A pot-type insulator

Abstract

The present invention belongs to the technical field of high-voltage power transmission, and discloses a pot-type insulator, including an insulating pot body and a central conductor, wherein the central conductor adopts a drum-shaped body of revolution structure, and the side surface of the central conductor includes a convex surface and cylindrical side surfaces at both ends of the convex surface, wherein the convex surface is a smooth curved surface, and the end of the convex surface is transitionally connected to the side surface through a chamfered transition surface, and the convex surface and the chamfered transition surface are both connected to the insulating pot body, and the chamfered transition surface includes a first straight line segment and a transition curved surface, wherein the first straight line segment is connected to the side surface, and the junction of the first straight line segment and the side surface is a three-intersection point, wherein the angle between the first straight line segment and the central axis of the central conductor is 30° to 60°, and one end of the transition curved surface is connected to the first straight line segment, and the other end is connected to the convex surface. The present invention can reduce the stress value at the three-intersection point of the central conductor, the insulating pot body, and the gas of the pot-type insulator through reasonable structural design, improve the mechanical strength of the pot-type insulator, and thus ensure the safe operation of the transmission line.

Description

Technical Field

[0001] The invention belongs to the technical field of high-voltage power transmission, and in particular relates to a pot-type insulator. Background Art

[0002] Gas-insulated metal-enclosed transmission lines (GIL) have the advantages of large transmission capacity, low energy loss, small footprint, and little environmental impact. They have broad application prospects in chemical industry, nuclear power, offshore wind power, flexible direct current transmission, urban pipeline transmission and other fields.

[0003] GIL uses compressed gas as the insulating medium, and uses insulators to mechanically support and electrically insulate the high-voltage guide rod. The basin insulator is a key component of GIL. It is affected by multiple effects such as electric field and temperature for a long time. It also needs to isolate the gas chamber and withstand a certain axial pressure load. Its operating conditions are complex. Insufficient mechanical strength can easily cause discharge and explosion, threatening the safe and stable operation of GIL.

[0004] Defects and shortcomings of the prior art: The bonding strength between the metal parts of the basin insulator and the epoxy casting is low, and due to uneven sandblasting, oil pollution, curing shrinkage and other reasons, the process dispersion of the bonding area near the three intersections of the center conductor, the insulating basin and the gas is much higher than the internal area of ​​the bonding surface of the center conductor and the insulating basin. However, under operating conditions, the stress concentration at the three intersections is serious, which may lead to the following results: (1) cracks form air gaps at the three junctions, and discharge under operating conditions; (2) cracks form at the three junctions, and the stress concentration at the crack tip is aggravated, resulting in interface debonding and the insulator bursting under pressure. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a pot-type insulator. Through reasonable structural design, the present invention can reduce the stress value at the three intersections of the central conductor, insulating pot body and gas of the pot-type insulator, improve the mechanical strength of the pot-type insulator, and thus ensure the safe operation of the transmission line.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A basin insulator comprises an insulating basin body and a central conductor arranged at the axis of the insulating basin body, wherein the central conductor adopts a drum-shaped body of revolution structure, and the side surface of the central conductor comprises a convex surface and cylindrical side surfaces at both ends of the convex surface, the convex surface is a smooth curved surface, and the end of the convex surface is transitionally connected to the side surface through a chamfered transition surface, and the convex surface and the chamfered transition surface are both connected to the insulating basin body, and the chamfered transition surface comprises a first straight line segment and a transition curved surface, the first straight line segment is connected to the side surface, and the connection between the first straight line segment and the side surface is a three-intersection point, and the angle between the first straight line segment and the central axis of the central conductor is 30°~60°, one end of the transition curved surface is connected to the first straight line segment, and the other end of the transition curved surface is connected to the convex surface.

[0008] Preferably, the junction between the first straight line segment and the side surface is connected by a circular arc surface transition.

[0009] Preferably, the transition curved surface comprises a second straight line segment, one end of the second straight line segment is connected to the first straight line segment via a first arc segment, and the other end of the second straight line segment is connected to the convex surface via a second arc segment;

[0010] One end of the first arc segment is tangent to the second straight line segment, the other end of the first arc segment is tangent to the first straight line segment, one end of the second arc segment is tangent to the second straight line segment, and the other end of the second arc segment is tangent to the convex surface.

