Three-phase common-box end bus device for reserved interval

Abstract

The invention provides a three-phase common-box end bus device for a reserved interval, which comprises a basin-type insulator, a conductor, a shielding ball, a common-box shell, a combination valve and an adsorbent explosion-proof device, and is characterized in that the conductor is fixed below the basin-type insulator, the shielding ball is fixed below the conductor through a bolt, the common-box shell is connected with the basin-type insulator through a bolt, and the combination valve is connected with the adsorbent explosion-proof device through a bolt. An inflation inlet is formed in one side of the common box shell, an adsorbent explosion-proof mounting hole is formed in the other side of the common box shell, the inflation inlet is connected with a combination valve, and an adsorbent explosion-proof device is fixed through the adsorbent explosion-proof mounting hole; the three-phase common box end bus device and the disconnecting switch connected with the upper portion of the three-phase common box end bus device share a basin-type insulator, a bus end air chamber and a disconnecting switch air chamber are separated through the basin-type insulator, and the surface of the conductor and the surface of the shielding ball are in a double-curvature gradual change shape. The three-phase common box end bus device for the reserved interval is reasonable in structure, convenient to install, uniform in electric field distribution, low in cost and short in extension power failure time.

Description

Technical Field

[0001] The invention belongs to the technical field of high-voltage gas-insulated switchgear, and particularly relates to a three-phase coaxial end bus device for a reserved bay. Background Art

[0002] In the power industry, gas-insulated switchgear (GIS) has a high market share due to its high degree of integration, space saving, stable operation performance, strong environmental adaptability, long service life and many other advantages. With the increase in power consumption, the number of large-scale power stations has gradually increased in the power grid planning. These power stations have a large number of bays, strong power transmission and transformation capabilities, but the budget for the entire project has also increased accordingly. According to the power system planning, there are situations where some lines do not need to supply power in the current period. To reduce the safety risks brought by the long-term non-operation of the bays and reduce the budget for the first phase of the project, when designing a substation, the non-powered bays can be designed as reserved bays, that is, only the main bus, disconnector, and isolating earthing switch of this bay are installed in the first phase, and the remaining parts (circuit breaker, current transformer, line-side disconnector, terminal components, etc.) will be installed during the subsequent expansion when there is a power supply demand for the bay.

[0003] When conducting the overall design of GIS, considering that the equipment in the first phase has been operating in the power grid system for a period of time during the expansion, and trying to minimize the impact on the previous equipment and power supply, generally, an end bus will be set at the expansion location of the first-phase equipment (below the disconnector) and communicated with the disconnector gas chamber. Since the bus of 252 kV GIS equipment is divided into three-phase separate boxes, and the phases need to be connected by bolts, and the bottom of the three-phase end bus housing is supported by brackets. The traditional end bus design has the following problems: on the one hand, the metal housing is manufactured in a split manner and needs to be fastened by multiple flanges and bolts (usually 30 - 40 bolts), and precise alignment is required during the installation process, which takes up to 8 - 10 hours; on the other hand, electric field distortion is likely to occur at the right-angle bend of the bus, and the maximum electric field strength of the traditional right-angle elbow can reach 12 - 15 kV / mm (the IEC 62271-203 standard limit is 10 kV / mm), resulting in excessive partial discharge.

[0004] During the expansion, the reserved intervals are used as ventilated basins at the interface. The later expansion and deflation will have a large impact range, resulting in a long power outage. In addition, during the second phase of equipment expansion, since the end busbar and the disconnector share a gas chamber, the insulating gas filled in the first phase of these two components needs to be recovered before opening. In order to ensure that the gas chambers adjacent to the open gas chamber will not damage the equipment components or burst due to the large pressure difference, the adjacent gas chambers need to be deflated and half-pressure reduced. After the GIS interval expansion is completed, all the above-mentioned gas chambers that have changed the gas pressure need to be vacuumed and inflated to normal operating conditions. Due to the large range of the affected gas chambers, each time the gas is recovered, vacuumed, and inflated, it takes a long time, which prolongs the entire construction schedule. At the same time, the adjacent half-pressure gas chambers cannot be powered normally, increasing the impact of the expansion construction. Moreover, in order to meet the insulation distance, the busbar shell design is redundant, which increases the volume of the equipment. Summary of the invention

