A three-phase common enclosure type GIL / GIS busbar

Abstract

The present invention discloses a three-phase coaxial GIL / GIS busbar, which includes a cylinder body, and three-phase current-carrying tubular busbars and support insulators arranged inside the cylinder body. Support insulators are installed on each of the three-phase current-carrying tubular busbars. The support insulator includes a conductor wrapping area sleeved outside the current-carrying tubular busbar and two legs respectively connected to both sides of the conductor wrapping area. Metal inserts are provided at the ends of the legs, and a shielding structure is connected to the metal inserts; the metal inserts at the ends of the two legs are connected to the inner wall of the cylinder body, and the projections of the support insulators installed on the three-phase current-carrying tubular busbars on the cross-section of the cylinder body are mutually at an angle of 40°-80°. In the present invention, the support insulators of the three-phase busbars are relatively independent, the insulating gas-solid interface between the busbars is cancelled, and the surface insulation between the phases is changed into gap insulation, providing a way to further reduce the volume and improve the safety margin between the phases.

Description

Technical Field

[0001] The present invention relates to the technical field of the design, production and manufacturing of power equipment, and particularly relates to a three-phase coaxial GIL / GIS busbar. Background Art

[0002] With the growth of the demand for power transmission in compact environments such as urban underground utility tunnels, nuclear power plants and hydropower stations, GIS / GIL is gradually moving towards the goal of miniaturized design. The three-phase coaxial GIS / GIL encloses the three-phase pipe busbars in the same metal pipe, which can effectively reduce the volume of the equipment, has low losses, large transmission capacity, and at the same time greatly improves the natural power of the electric energy transmission of GIS / GIL and saves the production and manufacturing costs. There are various complex factors in GIS / GIL, such as electricity, heat, force, surface defects, suspended particles, SF6 decomposition products, temperature changes, etc. The insulation structure is typical and the material properties are complex, and there are many factors that may cause discharge. When GIS / GIL develops into a three-phase box, in addition to considering the problems between the phase and the ground, the insulation margin between the phases also needs to be further considered. At the same time, with the development of environmentally friendly insulating gases, the insulating strength of the new insulating gas is lower than that of SF6 under the same conditions, which also requires compensating for the margin under compact conditions through the design of the insulation structure to achieve the safe and stable operation of GIS / GIL. Therefore, there is an urgent need to invent an insulating support structure suitable for environmentally friendly three-phase coaxial GIS / GIL to meet the engineering application requirements. Since it is necessary to put the three-phase pipe busbars into the same cylinder to achieve the compactness of GIS / GIL, the installation space of the insulating support will inevitably be further reduced. In an existing three-phase three-pillar insulator for a three-phase coaxial compact GIS / GIL (Publication No.: CN 111370188A), internal stress is easily generated inside the insulator due to temperature influence and surface flashover occurs on the abdomen of the insulator. The above defects pose certain safety risks during the use of the three-phase three-pillar insulator. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, the object of the present invention is to provide a three-phase coaxial GIL / GIS busbar, which can reduce the risks of generating internal stress and surface flashover.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A three-phase coaxial GIL / GIS busbar, comprising a cylinder body and three-phase current-carrying tubular busbars and support insulators arranged inside the cylinder body. Support insulators are installed on each of the three-phase current-carrying tubular busbars. Each support insulator includes a conductor wrapping area sleeved outside the current-carrying tubular busbar and two legs respectively connected to both sides of the conductor wrapping area. Metal inserts are provided at the ends of the legs, and a shielding structure is connected to the metal inserts; the metal inserts at the ends of the two legs are connected to the inner wall of the cylinder body, and the projections of the support insulators installed on the three-phase current-carrying tubular busbars on the cross-section of the cylinder body are mutually at an angle of 40° - 80°.

[0006] Preferably, the angle between the two legs of each support insulator is 120° - 180°, and this angle is the angle towards the cylinder body direction. A saddle-shaped shielding ring is connected to the metal insert.

