High voltage direct current gil / gis eccentric bus

Abstract

The application discloses a high-voltage direct-current GIL / GIS eccentric bus, a standard unit of which comprises a metal shell, a current-carrying conductor, a high-voltage shielding conductor, a support insulator and a concentric insulator, the concentric insulator is installed at both ends of the metal shell, and the current-carrying conductor is arranged in the metal shell; the current-carrying conductor comprises an eccentric section and a concentric current-carrying conductor, the eccentric section is connected with the concentric current-carrying conductor at both ends, and the axis of the concentric current-carrying conductor is coaxial with the axis of the metal shell; the eccentric section comprises a plurality of eccentric current-carrying conductors, the axis of the eccentric current-carrying conductor is parallel to and located above the axis of the metal shell, the plurality of eccentric current-carrying conductors are connected into the eccentric section through the high-voltage shielding conductor, the eccentric current-carrying conductor at the end of the eccentric section is connected with one end of a concentric current-carrying conductor through a corner unit, the other end of the concentric current-carrying conductor is connected with the concentric insulator, and the high-voltage shielding conductor is connected with the metal shell through the support insulator. The application can inhibit the surface charge accumulation of the support insulator.

Description

Technical Field

[0001] This invention belongs to the field of power equipment structural design technology, and specifically relates to a high-voltage DC GIL / GIS eccentric busbar. Background Technology

[0002] Insulators are key components of high-voltage direct current (HVDC) gas-insulated transmission lines (GILs) and gas-insulated switchgear (GIS), playing a crucial role in electrical insulation and supporting the central conductor. During long-term operation, HVDC GIL / GIS insulators are subjected to electrical, thermal, and mechanical coupling effects, and their safety and stability are essential for ensuring the operation of HVDC transmission lines. Compared to AC GIL / GIS insulators, the unipolar transmission mode of HVDC GIL / GIS causes a large amount of charge to accumulate on the insulator surface during long-term operation, significantly affecting the insulation performance of HVDC GIL / GIS insulators. Summary of the Invention

[0003] To address the problems existing in the prior art, the purpose of this invention is to propose an eccentric busbar for high-voltage DC GIL / GIS. This invention suppresses the accumulation of surface charge on high-voltage DC GIL / GIS insulators by eccentrically arranging the center conductor, thereby improving the insulation and electrical performance of high-voltage DC GIL / GIS post insulators and ultimately enhancing the safety and reliability of the post insulators.

[0004] The technical solution adopted in this invention is as follows:

[0005] A high-voltage DC GIL / GIS eccentric busbar includes a standard unit, which includes a metal shell, a current-carrying conductor, a high-voltage shielding conductor, a post insulator, and a concentric insulator. The concentric insulators are installed at both ends of the metal shell, and the current-carrying conductor is disposed inside the metal shell.

[0006] The current-carrying conductor includes an eccentric section and a concentric current-carrying conductor. Both ends of the eccentric section are connected to the concentric current-carrying conductor, and the axis of the concentric current-carrying conductor is coaxial with the axis of the metal shell.

[0007] The eccentric section includes several eccentric current-carrying conductors. The axis of the eccentric current-carrying conductors is parallel to the axis of the metal shell and is located above the axis of the metal shell. The several eccentric current-carrying conductors are connected to form the eccentric section by high-voltage shielding conductors. The eccentric current-carrying conductor at the end of the eccentric section is connected to one end of a concentric current-carrying conductor through a corner unit. The other end of the concentric current-carrying conductor is connected to a concentric insulator.

[0008] The high-voltage shielded conductor is connected to the metal casing through a post insulator.

[0009] Preferably, the eccentricity of the eccentric current-carrying conductor is the ratio of the distance between the central axis of the eccentric current-carrying conductor and the central axis of the metal shell to the radius of the metal shell, and the value of the eccentricity ranges from 0.1 to 0.2.

[0010] Preferably, a countersunk hole is provided on the high-voltage shielding conductor at the position where it connects to the post insulator, the high-voltage end of the post insulator extends into the countersunk hole, and the high-voltage metal insert of the post insulator is connected to the bottom of the countersunk hole;

[0011] Along the axial direction of the metal shell, the opening of the countersunk hole is provided with a sloping shield structure on both sides of the post insulator. The angle between the normal vector of the sloping shield structure facing the gas side and the axial direction of the post insulator is in the range of 40° to 50°. The axial direction of the post insulator is the direction from the high voltage end to the low voltage end on the axis of the post insulator.