[0005] In view of this, the present invention aims to propose a three-phase common box end busbar device for reserved intervals, so as to solve the problems that the end busbar involves complex structure and low installation efficiency, easy concentration of electric field, limited expansion process, and large shell space occupied by the busbar.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] The present invention provides a three-phase common box end busbar device for reserved intervals, comprising a pot-type insulator, a conductor, a shielding ball, a common box shell, a combination valve, and an adsorbent explosion-proof device. The conductor is fixed under the pot-type insulator, the shielding ball is fixed under the conductor by bolts, the common box shell and the pot-type insulator are connected by bolts, an air filling port is arranged on one side of the common box shell and an adsorbent explosion-proof mounting hole is arranged on the other side, the air filling port is connected to the combination valve, and the adsorbent explosion-proof mounting hole fixes the adsorbent explosion-proof device; the three-phase common box end busbar device and the disconnector connected to the upper part share the pot-type insulator, the pot-type insulator separates the busbar end air chamber from the disconnector air chamber, and the conductor surface and the shielding ball surface are both hyperbolic gradient.

[0008] Furthermore, the common box shell is a welded shell, the lower part of which is in the shape of a pipe, with a branch port on the top, and an inflation port and an adsorbent explosion-proof mounting hole on the left and right sides respectively. There are three branch ports and the top of any branch port is connected to the basin-type insulator. The common box shell is made of aluminum alloy and the shell surface paint film thickness is more than 120μm.

[0009] Furthermore, the lower diameter of the box shell is 640 mm and the wall thickness is 8 mm.

[0010] Furthermore, the pot-type insulator is a non-ventilated pot, and the pot-type insulator is a convex type, with the convex surface facing upward during installation.

[0011] Furthermore, the pot-type insulator includes a metal flange ring, a resin casting, a metal insert, a shielding ring, and a first cover plate. The metal insert, the shielding ring, and the metal flange ring are integrally cast in the resin casting. The resin casting is cast in the metal flange ring. The metal insert is fixedly cast at the center of the resin casting. The open-ring-shaped shielding ring is fixed in the metal flange ring and then cast. The first cover plate seals the casting port of the resin casting. A metal flange sealing groove is provided on the surface of the metal flange, and an epoxy resin casting sealing groove is provided on the surface of the resin casting, and the two sealing grooves form a double-sealing structure.

[0012] Furthermore, the resin casting includes an epoxy resin matrix and nano-aluminum oxide particles dispersed in the epoxy resin matrix, and the filling ratio of the nano-aluminum oxide particles is 15%.

[0013] Furthermore, the adsorbent explosion-proof device includes an adsorbent cover, a flange, an explosion-proof device, an explosion-proof film guide cover, an intermediate flange, and a second cover plate. The adsorbent is arranged in the adsorbent cover. The flange is fixed by bolts to fix the adsorbent explosion-proof device to the common box housing. The adsorbent cover is fixed on one side of the flange and installed inside the common box housing. The explosion-proof device is installed on the other side of the flange. The explosion-proof film is arranged inside the explosion-proof device. The explosion-proof device is fixed on the flange by the intermediate flange. The explosion-proof film guide cover is connected to the intermediate flange. The end of the explosion-proof film guide cover is provided with a second cover plate, and the opening direction of the second cover plate is vertically downward. A gasket is provided between the adsorbent cover and the flange to form a gap. The gap between the adsorbent cover and the flange, the through hole in the middle of the flange, and the explosion-proof film guide cover form a bent diversion channel.

[0014] Furthermore, the explosion-proof film is an arched explosion-proof film, and the concave surface of the explosion-proof film faces the inside of the common box housing, and the convex surface of the explosion-proof film faces the direction of the explosion-proof film guide cover.

[0015] Furthermore, the shielding ball is sprayed with a silver conductive coating on its surface.

