110kV GIS (Gas Insulated Switchgear) three-phase common-box bus-single-phase voltage transformer switching device

Abstract

The utility model relates to the technical field of gas insulated switchgear, and especially relates to a 110kV GIS three-phase common-box bus-single-phase voltage transformer switching device. The 110kV GIS three-phase common-box bus-single-phase voltage transformer switching device comprises a switching shell and an internal switching conductor in the switching shell, the internal switching conductor comprises a vertical section and an inclined section, the vertical section is internally provided with a stepped through hole axially penetrating through the vertical section, the stepped through hole is used for being in butt joint with a central conductor of a basin-type insulator, and the central conductor of the basin-type insulator is in butt joint with the central conductor of the basin-type insulator. The switching shell further comprises a large-diameter section shell connected with the bus connecting end and a small-diameter section shell connected with the insulating connecting end; the end part, far away from the insulating connecting end, of the vertical section is positioned in the large-diameter section shell of the switching shell; according to the 110kV GIS three-phase common-box bus-single-phase voltage transformer switching device, space switching between the single-phase voltage transformer and the three-phase common-box bus can be achieved, the positions are consistent when A, B and C phases are connected, the size is small, the occupied space is small when the switching device is installed in a GIS, and installation and use are convenient.

Description

Technical Field

[0001] This utility model relates to the technical field of gas-insulated switchgear, and in particular to a 110kV GIS three-phase common busbar to single-phase voltage transformer switching device. Background Technology

[0002] Gas-insulated metal-enclosed switchgear (GIS) is widely used in power systems due to its excellent insulation performance, high reliability, and miniaturization. The 126kV GIS is suitable for three-phase AC power systems and can interrupt and close line load current and short-circuit current. Most 126kV GIS on the market today are three-phase shared enclosure designs. A three-phase shared enclosure means that the A, B, and C phase busbars are installed in a common enclosure to save space and facilitate maintenance. In a three-phase shared enclosure design, the three phases... Phase conductors are often arranged in a triangular or straight line configuration. Currently, the triangular configuration is more commonly used and mature. When connecting a single-phase voltage transformer, it is important to ensure that it maintains an appropriate distance from other equipment in the three-phase enclosure to avoid mutual interference or influence. A single-phase voltage transformer is an electrical device that converts high voltage to low voltage proportionally. However, the inconsistent positions of the A, B, and C phases when connecting a single-phase voltage transformer result in a wide variety of gas-insulated connectors, grounding plates, conductive rods, and three-phase to single-phase welded cylinders, leading to a significant increase in production costs.

[0003] To address the aforementioned issues, Chinese utility model patent CN209640381U, with an authorization announcement date of November 15, 2019, discloses a conversion mechanism for testing three-phase common-enclosure GIS equipment. This conversion mechanism includes a housing and conductor assemblies within the housing. The conductor assemblies include three-phase conductors (A, B, and C), a central conductor, and an S-shaped connecting conductor. The axis of the central conductor passes perpendicularly through the center of the same circle containing the three-phase conductors (A, B, and C). The S-shaped connecting conductor includes a vertical portion and two extension portions extending in opposite directions from both ends of the vertical portion and perpendicular to the vertical portion. Through holes are provided on the two extension portions, and countersunk bolts are fitted into the through holes for detachable connection to the central conductor and any one of the three-phase conductors (A, B, and C). Rotating the central conductor around the housing, which in turn drives the S-shaped connecting conductor to rotate, allows for connections of different phase sequences and ensures the uniqueness of the connection position between any phase sequence and a single-phase voltage transformer.

[0004] Although the above solution can achieve connection of different phase sequences by rotating the S-shaped connecting conductor, the distance between the housing and the extension of the S-shaped connecting conductor connected to the three-phase conductor is much smaller than the distance to the extension connected to the center conductor. In addition, the setting of the through hole will cause the extension to form an annular wall edge, and the end of the wall edge is prone to charge concentration, which will lead to discharge. Since the distance between the housing and the extension of the S-shaped connecting conductor connected to the three-phase conductor is small, in order to avoid discharge, the housing needs to have a large volume to increase the distance between the housing and the extension of the S-shaped connecting conductor connected to the three-phase conductor. This results in the entire conversion mechanism being large in volume and complex in structure. Installing this conversion mechanism inside the gas-insulated closed switchgear will occupy a lot of space and is inconvenient to use. Utility Model Content

[0005] The purpose of this utility model is to provide a 110kV GIS three-phase common busbar to single-phase voltage transformer conversion device, which aims to solve the problem of large size and complex structure of the entire conversion mechanism.

