Particle trap for direct-current GIS (Gas Insulated Switchgear) and direct-current bushing

Abstract

The invention discloses a particle trap for a direct-current GIS (gas insulated switchgear) and a direct-current bushing, and belongs to the technical field of high-pressure gas insulated equipment. The particle trap comprises multiple layers of trap bodies, the multiple layers of trap bodies are arranged at intervals, and every two adjacent layers of trap bodies are fixedly connected; a plurality of capturing through grooves used for capturing particles are formed in each layer of trap body, and in the arrangement direction of the trap bodies, the projection of any capturing through groove in one layer of trap body and the projections of all capturing through grooves in the adjacent layer of trap body are at least partially staggered. According to the particle trap, due to the fact that the structure of the multiple layers of trap bodies is matched with the staggered arrangement of the projections of the capturing through grooves in the adjacent layers of trap bodies, when penetrating into the space between the two trap bodies, metal particles collide and rebound multiple times between the multiple layers of trap bodies, kinetic energy is gradually lost, and then the metal particles are captured; escaped metal particles are prevented from directly returning to the interior of the GIS cylinder, and the capturing capacity and the inhibiting effect of the particle trap on the metal particles are enhanced.

Description

Technical Field

[0001] This invention relates to the field of high-voltage gas insulation equipment technology, and more particularly to a particulate trap and DC bushing for DC GIS. Background Technology

[0002] During the production, installation, and operation of gas-insulated switchgear (GIS), metal particles are inevitably generated. The presence of these particles can severely affect the insulation performance of GIS. Compared to AC GIS, the movement of metal particles is more intense under a DC electric field. Irregular particles, such as linear particles, can generate more severe partial discharges, affecting the space charge near the particles and causing them to exhibit movement patterns such as "standing" or "flying". Metal particles near basin insulators tend to move towards the insulator. When they reach the insulator surface, they may cause partial discharges on the basin insulator surface. In severe cases, this can lead to surface flashover on the insulator surface, endangering the safety of the GIS.

[0003] To suppress the movement of metal particles, existing technologies typically employ particle traps for capture and suppression. The capture and suppression mechanisms of particle traps are mainly divided into two categories. One category involves creating a low-field region inside the trap, where particles lose a large amount of charge after colliding with it, thus becoming almost unaffected by the electric field force and suppressing the particle's movement. The other category involves particles losing kinetic energy through multiple collisions inside the trap. That is, each time a particle bounces off the trap wall, its speed decreases. When the number of collisions increases to a level that reduces the particle's speed to a point where it cannot escape from the trap, the particle's movement can be suppressed.

[0004] However, current particle traps are usually single-layered. When a small number of trapped metal particles escape, they will jump out of the trap and re-enter the GIS cylinder through the slot, reducing the effectiveness of the particle trap in capturing metal particles. This leads to a decrease in the insulation withstand voltage of the GIS or even damage. Summary of the Invention

[0005] This invention provides a particle trap and DC bushing for DC GIS, aiming to solve the problem of low capture efficiency of particle traps for metal particles in the prior art, and to improve the ability of particle traps to capture metal particles.

[0006] The first aspect of the present invention provides a particle trap for DC GIS, comprising a multi-layer trap body;

[0007] The trap bodies in multiple layers are arranged at intervals, and the trap bodies in adjacent layers are connected and fixed.

[0008] Each layer of the trap body has multiple trapping channels for capturing particles. Along the arrangement direction of the trap body, the projection of any trapping channel on one layer of the trap body is at least partially staggered from the projection of all trapping channels on the trap body of the adjacent layer.

[0009] In some embodiments of the first aspect, along the arrangement direction of the trap bodies, the projection of the capture channel on the trap body is arranged parallel to the projection of the capture channel on the adjacent trap body;

[0010] Alternatively, along the arrangement direction of the trap body, the projections of the capture channels on the trap body and the projections of the capture channels on adjacent trap bodies are arranged alternately.

[0011] In some embodiments of the first aspect, the plurality of said trap bodies are arc-shaped;

[0012] The circular arc axes of multiple trap bodies are all the same preset axis;

[0013] On the same trap body, multiple capture channels are evenly arranged along the preset axis direction;

[0014] Alternatively, on the same trap body, multiple trap slots are evenly arranged circumferentially along the preset axis.