[0016] Compared with the prior art, the three-phase common box end bus device for reserved intervals of the present invention has the following advantages:

[0017] (1) In the present invention, the common box housing can effectively reduce the butt flange surfaces, thereby reducing the potential air leakage risk. At the same time, for the three-phase separate box housings, due to the need for centering with the basin above and centering on both the left and right sides, extremely high requirements for the tolerance grade are needed in processing and manufacturing to avoid poor centering during installation. After changing to the common box housing, such a situation will not occur. The installation efficiency is significantly improved: the installation time of the single-bay bus is shortened, the labor cost is reduced, the number of bolts is reduced, and the qualified rate of torque consistency is increased. The insulation distance of the common box housing is optimized, and the minimum insulation distance under the same voltage level is reduced through electric field simulation. The topology optimization technology is used to carry out lightweight design of the housing. While the overall weight is reduced, the water pressure can fully meet the requirements, and the cost is effectively saved on the premise of meeting the insulation distance. The material of the common box housing is aluminum alloy, and the thickness of the housing paint film reaches more than 120μm to homogenize the electric field distribution.

[0018] (2) In the present invention, sealing grooves are provided on the metal flange surface and the epoxy resin surface, which can effectively prevent air leakage and prevent rainwater from entering. The pot-type insulator is of a middle convex type, and the installation direction is with the convex surface facing upwards, which can effectively avoid the accumulation of tiny particles generated during operation at the root of the pot, causing tip discharge. A plastic first cover plate is set at the casting port, and the partial discharge detection can be carried out without opening the first cover plate.

[0019] (3) In the present invention, the conductor adopts a double-curvature gradual change design, and the bending angle is optimized through finite element simulation to reduce the maximum electric field strength.

[0020] (4) In the present invention, the adsorbent can effectively reduce the moisture content in the gas chamber at the end of the bus. When the pressure in the gas chamber at the end of the bus is too high due to abnormal conditions, the explosion-proof device can release the pressure to avoid the explosion of the common box housing and protect personal safety. An explosion-proof film deflector is installed above the explosion-proof device, and the gas can be ejected along the diversion channel to avoid harm to personnel. The shielding ball is subjected to silver plating treatment on the surface to reduce the contact resistance and avoid local heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0022] In the drawings:

[0023] Figure 1 is a schematic structural diagram of the three-phase common box end bus device for reserved intervals described in the embodiment of the present invention;

[0024] Figure 2 is a schematic structural diagram of the pot-type insulator in the three-phase common box end bus device for reserved intervals described in the embodiment of the present invention;

[0025] Figure 3 Schematic cross-sectional view of a pot insulator in the three-phase common-box end busbar device for reserved intervals according to an embodiment of the present invention;

[0026] Figure 4 Schematic connection diagram of a shielding ring in the three-phase common-box end busbar device for reserved intervals according to an embodiment of the present invention;

[0027] Figure 5 Schematic diagram of a conductor structure in the three-phase common-box end busbar device for reserved intervals according to an embodiment of the present invention;

[0028] Figure 6 Schematic front view of a conductor in the three-phase common-box end busbar device for reserved intervals according to an embodiment of the present invention;

[0029] Figure 7 Enlarged schematic view at I-I in the front view of the conductor in the three-phase common-box end busbar device for reserved intervals according to an embodiment of the present invention;

[0030] Figure 8 Schematic diagram of a shielding ball structure in the three-phase common-box end busbar device for reserved intervals according to an embodiment of the present invention;

[0031] Figure 9 Schematic cross-sectional view of a shielding ball in the three-phase common-box end busbar device for reserved intervals according to an embodiment of the present invention;

[0032] Figure 10 Schematic diagram of a common-box housing structure in the three-phase common-box end busbar device for reserved intervals according to an embodiment of the present invention;

[0033] Figure 11 Schematic semi-cross-sectional view of an adsorbent explosion-proof device structure in the three-phase common-box end busbar device for reserved intervals according to an embodiment of the present invention;

[0034] Figure 12 Schematic diagram of the installation position of the three-phase common-box end busbar device for reserved intervals according to an embodiment of the present invention.

