and installation method of the present invention utilizes the double-break structure and the intermediate grounding path to realize the expansion installation and withstand voltage test of the expansion equipment under the live state without affecting the live operation of the main busbar. When an accidental breakdown occurs during the test, the current can be released through the grounding loop, effectively preventing the breakdown arc from conducting to the operating busbar side, improving the stability of system operation and the safety of construction, and greatly reducing the power outage time and economic losses. Description of the Drawings

[0024] Figure 1 is a top view cross-sectional view mainly showing the internal structure of the double-break isolating earthing switch with position indication in Embodiment 1 of the present application; Figure 2 is a front view cross-sectional view mainly showing part of the structure when the switch body of the double-break isolating earthing switch with position indication is opened and the earthing switch is closed in Embodiment 1 of the present application; Figure 3 is a front view cross-sectional view mainly showing part of the structure when the switch body of the double-break isolating earthing switch with position indication is closed and the earthing switch is opened in Embodiment 1 of the present application; Figure 4 is a front view mainly showing the position indicating device indicating the closing of the switch body in Embodiment 1 of the present application; Figure 5 is a top view of the equipment expansion plane in Embodiment 2 of the present application; Figure 6 is the main wiring diagram of the equipment expansion in Embodiment 2 of the present application.

[0025] Reference numerals: 1, housing; 11, first flange; 111, pot insulator; 112, insert; 12, second flange; 121, insulating block; 122, insert; 123, copper busbar; 13, cover body; 14, insulating support column; 15, opening and closing indicator; 151, stop piece; 152, indicating piece; 16, driving device; 161, rotating shaft; 162, second position indicating device; 17, insulating transmission shaft; 2, switch body; 21, first static contact seat; 22, second static contact seat; 23, moving contact mounting seat; 231, needle roller bearing; 24, first moving contact; 25, second moving contact; 26, flexible contact finger; 27, gear; 28, first rack; 29, second rack; 3, earthing switch; 31, earthing transmission shaft; 32, toggle arm; 33, earthing static contact seat; 34, earthing moving contact; 10, isolation break one; 20, isolation break two; 100, first-phase equipment; 200, extension equipment. Detailed implementation manners

[0026] The following further describes Figures 1-6 this application in detail with reference to the accompanying drawings.

[0027] The embodiment of this application discloses a double-break isolation earthing switch with position indication and an extension installation method.

[0028] Embodiment 1 Referring to Figures 1-3 , the double-break isolation earthing switch with position indication includes a housing 1. Both ends of the housing 1 are open, and first flanges 11 are respectively fixed at both ends by bolts. An open opening is also provided on the upper side of the housing 1, and a second flange 12 is installed on the open opening. The lower side of the housing 1 is also open, and a cover body 13 is installed on the open opening. A first position indicating device is provided on the front side of the housing 1, and a driving device 16 is provided on the rear side. The housing 1 is integrally formed by casting. After installing each device, a sealed chamber will be formed inside the housing 1. When the device operates, SF6 gas or a mixed gas of SF6 and N2 with a rated air pressure will be filled into the housing 1 to form a sealed pressure chamber inside the housing 1.

[0029] A pot insulator 111 is fixed on any one of the first flanges 11. The pot insulator 111 includes a resin layer and an insert 112, and the insert 112 is embedded and fixed in the resin layer. A switch body 2 is arranged inside the housing 1. The switch body 2 includes a first static contact seat 21 and a second static contact seat 22 arranged at both ends. The first static contact seat 21 and the second static contact seat 22 are respectively fixedly connected to the corresponding inserts 112 by bolts and are conductively connected to each other.