[0011] Preferably, one end of the convex surface is set as a first arc surface, and the other end of the convex surface is set as a second arc surface, the curvature radius of the first arc surface and the second arc surface are both 10~20mm, the distance between the arc center of the first arc surface and the central axis of the center conductor is not less than the distance between the three intersections and the central axis of the center conductor, the distance between the arc center of the second arc surface and the central axis of the center conductor is not less than the distance between the three intersections and the central axis of the center conductor, and the distance between the arc center of the first arc surface and the arc center of the second arc surface is 40~50mm.

[0012] Preferably, the maximum distance between the raised surface and the central axis of the central conductor is 1.1 to 1.25 times the distance between the three intersection points and the central axis of the central conductor.

[0013] Preferably, both side end surfaces of the central conductor are provided with an annular stress relief groove, and the stress relief groove is coaxial with the central conductor.

[0014] Preferably, the stress release groove is a U-shaped groove.

[0015] Preferably, the stress relief groove has a depth of 10-15 mm and a width of 3-8 mm, and a net distance between the stress relief groove and the side surface does not exceed 5 mm.

[0016] Preferably, the low-voltage end of the insulating basin is provided with a low-voltage end shielding spring and a grounding metal insert, wherein the low-voltage end shielding spring is arranged inside the low-voltage end of the insulating basin.

[0017] Preferably, the insulating basin body adopts a bowl-shaped rotating body structure, and the thickness of the high-voltage end and the low-voltage end of the insulating basin body is greater than the thickness of the portion between the high-voltage end and the low-voltage end.

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

[0019] In the basin-type insulator of the present invention, the side of the central conductor has a convex surface, and the convex surface can penetrate into the center conductor-basin bonding surface at the center of the insulating basin body, so that the convex surface can bear a certain axial force, resist the transmission of stress, and then reduce the stress distribution at the three intersections, and indirectly reduce the stress value of the three intersections. The angle between the first straight line segment in the chamfered transition surface and the central axis of the central conductor is 30°~60°. The force direction of the bonding surface at the three intersections is changed by the first straight line segment, that is, the stress of the three intersections is decomposed into normal stress and shear stress along the first straight line segment and the direction perpendicular to the first straight line segment by the first straight line segment, and the stress value of the three intersections can be reduced to below the maximum stress value of the convex surface. Therefore, the position of the maximum stress of the bonding surface moves from the three intersections to the inside of the interface curve, thereby reducing the stress value of the three intersections, which is conducive to avoiding the formation of air gaps and cracks at the three junctions (i.e., the three intersections). It can be seen from the above scheme that the present invention can reduce the stress value at the three intersections of the central conductor, insulating basin and gas of the basin insulator through reasonable structural design, improve the mechanical strength of the basin insulator, and thus ensure the safe operation of the transmission line. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A three-dimensional cross-sectional view (along the central axis x) of a pot-type insulator in an embodiment of the present invention;

[0021] FIG2( a ) is a top view of a pot-type insulator in an embodiment of the present invention; FIG2( b ) is an AA cross-sectional view of FIG2( a );

[0022] Figure 3 is a cross-sectional view of a central conductor in an embodiment of the present invention;

[0023] Figure 4 It is an enlarged schematic diagram of area B in Figure 2 (b);

[0024] Figure 5 A detailed structural diagram of the lower chamfered transition surface connecting the raised surface and the lower three intersection points in an embodiment of the present invention;

[0025] Figure 6 is a cross-sectional view of a central conductor of a comparative example (i.e., prior art);

[0026] Figure 7 A comparison diagram of stress distribution on the bonding surface of the central conductor insulation basin of the embodiment of the present invention and the comparative example;

[0027] Figure 8 The figure is a comparison diagram of the electric field distribution on the bonding surface of the central conductor-insulating basin body of the embodiment of the present invention and the comparative example.