[0007] Preferably, the leg and the conductor wrapping area are smoothly connected through a first arc segment. The shape of the conductor wrapping area is a drum-shaped covering shape. A central hole for the current-carrying tubular busbar to pass through is opened at the center of the drum surface of the conductor wrapping area. The diameter of the central hole is smaller than the diameter of the drum surface, and the side surface of the conductor wrapping area adopts a smooth arc segment.

[0008] Preferably, the metal insert at the end of the leg is fixedly connected to the inner wall of the cylinder body;

[0009] Or, a roller is connected to the metal insert at the end of the leg, and the roller contacts the inner wall of the cylinder body.

[0010] Preferably, the support insulators installed on each of the three-phase current-carrying tubular busbars are spaced apart by a preset distance along the length direction of the current-carrying tubular busbar, and the metal inserts at the ends of the two legs of the support insulator are fixedly connected to the inner wall of the cylinder body.

[0011] Preferably, the support insulators installed on the three-phase current-carrying tubular busbars are located in the same plane. The metal inserts at the ends of the adjacent legs of adjacent two support insulators are connected to the same mounting base, and the mounting base is fixedly connected to the inner wall of the cylinder body, or rollers are installed on the mounting base, and the rollers contact the inner wall of the cylinder body.

[0012] Preferably, the mounting base includes a shielding cover. Connecting columns are provided on the side of the shielding cover facing the cylinder body. The connecting columns are welded to the inner wall of the cylinder body through pads, or rollers are installed on the connecting columns, and the rollers contact the inner wall of the cylinder body;

[0013] The connection between the side of the shielding cover facing the leg and the metal insert at the end of the leg is a fixed connection or a relatively movable connection. When it is a relatively movable connection, a roller is provided on the metal insert at the end of the leg, and the rolling direction of the roller is along the axial direction of the current-carrying tubular busbar. A keyway for the roller to be embedded is opened on the shielding cover.

[0014] Preferably, when the side of the shielding cover facing the support leg is connected to the end of the support leg in a relatively movable manner, a cavity communicating with the keyway is provided inside the shielding cover;

[0015] The shielding cover is also provided with a plurality of long holes for capturing metal chips at the keyway and around the shielding cover, and all the long holes communicate with the cavity.

[0016] Preferably, the structure of the shielding cover is a rectangular structure bent into a smooth arc shape, the concave surface of the shielding cover faces the inner wall of the cylinder body, and each corner part of the shielding cover adopts a smooth arc transition.

[0017] Preferably, the shape of the mounting base is Y-shaped, the metal inserts at the ends of the adjacent support legs on the adjacent two support insulators are fixedly connected to the ends of the two branches of the mounting base, and the end of the other branch of the mounting base is fixedly connected to the inner wall of the cylinder body.

[0018] The present invention has the following beneficial effects:

[0019] In the three-phase coaxial GIL / GIS busbar of the present invention, at each position where the current-carrying busbar is supported, three independent support insulators are adopted, and each phase of the current-carrying tube bus is provided with a support insulator. Therefore, there are gaps between the three independent support insulators, which are gap insulations, reducing the risk of surface flashover. At the same time, there are gaps between the three independent support insulators and there is no insulator material connected to each other. Therefore, the problem that the three independent support insulators generate internal stress due to the interaction between them caused by temperature change is reduced. To sum up, the three-phase coaxial GIL / GIS busbar of the present invention can reduce the risk of generating internal stress and surface flashover.

[0020] Further, the shape of the conductor wrapping area is a drum-shaped wrapping shape, and a central hole for the current-carrying tube bus to pass through is provided at the center of the drum surface of the conductor wrapping area. The diameter of the central hole is smaller than the diameter of the drum surface. Therefore, when relative deformation occurs between the current-carrying tube bus and the conductor wrapping area, it can prevent plastic deformation from occurring at the edge of the conductor wrapping area (i.e., the edge of the drum shape and the central hole), which affects the electric field distribution. If the conductor wrapping area smoothly transitions to the current-carrying tube bus, it will cause the edge thickness of the conductor wrapping area to be thinner and the strength to be lower, and irreversible plastic deformation is likely to occur, affecting the electric field distribution.