[0012] Preferably, the annular gap width between the countersunk hole and the epoxy composite material part of the post insulator is in the range of 7 to 12 mm, and the distance from the bottom of the countersunk hole to the junction of the high-voltage metal insert and the epoxy composite material part is in the range of 7 to 12 mm.

[0013] Preferably, on the plane containing the axis of the eccentric current-carrying conductor and the axis of the high-voltage shielding conductor, between the high-voltage metal insert and the low-voltage metal insert of the post insulator, the tangent direction at any point on the outer contour of the epoxy composite material part of the post insulator is not perpendicular to the axis of the post insulator.

[0014] In the epoxy composite part, the maximum outer diameter D1 of the epoxy composite within 25mm±20mm beyond the top of the low-pressure metal insert is greater than the maximum outer diameter D2 of the epoxy composite within 15mm±10mm beyond the top of the high-pressure metal insert; the outer diameter of the epoxy composite part transitions smoothly from the maximum outer diameter of the oxygen composite to the maximum outer diameter of the epoxy composite.

[0015] Preferably, the side of the low-voltage metal insert and the high-voltage metal insert of the post insulator that contacts the epoxy composite material part of the post insulator includes a cylindrical side surface and a smooth curved surface structure with multiple tangent circular arcs at the end of the cylindrical side surface. The smooth curved surface structure and a part of the cylindrical side surface are covered by the epoxy composite material part of the post insulator.

[0016] At the junction of the epoxy composite part and the low-pressure metal insert, the outer contour of the epoxy composite part is perpendicular to the cylindrical side of the low-pressure metal insert.

[0017] At the junction of the epoxy composite part and the high-pressure metal insert, the outer contour of the epoxy composite part is perpendicular to the cylindrical side of the high-pressure metal insert.

[0018] Preferably, the outer surface of the corner unit is a smooth arc-connected curved surface, and the corner unit has concentric connecting holes adapted to and connected to concentric current-carrying conductors and eccentric connecting holes adapted to and connected to eccentric current-carrying conductors at both ends in the axial direction of the metal shell.

[0019] Preferably, the maximum radius on the outer contour of the corner unit is R3, the minimum radius arc on the side with the concentric connecting hole is r1, and the minimum radius arc on the side with the eccentric connecting hole is r2; the radii of both the concentric current-carrying conductor and the eccentric current-carrying conductor are R.

[0020] r1, r2, R3, and R satisfy the following relationship:

[0021]

[0022] Preferably, a particle trap is provided inside the metal casing below the high-voltage shielding conductor.

[0023] Preferably, the post insulator is a single-post insulator and / or a double-post insulator;

[0024] Among them, the single-post insulator is set below the high-voltage shield conductor, and the axis of the single-post insulator is set along the vertical direction;

[0025] The double-post insulator is installed below the high-voltage shielded conductor, and the two legs of the double-post insulator are located on both sides of the high-voltage shielded conductor.

[0026] The present invention has the following beneficial effects:

[0027] In this invention, the eccentric busbar of the high-voltage DC GIL / GIS is configured with three segments for the current-carrying conductor. Specifically, it includes concentric current-carrying conductors at both ends of the eccentric segment. Because the eccentric segment is positioned eccentrically relative to the metal casing and above its axis, the surface insulation distance of the post insulator is increased. Furthermore, the eccentric segment reduces the electric field strength on the lower inner surface of the metal casing, making it more difficult for free metal particles to be lifted, further reducing the hazards caused by metal particles. Since the insulators connecting the metal casing segments still require concentric insulators (such as basin-type insulators), this invention designs a corner unit to connect the eccentric current-carrying conductor in the eccentric segment with the concentric current-carrying conductor. Therefore, this invention can simultaneously use post insulators and concentric insulators (such as basin-type insulators), improving the safety and reliability of the insulators during operation. Attached Figure Description

[0028] Figure 1This is a schematic diagram of the overall structure of the single-support method for the eccentric busbar of the high-voltage DC GIL / GIS in this invention.