[0035] Explanation of reference numerals:

[0036] 1. Pot type insulator; 2. Conductor; 3. Shielding ball; 4. Common box housing; 5. Combination valve; 6. Adsorbent explosion-proof device; 7. Adsorbent explosion-proof installation hole; 8. Inflation port; 9. Branch port; 10. Busbar end gas chamber; 11. Metal flange ring; 12. Resin casting; 13. Metal insert; 14. Shielding ring; 15. First cover plate; 16. Disconnector gas chamber; 17. Isolated earthing switch gas chamber; 18. Three-phase common box end busbar device; 19. Epoxy resin casting seal groove; 20. Metal flange seal groove; 21. Conductor double curvature design location; 31. Shielding ball top double curvature design location; 32. Shielding ball side double curvature design location; 61. Adsorbent cover; 62. Flange; 63. Explosion-proof film; 64. Explosion-proof film flow guide cover; 65. Washer; 66. Intermediate flange; 67. Second cover plate. Detailed implementation manners

[0037] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0038] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0040] The present invention will be described in detail below with reference to the drawings and in combination with embodiments.

[0041] Refer to Figures 1 - 12 As shown, the actual installation position is as Figure 12As shown, Figure 12 The busbar device 18 at the end of the three-phase common box is the actual overall solution involved. The busbar end air chamber 10, the disconnector air chamber 16, and the disconnector grounding switch air chamber 17 are all independent air chambers that are individually inflated, and the connected positions are all connected with pot-type insulators without pots.

[0042] The present embodiment provides a three-phase common box end busbar device for reserving intervals, comprising a pot-type insulator 1, a conductor 2, a shielding ball 3, a common box shell 4, a combination valve 5, and an adsorbent explosion-proof device 6. The conductor 2 is fixed under the pot-type insulator 1, the shielding ball 3 is fixed under the conductor 2 by bolts, the common box shell 4 is connected to the pot-type insulator 1 by bolts, an air filling port 8 is provided on one side of the common box shell 4 and an adsorbent explosion-proof mounting hole 7 is provided on the other side, the air filling port 8 is connected to the combination valve 5, and the adsorbent explosion-proof mounting hole 7 fixes the adsorbent explosion-proof device 6; the three-phase common box end busbar device shares the pot-type insulator 1 with the disconnector connected to its upper part, the pot-type insulator 1 separates the busbar end air chamber from the disconnector air chamber, and the surfaces of the conductor 2 and the shielding ball 3 are both hyperbolic gradient shapes.

[0043] See also Figures 5 - 9 As shown, the conductor adopts a hyperbolic gradient design, and the bending angle is optimized through finite element simulation (ANSYS Maxwell software), so that the maximum field strength is reduced from 12kV / mm to 8.4kV / mm (a decrease of 30%). In the embodiment, conductor 2 adopts a hyperbolic curvature, that is, an arc curve composed of two radii. This part of the curve has a great influence on the electric field between the conductor and the basin. According to the electric field results, continuous optimization is performed, and finally a set of values with the best effect, namely R25 and R17, are obtained. The hyperbolic curvature of conductor 2 is set at the bend where conductor 2 connects to shielding ball 3 (i.e. Figure 7 The conductor double curvature design is at 21, and the bend is actually designed to be a variable diameter bend from R25 to R17. The R17 bend is close to the lower part where the conductor 2 is connected to the shielding ball 3. The shielding ball 3 is also designed with a gradual curvature change. The horizontal end face at the bottom and the side face change from R93 to R63 (i.e. Figure 9 The shielding ball side double curvature design point 32), the shielding ball 3 top is designed to change the curvature from R9.5 to R1.5 (i.e. Figure 9 The double curvature design of the top of the shielding ball points to 31).

[0044] Specifically, in this embodiment, refer to Figure 10 As shown, the common box shell 4 is a welded shell, the lower part of which is in the shape of a pipe, with a branch port 9 on the top, and an inflation port 8 and an adsorbent explosion-proof mounting hole 7 on the left and right sides respectively. There are three branch ports 9 and the top of any branch port is connected to the basin insulator 1. The common box shell is made of aluminum alloy and the shell surface paint film thickness is more than 120μm.