[0030] An insulating support column 14 is provided on the cover body 13, and the insulating support column 14 is fixedly connected to the cover body 13 by bolts. The switch body 2 further includes a moving contact mounting seat 23, and the moving contact mounting seat 23 is fixedly mounted on the insulating support column 14 by screws. The moving contact mounting seat 23 is made of an aluminum conductive material. A first moving contact 24 and a second moving contact 25 are provided in the moving contact mounting seat 23. The first moving contact 24 is inserted and matched with the first static contact seat 21, and the second moving contact 25 is inserted and matched with the second static contact seat 22. The first moving contact 24 and the second moving contact 25 are electrically connected. A transmission mechanism is provided between the first moving contact 24 and the second moving contact 25. The driving device 16 drives the transmission mechanism, thereby driving the first moving contact 24 and the second contact to move in directions away from or close to each other simultaneously. After the first moving contact 24 and the second moving contact 25 move in directions away from each other, they will gradually insert into the corresponding first static contact seat 21 and second static contact seat 22 respectively, so that the first static contact seat 21 and the first moving contact 24 are conducted, and the second moving contact 25 and the second static contact seat 22 are conducted. And because the first moving contact 24 and the second moving contact 25 are electrically connected, at this time, the first static contact seat 21 and the second static contact seat 22 are conducted, and the current forms a loop from the insert 112 in the left-end pot insulator 111 to the insert 112 in the right-end pot insulator 111 as shown in Figure 2 the figure. After the first moving contact 24 and the second moving contact 25 move in the direction of approaching each other, an isolation break 10 is formed between the first static contact seat 21 and the first moving contact 24, and an isolation break 20 is formed between the second static contact seat 22 and the second moving contact 25.

[0031] The transmission mechanism includes a gear 27. The driving device 16 drives the gear 27 to rotate around its own axis. A first rack 28 and a second rack 29 are respectively provided on the upper and lower sides of the gear 27. The first rack 28 is fixed and conducted with the first moving contact 24, and the second rack 29 is fixed and conducted with the second moving contact 25. The gear 27 is respectively meshed with the first rack 28 and the second rack 29. The driving device 16 drives the gear 27 to rotate. The gear 27 is simultaneously meshed with the first rack 28 and the second rack 29 respectively, thereby converting the rotation into a linear movement. The first rack 28 and the second rack 29 drive the first moving contact 24 and the second moving contact 25 to approach or separate from each other.

[0032] A grounding switch 3 is also provided on the upper side of the moving contact mounting seat 23. The grounding switch 3 includes a grounding static contact seat 33 and a grounding moving contact 34. The grounding static contact seat 33 is mounted on the moving contact mounting seat 23 and is in electrical communication with the moving contact mounting seat 23. An insulating block 121 is also fixed on the second flange 12. An insert 122 is embedded in the insulating block 121. A copper busbar 123 is fixed on the upper side of the insert 122. The copper busbar 123 is arranged on the outside of the shell 1 and can be connected to the external ground wire. The grounding moving contact 34 includes a retractable grounding moving rod. The upper end of the grounding moving rod is fixed on the insert 122 and is connected to the insert 122. A grounding transmission shaft 31 is also provided on one side of the grounding moving rod in the horizontal direction. The axis of the grounding transmission shaft 31 is parallel to the axis of the gear 27. The driving device 16 drives the grounding transmission shaft 31 to rotate around its own axis. A crank arm 32 is fixed on the grounding transmission shaft 31. The other end of the crank arm 32 is rotatably connected to the extended end of the grounding moving rod. The grounding transmission shaft 31 drives the crank arm 32 to rotate, and the crank arm 32 drives the grounding movable rod to extend and retract, and the lower end of the grounding movable rod is inserted into the grounding static contact seat 33, so that the grounding movable rod and the grounding static contact seat 33 are connected, thereby connecting the movable contact mounting seat 23 with the outer ground wire.