[0006] To achieve the above objectives, the 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device of this utility model adopts the following technical solution:

[0007] A 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device includes a switching housing and an internal switching conductor within the switching housing. The switching housing includes a busbar connection end for connecting to the common-enclosure busbar and an insulating connection end for connecting to a basin-type insulator. One end of the internal switching conductor is used to connect to the center conductor of the basin-type insulator, and the other end is used to connect to any one of the three phases (A, B, and C) of the common-enclosure busbar. The internal switching conductor includes a vertical section and an inclined section. The vertical section has a stepped through-hole that axially penetrates the vertical section. The stepped through-hole is used to connect to the center conductor of the basin-type insulator. The switching housing also includes a large-diameter section housing connected to the busbar connection end and a small-diameter section housing connected to the insulating connection end. The end of the vertical section away from the insulating connection end is located inside the large-diameter section housing of the switching housing.

[0008] Furthermore, a boss is provided on the end face of the vertical section of the internal transition conductor near the insulated connection end, and the stepped through hole is located at the center of the boss.

[0009] Furthermore, the vertical section of the internal transition conductor is provided with three positioning holes arranged in a ring around the boss on the end face near the insulated connection end, and the included angle between two adjacent positioning holes is 120°.

[0010] Furthermore, the stepped through hole includes a large-diameter hole segment and a small-diameter hole segment, with the small-diameter hole segment located near the boss, and the positioning hole surrounding the outer side of the small-diameter hole segment.

[0011] Furthermore, the depth of the positioning hole is less than the depth of the small-diameter section of the stepped through hole.

[0012] Furthermore, the vertical segment and the inclined segment are connected by a circular arc transition.

[0013] Furthermore, the end face of the inclined section near the busbar connection end is horizontally positioned.

[0014] Furthermore, the inclined section has a threaded hole on its end face near the busbar connection end for connecting with the three-phase conductors on the common busbar.

[0015] Furthermore, the large-diameter section of the adapter housing is connected to the small-diameter section of the housing by a circular arc transition.

[0016] Beneficial Effects: This utility model's 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer transfer device is an improved invention. The transfer housing achieves a fixed connection between the transfer housing and the common-enclosure busbar and the single-phase voltage transformer through the busbar connection end and insulation connection end on the transfer housing. It connects the center conductor of the basin-type insulator to the single-phase voltage transformer, and achieves a conductive connection between the common-enclosure busbar and the single-phase voltage transformer through the connection of the internal transfer conductor within the transfer housing with the center conductor of the basin-type insulator and any one of the A, B, and C phase conductors on the common-enclosure busbar. The stepped through-hole design allows the countersunk bolts installed in the stepped through-hole to engage with the stepped surface of the stepped through-hole, thereby achieving the connection between the internal transfer conductor and the center conductor. The inclined section allows the internal transfer conductor to rotate around the straight section as the central axis when rotating with the center conductor. The circular path allows for spatial conversion between the three-phase common busbar and the single-phase voltage transformer, enabling the single-phase voltage transformer to connect with the A, B, and C phase conductors of the common busbar, with the connection positions consistent with those of the A, B, and C phase conductors. Placing the end of the vertical section furthest from the insulated connection point within the large-diameter section housing increases the breakdown distance between the annular wall edge formed by the stepped through-hole extending away from the busbar connection point on the vertical section and the transition housing. This reduces the likelihood of the concentrated charge on the annular wall edge breaking down the gas between the annular wall edge and the transition housing, enhancing insulation isolation. Simultaneously, the small-diameter section housing reduces the overall size of the device, and the device's simple structure facilitates installation and use. Attached Figure Description

[0017] Figure 1 This is a schematic cross-sectional view of the internal transfer conductor in one embodiment of the 110kV GIS three-phase common busbar-single-phase voltage transformer transfer device of this utility model.

[0018] Figure 2This is a top view of the internal connecting conductor in one embodiment of the 110kV GIS three-phase common busbar-single-phase voltage transformer switching device of this utility model.

[0019] Figure 3 This is a bottom view of the internal transfer conductor in one embodiment of the 110kV GIS three-phase common busbar to single-phase voltage transformer transfer device of this utility model.

[0020] Figure 4 This is a cross-sectional structural diagram of the transfer housing in one embodiment of the 110kV GIS three-phase common busbar-single-phase voltage transformer transfer device of this utility model.