[0028] In the figure, 1-insulating basin, 2-center conductor, 3-low-voltage end shielding spring, 4-grounding metal insert, 5-concave surface, 6-convex surface, 7-grounding surface, 8-center conductor-basin bonding surface, 9-inner end surface, 10-outer end surface, 11-side surface, 12-stress release groove, 13-insulating gas, 14-lower three intersection points, 15-convex surface, 16-upper chamfered transition surface, 17-lower chamfered transition surface, 18-upper three intersection points, L1-first straight line segment, L2-second straight line segment, R1-first arc surface, R2-second arc surface, R3-first arc segment, R4-second arc segment, R5-third arc surface. DETAILED DESCRIPTION

[0029] According to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structures and implementations. Therefore, the following specific implementation methods and drawings are only examples of the technical solution of the present invention and should not be regarded as the entirety of the present invention or the limitation of its technical solution.

[0030] Reference Figure 1-Figure 5 The pot-type insulator of this embodiment includes an insulating pot body 1 and a central conductor 2 arranged at the axis of the insulating pot body 1. The central conductor 2 adopts a drum-shaped rotating body structure. The side surface of the central conductor 2 includes a convex surface 15 and cylindrical side surfaces 11 at both ends of the convex surface 15. The convex surface 15 is a smooth curved surface. Figure 4 and Figure 5 , the end of the convex surface 15 (ie Figure 3 In the orientation shown, the upper and lower ends of the convex surface 15 are transitionally connected to the side surface 11 through a chamfered transition surface. The convex surface 15 and the chamfered transition surface are both connected to the insulating basin 1. The chamfered transition surface includes a first straight line segment L1 and a transition curved surface. The first straight line segment L1 is connected to the side surface 11. The junction of the first straight line segment L1 and the side surface 11 is a triple intersection (i.e., the triple point of the central conductor 2, the insulating basin 1 and the gas). The convex surface 15 and the chamfered transition surface are both connected to the insulating basin 1. The convex surface 15 and the chamfered transition surface together constitute the central conductor-basin bonding surface 8, see Figure 3After the center conductor 2 is connected to the insulating basin 1, the center conductor-basin bonding surface 8 is covered by the side of the center hole of the insulating basin 1, the angle between the first straight line segment L1 and the center axis of the center conductor 2 is 30°~60°, one end of the transition curve is connected to the first straight line segment L1, and the other end of the transition curve is connected to the convex surface 15. In this embodiment, the function of the first straight line segment L1 is to adjust the stress of the center conductor-basin bonding surface 8 at the three intersections: if there is no first straight line segment L1, the bonding surface at the three intersections is parallel to the center axis, and the insulating basin 1 is mainly subjected to the tensile stress perpendicular to the bonding surface. σ y and shear stress τ xy When the angle between the first straight line segment L1 and the central axis of the central conductor 2 is 30°~60°, the inclined first straight line segment L1 bears part of the shear strain, so that the tensile stress σ y and shear stress τ xy Both can be reduced.

[0031] As a preferred implementation scheme of the above scheme, in this embodiment, the transition position between the side surface 11 and the upper and lower end surfaces of the center conductor 2 is transitioned by arc chamfering, which helps to evenly distribute the electric field at the edge of the center conductor 2.

[0032] As a preferred implementation scheme of the above scheme, in this embodiment, the transition curved surface is tangent to both the first straight line segment L1 and the convex surface 15, which can avoid stress concentration at the connection.

[0033] As a preferred implementation scheme of the above scheme, in this embodiment, the junction of the first straight segment L1 and the side surface 11 is connected by a circular arc surface transition. Since the cross-sections of the first straight segment L1 and the side surface 11 along the axial direction of the center conductor 2 are both straight lines, the stress concentration phenomenon at the corner where the first straight segment L1 and the side surface 11 meet can be reduced or avoided after the circular arc surface transition connection is adopted, and the three intersections are located on the circular arc surface, so that the thickness of the central hole of the insulating basin body 1 at this location is in a gradual (i.e., gradually decreasing) state, and the material of the thinner insulating basin body 1 is relatively more deformable, so even if the insulating basin body 1 and the center conductor 2 are relatively deformed after being subjected to force, the portion of the insulating basin body 1 with a smaller thickness (i.e., the three intersections) is easy to deform to a certain extent along with the corner where the first straight segment L1 meets the side surface 11, thereby reducing the possibility of the insulating basin body 1 and the center conductor 2 being easily separated at the three intersections to produce air gaps and cracks, thereby improving the safety of the basin insulator.