[0015] In some embodiments of the first aspect, in two adjacent trap bodies, the length of the trap body closer to the preset axis is less than the length of the trap body farther from the preset axis;

[0016] And / or, in two adjacent trap bodies, the width of the trap body closer to the preset axis is smaller than the width of the trap body farther from the preset axis.

[0017] In some embodiments of the first aspect, the width of the capture channel gradually increases along a direction away from the preset axis.

[0018] In some embodiments of the first aspect, the number of capture channels in two adjacent trap bodies is different.

[0019] In some embodiments of the first aspect, an elastic coating is provided on the outer surface of the trap body, the elastic coating being used to absorb the kinetic energy of the particles.

[0020] In some embodiments of the first aspect, the elastic coating is a polyimide coating containing silicon carbide particles, wherein the silicon carbide particles are uniformly and isotropically dispersed.

[0021] In some embodiments of the first aspect, the silicon carbide particles are irregular polyhedra.

[0022] A second aspect of the present invention provides a DC bushing, comprising:

[0023] GIS cylinder;

[0024] A conductive rod is installed inside the GIS cylinder;

[0025] An insulator is installed inside the GIS cylinder and is sleeved on the conductive rod;

[0026] A driving electrode is installed inside the GIS cylinder and is sleeved on the conductive rod.

[0027] The particulate trap described in the first aspect is installed inside the GIS cylinder and is arranged adjacent to the repelling electrode.

[0028] As can be seen from the above technical solutions, the present invention has the following advantages:

[0029] This embodiment provides a particle trap and DC bushing for DC GIS, including a multi-layer trap body; the multiple trap bodies are arranged at intervals, and adjacent trap bodies are connected and fixed; each trap body has multiple trap slots for capturing particles, and the projection of the trap slots on the trap body is at least partially offset from the projection of the trap slots on the adjacent trap bodies along any normal direction; therefore, in application, on the one hand, due to the structural design of the multi-layer trap body, when metal particles enter between two trap bodies, they will collide and bounce multiple times between the multiple trap bodies, gradually losing kinetic energy and thus being captured; on the other hand, due to the offset arrangement of the projection of the trap slots on the adjacent trap bodies, metal particles escaping from the lower trap body are easily blocked by the upper trap body, reducing the direct return of escaping metal particles to the GIS cylinder, which helps to keep the metal particles moving between the multiple trap bodies, thereby enhancing the particle trap's ability to capture and suppress metal particles, and improving the insulation reliability of the GIS. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram of the overall structure of a particle trap (double layer) for DC GIS provided in the first aspect of the present invention;

[0032] Figure 2 This is a schematic cross-sectional view of a particle trap (double layer) for DC GIS provided in the first aspect of the present invention;

[0033] Figure 3 A schematic diagram of the overall structure of a three-layer particle trap for DC GIS provided in the first aspect of the present invention;

[0034] Figure 4 This is a schematic diagram of the overall structure of a DC bushing provided in the second aspect of an embodiment of the present invention.

[0035] Figure label:

[0036] Particle trap 1; trap body 10; capture channel 100; connecting column 11; GIS cylinder 2; conductive rod 3; insulator 4; driving electrode 5. Detailed Implementation

[0037] This invention provides a particle trap and DC bushing for DC GIS, which solves the problem of low capture efficiency of particle traps for metal particles in the prior art, thereby improving the ability of particle traps to capture metal particles.

[0038] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0039] Please see Figures 1 to 3 The present invention provides a particle trap for DC GIS, comprising a multi-layer trap body 10;

[0040] The multi-layered trap bodies 10 are arranged at intervals, and adjacent trap bodies 10 are connected and fixed by connecting columns 11.

[0041] Each trap body 10 has multiple trapping channels 100 for capturing particles. Along the arrangement direction of the trap body 10, the projection of any trapping channel 100 on one layer of trap body 10 is at least partially staggered from the projection of all trapping channels 100 on the adjacent layer of trap body 10.