[0021] Figure 5 This is a schematic diagram of the structure of the transfer housing in one embodiment of the 110kV GIS three-phase common busbar-single-phase voltage transformer transfer device of this utility model;

[0022] Figure 6 This is a schematic diagram of the connection structure between the center conductor and the A-phase conductor of an embodiment of the 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device of this utility model.

[0023] Figure 7 This is a top view schematic diagram of an embodiment of the 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device of this utility model, showing the structure of the center conductor and the A-phase conductor.

[0024] Figure 8 This is a schematic diagram of the connection structure between the center conductor and the B-phase conductor of an embodiment of the 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer conversion device of this utility model.

[0025] Figure 9 This is a top view schematic diagram of an embodiment of the 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device of this utility model, showing the structure of the center conductor and the B-phase conductor.

[0026] Figure 10 This is a top view schematic diagram of an embodiment of the 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device of this utility model, showing the structure of the center conductor and the C-phase conductor.

[0027] In the diagram: 1. Adapter housing; 2. Internal adapter conductor; 3. Busbar connection end; 4. Basin insulator; 5. Insulation connection end; 6. Center conductor; 7. Vertical section; 8. Inclined section; 9. Stepped through hole; 10. Countersunk bolt; 11. Large diameter section housing; 12. Small diameter section housing; 13. Annular wall edge; 14. Boss; 15. Positioning hole; 16. Threaded hole; 17. Bolt; 18. Phase A conductor; 19. Phase B conductor; 20. Phase C conductor. Detailed Implementation

[0028] The features and performance of this utility model will be further described in detail below with reference to the embodiments.

[0029] Gas-insulated metal-enclosed switchgear often adopts a three-phase common-enclosure design. The inconsistent connection positions of the three-phase conductors and single-phase voltage transformers result in a wide variety of components for the single-phase voltage transformers, leading to poor versatility. Existing technology uses an S-shaped connecting conductor between the single-phase voltage transformer and the three-phase conductors, detachably connecting both ends to the single-phase voltage transformer and the three-phase conductors. Rotating the S-shaped connecting conductor allows connection of the single-phase voltage transformer to different phase sequences. However, the two extensions of the S-shaped connecting conductor have through holes, creating annular wall edges that easily lead to charge concentration. Furthermore, the small distance between the extensions connecting the S-shaped connecting conductor and the three-phase conductors easily triggers discharge. Therefore, a large housing is required, resulting in a large volume, complex structure, and inconvenient use. To avoid these problems, the housing can be designed as a variable-diameter housing. The parts of the internal connecting conductor prone to discharge are located in the larger diameter section of the housing, while the less prone parts are located in the smaller diameter section, thus reducing the overall size of the device. Based on the above inventive concept, this utility model proposes a 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer transfer device. By setting the transfer housing as a large-diameter section housing and a small-diameter section housing connected together, the part of the internal transfer conductor that is prone to discharge is set in the large-diameter section housing to avoid discharge, and the part that is not prone to discharge is set in the small-diameter section housing to reduce the size of the device.

[0030] The implementation method of the 110kV GIS three-phase common-enclosure busbar to single-phase voltage transformer switching device of this utility model:

[0031] See Figures 1 to 5As a basic embodiment of this utility model, it includes a transition housing 1 and an internal transition conductor 2 within the transition housing 1. The transition housing 1 includes a busbar connection end 3 for connecting to the common busbar and an insulating connection end 5 for connecting to the basin-type insulator 4. The transition housing 1 enables simultaneous fixed connection to both the common busbar and a single-phase voltage transformer. One end of the internal transition conductor 2 is used to connect to the center conductor 6 of the basin-type insulator 4, and the other end is used to connect to any one of the three phases (A, B, and C) of the common busbar. The center conductor 6 of the basin-type insulator 4 is connected to... Connecting single-phase voltage transformers enables conductive connection between the common busbar and the single-phase voltage transformers. The internal transition conductor 2 includes a vertical section 7 and an inclined section 8. The vertical section 7 has a stepped through-hole 9 that axially penetrates the vertical section 7. The stepped through-hole 9 is used to mate with the center conductor 6 of the basin insulator 4. When the internal transition conductor 2 is connected to the center conductor 6 of the basin insulator 4, a countersunk bolt 10 is installed into the stepped through-hole 9. The countersunk bolt 10 engages with the stepped surface of the stepped through-hole 9 to achieve the connection between the internal transition conductor 2 and the center conductor 6. Simultaneously, when the internal transition conductor 2 rotates with the central conductor 6, the inclined section 8 can rotate around the vertical section 7 as the central axis, forming a circular path. This allows for spatial conversion between the three-phase common busbar and the single-phase voltage transformer, thereby enabling connection with the A, B, and C phase conductors of the common busbar, and ensuring that the connection positions are consistent with the A, B, and C phase conductors. The transition housing 1 also includes a large-diameter section housing 11 connected to the busbar connection end 3 and a small-diameter section housing 12 connected to the insulated connection end 5. The end of the vertical section 7 furthest from the insulated connection end 5 is located in the large-diameter section of the transition housing 1. Inside the housing 11, this arrangement increases the breakdown distance between the annular wall blade 13 formed by the stepped through hole 9 on the vertical section 7 extending away from the busbar connection end 3 and the transition housing 1, thereby reducing the possibility of the gas between the annular wall blade 13 and the transition housing 1 being broken down when the concentrated charge on the annular wall blade 13 discharges, and enhancing insulation isolation; at the same time, the arrangement of the small-diameter section housing 12 can reduce the volume of the entire device, and the structure of the device is simple. Installing the device inside the GIS can save the internal space of the GIS and facilitate installation and use.