[0034] As an alternative implementation of the above scheme, see Figure 5In this embodiment, the transition surface can adopt the following structure, that is, the transition surface includes a second straight line segment L2, a first arc segment R3 and a second arc segment R4, wherein the right end of the second straight line segment L2 is connected to the left end of the first straight line segment L1 through the first arc segment R3, and the left end of the second straight line segment L2 is connected to the end of the convex surface 15 through the second arc segment R4; wherein the two ends of the first arc segment R3 are tangent to the second straight line segment L2 and the first straight line segment L1 respectively, and the two ends of the second arc segment R4 are tangent to the second straight line segment L2 and the convex surface 15 respectively. The above structure can avoid the stress concentration phenomenon at the connecting corners. The transition surface designed in this embodiment ensures that the insulating basin 1 has a certain thickness along the central axis direction at the three intersections, which is conducive to uniform electric field distribution.

[0035] As an alternative implementation of the above scheme, see Figure 3 In this embodiment, the upper and lower ends of the convex surface 15 are set as arc surfaces with a curvature radius of 10~20mm. The arc surface at the upper end of the convex surface 15 is recorded as the first arc surface R1, and the arc surface at the lower end of the convex surface 15 is recorded as the second arc surface R2. The distance between the arc center of the first arc surface R1 and the central axis of the center conductor 2 is not less than the distance between the three intersections and the central axis of the center conductor 2, and the distance between the arc center of the second arc surface R2 and the central axis of the center conductor 2 is not less than the distance between the three intersections and the central axis of the center conductor 2, that is, the radius corresponding to the arc center of the first arc surface R1 and the second arc surface R2 is greater than the radius corresponding to the three intersections; the distance between the arc center of the first arc surface R1 and the arc center of the second arc surface R2 is 40~50mm. In this embodiment, the combination of the first arc surface R1 and the second arc surface R2 constructs the main structure of the "drum-shaped" center conductor 2, increases the contact area between the insulating basin 1 and the center conductor 2, and bears most of the stress on the center conductor-basin bonding surface 8, thereby reducing the stress at the three intersections; at the same time, it plays a role in uniform electric field distribution.

[0036] As a preferred implementation scheme of the above scheme, in this embodiment, the maximum diameter of the raised surface 15 is 1.1 to 1.25 times the diameter of the side surface 11. The central conductor 2 is raised toward the insulating basin 1, so that the raised surface 15 can withstand a certain axial force, thereby reducing the three-point stress. However, when it exceeds a certain value, the electric field strength on the surface of the insulator will increase, reducing the electrical performance of the insulator. Therefore, the size of the central conductor 2 (i.e., the diameter of the raised surface 15) needs to be constrained.

[0037] As a preferred embodiment of the above scheme, see Figure 3In this embodiment, an annular stress release groove 12 is provided on both side end surfaces of the center conductor 2 (i.e., the upper end surface and the lower end surface of the center conductor 2), and the stress release groove 12 is coaxial with the center conductor 2. The use of the stress release groove 12 can improve the deformability of the center conductor 2, which is conducive to reducing the deformation at the three intersections, thereby reducing the stress at the three intersections.

[0038] As a preferred embodiment of the above scheme, see Figure 3 In this embodiment, the stress release groove 12 is a U-shaped groove, and the bottom of the stress release groove 12 is an arc surface, which can avoid stress concentration.