[0033] The driving device 16 includes an operating mechanism and a rotating shaft 161. The operating mechanism can be set as two motors, or a motor and a transmission structure connected to the output shaft of the motor, so that the driving device 16 includes a first output shaft and a second output shaft. The staff can switch the rotation direction of the first output shaft and the second output shaft. The rotating shaft 161 is arranged in the housing 1, and the first output shaft is connected to the rotating shaft 161. Three switch bodies 2 can be provided in the housing 1 to form three phases, and the three-phase switch bodies 2 are arranged at intervals in the horizontal direction. Insulating transmission shafts 17 are respectively provided between the three-phase switch bodies 2, and an insulating transmission shaft 17 is also provided on the side of the outermost two-phase switch bodies 2 facing away from each other. The axial direction of any insulating transmission shaft 17 is parallel to the axial direction of the rotating shaft 161. The rotating shaft 161 drives an adjacent insulating transmission shaft 17 to rotate around its own axial direction, and any insulating transmission shaft 17 rotates synchronously with the adjacent gear 27. See Figure 1 、 Figure 4 The first position indicator is configured as an open / close indicator 15. This indicator 15 includes a flap 151 and an indicator 152. The words "Open" and "Closed" are written on the indicator 152, respectively. The words on the indicator 152 are visible to the operator from the outside of the housing 1. The flap 151 rotates parallel to the axis of the gear 27, obscuring either word. The insulated drive shaft 17, facing away from the drive unit 16, rotates the flap 151. Simultaneously, the operator can control the second output shaft to simultaneously rotate multiple grounded drive shafts 31 about their own axes.

[0034] The implementation principle of a double-break disconnecting earthing switch with position indication in this embodiment is as follows: In the state of needing to open the switch, the operator controls the operating mechanism to drive the first output shaft and the second output shaft to rotate. The first output shaft drives the rotating shaft 161 in the housing 1 to rotate, and the rotating shaft 161 drives the adjacent insulating transmission shaft 17 to rotate, thereby driving the adjacent gear 27 to rotate, and further driving other insulating transmission shafts 17 and gears 27 to rotate. Any gear 27 meshes with the corresponding first rack 28 and second rack 29, thereby driving the corresponding first moving contact 24 and second moving contact 25 to move towards each other. Thus, an isolation break 10 is formed between all the first moving contacts 24 and the corresponding first static contact seats 21 in the three-phase switch body 2, and an isolation break 20 is formed between all the second moving contacts 25 and the corresponding second static contact seats 22. At the same time, the second output shaft drives all the earthing transmission shafts 31 to rotate, and any earthing transmission shaft 31 drives the corresponding toggle arm 32 to rotate, thereby driving the earthing moving rod to insert into the lower earthing static contact seat 33, so that all the moving contact mounting seats 23 are respectively conducted with the outer earthing wire. In the case of needing to close the switch, the operator controls the operating mechanism to drive the first output shaft and the second output shaft to reverse respectively, and further drives all the first moving contacts 24 to insert into the corresponding first static contact seats 21, all the second moving contacts 25 to insert into the corresponding second static contact seats 22, all the earthing moving rods to separate from the corresponding earthing static contact seats 33, and a current loop is formed between the left inlays 112 and the corresponding right inlays 112 of all the housings 1 to achieve closing.

[0035] See Figures 1-3 , in the actual design, the torque transmission can be realized by the spline fit of the same specification between each shaft or between the shaft and the gear 27; the moving contact mounting seat 23 is formed by casting, the shielding cover on the moving contact side of the break in the conventional design is cancelled, and the shielding shape of the break is directly cast, so that the heat dissipation area of the moving contact mounting seat 23 can be increased, and the current-carrying capacity of the moving contact mounting seat 23 can be improved.

[0036] In the actual design, the electrical connection method of the strap finger 26 is adopted between the moving contact mounting seat 23 and the first moving contact 24, the second moving contact 25, or between the first moving contact 24 and the first static contact seat 21, and between the second moving contact 25 and the second static contact seat 22 during closing. Compared with the electrical connection structures of other plum blossom contacts or self-acting contacts, the electrical connection structure of the strap finger 2614 greatly increases the number of electrical contact points, can reduce the resistance, and improve the current-carrying capacity of the product. Moreover, with the increase in the number of electrical contact points, the wear generated by the sliding friction of the first moving contact 24 and the second moving contact 25 during opening and closing can also be improved, and the generation of foreign debris can be reduced.

