A three-phase three-pillar insulator for three-phase common box compact GIS / GIL

Abstract

The present invention discloses a three-phase three-pillar insulator for a three-phase common-box compact GIS / GIL, comprising an insulator belly and a conductor coating area and legs arranged on the insulator belly, the conductor coating area and the legs are alternately distributed in the circumferential direction of the insulator belly, a metal insert is arranged in the leg, the conductor coating area has an axial width greater than the axial thickness of the insulator belly, the conductor coating area and the insulator belly have a smooth transition through a first chamfer, the width of the legs is greater than the axial thickness of the insulator belly, the legs and the insulator belly have a smooth transition through a second chamfer, and the portion of the insulator belly between the legs and the conductor coating area has a smooth transition through a first arc segment, and the first arc segment is a concave arc segment. The surface composite field intensity, tangential field intensity and metal insert surface field intensity of the three-phase three-pillar insulator of the present invention can be greatly reduced, meeting the control value requirements in the project, thereby improving the stability of the insulator under long-term operation.

Description

Technical Field

[0001] The invention relates to the technical field of design, production and manufacturing of electric power equipment, and in particular to a three-phase three-pillar insulator for a three-phase common-box type compact GIS / GIL. Background Art

[0002] In order to realize the miniaturization design of GIS / GIL, improve the natural power of GIS / GIL power transmission, and save production and manufacturing costs, the design of GIS / GIL will develop into a three-phase common box type. When the system load and ambient temperature change, the change in temperature field will cause relative displacement between the conductor and the shell. To compensate for this phenomenon, a three-phase common box compact GIS / GIL requires an insulating support component suitable for the structural characteristics. GIS / GIL has many complex factors such as electrical, thermal, mechanical and surface defects, suspended particles, SF6 decomposition products, temperature changes, etc. The insulation structure is typical, the material properties are complex, and there are many factors that may cause discharge. When the three phases are in the same box, these problems are more prominent, which will become the cause of unknown discharge accidents. Therefore, there is an urgent need for a post insulator suitable for a three-phase common box compact GIS / GIL. Summary of the invention

[0003] The purpose of this patent is to propose a three-phase three-pillar insulator for a three-phase common-box compact GIS / GIL to solve the insulation problem of the three-phase common-box compact GIS / GIS during long-distance power transmission.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A three-phase three-pillar insulator for a three-phase common-box compact GIS / GIL comprises an insulator belly and a conductor coating area and legs arranged on the insulator belly, wherein the conductor coating area and the legs are alternately distributed in the circumferential direction of the insulator belly, a metal insert is arranged in the leg, the conductor coating area has an axial width greater than the axial thickness of the insulator belly, a first chamfer forms a smooth transition between the conductor coating area and the insulator belly, a second chamfer forms a smooth transition between the leg and the insulator belly, and a portion of the insulator belly between the leg and the conductor coating area forms a smooth transition through a first arc segment, wherein the first arc segment is an inwardly concave arc segment.

[0006] The conductor covering areas are arranged at three locations, which are located at the edge of the insulator belly and the distance from the insulator center should be greater than 100 mm. The side wall of the conductor covering area protruding from the insulator belly is an arc surface. The three conductor covering areas are respectively located at the vertices of the same isosceles triangle, and the vertex angle of the isosceles triangle ranges from 40° to 80°.

[0007] The legs are arranged at three locations, which are located at the edge of the belly of the insulator. The legs are cylindrical, truncated cone, prism and prism-shaped. The central axis of the legs is perpendicular to the central axis of the belly of the insulator. The three legs are respectively located at the vertices of the same isosceles triangle. The distance between the bottom of the legs and the center of the insulator is greater than 150 mm. The vertical angles between the central axes of the three legs are respectively the first angle, the second angle and the third angle. The first angle is equal to the second angle, and the size of the first angle and the second angle is between 110° and 130°.

[0008] The first chamfer and the second chamfer are circular chamfers, the first arc segment is a circular arc segment, the radius of the first chamfer is greater than or equal to 15 mm, and the radius of the second chamfer is greater than or equal to 20 mm.