[0021] Further, since metal chips are generated when the roller at the end of the support leg rolls in the keyway of the shielding cover or when the mounting base rolls in the cylinder wall. Therefore, the present invention is provided with a shielding cover, a cavity communicating with the keyway is provided inside the shielding cover, and a plurality of long holes communicating with the cavity are also provided on the shielding cover. The cavity can collect the metal chips generated by sliding friction at the keyway and capture the metal chips around the shielding cover. The cavity captures and shields the metal chips to prevent them from moving to the surface of the insulator under the action of the electric field. Brief Description of the Drawings

[0022] To more clearly illustrate the technical routes and solutions of the embodiments of the present invention, the drawings required in the embodiments are briefly introduced below. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on the following description of the drawings without creative efforts.

[0023] Figure 1 Isometric view of the split insulation support and configuration scheme for the three-phase coaxial GIL / GIS bus in the embodiments of the present invention;

[0024] Figure 2 Front view of the split insulation support and configuration scheme for the three-phase coaxial GIL / GIS bus in the embodiments of the present invention;

[0025] Figure 3(a) is a radial cross-sectional view of the split insulation support and configuration scheme for the three-phase coaxial GIL / GIS bus in the embodiments of the present invention; Figure 3(b) shows the situation after Figure 3(a) is rotated by a certain angle to the right.

[0026] Figure 4 Is the schematic view of the A-A cross-section in Figures 3(a) and 3(b);

[0027] Figure 5(a) is the first schematic view of the mushroom-shaped shielding cover of the split insulation support and configuration scheme for the three-phase coaxial GIL / GIS bus in the embodiments of the present invention; Figure 5(b) is the second schematic view of the mushroom-shaped shielding cover of the split insulation support and configuration scheme for the three-phase coaxial GIL / GIS bus in the embodiments of the present invention;

[0028] Figure 6(a) is an isometric view of the misaligned installation of the insulator in the split insulation support and configuration scheme for the three-phase coaxial GIL / GIS bus in the embodiments of the present invention; Figure 6(b) is the front view of the misaligned installation of the insulator in the split insulation support and configuration scheme for the three-phase coaxial GIL / GIS bus in the embodiments of the present invention;

[0029] Figure 7 Is the schematic view of the Y-shaped mounting base and the saddle-shaped shielding ring of the split insulation support and configuration scheme for the three-phase coaxial GIL / GIS bus in the embodiments of the present invention;

[0030] Figure 8 Is the distribution diagram of the synthetic electric field strength on the surface of the insulator under lightning impulse withstand in the 550kV design of the split insulation support and configuration scheme for the three-phase coaxial GIL / GIS bus in the embodiments of the present invention;

[0031] Figure 9This is the distribution diagram of the tangential field strength on the surface of the insulator under lightning impulse withstand in the 550kV design of the split insulation support and configuration scheme for the three-phase common box type GIL / GIS busbar in the implementation of the present invention;

[0032] Figure 10 This is the electric field distribution diagram on the surface of the metal insert of the insulator under lightning impulse withstand in the 550kV design of the split insulation support and configuration scheme for the three-phase common box type GIL / GIS busbar in the implementation of the present invention;

[0033] In the figure: 1 - current-carrying tube busbar, 2 - support insulator, 3 - mounting base, 3-1 - connecting column, 4 - conductor wrapping area, 5 - leg, 6 - first arc segment, 7 - metal insert, 8 - cylinder, 9 - mounting gap, 11 - straight segment, 12 - arc surface segment, 13 - roller, 14 - keyway, 15 - mushroom-shaped mounting base, 15-1 - shielding cover, 15-2 - cavity, 17 - Y-shaped mounting base, 18 - saddle-shaped shielding ring. Specific embodiments

[0034] The present invention will be further described below with reference to the drawings and embodiments.