[0039] As an optional implementation scheme of the above scheme, in this embodiment, the depth of the stress release groove 12 is 10-15 mm, the width is 3-8 mm, and the net distance between the stress release groove 12 and the side surface 11 does not exceed 5 mm. The stress release groove 12 of the above structure of this embodiment is a narrow, deep and long structure close to the edge, and the stress release groove 12 of this structure is conducive to releasing the stress of the three intersections; when the net distance between the stress release groove 12 and the side surface 11 is too small, it is easy to cause the central conductor 2 to deform, so the size and position of the stress release groove 12 should be limited.

[0040] As an alternative implementation of the above scheme, see Figure 1 2 (a) and 2 (b), in this embodiment, the low-voltage end of the insulating basin 1 is provided with a low-voltage end shielding spring 3 and a grounding metal insert 4, wherein the low-voltage end shielding spring 3 is arranged inside the low-voltage end of the insulating basin 1. In this embodiment, the functions of the low-voltage end shielding spring 3 and the grounding metal insert 4 are to achieve grounding and shield the electric field of the grounding end.

[0041] As an alternative implementation of the above scheme, see Figure 1 As shown in FIG. 2 ( b ), the insulating basin 1 adopts a bowl-shaped rotating body structure, and the thickness of the high-voltage end and the low-voltage end of the insulating basin 1 is greater than the thickness of the part between the high-voltage end and the low-voltage end. The insulating basin 1 of this structure can increase the creepage distance and uniformly distribute the stress of the insulating basin 1 .

[0042] As a preferred implementation scheme of the above scheme, the three intersection points are located at the apex of the angle, and the concave surface 5 of the insulating basin 1 (i.e., the inner surface of the bowl-shaped rotating body structure) is perpendicular to the central axis of the central conductor 2 at the three intersection points, see Figure 5The convex surface 6 of the insulating basin body 1 (i.e., the outer surface of the bowl-shaped gyratory structure) is perpendicular to the central axis of the central conductor 2 at the three intersections, so the thickness of the insulating basin body 1 at the three intersections is in a gradual state, and the closer to the three intersections, the thinner the insulating basin body 1 is. The material of the thinner insulating basin body 1 is relatively more deformable. Therefore, even if the insulating basin body 1 and the central conductor 2 are relatively deformed after being subjected to force, the portion of the insulating basin body 1 with a smaller thickness (i.e., the three intersections) is easy to deform to a certain extent along with the corner where the first straight line segment L1 and the side surface 11 meet, thereby reducing the possibility of the insulating basin body 1 and the central conductor 2 being easily separated at the three intersections to produce air gaps and cracks, thereby improving the safety of the basin insulator.

[0043] Example 1

[0044] like Figure 1-Figure 5 As shown, the pot-type insulator provided in this embodiment includes an insulating pot body 1, a center conductor 2, a low-voltage end shielding spring 3 and a grounding metal insert 4. The insulating pot body 1 and the center conductor 2 are coaxially arranged, and the low-voltage end shielding spring 3 is placed inside the insulating pot body 1 and grounded through the grounding metal insert 4.

[0045] like Figure 1 As shown, in this embodiment, the insulating basin body 1 is a bowl-shaped rotating body structure, and the high-voltage end and the low-voltage end of the insulating basin body 1 are thicker than the middle part (i.e., the part between the high-voltage end and the low-voltage end). Specifically, the insulating basin body 1 includes a concave surface 5, a convex surface 6, a grounding surface 7 and a center hole. The center hole of the insulating basin body 1 is used to install the center conductor 2. Specifically, during installation, the center hole of the insulating basin body 1 is covered on the center conductor-basin body bonding surface 8 of the center conductor 2. The above-mentioned concave surface 5 and convex surface 6 are both smooth curves formed by multiple tangent arcs. The central axis direction of the insulating basin body 1 is set to the axial direction x, and the direction perpendicular to the central axis of the insulating basin body 1 is set to the radial direction y. The center conductor 2 is a drum-shaped rotating body structure as a whole, refer to Figure 1 The inner end surface 9 (i.e., the end surface of the center conductor 2 located on the concave surface 5 side) and the outer end surface 10 (i.e., the end surface of the center conductor 2 located on the convex surface 6 side) can be connected to the current-carrying structure of the GIL or GIS, such as Figure 3 As shown, the side surface of the center conductor 2 includes a center conductor-basin bonding surface 8 and a side surface 11 exposed to the insulating gas 13, wherein the side surface 11 is a cylindrical surface.