[0009] A central conductor liner is provided at the conductor sheathing area. The central conductor liner passes through the conductor sheathing area. The central conductor liner is connected to the conductor sheathing area via an interface coating.

[0010] One end of the metal insert is connected to the support leg, and the other end of the metal insert is provided with a mounting hole. The metal insert is connected to the sliding contact through the mounting hole or is fixed to the mounting position by welding.

[0011] One end of the metal insert connected to the leg is connected to the leg via an interface coating. The end of the metal insert includes a plane segment and a curved segment. The plane segment and the curved segment are smoothly connected, and the curvature radius of the tangent curve of the curved segment is not less than 10 mm.

[0012] The metal insert is coaxial with the supporting leg connected thereto, and the axis thereof is perpendicular to the central axis of the insulator abdomen.

[0013] A central through hole for releasing internal stress is provided at the center of the insulator abdomen. The central through hole is a circular hole, and the edge thereof is arranged as an arc-shaped chamfer.

[0014] The first arc segment is in the shape of an arc, and the edge of the first arc segment is configured as an arc-shaped chamfer.

[0015] The present invention has the following beneficial effects:

[0016] In the three-phase three-pillar insulator for the three-phase common-box compact GIS / GIL of the present invention, the axial width of the conductor coating area is greater than the axial thickness of the insulator belly. Selecting a larger axial width of the conductor coating area is conducive to smoothing the outer contour of the conductor coating area, improving the capacitance distribution between the conductor and the metal insert, and uniformizing the synthetic field strength on the surface of the insulator, so that it meets the control index requirements of the insulator design. The width of the leg is greater than the axial thickness of the insulator belly, and the first arc segment between the leg and the conductor coating area adopts a concave arc segment design, which can effectively reduce the maximum value of the electric field intensity on the surface of the metal insert, so that the control index of the metal-epoxy interface field strength at the metal insert meets the requirements. The present invention can integrate three-phase conductors on one insulator to achieve three-phase common box. While meeting the design control index requirements, it solves the insulation technology problems of equipment miniaturization and compact design.

[0017] Furthermore, the distance between the bottom of the leg and the center of the insulator is ensured to be greater than 150 mm, the first angle is equal to the second angle and the size is between 110° and 130°, the pole spacing between the high-voltage and ground-voltage electrodes is controlled, the distribution of power lines passing through the surface of the insulator is improved, the tangential field strength value on the surface of the insulator is greatly reduced, the maximum value of the tangential field strength on the surface of the insulator is limited to below the control value, and the risk of surface discharge of the insulator during operation is reduced.

[0018] Furthermore, a central through hole for releasing internal stress is opened in the center of the insulator abdomen. The central through hole can not only relieve the internal stress generated by the insulator during the pouring and curing process to ensure the stability of the structure, but also reduce the weight of the insulator. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical route and scheme of the embodiment of the present invention, the following briefly introduces the drawings required for use in the embodiment. Obviously, for ordinary technicians in this field, other drawings can be obtained according to the following drawing descriptions without paying any creative work.

[0020] Figure 1 It is a schematic diagram of the axial side of a three-phase three-pillar insulator used for a three-phase common-box compact GIS / GIL in the implementation of the present invention;

[0021] Figure 2 It is a radial cross-sectional view of a three-phase three-pillar insulator used for a three-phase common-box compact GIS / GIL in the implementation of the present invention.

[0022] Figure 3 It is an axial cross-sectional view of a three-phase three-pillar insulator used for a three-phase common-box compact GIS / GIL in the implementation of the present invention.

[0023] FIG4 (a) is a schematic diagram of key parameters of a three-phase three-pillar insulator used for a three-phase common-box compact GIS / GIL in an embodiment of the present invention;

[0024] FIG4( b ) is an enlarged schematic diagram of portion A in FIG4( a ).

[0025] Figure 5 This is a diagram showing the electric field distribution on the surface of the metal insert under operating conditions in an embodiment of the present invention.