[0035] Refer to Figure 1 - Figures 3(b), 6(a), 6(b) and Figure 7 The three-phase common box type GIL / GIS busbar of the present invention includes a cylinder 8 and three-phase current-carrying tube busbars and support insulators 2 arranged inside the cylinder 8. Each phase of the current-carrying tube busbar 1 in the three-phase current-carrying tube busbars is provided with a support insulator 2. The support insulator 2 includes a conductor wrapping area 4 sleeved outside the current-carrying tube busbar 1 and two legs 5 respectively connected to both sides of the conductor wrapping area 4. A metal insert 7 is provided at the end of the leg 5, and a shielding structure is connected to the metal insert 7; the metal inserts 7 at the ends of the two legs 5 are connected to the inner wall of the cylinder 8, and the projections of the support insulators 2 installed on the three-phase current-carrying tube busbars on the cross-section of the cylinder 8 are mutually at an angle of 40° - 80°.

[0036] As a preferred embodiment of the present invention, referring to Figures 3(a) and 3(b), the angle between the two legs 5 on each support insulator 2 is 120° - 180°, and this angle is the angle facing the direction of the cylinder 8; a saddle-shaped shielding ring 18 is connected to the metal insert 7, as shown in Figure 7 .

[0037] As a preferred embodiment of the present invention, referring to Figure 1 - Figure 3(b), the leg 5 and the conductor wrapping area 4 are smoothly connected through a first arc segment 6, and the shape of the conductor wrapping area 4 is a drum-shaped coating shape, referring to Figure 4, At the center of the drum surface of the conductor wrapping area 4, a central hole for the current-carrying pipe bus 1 to pass through is provided. The diameter of the central hole is smaller than the diameter of the drum surface. There is a straight-line segment 11 with a certain length between the central hole and the side of the conductor wrapping area 4, and the side surface of the conductor wrapping area 4 adopts a smooth arc segment 12.

[0038] As a preferred embodiment of the present invention, a fixed connection is provided between the metal insert 7 at the end of the leg 5 and the inner wall of the cylinder 8;

[0039] Or, referring to FIGS. 5(a) and 5(b), a roller 13 is connected to the metal insert 7 at the end of the leg 5, and the roller 13 contacts the inner wall of the cylinder 8.

[0040] As a preferred embodiment of the present invention, referring to FIGS. 6(a) and 6(b), the support insulators 2 installed on each phase of the current-carrying pipe bus in the three-phase current-carrying pipe bus are spaced apart by a preset distance along the length direction of the current-carrying pipe bus 1. A fixed connection is provided between the metal inserts 7 at the ends of the two legs 5 on the support insulator 2 and the inner wall of the cylinder 8.

[0041] As a preferred embodiment of the present invention, Figure 1 - FIG. 3(b) and Figure 7 , the support insulators 2 installed on the three-phase current-carrying pipe bus are located in the same plane. The metal inserts 7 at the ends of the adjacent legs 5 on the adjacent two support insulators 2 are connected to the same mounting base, and a fixed connection is provided between the mounting base 3 and the inner wall of the cylinder 8; or, referring to FIGS. 5(a) and 5(b), rollers 13 are installed on the mounting base 3, and the rollers 13 contact the inner wall of the cylinder 8.

[0042] As a preferred embodiment of the present invention, Figure 1 - FIG. 3(b) and FIGS. 5(a) and 5(b), the mounting base 3 includes a shielding cover 15. On the side of the shielding cover 15 facing the cylinder 8, a connecting column 3-1 is provided, and the connecting column 3-1 is welded to the inner wall of the cylinder 8 through a spacer block; or a roller 13 is installed on the connecting column 3-1, and the roller 13 contacts the inner wall of the cylinder 8;

[0043] A fixed connection or a relatively movable connection is provided between the side of the shielding cover 15 facing the leg 5 and the metal insert 7 at the end of the leg 5; referring to FIG. 5(a), when it is a relatively movable connection, the metal insert 7 at the end of the leg 5 is provided with a roller, and the rolling direction of the roller is along the axial direction of the current-carrying pipe bus 1. A key groove 14 for the roller to be embedded is provided on the shielding cover 15.