[0045] The common box housing can effectively reduce the docking flange surfaces, thereby reducing the potential air leakage risk. At the same time, for the three-phase split box housing, due to the need for centering with the basin above and centering on both the left and right sides, extremely high requirements for the tolerance level are needed in processing and manufacturing to avoid poor centering during installation. After changing to the common box housing, such a situation will not occur. The installation efficiency is significantly improved: the installation time of a single-section bus is shortened from 5 hours to 2.5 hours, the labor cost is reduced by 40%; the number of bolts is reduced by 60%, and the qualified rate of torque consistency is increased from 75% to 98%.

[0046] Specifically, in this embodiment, the lower diameter of the common box housing 4 is 640 mm, and the overall wall thickness is 8 mm. The insulation distance of the common box housing is optimized, and the minimum insulation distance under the same voltage level is reduced through electric field simulation, so that the housing diameter can be reduced from 800 mm to 640 mm. The topology optimization technology (Altair OptiStruct software) is used to carry out lightweight design for the housing, the wall thickness is reduced from 12 mm to 8 mm, the overall weight is reduced by 25%, and at the same time, the water pressure can fully meet the requirements. Cost is effectively saved on the premise of meeting the insulation distance. The material of the common box housing is aluminum alloy, and the thickness of the housing paint film reaches more than 120 μm to homogenize the electric field distribution.

[0047] Specifically, in this embodiment, refer to Figures 2 - 4 As shown, the pot-type insulator 1 is an airtight pot, and the pot-type insulator 1 is a convex type, with the convex surface facing upwards during installation. The pot-type insulator 1 divides the bus end chamber and the disconnector chamber into two independent chambers. In this way, during later expansion, only the end bus chamber needs to be opened, and the disconnector chamber can be used as a transition chamber, only half of the voltage needs to be reduced, the range of the half-voltage reduction chamber is reduced, the time for vacuum pumping and gas filling is reduced, and the power outage time is shortened.

[0048] Specifically, in this embodiment, the pot-type insulator 1 includes a metal flange ring 11, a resin casting 12, a metal insert 13, a shielding ring 14, and a first cover plate 15. The metal insert 13, the shielding ring 14, and the metal flange ring 11 are integrally cast in the resin casting 12. The resin casting 12 is cast in the metal flange ring 11. The metal insert 13 is cast and fixed at the center of the resin casting 12. The open-ring-shaped shielding ring 14 is fixed in the metal flange ring 11 and then cast. The first cover plate 15 seals the casting port of the resin casting 12. A metal flange sealing groove 20 is provided on the metal flange surface, and an epoxy resin casting sealing groove 19 is provided on the surface of the resin casting 12, and the two sealing grooves form a double-sealing structure.

[0049] Before the epoxy resin is poured, the shielding ring 14 is fixed to the metal flange ring 11, and the metal insert 13 is fixed by the pot insulator mold. After the pouring is completed, the shielding ring 14 and the metal insert 13 are embedded inside the resin casting 12. Finally, one pouring port on the metal flange ring 11 is blocked by the first cover plate 15.

[0050] Sealing grooves are provided on the metal flange surface and the epoxy resin surface, which can effectively prevent air leakage and rainwater intrusion. The pot insulator is of a middle convex type, and the installation direction is with the convex surface facing upwards, which can effectively avoid the accumulation of tiny particles generated during operation at the root of the pot, causing tip discharge. A first cover plate is set at the pouring port, and the material of the first cover plate is plastic, so that the partial discharge detection can be carried out without opening the first cover plate. The partial discharge detection of GIS detects the electromagnetic waves generated by discharge inside the detection equipment. If the metal flange ring outside the pot is in the form of a completely closed metal ring, the ultra-high frequency partial discharge electromagnetic waves cannot be conducted out. Therefore, the cover plate of the pot pouring port is made of plastic to achieve the partial discharge detection without opening the cover plate.