[0026] Figure 6 This is a synthetic field strength distribution diagram of a three-phase three-pillar insulator under a lightning impulse for a three-phase common-box compact GIS / GIL in an embodiment of the present invention.

[0027] Figure 7 This is a tangential field strength distribution diagram of a three-phase three-pillar insulator under lightning impulse for a three-phase common-box compact GIS / GIL in an embodiment of the present invention.

[0028] Figure 8 It is a schematic cross-sectional view of a three-phase three-pillar insulator used for a three-phase common-box compact GIS / GIL in the implementation of the present invention.

[0029] In the figure: 1-conductor coating area, 2-rib belly, 3-leg, 4-metal insert, 5-first chamfer, 6-center conductor liner, 7-second chamfer, 8-first vertex, 9-second vertex, 10-first arc segment, 11-mounting hole, 12-plane segment, 13-arc segment. DETAILED DESCRIPTION

[0030] In order to more clearly illustrate the embodiments of the present invention, the drawings required for the embodiments will be briefly introduced below, and the technical routes and solutions of the present invention will be described in detail. Obviously, for ordinary technicians in this field, other drawings can be obtained based on the drawings without paying any creative work.

[0031] The present invention is further described below in conjunction with the accompanying drawings.

[0032] Reference Figure 1~ Figure 4 (a), Figure 4 (b), the three-phase three-pillar insulator for three-phase common-box compact GIS / GIL of the present invention includes an insulator belly 2 and a conductor coating area 1 and a leg 3 arranged on the insulator belly 2, the conductor coating area 1 and the leg 3 are alternately distributed in the circumferential direction of the insulator belly 2, a metal insert 4 is arranged in the leg 3, the axial width of the conductor coating area 1 is greater than the axial thickness of the insulator belly 2, the conductor coating area 1 and the insulator belly 2 are smoothly transitioned through a first chamfer 5, the width of the leg 3 is greater than the axial thickness of the insulator belly 2, the leg 3 and the insulator belly 2 are smoothly transitioned through a second chamfer 7, and the portion of the insulator belly 2 between the leg 3 and the conductor coating area 1 is smoothly transitioned through a first arc segment 10, and the first arc segment 10 is an inwardly concave arc segment.

[0033] As a preferred embodiment of the present invention, the conductor coating area 1 is provided at three locations, the three conductor coating areas 1 are located at the edge of the insulator belly 2, and the distance from the insulator center is greater than 100 mm, the side wall of the conductor coating area 1 protruding from the insulator belly 2 is an arc surface, and the three conductor coating areas 1 are respectively located at the vertices of the same isosceles triangle, and the vertex angle of the isosceles triangle ranges from 40° to 80°.

[0034] As a preferred embodiment of the present invention, three legs 3 are provided, and the three legs 3 are located at the edge of the insulator belly 2. The legs 3 are cylindrical, truncated, prism-shaped or prism-shaped. The central axis of the legs 3 is perpendicular to the central axis of the insulator belly 2. The three legs 3 are respectively located at the vertices of the same isosceles triangle. Figure 8 , upper leg (i.e. Figure 8 The axis of the top leg in the middle is connected to the side leg (i.e. Figure 8 The angle between the axes of the two legs at the bottom (i.e., the first angle 14 and the second angle 15) is between 110° and 130°, and the distance between the bottom of the legs and the center of the insulator is greater than 150 mm. As a preferred embodiment of the present invention, the first chamfer 5 and the second chamfer 7 are circular chamfers, the first arc segment 10 is a circular arc segment, the radius of the first chamfer 5 is greater than 15 mm, and the radius of the second chamfer 5 is greater than or equal to 20 mm.

[0035] As a preferred embodiment of the present invention, a central conductor liner 6 is provided at the conductor coating area 1. The central conductor liner 6 passes through the conductor coating area 1. The central conductor liner 6 is connected to the conductor coating area 1 via an interface coating.