[0046] The main part of the center conductor-basin bonding surface 8 is a convex surface 15 facing the insulating basin 1. Figure 3Taking the orientation shown as an example, the upper end of the convex surface 15 is connected to the upper three intersections 18 between the insulating basin 1, the central conductor 2 and the insulating gas 13 through the chamfered transition surface close to the concave surface 5 (i.e., the upper chamfered transition surface 16). The lower end of the convex surface 15 is connected to the lower three intersections 14 between the insulating basin 1, the central conductor 2 and the insulating gas 13 through the chamfered transition surface close to the convex surface 6 (i.e., the lower chamfered transition surface 17). The coordinates of the lower three intersections 14 and the upper three intersections 18 are recorded as (x14, y14) and (x18, y18) respectively. The convex surface 15 is formed by connecting multiple tangent arcs and straight line segments. Figure 3 Taking the orientation shown as an example, the upper end of the section of the convex surface 15 is constrained by the first arc surface R1 with a curvature radius of 10-20 mm, and the lower end of the section of the convex surface 15 is constrained by the second arc surface R2 with a curvature radius of 10-20 mm. The coordinates of the arc centers of the first arc surface R1 and the second arc surface R2 are recorded as (x1, y1) and (x2, y2) respectively, and the following relationship is required:

[0047] 40≤|x1-x2|≤50mm

[0048] |y1|≥|y18|, |y2|≥|y14|

[0049] The rest of the convex surface 15 is connected by a plurality of line segments and arcs to make the convex surface 15 smooth. The convex surface 15 increases the contact area between the insulating basin 1 and the central conductor 2, enhances the bonding strength between the two, and bears most of the stress on the central conductor-basin bonding surface 8, thereby reducing the stress near the upper three intersections 18 and the lower three intersections 14.

[0050] The upper chamfered transition surface 16 and the lower chamfered transition surface 17 have the same structure, and both include a first straight line segment L1, a second straight line segment L2, a first arc segment R3, and a second arc segment R4. The first straight line segment L1 and the central conductor 2 have an axial angle of 30° to 60°. The two ends of the first arc segment R3 are tangent to the first straight line segment L1 and the second straight line segment L2, respectively. One end of the second arc segment R4 is tangent to one end of the second straight line segment L2, and the other end of the second arc segment R4 is tangent to the end of the convex surface 15. The chamfered transition surface (i.e., the upper chamfered transition surface 16 and the lower chamfered transition surface 17) functions to decompose the stress of the three intersections along the first straight line segment L1 and the direction perpendicular to the first straight line segment L1 into normal stress and shear stress, so as to reduce the stress value of the three intersections, so as to achieve that the stress value of the three intersections is lower than the maximum stress value on the convex surface 15, thereby transferring the position of the maximum stress value on the central conductor-basin bonding surface 8 from the three intersections to the inside of the cross section of the central conductor-basin bonding surface 8.

[0051] A stress release groove 12 with a U-shaped cross-section is provided on the upper end surface (i.e., the inner end surface 9) and the lower end surface (i.e., the outer end surface 10) of the center conductor 2. The depth of the stress release groove 12 is 10-15 mm, the width is 3-8 mm, and the distance between the stress release groove 12 and the side surface 11 of the center conductor does not exceed 5 mm. The function of the stress release groove 12 is to release residual stress and reduce deformation during the solidification and shrinkage process of the material of the insulating basin body 1, and to cooperate with the chamfered transition surface (i.e., the upper chamfered transition surface 16 and the lower chamfered transition surface 17) to reduce the stress value at the three intersections.

