Insulating material flashover experiment device and method capable of simulating metal particle attachment

Abstract

The invention discloses an insulating material flashover experiment device and method capable of simulating metal particle attachment. The device comprises a metal tank body, an insulator upper cover, a frustum-shaped insulating sample, a charge injection assembly, a charge measurement assembly, a sample bearing and flashover assembly and a metal particle attachment simulation assembly. The sample bearing and flashover assembly is arranged between the high-pressure guide rod and the bottom plate of the metal tank body; the metal particle adhesion simulation assembly is arranged on the metal tank body through an insulating sealing cover; the frustum-shaped insulation sample is arranged on the sample bearing and flashover assembly; according to the invention, a metal particle adhesion layer can be formed on the surface of the insulation sample before a flashover experiment, so that technical support is provided for carrying out surface flashover characteristic related research under different metal particle adhesion conditions, and the research range of the device is widened; the insulation sample configuration and the sample bearing structure are optimized, and the test requirement of the insulation sample with the flashover surface being a conical surface is met; and a flashover triggering structure is optimized, so that the flashover triggering working condition in an experiment is consistent with the flashover triggering working condition in practical application.

Description

Technical Field

[0001] This invention belongs to the field of electrical experimental technology, and in particular relates to an experimental apparatus and method for simulating flashover of insulating materials by simulating the adhesion of metal particles. Background Technology

[0002] In power systems, the large-scale application of AC gas-insulated metal-enclosed switchgear (GIS) and gas-insulated transmission lines (GIL) has effectively promoted the miniaturization and gas insulation of power equipment. However, due to the problem of surface flashover of basin insulators caused by charge accumulation, AC gas-insulated metal-enclosed switchgear (GIS) and gas-insulated transmission lines (GIL) have not achieved substantial breakthroughs for a long time, and their industrial application still faces difficulties.

[0003] Therefore, studying the influence and mechanism of surface charge on the surface flashover characteristics of insulating media under the action of DC electric field is of great significance for promoting the industrial application of AC gas-insulated metal-enclosed switchgear (GIS) and gas-insulated transmission lines (GIL).

[0004] The accumulation of charge at the gas-solid interface is a significant factor leading to insulation breakdown. It exacerbates the electric field distortion in local areas on the surface of the solid dielectric, thereby ionizing more free charges and providing conditions for flashover, which can lead to malfunctions or even severe burnout of high-voltage equipment.

[0005] Currently, existing research mainly uses the measurement of surface charge density of insulating materials as a research method. There is a lack of quantitative research on the surface flashover characteristics of insulators after surface charge accumulation. The changes in surface flashover characteristics of insulating media under the influence of surface charge are still unclear. With existing research methods, it is impossible to construct the correlation between surface charge accumulation and surface flashover of insulating materials, and therefore it is impossible to provide effective theoretical guidance for the insulation optimization design of pot insulators.

[0006] To this end, Chinese patent application No. 202311256645.7 discloses a device and method for surface charge injection, measurement, and surface flashover experiment of insulating materials. This scheme can complete the charge injection on the surface of insulating materials and measure the charge density on the surface of insulating materials. Under the action of surface charge, it can further realize the surface flashover experiment of insulating materials. Through the experiment, the changing characteristics of surface flashover of insulating medium are clarified, and the correlation characteristics between charge accumulation on the surface of insulating materials and surface flashover can be constructed, so as to provide effective theoretical guidance for the insulation optimization design of pot insulators.

[0007] However, the above-mentioned scheme lacks the ability to simulate the adhesion of different metal particles, thus limiting the scope of research on surface flashover characteristics under different metal particle adhesion conditions. Furthermore, since the above scheme is applicable to insulating sample sheets, whose flashover test surface is planar, while the flashover surfaces of actual insulator components are conical, the above scheme cannot meet the testing requirements for insulating samples with conical flashover surfaces. Moreover, the above scheme utilizes finger-shaped electrode pairs during flashover experiments, but in actual applications, flashover does not involve finger-shaped electrode pairs; instead, it is triggered by direct pressure applied to both sides of the insulator component along its axial direction. Therefore, the flashover triggering conditions in the experiment are inconsistent with those in actual applications. Summary of the Invention

[0008] To address the problems existing in the prior art, this invention provides an experimental apparatus and method for simulating flashover of insulating materials with metal particle adhesion. This apparatus can form a predetermined metal particle adhesion layer on the surface of the insulating sample before the flashover test, providing technical support for research on surface flashover characteristics under different metal particle adhesion conditions and broadening the research scope of the device. The configuration of the insulating sample and the sample support structure are optimized to meet the testing requirements of insulating samples with a conical flashover surface. The flashover triggering structure is also optimized to ensure that the flashover triggering conditions in the experiment are consistent with those in actual applications.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: an insulating material flashover experimental device capable of simulating metal particle adhesion, comprising a metal can, an insulator cover, a frustum-shaped insulating sample, a charge injection component, a charge measurement component, a sample support and flashover component, and a metal particle adhesion simulation component; the insulator cover is sealed and fastened at the top opening of the metal can; four openings are arranged circumferentially in the middle of the side plate of the metal can, and a first insulating cover, a second insulating cover, a third insulating cover, and an observation window are respectively fixed in the four openings; the first insulating cover is used to mount the charge injection component; the second insulating cover is used to mount the charge measurement component; the third insulating cover is used to mount the metal particle adhesion simulation component; a high-voltage guide rod is vertically fixed at the center of the insulator cover; the sample support and flashover component is disposed between the high-voltage guide rod and the center of the bottom plate of the metal can; the frustum-shaped insulating sample is disposed on the sample support and flashover component; an insulating gas injection port is provided on the bottom plate of the metal can, and the metal can is grounded through a wire.