[0051] Specifically, in this embodiment, the resin casting 12 includes an epoxy resin matrix and nano-aluminum oxide particles dispersed in the epoxy resin matrix, and the filling ratio of the nano-aluminum oxide particles is 15%. The resin casting is formed by a vacuum casting process, which improves the dielectric strength and reduces the thermal expansion coefficient while making it better match with the metal insert. Its surface flashover voltage is increased from 180 kV of the traditional epoxy resin to 207 kV (a 15% increase).

[0052] Specifically, in this embodiment, refer to Figure 11 As shown, the adsorbent explosion-proof device 6 includes an adsorbent cover 61, a flange 62, an explosion-proof device, an explosion-proof film guide cover 64, an intermediate flange 66, and a second cover plate 67. The adsorbent is arranged inside the adsorbent cover 61. The flange 62 is fixed to the common box housing 4 by bolts to fix the adsorbent explosion-proof device 6. The adsorbent cover 61 is fixed on one side of the flange 62 and installed inside the common box housing 4. An explosion-proof device is installed on the other side of the flange 62. The explosion-proof film 63 is arranged inside the explosion-proof device. The explosion-proof device is fixed to the flange 62 by the intermediate flange 66. The explosion-proof film guide cover 64 is connected to the intermediate flange 66. The second cover plate 67 is arranged at the end of the explosion-proof film guide cover 64, and the opening direction of the second cover plate 67 is vertically downward. A gasket 65 is arranged between the adsorbent cover 61 and the flange 62 to form a gap. The gap between the adsorbent cover 61 and the flange 62, the through hole in the middle of the flange 62, and the explosion-proof film guide cover 64 form a bent diversion channel. The explosion-proof device is fixed to the flange 62 by the intermediate flange 66, and an additional explosion-proof film guide cover 64 is provided, and the second cover plate 67 is arranged at the end to guide the outlet direction of the blasting air flow so that it cannot directly face the inspection passage to avoid harm to personnel from the gap (formed by raising the gasket 65) between the adsorbent cover 61 and the flange 62.

[0053] Specifically, in this embodiment, the explosion-proof disc 63 is an inverse arch explosion-proof disc, and the concave surface of the explosion-proof disc 63 faces the inside of the coaxial housing 4, while the convex surface of the explosion-proof disc 63 faces the direction of the explosion-proof disc flow guide cover 64. Explosion-proof principle: The main explosion-proof device refers to the explosion-proof disc 63. Since GIS belongs to a pressure vessel, the pressure inside the equipment needs to be maintained within a certain range. When the pressure is too high and exceeds the pressure-bearing value of the explosion-proof disc, the explosion-proof disc will be triggered to reduce the internal pressure and ensure personal safety. Explosion-proof structure: The explosion-proof disc is composed of an upper clamp, an explosion-proof disc, and a lower clamp, and belongs to an inverse arch explosion-proof disc. The explosion-proof disc 63 is purchased from Dalian University of Technology Safety System Co., Ltd., and the model used is YCH.

[0054] The adsorbent can effectively reduce the moisture content in the gas chamber at the end of the busbar, avoiding the influence of excessive moisture in the gas on the gas insulation performance. When the pressure in the gas chamber at the end of the busbar is too high due to abnormal conditions, the explosion-proof device can release the pressure to avoid the explosion of the coaxial housing and protect personal safety. The adsorbent is installed in the adsorbent cover and fixed inside the coaxial housing below the flange. Above the flange is the explosion-proof device. The core component of the explosion-proof device is the explosion-proof disc 63. The structure of the explosion-proof device is a clamping type. An explosion-proof disc flow guide cover is installed above the explosion-proof device, and the gas can be ejected along the flow guide channel to avoid harm to personnel.

[0055] Specifically, in this embodiment, the surface of the shielding ball 3 is sprayed with a silver conductive coating. The surface of the shielding ball is silver-plated (so that the sheet resistance of the shielding ball is less than 0.1 Ω / sq) to reduce the contact resistance and avoid local heating. The above-mentioned three-phase coaxial end busbar device has a reasonable structure, is easy to install, has a uniform electric field distribution, low cost, and short power outage time for expansion.