[0037] In the actual design, the moving contact mounting seat 23 is integrally formed by casting, enabling the grooves for mounting the watchband contact fingers 26 at both its left and right ends to be formed. This allows for all the grooves at both ends to be machined in one clamping, which is conducive to ensuring the coaxiality of the grooves, thereby ensuring the coaxiality when the two moving contacts slide with the moving contact mounting seat 23, reducing the wear caused by sliding friction, and reducing the generation of foreign debris.

[0038] In the actual design, a bolt-type needle bearing 231 is installed between the moving contact mounting seat 23 and the first rack 28 or the second rack 29. There is only relative rolling between the needle bearing 231 and the adjacent first rack 28 or second rack 29, preventing the first rack 28 from tilting with the corresponding first moving contact 24 or the second rack 29 from tilting with the corresponding second moving contact 25, thus ensuring that each moving contact and each rack move in a straight line.

[0039] In the actual design, the insulating support column 14 is a pillar-type insulator, and curved wrinkles are added to the surface of the insulator to increase the creepage distance of the insulator and improve the electric field margin.

[0040] To facilitate the staff to observe whether the break is formed, a second position indicating device 162 can also be provided on the outer shell of the driving device 16. It can have the same structure as the first position indicating device in the housing 1. The shutter inside it is driven to rotate by the first output shaft through a transmission structure, which is convenient for the staff to observe and confirm the opening and closing positions of the disconnector.

[0041] Embodiment 2 See Figures 5-6 , and the expansion installation method is as follows: The staff connects the double-break disconnector with position indication in Embodiment 1 in series in the main bus. The first-phase equipment 100 is connected in series in the main bus, or it can also be directly connected in series with the double-break disconnector with position indication. The three-phase six inserts 112 at both ends of the housing 1 are connected in series to the three-phase alternating current in the main bus. Under normal working conditions, a current loop is formed between any two corresponding inserts 112, and the main bus is in a connected and energized state.

[0042] During the expansion and installation, keep the main busbar energized. The staff controls the operating mechanism to open the three-phase disconnector, and at the same time, the earthing switch 3 closes. At this time, two series-connected isolation breaks (i.e., the series-connected isolation break one 10 and the isolation break two 20) are formed between the docking operation surface and the energized operating busbar. Each moving contact mounting seat 23 between the two isolation breaks is grounded. At this time, the docking of the expansion equipment 200 can be started, and the substation is operating energized. When the expansion equipment 200 is being docked, once a breakdown occurs at the break between the busbar and the de-energized docking part, only the isolation break one 10 near the energized side will be broken down, and the isolation break two 20 near the de-energized side will not be broken down. Moreover, since the earthing switch 3 is already grounded, even if the isolation break one 10 is broken down, the generated breakdown current is directly discharged to the ground through the earthing switch 3, and it will not affect the isolation break two 20. Ensure the safety of the installation staff when the expansion equipment 200 is being docked. The double busbar structure is the same.

[0043] After the docking of the expansion equipment 200 is completed, it is necessary to conduct a power frequency withstand voltage test on the newly installed expansion equipment 200 alone. At this time, the busbar is still energized (or a single busbar can also be energized, adjusted according to the actual working conditions of the substation), and the three-phase switch bodies 2 are all open, and the earthing switch 3 is closed. There are two series-connected isolation breaks (i.e., the series-connected isolation break one 10 and the isolation break two 20) between the energized busbar and the test unit respectively. When the withstand voltage test is in progress, once a breakdown occurs at the break between the test unit and the energized operating part, only the isolation break two 20 near the test unit will be broken down, and the isolation break one 10 near the energized operating busbar side will not be broken down. Moreover, since the earthing switch 3 is already grounded, even if the isolation break two 20 is broken down, the generated breakdown current is directly discharged to the ground through the earthing switch 3, and it will not affect the isolation break one 10. Ensure the safety of the installation staff when the expansion equipment 200 is being docked. The double busbar structure is the same.