[0042] It should be noted that the adjacent trap bodies 10 are arranged in parallel, and the two opening ends of the capture channels 100 are located on the front and back of the trap bodies 10, respectively; the projection of any capture channel 100 of a trap body 10 in one layer is at least partially offset from the projections of all capture channels 100 of the trap bodies 10 in the adjacent layer, meaning that the projection direction is the arrangement direction, and the orthographic projection of a capture channel 100 on a trap body 10 in one layer is offset from the orthographic projection of the capture channel 100 of the trap body 10 in the next layer closest to that capture channel; the specific number of trap bodies 10 can be selected according to actual needs, and can be two layers (e.g., Figure 1 and Figure 2 As shown), three layers (as shown) Figure 3 (as shown) or even more.

[0043] In the operation of this embodiment, when there are metal particles inside the DC GIS, these particles will move towards the particle trap 1 under the action of the electric field force. During the movement, the metal particles will enter the multi-layer trap body 10 from the capture channel 100. Since the capture channels 100 on the adjacent trap bodies 10 are at least partially staggered in the projection, the metal particles will continuously collide and bounce during the movement, gradually lose kinetic energy, and thus be captured.

[0044] As can be seen from the above working process, the advantages of this embodiment are as follows: On the one hand, due to the structural design of the multi-layer trap body 10, when metal particles penetrate between two trap bodies 10, they will collide and bounce multiple times between the multi-layer trap bodies 10, gradually losing kinetic energy and thus being captured; on the other hand, due to the staggered arrangement of the projection of the capture slots 100 on the adjacent trap bodies 10, metal particles escaping from the lower trap body 10 are easily blocked by the upper trap, thus reducing the number of escaped metal particles that directly return to the interior of the GIS cylinder 2, which is conducive to keeping the metal particles moving between the multi-layer trap bodies 10, thereby enhancing the capture ability and suppression effect of the particle trap 1 on the metal particles, and thus improving the insulation reliability of the GIS.

[0045] In one specific embodiment, such as Figure 1 As shown, a further feasible staggered arrangement of the capture channels 100 is provided. Along the arrangement direction of the trap body 10, the projections of the capture channels 100 on the trap body 10 are arranged parallel to the projections of the capture channels 100 on adjacent trap bodies 10. For example, when the trap body 10 is a flat structure, the capture channels 100 of the upper and lower layers are parallel, but there is a horizontal distance difference between them; when the trap body 10 is an arc-shaped structure, the capture channels 100 of the upper and lower layers are parallel, but an angle is formed between them and the line connecting them to the central axis of the arc-shaped structure, that is, the angles between them on the arc are different. Figure 1 and Figure 2Alternatively, along the arrangement direction of the trap body 10, the projections of the capture channels 100 on the trap body 10 and the projections of the capture channels 100 on the adjacent trap body 10 are arranged alternately. For example, the capture channels 100 on the upper and lower layers can be perpendicularly staggered or staggered at any angle less than 90°.

[0046] In the specific implementation of this embodiment, after the metal particles enter the multi-layer trap body 10, if the capture channels 100 are arranged in a parallel projection manner, when the metal particles attempt to escape through the capture channels 100, they will continuously change their direction of movement between adjacent trap bodies 10 due to differences in horizontal distance or angle, continuously colliding and bouncing, further losing kinetic energy and improving the capture effect; if the capture channels 100 are arranged in an interleaved projection manner, when the metal particles pass through different layers of trap bodies 10, they will be directly blocked by the interleaved capture channels 100, making it difficult for them to escape in a straight line, and they can only move in a tortuous manner between the multi-layer trap bodies 10, continuously consuming energy, and finally being effectively captured.

[0047] It is understandable that, through the above arrangement methods, whether it is a parallel projection arrangement or an interlaced projection arrangement, the trap's capture capability can be enhanced from different mechanisms. The parallel projection arrangement increases the number of collisions by causing the metal particles to constantly change their direction of movement between adjacent trap bodies 10, thereby consuming more kinetic energy. The interlaced projection arrangement, on the other hand, directly blocks the straight escape path of the metal particles, forcing them to move in a tortuous manner between multiple layers of trap bodies 10, thus achieving the same purpose of consuming energy and improving the capture effect.