[0052] Example 2

[0053] The pot-type insulator of this embodiment has the same structure as that of the pot-type insulator of Embodiment 1. Figure 1~Figure 5 As shown, the radii of the first arc surface R1 and the second arc surface R2 are 10 mm and 18 mm respectively, the distance between the arc centers corresponding to the first arc surface R1 and the second arc surface R2 is 50 mm, the radius of the first arc segment R3 and the second arc segment R4 is 1 mm, the length of the first straight line segment L1 is 1 mm, the length of the second straight line segment L2 is 1.55 mm, the depth of the stress release groove 12 is 12 mm and the width is 6 mm, the distance between the stress release groove 12 and the side surface 11 is 5 mm, the axial angle between the first straight line segment L1 and the center conductor 2 is 45°, the distance between the upper end surface and the lower end surface of the center conductor 2 is 98 mm, the diameter of the side surface 11 is 200 mm, the maximum diameter of the raised surface 15 is 240 mm, and the outer diameter and height of the insulating basin body 1 are 900 mm and 364 mm respectively.

[0054] Comparative Example

[0055] The structure of this comparative example is as follows Figure 6 As shown, in this comparative example, the central conductor-basin bonding surface 8 of the central conductor 2 includes a third arc surface R5 with a radius of 30 mm and two straight segments of the same length, the straight segments are located at the upper and lower ends of the third arc surface R5, the arc center angle corresponding to the third arc surface R5 is 60°, the third arc surface R5 is recessed toward the side of the central conductor 2 and smoothly connected to the straight segment through a 1 mm fillet, the stress release groove 12 has a depth of 6 mm and a width of 3.5 mm, and the distance between the stress release groove 12 and the side surface 11 is 6.5 mm. The difference between Example 2 and this comparative example lies in the shape of the central conductor-basin bonding surface 8 and the position and size of the stress release groove 12, and the comparative example does not have an upper chamfered transition surface 16 and a lower chamfered transition surface 17. The dimensions of the rest of the central conductor 2 of this comparative example are the same as those of the rest of the central conductor 2 in Example 2, and the dimensions of the insulating basin 1 of this comparative example are the same as those of the insulating basin 1 in Example 2.

[0056] When finite element calculation is performed, the insulating basin 1 in the comparative example and embodiment 2 is made of epoxy composite material, with a dielectric constant of 6.3 and a density of 2.3 g / cm 3 , Young's modulus is 11 GPa, Poisson's ratio displacement is 0.35; the material of the central conductor 2 is aluminum alloy, and the density is 2.7 g / cm 3 , Young's modulus is 69 GPa, Poisson's ratio is 0.33; insulating gas 13 is SF6 gas, and dielectric constant is 1.002. Using finite element simulation, when the basin insulators of Example 2 and the comparative example are loaded with 1 MPa water pressure on the concave surface 5, the stress distribution on the center conductor-basin bonding surface 8 is as follows: Figure 7 As shown, Figure 7 In FIG. 1 , the lower three intersection points 14 are the starting points, the upper three intersection points 18 are the end points, and the distance Y along the direction perpendicular to the central axis of the central conductor 2 is the horizontal coordinate. Figure 7 It can be seen that the maximum stress of the basin-type insulator of Example 2 on the center conductor-basin bonding surface 8 is 4.03MPa, the point corresponding to the maximum stress is located within the range of the convex surface 15, and the stress values ​​of the lower three intersections 14 and the upper three intersections 18 are 1.7MPa and 0.6MPa respectively; the maximum stress of the center conductor-basin bonding surface 8 of the comparative example is 24.2MPa, the point corresponding to the maximum stress is located at the lower three intersections 14, and the stress value of the upper three intersections 18 is 4.5MPa. By comparison, it can be seen that the technical solution of Example 2 can significantly reduce the stress on the lower three intersections 14 and the upper three intersections 18, and can evenly distribute the stress on the center conductor-basin bonding surface 8.

[0057] The electric field distribution on the center conductor-basin bonding surface 8 of the basin-type insulator of Example 2 and the comparative example at 635 kV is as follows: Figure 8 The maximum value of the electric field strength at the center conductor-basin bonding surface 8 of Example 2 and the comparative example is 1.7 kV / mm. In the technical solution of Example 2, the electric field strength at the lower three intersections 14 and the upper three intersections 18 is significantly smaller than that of the comparative example. It can be seen that Example 2 can reduce the electric field strength at the three intersections and has a better structural design.