[0029] Figure 2 This is a radial cross-sectional view along the insulator axis of the single-support method of the eccentric busbar of the high voltage DC GIL / GIS in this invention.

[0030] Figure 3 This is an axial cross-sectional view along the vertical direction of the single-support method of the eccentric busbar of the high voltage DC GIL / GIS in this invention.

[0031] Figure 4 This is a schematic diagram of the high-voltage shielded conductor in the single-support method of the eccentric busbar of the high-voltage DC GIL / GIS in this invention;

[0032] Figure 5 This is a schematic diagram of a single-support insulator in the single-support method of the eccentric busbar of the high voltage DC GIL / GIS in this invention;

[0033] Figure 6(a) shows the composite field strength distribution on the surface of a single-support insulator under lightning impulse voltage in the eccentric busbar of the present invention; Figure 6(b) shows the tangential field strength distribution on the surface of a single-support insulator under lightning impulse voltage in the eccentric busbar of the present invention; Figure 6(c) shows the normal field strength distribution on the surface of a single-support insulator at the maximum operating voltage in the eccentric busbar of the present invention.

[0034] Figure 7(a) shows the surface electric field distribution of the high-voltage metal insert of a single-support insulator at the maximum operating voltage in the eccentric busbar of the present invention; Figure 7(b) shows the surface electric field distribution of the low-voltage metal insert of a single-support insulator at the maximum operating voltage in the eccentric busbar of the present invention.

[0035] Figure 8 This is a schematic diagram of the double-support method in the eccentric busbar of the high-voltage DC GIL / GIS in this invention;

[0036] Figure 9(a) is a three-dimensional schematic diagram of the corner unit in the eccentric busbar of the high voltage DC GIL / GIS in this invention; Figure 9(b) is a three-dimensional schematic diagram of the corner unit in the eccentric busbar of the high voltage DC GIL / GIS with a 3 / 4 cross section; Figure 9(c) is a cross-sectional view of the corner unit in the eccentric busbar of the high voltage DC GIL / GIS in this invention.

[0037] Figure 10 This is a schematic diagram of a standard unit in the high-voltage DC GIL / GIS eccentric busbar of the present invention;

[0038] In the figure, 1-metal shell, 2-eccentric current-carrying conductor, 3-high voltage shielding conductor, 4-particle trap, 5-insulator body, 6-countersunk hole, 7-sloping shielding structure, 8-circular socket, 9-mounting hand hole, 10-through hole, 11-epoxy composite material part, 12-high voltage metal insert, 13-low voltage metal insert, 14-threaded hole, 15-smooth curved surface structure, 16-cylindrical side, 18-concentric current-carrying conductor, 19-corner unit, 20-concentric connection hole, 21-eccentric connection hole, 22-annular gap, 23-pot-type insulator. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0040] See Figures 1-3 , combined Figure 10 This invention relates to a high-voltage DC GIL / GIS eccentric busbar, comprising a standard unit. Each standard unit includes a metal casing 1, current-carrying conductors, a high-voltage shielding conductor 3, post insulators, and concentric insulators. The concentric insulators are installed at both ends of the metal casing 1, and the current-carrying conductors are disposed within the metal casing 1. The current-carrying conductors include an eccentric section and concentric current-carrying conductors 18. Both ends of the eccentric section are connected to concentric current-carrying conductors 18, and the axis of the concentric current-carrying conductors 18 is coaxial with the axis of the metal casing 1. The eccentric section includes several eccentric current-carrying conductors 2, whose axes are parallel to the axis of the metal casing 1 and located above the axis of the metal casing 1. The several eccentric current-carrying conductors 2 are connected to each other via the high-voltage shielding conductors 3 to form the eccentric section. The eccentric current-carrying conductor 2 at the end of the eccentric section is connected to one end of a concentric current-carrying conductor 18 via a corner unit 19. The other end of the concentric current-carrying conductor 18 is connected to a concentric insulator. The high-voltage shielding conductor 3 is connected to the metal casing 1 via post insulators. (See also...) Figure 8 In the above-described scheme of the present invention, the number of post insulators in the standard unit is 2 to 3, and the post insulators can be single-post insulators and / or double-post insulators. Figure 8 The image shows cases where post insulators are used in both single-post and double-post configurations. Concentric insulators are generally pot-type insulators.