[0032] In a preferred embodiment of this utility model, a boss 14 is provided on the end face of the vertical section 7 of the internal transition conductor 2 near the insulating connection end 5. A stepped through hole 9 is provided at the center of the boss 14. The boss 14 is provided to facilitate the connection and positioning of the vertical section 7 of the internal transition conductor 2 and the central conductor 6. The boss 14 can fit into the central hole of the central conductor 6, and the internal transition conductor 2 and the central conductor 6 can be fixed by installing countersunk bolts 10 into the stepped through hole 9, which can improve the connection stability of the internal transition conductor 2 and the central conductor 6.

[0033] As a preferred embodiment of this utility model, the vertical section 7 of the internal transition conductor 2 is provided with three positioning holes 15 arranged in a ring around the boss 14 on the end face near the insulating connection end 5. The included angle between two adjacent positioning holes 15 is 120°. The positioning holes 15 can position the internal transition conductor 2, ensuring that the position of the single-phase voltage transformer remains unchanged, and the internal transition conductor 2 can be connected to any one of the three phases A, B, and C conductors.

[0034] In a preferred embodiment of this utility model, the stepped through hole 9 includes a large-diameter hole segment and a small-diameter hole segment. The small-diameter hole segment is located close to the boss 14, and the large-diameter hole segment is located away from the boss 14. The positioning hole 15 is arranged around the outside of the small-diameter hole segment. This arrangement allows the stepped surface between the large-diameter hole segment and the small-diameter hole segment to block the countersunk bolt 10 when it is assembled in the stepped through hole 9, thereby realizing the connection and positioning of the internal transition conductor 2 and the center conductor 6, and also avoiding excessive fit between the countersunk bolt 10 and the stepped through hole 9.

[0035] In a preferred embodiment of this utility model, the vertical section 7 and the inclined section 8 are connected by a circular arc transition. This arrangement makes the surface of the internal transition conductor 2 smooth and fluid, reduces charge concentration, and thus reduces the occurrence of discharge.

[0036] In a preferred embodiment of this utility model, the depth of the positioning hole 15 is less than the depth of the small-diameter section of the stepped through hole 9. This arrangement can prevent the positioning hole 15 from interfering with the countersunk bolt 10 assembled in the stepped through hole 9, ensuring that the countersunk bolt 10 can be stably connected with the stepped through hole 9, thereby ensuring a stable connection between the vertical section 7 of the internal transition conductor 2 and the center conductor 6.

[0037] In a preferred embodiment of this utility model, the inclined section 8 is horizontally positioned at the end face near the busbar connection end 3. The horizontally positioned end face allows for better contact and fit between the internal transition conductor 2 and the three-phase conductors on the common busbar, avoiding large gaps between the internal transition conductor 2 and the three-phase conductors A, B, and C. This improves the connection reliability between the inclined section 8 of the internal transition conductor 2 and the three-phase conductors A, B, and C, and prevents poor contact from causing current transmission failure.

[0038] As a preferred embodiment of this utility model, the inclined section 8 is provided with a threaded hole 16 on the end face near the busbar connection end 3 for connecting with the three-phase conductors A, B, and C on the common busbar. By connecting the bolt 17 in the threaded hole 16, a reliable connection between the internal transfer conductor 2 and the three-phase conductors A, B, and C on the common busbar can be achieved.