[0044] As a preferred embodiment of the present invention, when the side of the shielding cover 15 facing the leg 5 is a relatively movable connection with the end of the leg 5, referring to FIGS. 5(a) and 5(b), a cavity 15-2 communicating with the keyway 14 is provided inside the shielding cover 15, and a plurality of long holes for capturing metal chips at the keyway 14 and around the shielding cover 15 are also formed on the shielding cover 15, and all the long holes communicate with the cavity 15-2.

[0045] As a preferred embodiment of the present invention, referring to Figure 1 -FIG. 3(b), the structure of the shielding cover 15 is a rectangular structure bent into a smooth arc shape, the concave surface of the shielding cover 15 faces the inner wall of the cylinder body 8, and each corner part of the shielding cover 15 adopts a smooth arc transition.

[0046] As a preferred embodiment of the present invention, referring to Figure 7 , the shape of the mounting base 3 is Y-shaped, the metal inserts 7 at the ends of the adjacent legs 5 on the adjacent two support insulators 2 are fixedly connected to the ends of the two branches of the mounting base 3, and a fixed connection is provided between the end of the other branch of the mounting base 3 and the inner wall of the cylinder body 8.

[0047] As a preferred embodiment of the present invention, referring to FIGS. 3(a) and 3(b), the structure in which the insulator of the present invention rotates by any angle around the axis is also applicable. This situation also falls within the protection scope of the present invention.

[0048] Embodiment

[0049] Referring to Figure 1 -FIG. 3(b), the three-phase coaxial GIL / GIS busbar of this embodiment includes three-phase current-carrying tubular busbars 1, support insulators 2, a mounting base 3 and a cylinder body 8. The three support insulators 2 are arranged in a triangle along the axial direction inside the cylinder body 8, approximately distributed on the three sides of a triangle in a radial plane; the three mounting bases 3 are arranged at the three vertices of the triangle formed by the three support insulators, and the vertices of the triangle can form an inscribed circle concentric with the cylinder body 8; the support insulator 2 includes a conductor wrapping area 4 and two legs 5 respectively connected to both sides of the conductor wrapping area 4. The two legs 5 of the conductor wrapping area 4 are connected as a whole through a first arc section 6 to form a spindle-shaped insulating structure that is small at both ends and large in the middle. Metal inserts 7 are respectively embedded at both ends of the leg 5 to form an insulating support as a whole.

[0050] The rotation axes of the two legs 5 of the support insulator form a first included angle ∠A, and ∠A can be any value. Generally, the first included angle ∠A is greater than 120° and less than 180°; there may be differences in the first included angle ∠A of the support insulators located on the three sides of the triangle. The design allows the included angle between the two legs of the insulator to be adjusted to a certain extent, ensuring the flexibility of insulator installation in a compact environment and expanding the application range of the present invention.

[0051] The conductor wrapping area 4 is a rotating body that rotates around the current-carrying pipe bus 1 and uniformly wraps the current-carrying pipe bus 1. Refer to Figure 4 , the contour of the conductor wrapping area 4 at the A-A cross-section includes a straight-line segment 11 and an arc-shaped segment 12, forming a drum-shaped wrapping shape.

[0052] Refer to FIGS. 3(a) and 3(b). There is an installation gap 9 between the installation base 3 and the inner wall of the cylinder 8. The installation base 3 and the inner wall of the cylinder 8 can be fixedly connected or slidably connected through the installation gap 9. When the insulating support needs to be integrally fixed, the installation base 3 and the inner wall of the cylinder 8 are welded and fixed in the installation gap 9 through a spacer block; when the insulating support needs to be integrally slid, a roller 13 is assembled in the connecting column 3-1 of the installation base 3 to contact the inner wall of the cylinder 8. Each installation base 3 has an independent contact connected to the inner wall of the cylinder 8.

[0053] The support insulator 2 and the installation base 3 can be fixedly connected or slidably connected. When the three support insulators 2 need to be integrally slid or fixed, the metal insert 7 and the installation base 3 are fixedly connected by bolts. When the three-phase three insulators 2 need to be slid independently, rollers are installed at the end of the metal insert. Refer to FIG. 5(a) and slide through the axial keyway 14 opened on the installation base 3. As shown in FIGS. 6(a) and 6(b), the three support insulators 2 can be installed in the three-phase common-box GIL / GIS bus by means of a staggered installation method.