[0041] As a preferred embodiment of the present invention, see Figure 2 O1 is the center of the eccentric current-carrying conductor 2, and O2 is the center of the metal shell 1. The eccentricity e is defined as the ratio of the distance R1 between the central axis of the eccentric current-carrying conductor 2 and the central axis of the metal shell 1 to the radius R2 of the metal shell 1. To ensure the uniformity of the electric field distribution between the central conductor and the shell, the range of values ​​for the eccentricity e is shown in the following formula:

[0042]

[0043] As a preferred embodiment of the present invention, see Figures 1-5 The high-voltage shielding conductor 3 has a countersunk hole 6 at the position where it connects to the post insulator. This countersunk hole is used to shield the high-voltage metal insert 12, the epoxy composite material part 11, and the SF6 gas (the inner cavity of the metal shell 1 is generally filled with SF6 gas during normal operation) at the three-way junction. The high-voltage end of the post insulator extends into the countersunk hole 6. The high-voltage metal insert 12 of the post insulator is connected to the bottom of the countersunk hole 6. The connection can be made by bolts. Along the axial direction of the metal shell 1, the opening of the countersunk hole 6 has a sloping shielding structure 7 on both sides of the post insulator to improve the electric field distribution on the surface of the post insulator. The angle between the normal vector of the sloping shielding structure 7 facing the gas (SF6 gas) side and the axial direction of the post insulator is in the range of 40° to 50°. The axial direction of the post insulator is the direction from the high-voltage end to the low-voltage end on the axial direction of the post insulator.

[0044] As a preferred embodiment of the present invention, in order to prevent local distortion of the electric field strength on the surface of the post insulator, based on the above solution, see [reference needed]. Figure 3 The width of the annular gap 22 between the countersunk hole 6 and the epoxy composite material part 11 of the post insulator ranges from 7 to 12 mm, and the distance from the bottom of the countersunk hole 6 to the junction of the high-voltage metal insert 12 and the epoxy composite material part 11 ranges from 7 to 12 mm.

[0045] As a preferred embodiment of the present invention, in order to facilitate assembly, a mounting hand hole 9 is provided on the high-voltage shielding conductor 3 on the opposite side of the countersunk hole 6 to facilitate the installation of the high-voltage metal insert 12. The mounting hand hole 9 is used to provide installation space.

[0046] As a preferred embodiment of the present invention, see Figure 2 and Figure 5 On the plane where the axis of the eccentric current-carrying conductor 2 and the axis of the high-voltage shielding conductor 3 lie, between the high-voltage metal insert 12 and the low-voltage metal insert 13 of the post insulator, the tangent direction at any point on the outer contour of the epoxy composite material part 11 of the post insulator is not perpendicular to the axis of the post insulator; on the epoxy composite material part 11, the maximum outer diameter D1 of the epoxy composite material within 25mm±20mm beyond the top of the low-voltage metal insert 13 is greater than the maximum outer diameter D2 of the epoxy composite material within 15mm±10mm beyond the top of the high-voltage metal insert 12; on the epoxy composite material part 11, the outer diameter of the epoxy composite material smoothly transitions from the maximum outer diameter of the epoxy composite material to the maximum outer diameter of the epoxy composite material.

[0047] As a preferred embodiment of the present invention, see Figure 5The side of the low-voltage metal insert 13 and the high-voltage metal insert 12 of the post insulator that contacts the epoxy composite material part 11 of the post insulator includes a cylindrical side surface 16 and a smooth curved surface structure 15 with a multi-segment circular arc tangent outer contour that is smoothly connected to the end of the cylindrical side surface 16. The smooth curved surface structure 15 and a part of the cylindrical side surface 16 are covered by the epoxy composite material part 11 of the post insulator.

[0048] At the junction of the epoxy composite part 11 and the low-pressure metal insert 13 (that is, the three-way junction of the epoxy composite part 11, the low-pressure metal insert 13 and the SF6 gas), the outer contour of the epoxy composite part 11 is perpendicular to the cylindrical side 16 of the low-pressure metal insert 13.

[0049] At the junction of the epoxy composite part 11 and the high-pressure metal insert 12 (that is, the junction of the high-pressure metal insert 12, the low-pressure metal insert 13 and the SF6 gas), the outer contour of the epoxy composite part 11 is perpendicular to the cylindrical side 16 of the high-pressure metal insert 12.