[0058] The specific embodiments of the present invention are described in detail above. It should be understood that ordinary technicians in the field can make many modifications and changes based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by technicians in the technical field through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection of the claims of the present invention.

Claims

1. A pot-type insulator, characterized in that: The invention comprises an insulating basin body (1) and a central conductor (2) arranged at the axis of the insulating basin body (1), wherein the central conductor (2) adopts a drum-shaped rotating body structure, and the side surface of the central conductor (2) comprises a convex surface (15) and cylindrical side surfaces (11) at both ends of the convex surface (15), the convex surface (15) is a smooth curved surface, and the end of the convex surface (15) is transitionally connected to the side surface (11) via a chamfered transition surface, and the convex surface (15) and the chamfered transition surface are both connected to the insulating basin body (1), and the chamfered transition surface comprises a first straight line segment (L1) and a transition curved surface, the first straight line segment (L1) is connected to the side surface (11), and the connection between the first straight line segment (L1) and the side surface (11) is a three-intersection point, the angle between the first straight line segment (L1) and the central axis of the central conductor (2) is 30° to 60°, one end of the transition curved surface is connected to the first straight line segment (L1), and the other end of the transition curved surface is connected to the convex surface (15).

2. A pot-type insulator according to claim 1, characterized in that: The junction between the first straight line segment (L1) and the side surface (11) is connected via an arc surface transition.

3. A pot-type insulator according to claim 1 or 2, characterized in that: The transition curved surface comprises a second straight line segment (L2), one end of the second straight line segment (L2) is connected to the first straight line segment (L1) via a first arc segment (R3), and the other end of the second straight line segment (L2) is connected to the convex surface (15) via a second arc segment (R4); One end of the first arc segment (R3) is tangent to the second straight line segment (L2), the other end of the first arc segment (R3) is tangent to the first straight line segment (L1), one end of the second arc segment (R4) is tangent to the second straight line segment (L2), and the other end of the second arc segment (R4) is tangent to the convex surface (15).

4. A pot-type insulator according to claim 1, characterized in that: One end of the convex surface (15) is set as a first arc surface (R1), and the other end of the convex surface (15) is set as a second arc surface (R2). The curvature radius of the first arc surface (R1) and the second arc surface (R2) are both 10-20 mm. The distance between the arc center of the first arc surface (R1) and the central axis of the central conductor (2) is not less than the distance between the three intersections and the central axis of the central conductor (2). The distance between the arc center of the second arc surface (R2) and the central axis of the central conductor (2) is not less than the distance between the three intersections and the central axis of the central conductor (2). The distance between the arc center of the first arc surface (R1) and the arc center of the second arc surface (R2) is 40-50 mm.

5. The pot-type insulator according to claim 1, characterized in that: The maximum distance between the raised surface (15) and the central axis of the central conductor (2) is 1.1 to 1.25 times the distance between the three intersection points and the central axis of the central conductor (2).

6. A pot-type insulator according to claim 1, characterized in that: Both side end surfaces of the central conductor (2) are provided with an annular stress release groove (12), and the stress release groove (12) is coaxial with the central conductor (2).

7. A pot-type insulator according to claim 6, characterized in that: The stress relief groove (12) is a U-shaped groove.

8. A pot-type insulator according to claim 6 or 7, characterized in that: The stress relief groove (12) has a depth of 10 to 15 mm and a width of 3 to 8 mm, and a net distance between the stress relief groove (12) and the side surface (11) does not exceed 5 mm.

9. The pot-type insulator according to claim 1, characterized in that: The low-voltage end of the insulating basin (1) is provided with a low-voltage end shielding spring (3) and a grounding metal insert (4), wherein the low-voltage end shielding spring (3) is arranged inside the low-voltage end of the insulating basin (1).

10. The pot-type insulator according to claim 1, characterized in that: The insulating basin body (1) adopts a bowl-shaped rotating body structure, and the thickness of the high-voltage end and the low-voltage end of the insulating basin body (1) is greater than the thickness of the portion between the high-voltage end and the low-voltage end.

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