[0056] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A three-phase common box end busbar device for reserving a gap, characterized in that, It includes a basin insulator, a conductor, a shielding ball, a common box shell, a combination valve, and an adsorbent explosion-proof device. The conductor is fixed under the basin insulator, the shielding ball is fixed under the conductor by bolts, the common box shell and the basin insulator are connected by bolts, an air filling port is provided on one side of the common box shell and an adsorbent explosion-proof mounting hole is provided on the other side, the air filling port is connected to the combination valve, and the adsorbent explosion-proof mounting hole fixes the adsorbent explosion-proof device; the three-phase common box end busbar device and the disconnector connected to its upper part share the basin insulator, the basin insulator separates the busbar end air chamber from the disconnector air chamber, and the conductor surface and the shielding ball surface are both hyperbolic gradient.

2. The three-phase common box end busbar device for reserving intervals according to claim 1, wherein, The common box shell is a welded shell, the lower part of which is in the shape of a pipe, with a branch port on the top, and an inflation port and an adsorbent explosion-proof installation hole on the left and right sides respectively. There are three branch ports and the top of any branch port is connected to the basin-type insulator. The common box shell is made of aluminum alloy and the shell paint film thickness is more than 120μm.

3. The three-phase common box end busbar device for reserving intervals according to claim 2, wherein The lower diameter of the box shell is 640mm and the overall wall thickness is 8mm.

4. The three-phase common-box end busbar device for reserving intervals according to claim 1, wherein, The pot-type insulator is a non-ventilated pot, and the pot-type insulator is a convex type, and the convex surface faces upward when installed.

5. The three-phase common box end busbar device for reserving intervals according to claim 4, characterized in that, The pot-type insulator includes a metal flange ring, a resin casting, a metal insert, a shielding ring, and a first cover plate. The metal insert, the shielding ring, and the metal flange ring are integrally cast in the resin casting. The resin casting is cast in the metal flange ring. The metal insert is cast and fixed at the center of the resin casting. The open ring-shaped shielding ring is fixed in the metal flange ring and then cast. The first cover plate blocks the casting port of the resin casting. A metal flange sealing groove is provided on the surface of the metal flange. A sealing groove for an epoxy resin casting is provided on the surface of the resin casting, and the two sealing grooves form a double sealing structure.

6. The three-phase common-box end busbar device for reserving a space according to claim 5, wherein, The resin casting comprises an epoxy resin matrix and nano-aluminum oxide particles dispersed in the epoxy resin matrix, wherein the filling ratio of the nano-aluminum oxide particles is 15%.

7. The three-phase common-box end busbar device for reserving intervals according to claim 1, wherein The adsorbent explosion-proof device includes an adsorbent cover, a flange, an explosion-proof device, an explosion-proof disk flow guide cover, an intermediate flange, and a second cover plate. The adsorbent is arranged in the adsorbent cover, and the flange is fixed to the adsorbent explosion-proof device and the common box shell by bolts. The adsorbent cover is fixed to one side of the flange and installed inside the common box shell, and the explosion-proof device is installed on the other side of the flange. The explosion-proof disk is arranged inside the explosion-proof device. The explosion-proof device is fixed to the flange by the intermediate flange, and the explosion-proof disk flow guide cover is connected to the intermediate flange. A second cover plate is arranged at the end of the explosion-proof disk flow guide cover, and the opening direction of the second cover plate is vertically downward. A gasket is arranged between the adsorbent cover and the flange to form a gap, and the gap between the adsorbent cover and the flange, the through hole in the middle of the flange, and the explosion-proof disk flow guide cover form a bent diversion channel.

8. The three-phase common box end busbar device for reserving intervals according to claim 7, characterized in that, The explosion-proof disc is a reverse-arch type bursting disc, and the concave surface of the explosion-proof disc faces the interior of the common box shell, and the convex surface of the explosion-proof disc faces the direction of the explosion-proof disc flow guide cover.

9. The three-phase common box end busbar device for reserving intervals according to claim 1, characterized in that, The surface of the shielding ball is sprayed with silver conductive coating.

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