[0050] As a preferred embodiment of the present invention, see Figures 9(a)-9(c) The outer surface of the corner unit 19 is a smooth arc-connected curved surface. The corner unit 19 has concentric connecting holes 20 adapted to and connected to the concentric current-carrying conductor 18 and eccentric connecting holes 21 adapted to and connected to the eccentric current-carrying conductor 2 at both ends of the metal shell 1 along the axial direction (i.e., the left and right ends in Figure 9(c)). The specific openings are shown in Figure 9(b).

[0051] As a preferred embodiment of the present invention, based on the above scheme and referring to Figure 9(c), the maximum radius on the outer contour of the corner unit 19 is R3. The plane containing the maximum radius on the outer contour of the corner unit 19 is located on the bisecting plane between the adjacent end faces of the eccentric current-carrying conductor 2 and the concentric current-carrying conductor 18 on both sides of the corner unit 19. Point A shown in Figure 9(c) is the highest point of the plane containing the maximum radius. The minimum radius arc on the side where the concentric connecting hole 20 is opened is r1, and the minimum radius arc on the side where the eccentric connecting hole 21 is opened is r2. The radii of the concentric current-carrying conductor 18 and the eccentric current-carrying conductor 2 are both R.

[0052] To ensure that the electric field intensity on the surface of the corner element is less than the control value, r1, r2, R3, and R satisfy the following relationship:

[0053]

[0054] As a preferred embodiment of the present invention, see Figure 3 and Figure 4The high-voltage shielding conductor 3 has circular sockets 8 on both sides of its axis for connecting the eccentric current-carrying conductor 2. The high-voltage shielding conductor 3 and the eccentric current-carrying conductor 2 are assembled together through the circular sockets 8.

[0055] As a preferred embodiment of the present invention, see Figure 1 , Figure 2 , Figure 3 , Figure 8 as well as Figure 10 The metal casing 1 contains a particle trap 4 located below the high-voltage shielding conductor 3. This invention further reduces the harm of metal particles by configuring a grid-type annular metal particle trap. Furthermore, the particle trap 4 can be a grid-type particle trap. The grid of the particle trap 4 is a rectangular slot, and the long side of the grid is perpendicular to the axis of the metal casing 1. The length of the particle trap 4 along the axis of the metal casing 1 is 3 to 5 times the maximum outer diameter of the support insulator (the leg of a single-support insulator or a double-support insulator). The distribution of the grid-type particle traps in the circumferential direction of the metal casing 1 is at least greater than 90°. The distance between the inner surface of the grid-type particle trap and the inner surface of the metal casing 1 is 5 to 15 mm.

[0056] In a preferred embodiment of the present invention, the post insulator is a single-post insulator and / or a double-post insulator;

[0057] See Figures 1-3 as well as Figure 10 The single-post insulator is set below the high-voltage shield conductor 3, and the axis of the single-post insulator is set along the vertical direction. At this time, the central axes of the epoxy composite part 11, the high-voltage metal insert 12 and the low-voltage metal insert 13 of the insulator coincide. This setting method of the single-post insulator can reduce the tangential stress at the bonding interface between the high-voltage metal insert 12 and the epoxy composite part 11 and reduce the tangential stress at the bonding interface between the low-voltage metal insert 13 and the epoxy composite part 11.

[0058] See Figure 8 and Figure 10 The double-post insulator is installed below the high-voltage shield conductor 3, and the two legs of the double-post insulator are located on both sides of the high-voltage shield conductor 3. The two legs of the double-post insulator are set at a preset angle. The arrangement of each leg is the same as that of the single-post insulator. Correspondingly, there is an additional position for installing a leg on the high-voltage shield conductor 3. The plane containing the axes of the two legs of the double-post insulator is perpendicular to the axis of the metal shell 1.