[0054] The installation base 3 can be a mushroom-shaped installation base 15 (such as Figure 1 the cases shown in FIGS. 3(b), 5(a) and 5(b)) or a Y-shaped installation base 17 (such as Figure 7 the case shown).

[0055] According to the 550 kV three-phase coaxial GIL split-type insulating support and configuration scheme designed by the structure of the present invention, the finite element calculation method is used to simulate the electric field distribution at the key parts. Since the insulator gap and the surface design mainly consider the electric field distribution under lightning impulse, during the calculation, a corresponding lightning impulse voltage is applied to one-phase current-carrying pipe bus, and the other two-phase pipe buses and the cylinder wall are grounded. Figure 8 , Figure 9 and Figure 10 are the synthetic field strength on the insulator surface, the tangential field strength on the insulator surface and the electric field distribution on the metal insert surface respectively. The maximum value of the synthetic field strength on the insulator surface is 19.3 kV / mm, and the maximum value of the tangential field strength is 6.79 kV / mm, which are respectively lower than the 0.4 MPa SF6 control field strength indexes of 24 kV / mm and 12 kV / mm. The electric field on the metal insert surface is uniform and lower than the control field strength value after conversion to power frequency. In the above scheme, a saddle-shaped shielding ring 18 can be configured at the connection position between the metal insert 7 and the installation base 3.

[0056] As can be seen from the above solution, in the present invention, the support insulators of the three-phase pipe bus are relatively independent. The insulating gas-solid interface between the phases of the pipe bus is eliminated, and the surface insulation between the phases is transformed into gap insulation, providing a way to further reduce the volume and improve the safety margin between the phases. The insulators of the three phases are arranged in a triangular pattern to form an insulation support solution for the three-phase pipe bus. Each phase insulator is designed as a spindle shape, which can effectively and evenly distribute the resultant electric field strength and tangential electric field strength on the surface of the insulator, increase the creepage distance along the surface of the insulator relative to the ground, and improve the surface insulation performance of the insulator relative to the ground. The present invention can integrate the three-phase conductors on one insulator to achieve three-phase coaxial enclosure, and solve the insulation technology problems and safe and reliable operation problems of equipment miniaturization and compact design while meeting the requirements of design control indicators. The insulator and the mounting base, and the mounting base and the cylinder wall can be selected for fixed or sliding installation. At the same time, the support insulators of the three-phase pipe bus can be selected for staggered installation, providing a way for flexible installation of zero-defect insulators under compact conditions while ensuring that the insulator structure can effectively relieve the stress concentration problem of the insulator caused by the thermal expansion and contraction of the current-carrying pipe bus due to the temperature field change caused by the change of environmental temperature and load. The optional fixed and sliding configuration methods of the insulator and the mounting base, and the mounting base and the cylinder wall enable the independent sliding of the insulators of the three phases. When the three-phase current is unbalanced, it can effectively reduce the non-synchronism of thermal expansion and contraction caused by thermal expansion and contraction between different phases, and the insulator can effectively relieve the stress concentration in this case. Each guide rod (current-carrying busbar) is independently supported, which can effectively reduce the stress borne by the insulator body and the metal insert, and reduce the occurrence of local stress concentration. The saddle-shaped shielding ring provides space for flexible installation of the insulator, and solves the problem that defects are easily generated at the low-voltage end of the insulator during installation, but the ability to clean and suppress defects is insufficient. The relatively large shielding space of the saddle-shaped shielding ring can effectively shield the interface defects caused by insufficient bonding strength of the metal-epoxy bonding interface at the support leg, and at the same time provides space for flexible installation of the insulator.