[0036] As a preferred embodiment of the present invention, one end of the metal insert 4 is connected to the leg 3, and the other end of the metal insert 4 is provided with a mounting hole 11, and the metal insert 4 is connected to the sliding contact through the mounting hole 11 or is welded and fixed to the mounting position.

[0037] As a preferred embodiment of the present invention, one end of the metal insert 4 connected to the leg 3 is connected to the leg 3 via an interface coating, and the end of the metal insert 4 includes a plane segment 12 and a curved segment 13, the plane segment 12 and the curved segment 13 are smoothly connected, and the curvature radius of the tangent curve of the curved segment 13 is not less than 10 mm.

[0038] As a preferred embodiment of the present invention, the metal insert 4 is coaxial with the corresponding leg 3 connected thereto, and the axis is perpendicular to the central axis of the insulator abdomen 2 .

[0039] As a preferred embodiment of the present invention, a central through hole for releasing internal stress is provided at the center of the insulator abdomen 2 . The central through hole is a circular hole, and the edge thereof is provided with an arc-shaped chamfer.

[0040] As a preferred embodiment of the present invention, the first arc segment 10 is in an arc shape, and the edge of the first arc segment 10 is configured as an arc chamfer.

[0041] Example

[0042] like Figure 1 As shown in the figure, the three-phase three-post insulator for the three-phase common box type compact GIS / GIL of this embodiment comprises three main components: a conductor coating area 1, an insulator abdomen 2 and a leg 3. The leg is cylindrical and has a metal insert 4 inside. The center conductor 6 passes through the insulator through the conductor coating area 1 of the three-phase three-post insulator. Figure 2 ~ Figure 4 (a), Figure 4 (b), Figure 8 As shown, the conductor coating area 1 includes a first vertex 8, which is a point on the conductor coating area 1 away from the center of the insulator belly 2, and the leg 3 includes a second vertex 9, which is a point on the outer edge of the top of the leg 3 and adjacent to the conductor coating area 1. The first arc segment 10 of the insulator belly 2 should be on the side of the line between the first vertex 8 and the second vertex 9 close to the symmetric center of the insulator. The metal insert 4 is closely connected to the leg 3 through the interface coating layer. The metal insert 4 is provided with a mounting hole 11. The mounting hole 11 includes a threaded hole for threaded connection. The metal insert 4 can be connected to the sliding roller or fixed to the particle collector through the mounting hole 11 by bolts. The three leg axes form a first angle 14, a second angle 15 and a third angle 16. The upper leg is located on the perpendicular bisector of the two conductor coating areas 1, and the axis of the upper leg coincides with the perpendicular bisector. The three conductor coating areas 1 are respectively at the vertices of the same isosceles triangle, and the vertex angle of the isosceles triangle is 67°. The distance between the three conductor coating areas 1 and the center of the insulator is 157mm. The vertical angles of the central axis of the three legs 3 are: the first angle 14 is 122°, the second angle 15 is 122°, and the third angle 16 is 116°. A central through hole for internal stress release is opened in the center of the insulator abdomen 2. The central through hole is a circular hole with an arc chamfered edge. The diameter of the through hole is 110mm and the chamfer is 10mm.

[0043] See also Figure 3 4 (a) and 4 (b), the axial width D1 of the conductor coating area 1 is greater than the axial width of the insulator belly 2, and the conductor coating area 1 and the insulator belly 2 are smoothly transitioned by the first chamfer 5. Preferably, the value of D1 can be 120mm, the value of the first chamfer 5 can be 50mm, and the thickness of the insulator belly 2 can be 60mm. The diameter D2 of the leg 3 is greater than the axial width of the insulator belly 2, and the leg 3 and the insulator belly 2 are smoothly transitioned by the second chamfer 7. The metal insert 4 includes a smoothly connected plane segment 12 and an arc segment 13, the shape of the plane segment 12 is circular, the arc segment 13 is an arc surface, the plane segment 12 is tangent to the arc segment 13, and the curvature radius of the tangent curve of the arc segment 13 is not less than 10mm. The axis of the rotation axis of the metal insert 4 is perpendicular to the central axis of the three-phase three-pillar insulator. Preferably, D2 can be 112 mm, the diameter D3 of the plane segment 12 can be 12 mm, and the radius R4 of the arc segment 13 can be 35 mm. The portion of the insulator abdomen 2 between the leg 3 and the conductor coating area 1 smoothly transitions through the first arc segment 10, and the first arc segment 10 is a concave arc segment. Preferably, the first arc segment is composed of a straight line segment and an arc tangent to the arc, and the arc radius is 100 mm.