[0048] In one embodiment, such as Figures 1 to 3 As shown, a feasible arrangement structure of multiple trap bodies 10 is further provided. The multiple trap bodies 10 are arc-shaped, and the curvature of the arc matches the inner diameter curvature of the DC bushing to be installed. The arc axes of the multiple trap bodies 10 are all the same preset axis. The preset axis can be the axis of the DC bushing where the metal particles are located. That is, with the axis of the DC bushing as the central axis, the multiple arc-shaped trap bodies 10 are arranged outward in layers at intervals to form a multi-layer parallel arc structure. On the same trap body 10, multiple capture channels 100 are uniformly arranged on the particle trap body 1 along the preset axis direction. That is, the length direction of the multiple capture channels 100 is arranged along the preset axis direction. Alternatively, on the same trap body 10, multiple capture channels 100 are all uniformly arranged on the particle trap body 1 along the circumferential direction of the preset axis. That is, the length direction of the multiple capture channels 100 is all arranged along the circumferential direction of the preset axis. The arrangement directions of the capture channels 100 on two adjacent trap bodies 10 are the same or different.

[0049] In this specific implementation, when the metal particles mainly move along the axial direction, the capture channels 100 on two adjacent trap bodies 10 are identical and arranged along the preset axial direction along the length of the capture channels 100; when the metal particles move more frequently in the circumferential direction, the capture channels 100 on two adjacent trap bodies 10 are identical and arranged along the circumferential direction along the preset axial direction along the length of the capture channels 100; when the metal particles move more frequently in both the axial and circumferential directions, the arrangement directions of the capture channels 100 on two adjacent trap bodies 10 are different, the length direction of multiple capture channels 100 on one layer of trap body 10 is arranged along the preset axial direction, and the length direction of multiple capture channels 100 on the adjacent other layer of trap body 10 is arranged along the circumferential direction of the preset axial direction.

[0050] Understandably, when the length direction of multiple capture channels 100 is arranged along a preset axis, this arrangement allows the capture channels 100 to more directly face metal particles that may move along the axis, thereby improving the capture efficiency of metal particles moving along the axis. When the length direction of multiple capture channels 100 is arranged along the circumferential direction of the preset axis, this arrangement can more comprehensively cover the area around the trap body 10, and has a better capture effect on metal particles moving in the circumferential direction. Through these two different arrangement methods, the most suitable arrangement of capture channels 100 can be flexibly selected according to the actual application scenario and needs to achieve the best metal particle capture effect.

[0051] In one embodiment, such as Figures 1 to 3 As shown, in order to increase the number of metal particles entering from the side and improve particle capture efficiency, in two adjacent trap bodies 10, the length of the trap body 10 closer to the preset axis is less than the length of the trap body 10 farther from the preset axis. That is, in the vertical cross section where the length direction of the trap body 10 is located, the trap body 10 of the particle trap 1 is arranged in a multi-layer fan shape centered on the preset axis, and the sides of the particle trap 1 at both ends along the length direction will form inclined surfaces; and / or, in two adjacent trap bodies 10, the width of the trap body 10 closer to the preset axis is less than the width of the trap body 10 farther from the preset axis. That is, in the vertical cross section where the width direction of the trap body 10 is located, the trap body 10 of the particle trap 1 is arranged in a multi-layer fan shape centered on the preset axis, and the sides of the particle trap 1 at both ends along the width direction will form inclined surfaces.

[0052] In this embodiment, metal particles can not only enter between the two trap bodies 10 through the capture channel 100, but also through the openings on the sides of the two trap bodies 10. When the sides of the trap bodies 10 become inclined surfaces, the area that can be entered increases, thereby increasing the probability of capturing metal particles.

[0053] It is understandable that the side of the particle trap 1 forms an inclined surface. Compared with the vertical arrangement of the side, the area of ​​the inclined surface is larger than that of the vertical surface at the same height, which expands the capture range of metal particles and increases the possibility of metal particles entering from the side. This increases the capture ability of the particle trap 1 on different surfaces and improves the overall capture performance of the particle trap 1 for metal particles.