[0044] After the on-site test is completed, the switch bodies 2 and the earthing switch 3 can be adjusted to the corresponding states according to the actual working conditions of the substation.

[0045] From the above analysis, it can be seen that the GIS with a double-break isolation earthing switch with position indication in Embodiment 1 does not have a power outage during the whole process of the busbar expansion and the expansion equipment 200 (the installation docking process and the handover test process), which ensures the normal operation of the substation. And the withstand voltage test range covers all the newly installed expansion equipment 200, realizing full coverage and no blind area of the withstand voltage test range.

[0046] The above are all the preferred embodiments of this application. The protection scope of this application is not limited by this. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A double-break isolating earthing switch with position indication, characterized in that: It includes a housing (1), inside which a switch body (2) is arranged. The switch body (2) is horizontally arranged. The switch body (2) includes a first static contact seat (21) and a first moving contact (24) as well as a second static contact seat (22) and a second moving contact (25) that cooperate with each other respectively. The first moving contact (24) and the second moving contact (25) are electrically connected. On the sides of the first static contact seat (21) and the second static contact seat (22) facing away from each other, inlays (112) electrically connected to the outside of the housing (1) are respectively arranged. A driving device (16) is also arranged inside the housing (1). The driving device (16) drives the first static contact seat (21) and the first moving contact (24) as well as the second static contact seat (22) and the second moving contact (25) to be electrically connected or separated from each other. When the first static contact seat (21) and the first moving contact (24) are separated and the second static contact seat (22) and the second moving contact (25) are separated, two break points will be formed. The switch body (2) also includes a grounding static contact seat (33) and a grounding moving contact (34). The driving device (16) drives the grounding static contact seat (33) and the grounding moving contact to switch on and off. Three groups of the switch body (2) are arranged inside the housing (1) to form a three-phase switch, and the inside of the housing (1) is a sealed pressure chamber.

2. The double-break disconnecting and earthing switch with position indication according to claim 1, wherein: The driving device (16) includes an operating mechanism and a rotating shaft (161) arranged inside the housing (1). The outer shell of the operating mechanism is fixed on the outside of the housing (1). The rotating shaft (161) inside the housing (1) rotates synchronously with the first output shaft inside the operating mechanism. Insulating transmission shafts (17) are respectively arranged between the three switch bodies (2). The operating mechanism drives each insulating transmission shaft (17) to rotate synchronously around parallel axes through the rotating shaft (161).

3. The double-break disconnecting earthing switch with position indication according to claim 2, characterized in that: The first moving contact (24) and the second moving contact (25) inside any one of the switch bodies (2) are connected to each other through a transmission mechanism. The insulating transmission shaft (17) drives the transmission mechanism to make the first moving contact (24) and the second moving contact (25) approach or move away from each other. When the first moving contact (24) and the second moving contact (25) move in the direction away from each other, they will gradually insert into the corresponding first static contact seat (21) or second static contact seat (22) to make both ends of the switch body (2) conduct; when the first moving contact (24) and the second moving contact (25) move in the direction closer to each other, they will gradually disconnect from the first static contact seat (21) and the second static contact seat (22) to form two break points.

4. A double-break disconnecting earthing switch with position indication according to claim 3, characterized in that: The transmission mechanism includes a gear (27). The insulating transmission shaft (17) drives the gear (27) to rotate. On both sides in the radial direction of the gear (27), a first rack (28) and a second rack (29) are respectively arranged. The first rack (28) and the second rack (29) are respectively meshed with the gear (27). The first rack (28) is fixedly connected to the first moving contact (24), and the second rack (29) is fixedly connected to the second moving contact (25).