[0059] As a preferred embodiment of the present invention, see Figures 1-3 as well as Figure 5The high-voltage metal insert 12 and the low-voltage metal insert 13 can be finger-shaped electrodes. The surface of the high-voltage metal insert 12 that contacts the high-voltage shielding conductor 3 (i.e., the bottom surface of the countersunk hole 6) is a plane, and a threaded hole 14 perpendicular to the plane is provided on the plane side of the high-voltage metal insert 12; the surface of the low-voltage metal insert 13 that contacts the metal shell 1 is a plane, see [reference]. Figure 4 The bottom surface of the countersunk hole 6 is provided with a through hole 10 for the bolt to pass through. The size and position of the through hole 10 are consistent with the plane on the high-pressure metal insert 12 (see...). Figure 5 The threaded hole 14 on the upper side of the medium and high voltage metal insert 12 is consistent with that on the upper side of the insert.

[0060] As a preferred embodiment of the present invention, the metal shell 1, the low-pressure metal insert 13 and the particle trap 4 can be fixed by welding.

[0061] Example

[0062] See Figure 10In this embodiment, the high-voltage DC GIL / GIS eccentric busbar includes a standard unit, which includes a metal shell 1, a current-carrying conductor, a high-voltage shielding conductor 3, a post insulator, and a basin insulator 23. Basin insulators 23 are installed at both ends of the metal shell 1, and the current-carrying conductor is disposed inside the metal shell 1. The current-carrying conductor includes an eccentric section and a concentric current-carrying conductor 18. The eccentric section includes three eccentric current-carrying conductors 2, and the eccentricity e of the eccentric current-carrying conductors 2 is 0.15. The three eccentric current-carrying conductors 2 are connected together in series by two high-voltage shielding conductors 3. A single post insulator is connected to one of the high-voltage shielding conductors 3, and a double post insulator is connected to the other high-voltage shielding conductor 3. The eccentric current-carrying conductor 2 located at the end of the eccentric section is connected to one end of the concentric current-carrying conductor 18 through a corner unit 19, and the other end of the concentric current-carrying conductor 18 is connected to the basin insulator 23. Each high-voltage shielding conductor 3 has a particle trap 4 below it. The particle trap 4 is a grid-type annular particle trap, coaxially configured with the metal shell 1 and connected to the low-voltage metal insert 13. A countersunk hole 6 is provided on the high-voltage shielding conductor 3 at the position where it connects to the high-voltage end of the single-post insulator and double-post insulator. An inclined shielding structure 7 is provided at the opening of the countersunk hole 6. The angle between the normal vector of the inclined shielding structure 7 towards the gas side and the axis of the post insulator is 45°. The width of the annular gap 22 between the countersunk hole 6 and the epoxy composite material part 11 of the post insulator is 10mm. The bottom of the countersunk hole 6 is 5mm from the junction of the high-voltage metal insert 12 and the epoxy composite material part 11. A mounting hand hole 9 is provided on the high-voltage shielding conductor 3 opposite to the countersunk hole 6. The outer diameter D1 of the epoxy composite material at the top of the low-voltage metal insert 13 is 110mm, and the outer diameter D2 of the epoxy composite material at the top of the high-voltage metal insert 12 is 95.5mm. The maximum radius R3 on the outer contour of the corner unit 19 is 135mm. The minimum radius arc r1 on the side of the corner unit 19 with the concentric connecting hole 20 is 30mm, and the minimum radius arc r2 on the side with the eccentric connecting hole 21 is 23mm. The radius R of the concentric current-carrying conductor 18 and the eccentric current-carrying conductor 2 is 60mm. The length of the particle trap 4 along the axial direction of the metal shell 1 is three times the maximum outer diameter of the post insulator (including the legs of single-post insulators and double-post insulators). The grid-type particle traps are distributed at 90° around the metal shell 1. The distance between the inner surface of the grid-type particle trap and the inner surface of the metal shell 1 is 10mm.The high-voltage metal insert 12 and the low-voltage metal insert 13 can be finger electrodes. The side of the low-voltage metal insert 13 and the high-voltage metal insert 12 that contacts the epoxy composite material part 11 of the post insulator includes a cylindrical side surface 16 and a smooth curved surface structure 15 with multiple tangent circular arcs at the end of the cylindrical side surface 16. The smooth curved surface structure 15 and a part of the cylindrical side surface 16 are covered by the epoxy composite material part 11 of the post insulator. At the junction of the epoxy composite material part 11 and the low-voltage metal insert 13, the outer contour of the epoxy composite material part 11 is perpendicular to the cylindrical side surface 16 of the low-voltage metal insert 13. At the junction of the epoxy composite material part 11 and the high-voltage metal insert 12, the outer contour of the epoxy composite material part 11 is perpendicular to the cylindrical side surface 16 of the high-voltage metal insert 12.