[0044] Using the finite element calculation method, when the center conductor is loaded with the actual operating voltage, the electric field intensity on the surface of the insulator metal insert is as follows: Figure 5 As shown in Figure 2, the maximum electric field strength on the metal insert surface is 2.28 kV / mm, which is less than the control value of 3 kV / mm under operating conditions. When the central conductor is loaded with the lightning impulse test voltage, the composite field strength and tangential field strength on the insulator surface are as follows: Figure 6 and Figure 7 The maximum value of the composite electric field strength on the insulator surface is 21.5 kV / mm, and the maximum value of the tangential electric field strength is 11.7 kV / mm, which are lower than the control electric field strength index of 24 kV / mm and 12 kV / mm respectively.

[0045] The manufacturing and installation process of the present invention is as follows:

[0046] 1. Prepare the insulator raw materials in the installation ratio, and apply the interface material on the metal insert and the center conductor;

[0047] 2. Casting: The center conductor and metal insert are installed on the purchased mold, and the insulating parts are cast using vacuum casting equipment;

[0048] 3. Curing: Curing is divided into two stages. The casting mold is placed in a specified temperature environment for curing for a certain period of time, then taken out, the mold is filled with material through the gate, and then placed in a specified temperature environment for secondary curing for a certain period of time;

[0049] 4. After curing is completed, slowly cool down and then slowly heat up and cool down again to release the internal stress of the insulator.

[0050] 5. During installation, insert the current-carrying tube mother through the center conductor and crimp it to fix it. The metal insert is connected to the mounting bolts of the pulley, and the entire insulator contacts the shell through the roller.

[0051] The present invention proposes for the first time a three-pillar insulator for a three-phase common-box compact GIS / GIL, which is used to solve the problem of stress concentration inside the insulating part due to the different relative expansion degrees of the conductor and the shell caused by the change in temperature field distribution when the three-phase common-box compact GIS / GIL is used for long-distance power transmission. Under the design of the present invention, the surface composite field strength, tangential field strength and metal insert surface field strength of the three-phase three-pillar insulator can be greatly reduced, meeting the control value requirements in the project, thereby improving the stability of the insulator under long-term operation.

[0052] The three-phase three-pillar insulator can be scaled up or down in proportion and applied to AC three-phase transmission systems of different voltage levels. In addition, pillar insulators applied to three-phase common box GIS / GIL manufactured with different filling materials, different shapes of inserts, different numbers of legs and different design ideas are all within the scope of protection of this patent.

[0053] In summary, the three-phase three-pillar insulator of the present invention can significantly reduce the size of the insulator, reduce the volume of the insulator, and reduce the production cost when the maximum value of the insulator composite field strength, the maximum value of the insulator tangential field strength, and the maximum value of the metal insert surface field strength meet the design index requirements. At the same time, it can solve the stress concentration phenomenon of 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 coefficient of the insulator and the center conductor.

[0054] It should be understood that various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. The present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein. The scope of this application is limited by the appended claims.

[0055] The insulator design can maintain its surface electric field design index at a more optimal value, and at the same time can relieve the insulator stress concentration caused by temperature field changes caused by load and temperature changes during operation, thereby reducing the probability of insulator damage and improving the safety and operational reliability of three-phase common-box compact GIS / GIS.