[0054] In one embodiment, such as Figure 2 As shown, in order to reduce the interference of the electric field on the metal particles inside the particle trap 1, a specific implementation of the capture channel 100 is further provided. Along the direction away from the preset axis, the width of the capture channel 100 gradually increases. Specifically, in the cross-section of the width direction of the capture channel 100, the capture channel 100 is a wedge shape, keyway shape, strip shape, or square shape with a smaller top and a larger bottom. In specific implementation, the outward movement of the metal particles that have been trapped in the capture channel 100 will be blocked due to the setting of the capture channel 100 with a smaller top and a larger bottom, increasing the number of collisions of the metal particles in the trap. In addition, the arrangement of the capture channel 100 with a smaller top and a larger bottom makes its sidewalls and bottom have a certain angle, which is conducive to efficient shielding of the electric field.

[0055] Based on the above embodiments, such as Figures 1 to 3 As shown, in one embodiment, in order to further improve the capture capability of the trap body 10, the number of capture channels 100 of two adjacent trap bodies 10 is different. In specific implementation, the number of capture channels 100 of two adjacent trap bodies 10 is different. The different numbers of trap bodies 10 cooperate with each other, increasing the contact opportunities between particles and trap bodies 10, which can cover a larger spatial range, reduce the capture blind zone, and thus comprehensively improve the capture capability of metal particles, effectively improving the working efficiency of the entire particle trap 1.

[0056] In one specific embodiment, in order to improve the capture capability of the trap body 10, an elastic coating is provided on the outer surface of the trap body 10. The elastic coating is used to absorb the kinetic energy of the particles. In specific implementation, when the metal particles enter the trap and hit the elastic coating, the coating will undergo slight deformation, absorb part of the kinetic energy of the particles, reduce the rebound speed and height of the particles, and make it easier for the particles to be captured and retained in the trap body 10.

[0057] In one embodiment, the elastic coating is a polyimide coating containing silicon carbide particles, with a volume fraction of 8% to 20%. The silicon carbide particles are uniformly dispersed isotropically distributed. In practice, this ensures that the coating has a uniform dielectric constant and conductivity, preventing the generation of local distorted electric fields. It also avoids wear of the polyimide matrix due to insufficient particles and brittleness of the coating due to particle enrichment. Furthermore, the uniformly dispersed isotropic silicon carbide particles make the elastic coating more consistent in all directions, further improving the coating's ability to absorb the kinetic energy of particles. This significantly enhances the trap body 10's capture efficiency for metal particles, reduces the rebound and escape of particles on the surface of the trap body 10, and thus enhances the stability and reliability of the entire particle trap 1.

[0058] Based on the above embodiments, in this embodiment, the silicon carbide particles are irregular polyhedra. In specific implementation, since the silicon carbide particles are irregular polyhedra, the roughness of the polyimide coating surface containing silicon carbide particles is increased, which makes it easier to form mechanical interlocks between the metal particles that enter the trap, increases the energy required for the particles to escape, and improves the capture efficiency of the particle trap 1.

[0059] In one specific embodiment, a connection method between the trap body 10 and the connecting post 11 is further provided. Each of the four corners of two adjacent trap bodies 10 is connected to a connecting post 11, and adjacent connecting posts 11 are arranged at intervals. The connecting post 11 can be integrally formed with each trap body 10, or the connecting post 11 can be detachably fixed to each trap body 10 by fastening screws. The supporting post is not limited to a hexahedron, but can be a cylinder or a frustum.

[0060] Please refer to Figure 4 A second aspect of the present invention provides a DC bushing, comprising:

[0061] GIS cylinder 2;

[0062] Conductive rod 3 is coaxially installed inside GIS cylinder 2;

[0063] Insulator 4, which is a basin-type insulator 4, is installed inside the GIS cylinder 2 and is sleeved on the conductive rod 3;

[0064] The driving electrode 5 is installed inside the GIS cylinder 2 and is sleeved on the conductive rod 3. The driving electrode 5 is a hollow frustum with a certain angle of inclination and is set on the convex side of the insulator 4. The driving electrode 5 is used to drive the metal particles near the insulator 4 to move away from the insulator 4.