[0057] The present invention first proposes a split-type insulation support and configuration solution for a three-phase common-box GIL / GIS bus, aiming to solve the problems of local electric field concentration caused by limited space inside the three-phase common-box GIL / GIS bus and local defect-distorted electric fields brought about by the installation and configuration on the low-voltage side under compact conditions; to solve the problem of insufficient insulation structure design margin when applying new environmentally friendly insulating gases; and to solve the problem that when the three-phase common-box GIL / GIS bus is used for long-distance power transmission, the long pipe bus is affected by current-carrying, temperature changes in the environment, resulting in changes in the temperature field inside the GIS / GIL, and the existence of unbalanced three-phase currents in the system, which causes different current-carrying and different thermal expansion and contraction of the three-phase pipe buses, resulting in stress concentration inside the insulating parts. Under the design of the present invention, the synthetic electric field intensity, tangential electric field intensity on the surface of the insulation support, and surface electric field intensity between metal inserts can be homogenized to a great extent, meeting the control values and margin requirements in engineering, facilitating flexible installation and configuration, thereby improving the safety and stability of the insulator during long-term operation. The split-type insulation support of this three-phase common-phase GIS / GIL can be scaled up or down proportionally and applied to AC three-phase power transmission systems with different voltage levels. In addition, split-type insulation supports for three-phase common-phase GIS / GIL manufactured using different filling materials, different-shaped inserts, different numbers of legs, and different design concepts all fall within the scope of protection of this patent.

[0058] In summary, the split-type insulation support and configuration solution of the three-phase common-phase GIS / GIL of the present invention can significantly reduce the size of the insulator, reduce the volume of the insulator, and lower the production and manufacturing costs while ensuring that the maximum values of the synthetic electric field intensity of the insulator, the maximum value of the tangential electric field intensity of the insulator, and the maximum value of the surface electric field intensity of the metal insert meet the design index requirements. It can achieve the margin requirements for the insulation structure design under the application of new environmentally friendly insulating gases. At the same time, it can solve the stress concentration phenomenon at the metal-epoxy interface when the external temperature and load change due to the expansion and contraction of the conductor and the mismatch of the thermal expansion coefficients of the insulator and the central conductor. It can effectively shield the defects brought about during the installation and operation of the low-voltage end, and the insulator configuration is flexible.

[0059] It should be understood that various modifications to the embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. The present invention will not be limited to the embodiments shown herein, but rather will be accorded the widest scope consistent with the principles and novel features disclosed herein. The scope of this application is limited by the appended claims.

[0060] Based on the structure of the present invention, any changes in the shape of metal inserts, the included angle of insulator legs, the shape of insulator legs, and the installation and configuration method of the mounting seat fall within the scope of protection of the present invention.

[0061] This insulation support design can maintain the surface electric field design index at an optimal value. At the same time, it can relieve the stress concentration phenomenon of the insulator caused by the temperature field change resulting from the load and temperature changes during operation. The configuration scheme has multiple structural combinations and can be flexibly applied to different working conditions. It effectively shields the defects brought during the installation and operation at the low-voltage end, thereby reducing the failure probability of the insulator and the risk of surface flashover, and improving the safety and operation reliability of the three-phase coaxial GIL / GIS busbar.

[0062] Under actual scenarios, the transmission load and environmental temperature change periodically, resulting in a periodic change in the temperature field distribution of GIS / GIL. The thermal expansion and contraction phenomenon of the current-carrying pipe busbar of GIS / GIL requires the insulator connected to the pipe busbar to be able to achieve relative slip with the cylinder wall to compensate for this phenomenon and reduce the thermal stress borne by the insulator during operation. This also requires an insulation support component suitable for this structural feature to be assembled in GIS / GIL.

[0063] The present invention can meet the requirements of compact design and the application of environmentally friendly gases, achieve the uniform distribution of multi-physical fields inside the three-phase coaxial GIS / GIL, rationalize the structural design, ensure the safety and stability of GIS / GIL during operation, and reduce the risks of insulation defects, surface flashover, gap breakdown and other faults.