Claims

1. A three-phase three-pillar insulator for a three-phase common box compact GIS / GIL, characterized in that: The insulator comprises an insulator belly (2) and a conductor coating area (1) and a leg (3) arranged on the insulator belly (2), wherein the conductor coating area (1) and the leg (3) are alternately distributed in the circumferential direction of the insulator belly (2), a metal insert (4) is arranged in the leg (3), the width of the conductor coating area (1) along the axial direction is greater than the thickness of the insulator belly (2) along the axial direction, a first chamfer (5) is formed between the conductor coating area (1) and the insulator belly (2) to smoothly transition, the width of the leg (3) is greater than the thickness of the insulator belly (2) along the axial direction, a second chamfer (7) is formed between the leg (3) and the insulator belly (2), and a portion of the insulator belly (2) between the leg (3) and the conductor coating area (1) smoothly transitions through a first arc segment (10), and the first arc segment (10) is an inwardly concave arc segment; The conductor coating areas (1) are arranged at three locations, the three conductor coating areas (1) are located at the edge of the insulator belly (2), and the distance from the insulator center is greater than 100 mm, the side wall of the conductor coating area (1) protruding from the insulator belly (2) is an arc surface, and the three conductor coating areas (1) are respectively located at the vertices of the same isosceles triangle, and the vertex angle of the isosceles triangle ranges from 40° to 80°; The legs (3) are arranged at three locations, the three legs (3) are located at the edge of the insulator belly (2), the legs (3) are cylindrical, truncated cone, prism or prism-shaped, the central axis of the legs (3) is perpendicular to the central axis of the insulator belly (2), the three legs (3) are respectively located at the vertices of the same isosceles triangle, the distance between the bottom of the legs (3) and the center of the insulator is greater than 150 mm, the vertical angles of the central axes of the three legs (3) are respectively a first angle (14), a second angle (15) and a third angle (16), the first angle (14) is equal to the second angle (15), and the magnitude of the first angle (14) and the second angle (15) is between 110° and 130°.

2. A three-phase three-pillar insulator for a three-phase common-box compact GIS / GIL according to claim 1, characterized in that: The first chamfer (5) and the second chamfer (7) are circular chamfers, the first arc segment (10) is a circular arc segment, the radius of the first chamfer (5) is greater than or equal to 15 mm, and the radius of the second chamfer (7) is greater than or equal to 20 mm.

3. A three-phase three-pillar insulator for a three-phase common-box compact GIS / GIL according to claim 1, characterized in that: A central conductor liner (6) is provided at the conductor coating area (1). The central conductor liner (6) passes through the conductor coating area (1). The central conductor liner (6) and the conductor coating area (1) are connected via an interface coating.

4. A three-phase three-pillar insulator for a three-phase common box type compact GIS / GIL according to claim 1, characterized in that: One end of the metal insert (4) is connected to the support leg (3), and the other end of the metal insert (4) is provided with a mounting hole (11). The metal insert (4) is connected to the sliding contact through the mounting hole (11) or is fixed to the mounting position by welding.

5. A three-phase three-pillar insulator for a three-phase common-box compact GIS / GIL according to claim 4, characterized in that: One end of the metal insert (4) connected to the support leg (3) is connected to the support leg (3) via an interface coating, and the end of the metal insert (4) comprises a plane section (12) and a curved surface section (13), the plane section (12) and the curved surface section (13) are smoothly connected, and the curvature radius of the tangent curve of the curved surface section (13) is not less than 10 mm.

6. A three-phase three-pillar insulator for a three-phase common-box compact GIS / GIL according to claim 4, characterized in that: The metal insert (4) is coaxial with the supporting leg (3) to which it is connected, and the axis thereof is perpendicular to the central axis of the insulator belly (2).

7. The three-phase three-pillar insulator for a three-phase common-box compact GIS / GIL according to claim 1, characterized in that: A central through hole (2-1) for releasing internal stress is provided at the center of the insulator abdomen (2); the central through hole (2-1) is a circular hole, and the edge of the central through hole (2-1) is arranged as an arc-shaped chamfer.

8. The three-phase three-pillar insulator for a three-phase common-box compact GIS / GIL according to claim 1, characterized in that: The first arc segment (10) is in the shape of an arc, and the edge of the first arc segment (10) is arranged as an arc-shaped chamfer.

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