[0065] The first aspect is the particle trap 1, which is installed at the bottom of the GIS cylinder 2. The particle trap 1 is arranged adjacent to the repelling electrode 5 and is located near the junction of the conductive rod 3 and the repelling electrode 5.

[0066] During the operation of this embodiment, when the DC bushing is in working condition, the driving electrode 5 generates a specific electric field distribution. This electric field can drive the metal particles in the GIS cylinder 2, causing the metal particles to move towards the particle trap 1. The particle trap 1 installed in the GIS cylinder 2 can effectively capture the driven metal particles. Once the metal particles enter the particle trap 1, they will be bound and captured by its multi-layer structure and surface structure. The metal particles cannot move around in the GIS cylinder 2, thereby reducing faults such as partial discharge caused by metal particles and improving the stability and reliability of the DC bushing operation.

[0067] Understandably, metal particles enter the upper trap body 10 under the influence of gravity, electric field, and airflow. Since the sidewall of the capture channel 100 shields the electric field, the electric field strength inside the upper trap is low. The Coulomb force on the metal particles will rapidly decrease and become less than the gravity. At the same time, the metal particles lose energy when they collide with the wedge-shaped capture channel 100 sidewall of the upper trap body 10, and their speed gradually decreases. They will continue to fall into the lower trap body 10. Similarly, the metal particles will be captured by the lower trap body 10 and fall into the bottom of the inner wall of the GIS shell. Even if a small number of metal particles escape after entering the lower trap body 10, they will be blocked by the preset angle between the wedge-shaped capture channels 100 of the upper and lower trap bodies 10 and cannot directly return to the interior of the GIS cylinder 2. This effectively improves the particle capture efficiency of the particle trap 1.

[0068] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0070] Finally, it should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

Claims

1. A particle trap for DC GIS, characterized in that, Includes a multi-layered trap body; The trap bodies in multiple layers are arranged at intervals, and the trap bodies in adjacent layers are connected and fixed. Each layer of the trap body has multiple trapping channels for capturing particles. Along the arrangement direction of the trap body, the projection of any trapping channel on one layer of the trap body is at least partially staggered from the projections of all trapping channels on the adjacent layer of the trap body.

2. The particle trap according to claim 1, characterized in that: Along the arrangement direction of the trap body, the projection of the capture channel on the trap body is arranged parallel to the projection of the capture channel on the adjacent trap body; Alternatively, along the arrangement direction of the trap body, the projections of the capture channels on the trap body and the projections of the capture channels on adjacent trap bodies are arranged alternately.

3. The particle trap according to claim 2, characterized in that, The trap bodies are in the shape of arcs; The circular arc axes of multiple trap bodies are all the same preset axis; On the same trap body, multiple trap slots are uniformly arranged axially along the preset axis; Alternatively, on the same trap body, multiple trap slots are evenly arranged circumferentially along the preset axis.

4. The particle trap according to claim 3, characterized in that: In two adjacent trap bodies, the length of the trap body closer to the preset axis is less than the length of the trap body farther from the preset axis; And / or, in two adjacent trap bodies, the width of the trap body closer to the preset axis is smaller than the width of the trap body farther from the preset axis.

5. The particle trap according to claim 3, characterized in that, Along a direction away from the preset axis, the width of the capture channel gradually increases.

6. The particle trap according to claim 3, characterized in that, The number of capture channels differs between two adjacent trap bodies.

7. The particle trap according to claim 1, characterized in that, The outer surface of the trap body is provided with an elastic membrane, which is used to absorb the kinetic energy of the particles.

8. The particle trap according to claim 7, characterized in that, The elastic coating is a polyimide coating containing silicon carbide particles, which are uniformly dispersed isotropically distributed.

9. The particle trap according to claim 8, characterized in that, The silicon carbide particles are irregular polyhedra.

10. A DC bushing, characterized in that, include: GIS cylinder; A conductive rod is installed inside the GIS cylinder; An insulator is installed inside the GIS cylinder and is sleeved on the conductive rod; A driving electrode is installed inside the GIS cylinder and is sleeved on the conductive rod. The particulate trap according to any one of claims 1 to 9, wherein the particulate trap is installed inside the GIS cylinder and the particulate trap is arranged adjacent to the repelling electrode.

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