[0063] In this embodiment, the distance between the longitudinal symmetry planes of the single-post insulator and the double-post insulator is 6m, the distance between the longitudinal symmetry plane of the single-post insulator and the plane containing the maximum radius on the outer contour of the corner unit 19 is 5m, the distance between the longitudinal symmetry plane of the double-post insulator and the plane containing the maximum radius on the outer contour of the corner unit 19 is 5m, and the distance between the plane containing the maximum radius on the outer contour of the corner unit 19 and the basin insulator is 1m.

[0064] Based on the above structural size requirements, in this embodiment of the high-voltage DC GIL / GIS eccentric busbar, in order to reduce the accumulation of surface charge on the post insulator and to leave sufficient safety margin, the normal electric field strength E on the surface of the post insulator under the maximum operating voltage condition is... n Tangential electric field strength E on the surface of post insulator under lightning impulse conditions t The following conditions must be met. After optimization by the above-mentioned scheme of the present invention, the charge accumulation on the surface of the insulator body does not exceed 20 μC / m. 2 It meets the requirements for safe operation.

[0065]

[0066] Refer to Figures 6(a), 6(b), 6(c), 7(a), and 7(b). Figures 6(a), 6(b), and 6(c) show the distribution of the combined, tangential, and normal electric field strengths at the gas-solid interface of a single-post insulator under the operating voltage of a high-voltage DC GIL insulator, respectively. Figures 7(a) and 7(b) show the electric field strength distributions at the high-voltage and low-voltage solid-solid interfaces of a single-post insulator under the operating voltage of a high-voltage DC GIL insulator, respectively. Figures 6(a) and 6(b) show that under lightning impulse conditions, the combined and tangential electric field strengths at the gas-solid interface of the single-post insulator are both lower than their control values. Figure 6(c) shows that the normal electric field strength on the surface of the single-post insulator under the operating voltage is less than 1 kV / mm. Under eccentric configuration, the normal electric field strength on the surface of the single-post insulator is relatively low, indicating a reduction in surface charge accumulation. As can be seen from Figures 7(a) and 7(b), the surface electric field strength of the high-voltage and low-voltage metal inserts is less than 3kV / mm under the operating voltage conditions, which meets the requirements of the field strength control value of the internal insulator-metal interface of GIL / GIS and satisfies the operating conditions.

Claims

1. A high-voltage DC GIL / GIS eccentric busbar, characterized in that, The standard unit includes a metal shell (1), a current-carrying conductor, a high-voltage shielding conductor (3), a post insulator, and a concentric insulator. The concentric insulator is installed at both ends of the metal shell (1), and the current-carrying conductor is disposed inside the metal shell (1). The current-carrying conductor includes an eccentric section and a concentric current-carrying conductor (18). Both ends of the eccentric section are connected to the concentric current-carrying conductor (18). The axis of the concentric current-carrying conductor (18) is coaxial with the axis of the metal shell (1). The eccentric section includes several eccentric current-carrying conductors (2), the axis of which is parallel to the axis of the metal shell (1), and the axis of which is located above the axis of the metal shell (1). Several eccentric current-carrying conductors (2) are connected to form the eccentric section by high-voltage shielding conductors (3). The eccentric current-carrying conductor (2) at the end of the eccentric section is connected to one end of a concentric current-carrying conductor (18) through a corner unit (19). The other end of the concentric current-carrying conductor (18) is connected to a concentric insulator. The high-voltage shielding conductor (3) is connected to the metal shell (1) through the post insulator; a countersunk hole (6) is provided at the position where the high-voltage shielding conductor (3) is connected to the post insulator, the high-voltage end of the post insulator extends into the countersunk hole (6), and the high-voltage metal insert (12) of the post insulator is connected to the bottom of the countersunk hole (6); along the axial direction of the metal shell (1), the opening of the countersunk hole (6) is provided with a sloping shielding structure (7) on both sides of the post insulator, and the angle between the normal vector of the sloping shielding structure (7) facing the gas side and the axial direction of the post insulator is in the range of 40°~50°, and the axial direction of the post insulator is the direction from the high-voltage end to the low-voltage end on the axial direction of the post insulator.