5. A double-break disconnecting earthing switch with position indication according to claim 2, characterized in that: The switch body (2) further includes a moving contact mounting seat (23). The first moving contact (24) and the second moving contact (25) are both arranged within the moving contact mounting seat (23). An insulating support column (14) is fixed to the lower side of the moving contact mounting seat (23), and the insulating support column (14) is detachably fixed to the housing (1).

6. The double-break disconnecting earthing switch with position indication according to claim 5, characterized in that: The grounding static contact seat (33) is communicatively arranged on the moving contact mounting seat (23). The grounding moving contact (34) is communicatively arranged with the outer ground wire. The switch body (2) further includes a grounding transmission shaft (31). The driving device (16) drives the transmission shaft to rotate around its own axis. An arm (32) is arranged on the grounding transmission shaft (31). One end of the arm (32) is fixed to the grounding transmission shaft (31), and the other end is rotatably connected to a grounding moving rod. The grounding moving rod is in sliding fit with the grounding moving contact (34) and is communicatively arranged. The rotation of the arm (32) drives the grounding moving rod to be inserted into the grounding static contact seat (33), so that the grounding static contact seat (33) and the grounding moving contact (34) are closed.

7. A double-break disconnecting earthing switch with position indication according to claim 1, characterized in that: Both ends of the housing (1) are respectively arranged to be open. First flanges (11) are installed at both ends of the housing (1). A pot-type insulator (111) is fixed to any one of the first flanges (11). Any one of the inserts (112) is correspondingly embedded in the resin layer of the pot-type insulator (111) and is electrically connected to the outside of the housing (1).

8. A double-break disconnecting and earthing switch with position indication according to claim 1, characterized in that: An opening / closing indicator (15) is further arranged on the housing (1). The driving device (16) synchronously drives the opening / closing indicator (15) to rotate. When the driving device (16) drives the first moving contact (24) and the first static contact seat (21) in the three switch bodies (2) to separate, the second moving contact (25) and the second static contact seat (22) to separate, and the grounding moving contact (34) to communicate with the grounding static contact seat (33), the opening / closing indicator (15) indicates the open position. When the driving device (16) drives the first moving contact (24) and the first static contact seat (21) in the three switch bodies (2) to conduct, the second moving contact (25) and the second static contact seat (22) to conduct, a circuit is formed between the first static contact seat (21) and the second static contact seat (22), the grounding moving contact (34) is separated from the grounding static contact seat (34), and the opening / closing indicator (15) indicates the closed position.

9. An expansion installation method using a double-break isolating earthing switch with position indication according to any one of claims 1-8, characterized in that: When it is necessary to expand the equipment (200) on the main bus, the double-break disconnecting earthing switch with position indication is connected in series on the bus. The driving device (16) in the double-break earthing switch with position indication (3) drives the three-phase switch body (2) to trip respectively, forming an isolating break 1 (10) and an isolating break 2 (20). An earthing switch (3) is formed between the earthing static contact base (33) and the earthing moving contact (34) in the three-phase switch body (2). The earthing switch (3) is connected to the structure between the isolating break 1 (10) and the isolating break 2 (20). The driving device (16) drives the earthing switch (3) to close, keeping the main bus energized and at the same time conducting the earthing switch (3) and the external ground wire. At this time, the docking of the expansion equipment (200) can be started and the substation is in live operation. After the docking of the expansion equipment (200) is completed, the power frequency withstand voltage test is carried out on the newly installed equipment alone. At this time, the bus or single bus can still be kept energized. The three-phase switch bodies (2) in the double-break disconnecting earthing switch with position indication (3) are all tripped to form an isolating break 1 (10) and an isolating break 2 (20), and the earthing switch (3) is grounded. When the on-site test is completed, each switch body (2) and the earthing switch (3) are adjusted to the corresponding states according to the actual working conditions of the substation.

Images