[0039] In a preferred embodiment of this utility model, the large-diameter section 11 of the adapter housing 1 and the small-diameter section 12 are connected by a circular arc transition. This arrangement makes the surface of the adapter housing 1 smooth and rounded, reduces charge concentration, and thus reduces the occurrence of discharge.

[0040] See Figures 6 to 10 The usage process of the 110kV GIS three-phase common-box busbar-single-phase voltage transformer switching device of this utility model is as follows: First, align the vertical section 7 of the internal switching conductor 2 with the center conductor 6 of the basin insulator 4, so that the boss 14 fits into the center hole of the center conductor 6. Then, install the countersunk bolt 10 into the stepped through hole 9 of the vertical section 7. One end of the countersunk bolt 10 is stopped by the stepped surface of the stepped through hole 9, and the other end extends out from the small diameter hole of the stepped through hole 9 and connects to the center conductor 6. Thus, a detachable connection is formed between the vertical section 7 of the internal switching conductor 2 and the center conductor 6. Then, align the inclined section 8 of the internal switching conductor 2 with the A-phase conductor 18 of the three-phase conductors A, B, and C, and connect the bolt 17 by threading it into the threaded hole 16 of the inclined section 8. The bolt 17 connects the inclined section 8 of the internal switching conductor 2 with the A-phase conductor. Conductor 18 forms a detachable connection. At this time, a positioning pin is inserted into the positioning hole 15 to further position the internal transition conductor 2, preventing the internal transition conductor 2 from shaking or shifting during current transmission. When it is necessary to connect the single-phase voltage transformer to the B-phase conductor 19, the bolt 17 is removed to disconnect the inclined section 8 of the internal transition conductor 2 from the A-phase conductor 18. Then, the center conductor 6 is rotated. During this process, the positioning pin and the countersunk bolt 10 work together to rotate the internal transition conductor 2 until it is aligned with the B-phase conductor 19. The bolt 17 is then threaded back into the threaded hole 16, thus realizing the connection between the single-phase voltage transformer and the B-phase conductor 19. The connection with the C-phase conductor 20 is similar. This allows the internal transition conductor 2 to be connected to any one of the A, B, or C phase conductors without changing the position of the single-phase voltage transformer.

[0041] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. The patent protection scope of the present utility model shall be determined by the claims. Similarly, any equivalent structural changes made based on the description and drawings of the present utility model shall also be included within the protection scope of the present utility model.

Claims

1. A 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device, comprising a switching housing and an internal switching conductor within the switching housing, the switching housing including a busbar connection end for connecting to the common-enclosure busbar and an insulating connection end for connecting to a basin-type insulator, one end of the internal switching conductor being used to connect to the center conductor of the basin-type insulator, and the other end being used to connect to any one of the three phases A, B, and C of the common-enclosure busbar, characterized in that: The internal transition conductor includes a vertical section and an inclined section. The vertical section has a stepped through hole that axially penetrates the vertical section. The stepped through hole is used to connect with the center conductor of the basin insulator. The transition housing also includes a large-diameter section housing connected to the busbar connection end and a small-diameter section housing connected to the insulation connection end. The end of the vertical section away from the insulation connection end is located inside the large-diameter section housing of the transition housing.

2. The 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device according to claim 1, characterized in that: The vertical section of the internal transition conductor has a boss on its end face near the insulated connection end, and the stepped through hole is located at the center of the boss.

3. The 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device according to claim 2, characterized in that: The vertical section of the internal transition conductor is provided with three positioning holes arranged in a ring around the boss on the end face near the insulated connection end, and the included angle between two adjacent positioning holes is 120°.

4. The 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device according to claim 3, characterized in that: The stepped through hole includes a large-diameter hole section and a small-diameter hole section. The small-diameter hole section is located near the boss, and the positioning hole is located around the outside of the small-diameter hole section.

5. The 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device according to claim 4, characterized in that: The depth of the positioning hole is less than the depth of the small-diameter section of the stepped through hole.

6. The 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device according to claim 1, characterized in that: The vertical section and the inclined section are connected by a circular arc transition.

7. The 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device according to claim 6, characterized in that: The inclined section is horizontally positioned at the end face near the busbar connection end.

8. The 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device according to claim 7, characterized in that: The inclined section has a threaded hole on its end face near the busbar connection end for connecting to the three-phase conductors on the common busbar.

9. The 110kV GIS three-phase common-enclosure busbar-single-phase voltage transformer switching device according to claim 1, characterized in that: The large-diameter section of the adapter shell and the small-diameter section of the adapter shell are connected by an arc transition.

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