2. The high-voltage DC GIL / GIS eccentric busbar according to claim 1, characterized in that, The eccentricity of the eccentric current-carrying conductor (2) is the ratio of the distance between the central axis of the eccentric current-carrying conductor (2) and the central axis of the metal shell (1) to the radius of the metal shell (1). The value of the eccentricity ranges from 0.1 to 0.

2.

3. The high-voltage DC GIL / GIS eccentric busbar according to claim 1, characterized in that, The annular gap width between the countersunk hole (6) and the epoxy composite material part (11) of the post insulator is in the range of 7~12mm, and the distance from the bottom of the countersunk hole (6) to the junction of the high voltage metal insert (12) and the epoxy composite material part (11) is in the range of 7~12mm.

4. The high-voltage DC GIL / GIS eccentric busbar according to claim 1, characterized in that, On the plane where the axis of the eccentric current-carrying conductor (2) and the axis of the high-voltage shielding conductor (3) are located, between the high-voltage metal insert (12) and the low-voltage metal insert (13) of the post insulator, the tangent direction at any point on the outer contour of the epoxy composite material part (11) of the post insulator is not perpendicular to the axis of the post insulator. On the epoxy composite part (11), the maximum outer diameter of the epoxy composite material within 25mm ± 20mm outside the top of the low-pressure metal insert (13) is greater than the maximum outer diameter of the epoxy composite material within 15mm ± 10mm outside the top of the high-pressure metal insert (12); the outer diameter of the epoxy composite material on the epoxy composite part (11) is smoothly transitioned from the maximum outer diameter of the oxygen composite material to the maximum outer diameter of the epoxy composite material.

5. A high-voltage DC GIL / GIS eccentric busbar according to claim 1, characterized in that, The side of the low-voltage metal insert (13) and high-voltage metal insert (12) of the post insulator that contacts the epoxy composite material part (11) of the post insulator includes a cylindrical side surface (16) and a smooth curved surface structure (15) with multiple circular arcs tangent to the end of the cylindrical side surface (16). The smooth curved surface structure (15) and part of the cylindrical side surface (16) are covered by the epoxy composite material part (11) of the post insulator. At the junction of the epoxy composite part (11) and the low-pressure metal insert (13), the outer contour of the epoxy composite part (11) is perpendicular to the cylindrical side surface (16) of the low-pressure metal insert (13). At the junction of the epoxy composite part (11) and the high-pressure metal insert (12), the outer contour of the epoxy composite part (11) is perpendicular to the cylindrical side surface (16) of the high-pressure metal insert (12).

6. A high-voltage DC GIL / GIS eccentric busbar according to claim 1, characterized in that, The outer surface of the corner unit (19) is a smooth arc-connected curved surface. The corner unit (19) has concentric connection holes (20) adapted to and connected to the concentric current-carrying conductor (18) and eccentric connection holes (21) adapted to and connected to the eccentric current-carrying conductor (2) at both ends of the metal shell (1) along the axial direction.

7. A high-voltage DC GIL / GIS eccentric busbar according to claim 6, characterized in that, The maximum radius of the outer contour of the corner unit (19) is R3, the minimum radius arc on the side with the concentric connecting hole (20) is r1, and the minimum radius arc on the side with the eccentric connecting hole (21) is r2; the radii of the concentric current-carrying conductor (18) and the eccentric current-carrying conductor (2) are both R. r1, r2, R3, and R satisfy the following relationship: 。 8. A high-voltage DC GIL / GIS eccentric busbar according to claim 1, characterized in that, A particle trap (4) is provided below the high-voltage shielding conductor (3) inside the metal shell (1).

9. A high-voltage DC GIL / GIS eccentric busbar according to any one of claims 1-8, characterized in that, The post insulators are single-post insulators and / or double-post insulators; Among them, the single-post insulator is set below the high-voltage shield conductor (3), and the axis of the single-post insulator is set along the vertical direction; The double-post insulator is located below the high-voltage shield conductor (3), and the two legs of the double-post insulator are located on both sides of the high-voltage shield conductor (3).

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