Claims

1. A three-phase common-box GIL / GIS busbar, characterized in that, It includes a cylinder body (8), a three-phase current-carrying pipe bus and support insulators (2) arranged inside the cylinder body (8). Support insulators (2) are installed on each phase of the current-carrying pipe bus (1) in the three-phase current-carrying pipe bus. The support insulator (2) includes a conductor wrapping area (4) sleeved outside the current-carrying pipe bus (1) and two legs (5) respectively connected to both sides of the conductor wrapping area (4). Metal inserts (7) are provided at the ends of the legs (5), and a shielding structure is connected to the metal inserts (7); the metal inserts (7) at the ends of the two legs (5) are connected to the inner wall of the cylinder body (8). The projections of the support insulators (2) installed on the three-phase current-carrying pipe bus in the cross-section of the cylinder body (8) are at an angle of 40° - 80° to each other. The support insulators (2) installed on the three-phase current-carrying pipe bus are located in the same plane. The metal inserts (7) at the ends of the adjacent legs (5) of adjacent two support insulators (2) are connected to the same mounting base. The mounting base (3) is fixedly connected to the inner wall of the cylinder body (8), or rollers (13) are installed on the mounting base (3), and the rollers (13) are in contact with the inner wall of the cylinder body (8). The mounting base (3) includes a shielding cover (15). On the side of the shielding cover (15) facing the cylinder body (8), there is a connecting column (3-1). The connecting column (3-1) is welded to the inner wall of the cylinder body (8) through a spacer block, or rollers (13) are installed on the connecting column (3-1), and the rollers (13) are in contact with the inner wall of the cylinder body (8). The connection between the side of the shielding cover (15) facing the leg (5) and the metal insert (7) at the end of the leg (5) is a relatively movable connection. When it is a relatively movable connection, a roller is provided on the metal insert (7) at the end of the leg (5), and the rolling direction of the roller is along the axial direction of the current-carrying pipe bus (1). A keyway (14) for the roller to be embedded is provided on the shielding cover (15). When the connection between the side of the shielding cover (15) facing the leg (5) and the end of the leg (5) is a relatively movable connection, a cavity (15-2) communicating with the keyway (14) is provided inside the shielding cover (15). The shielding cover (15) is also provided with a number of long holes for capturing metal chips at the keyway (14) and around the shielding cover (15), and all the long holes communicate with the cavity (15-2). The included angle between the two legs (5) on each support insulator (2) is 120° - 180°, and this included angle is the included angle facing the direction of the cylinder body (8).

2. A three-phase common-box type GIL / GIS busbar according to claim 1, characterized in that, A saddle-shaped shielding ring (18) is connected to the metal insert (7).

3. A three-phase coaxial GIL / GIS busbar according to claim 1, characterized in that, The leg (5) and the conductor wrapping area (4) are smoothly connected through a first arc section (6). The shape of the conductor wrapping area (4) is a drum-shaped covering shape. A central hole for the current-carrying pipe bus (1) to pass through is provided at the center of the drum surface of the conductor wrapping area (4). The diameter of the central hole is smaller than the diameter of the drum surface. The side surface of the conductor wrapping area (4) adopts a smooth arc section (12).

4. A three-phase coaxial GIL / GIS busbar according to claim 1, characterized in that, The support insulators (2) installed on each phase of the current-carrying pipe bus (1) in the three-phase current-carrying pipe bus are spaced at a preset distance along the length direction of the current-carrying pipe bus (1).

5. A three-phase coaxial GIL / GIS busbar according to claim 1, characterized in that, The structure of the shielding cover (15) is a rectangular structure bent into a smooth arc shape. The concave surface of the shielding cover (15) faces the inner wall of the cylinder body (8), and each corner part of the shielding cover (15) adopts a smooth arc transition.

6. A three-phase coaxial GIL / GIS busbar according to claim 1, characterized in that, The shape of the mounting base (3) is Y-shaped. The metal inserts (7) at the ends of the adjacent legs (5) on two adjacent support insulators (2) are fixedly connected to the ends of the two branches of the mounting base (3), and there is a fixed connection between the end of the other branch of the mounting base (3) and the inner wall of the cylinder body (8).

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