[0010] The conical surface of the frustum-shaped insulating sample faces upward, and several measuring points are marked on the conical surface of the frustum-shaped insulating sample.

[0011] The measurement points are distributed radially in multiple rings relative to the center of the frustum-shaped insulating sample, and the measurement points on each ring are evenly spaced along the circumference.

[0012] The charge injection assembly includes a first DC power supply, a first resistor, a high-voltage guide post, a conductive spring, a first insulating support rod, a first metal support rod, a needle electrode, and a first translational drive mechanism. The positive terminal of the first DC power supply is connected to one end of the first resistor via a wire, and the other end of the first resistor is connected to the high-voltage guide post via a wire. The high-voltage guide post is horizontally fixedly mounted on the first insulating cover, with one end located outside the metal can and the other end located inside the metal can. The negative terminal of the first DC power supply is grounded via a wire. The first insulating support rod and the first metal support rod are coaxially fixed together. The combined support rod is horizontally sealed through the first insulating cover and has axial movement freedom relative to the first insulating cover. One end of the first metal support rod in the combined support rod always extends into the interior of the metal can. The needle electrode is vertically fixed to the end of the first metal support rod located inside the metal can. One end of the conductive spring is fixed to the end of the high-voltage guide column located inside the metal can, and the other end of the conductive spring is electrically connected to the first metal support rod. The first translation drive mechanism is located outside the metal can, and the first insulating support rod in the combined support rod is connected to the first translation drive mechanism.

[0013] The charge measurement assembly includes an electrostatic probe, a second insulating support rod, and a second translation drive mechanism; the second insulating support rod horizontally seals through the second insulating cover and has axial movement freedom relative to the second insulating cover; the electrostatic probe is vertically fixed to the end of the second insulating support rod located inside the metal can; the second translation drive mechanism is located outside the metal can, and the other end of the second insulating support rod is connected to the second translation drive mechanism.

[0014] The sample support and flashover assembly includes a second DC power supply, a second resistor, a first metal sample support rod, a second metal sample support rod, a third insulating support rod, a lifting drive mechanism, a rotary drive mechanism, a carbon brush conductive head, and a metal bracket. The positive terminal of the second DC power supply is connected to one end of the second resistor via a wire, and the other end of the second resistor is connected to a high-voltage conductor rod at the center of the insulator cover via a wire. The lifting drive mechanism and the rotary drive mechanism are located outside the metal tank, with the rotary drive mechanism mounted on the lifting drive mechanism. The third insulating support rod vertically and sealedly passes through the bottom plate of the metal tank. The lower end of the third insulating support rod is connected to the rotary drive mechanism, and the upper end of the third insulating support rod is screwed and fixed to the lower end of the vertically set second metal support rod. The upper end of the second metal support rod is screwed and fixed to the center of the lower surface of the frustum-shaped insulating sample, and the center of the upper surface of the frustum-shaped insulating sample is screwed and fixed to the lower end of the vertically set first metal support rod. The upper end of the first metal support rod is located directly below the high-voltage guide rod. The metal bracket is fixedly installed on the upper surface of the bottom plate of the metal tank, and the carbon brush conductive head is fixedly installed on the top of the metal bracket. The carbon brush conductive head slides and contacts the second metal support rod.

[0015] The metal particle adhesion simulation component includes a powder spraying head, a powder spraying pipe, a pipe connector, a metal particle powder storage tank, a pressure pump, a fourth insulating support rod, and a third translation drive mechanism. The fourth insulating support rod horizontally and sealed through the third insulating cover, and the fourth insulating support rod has axial movement freedom relative to the third insulating cover. The powder spraying head is fixed above the end of the fourth insulating support rod located inside the metal tank, with the nozzle of the powder spraying head facing upwards. The third translation drive mechanism is located outside the metal tank, and the other end of the fourth insulating support rod is connected to the third translation drive mechanism. The powder spraying pipe horizontally and sealed through the third insulating cover, with one end of the powder spraying pipe located inside the metal tank connected to the powder spraying head, and the other end of the powder spraying pipe located inside the metal tank connected to the metal particle powder storage tank through a pipe connector. The pressure pump is connected to the metal particle powder storage tank.

[0016] A flashover test method for insulating materials, employing the aforementioned flashover test apparatus for insulating materials capable of simulating the adhesion of metal particles, includes the following steps: Step 1: Open the insulator cover, first fix the frustum-shaped insulation sample at the upper end of the second metal support rod, then fix the first metal support rod at the upper end of the frustum-shaped insulation sample, and then close the insulator cover. Step 2: Insulating gas is injected into the metal canister through the insulating gas injection port until the gas pressure reaches the set value, and then the insulating gas injection port is closed. Step 3: Activate the third translation drive mechanism to move the fourth insulating support rod into the metal can until the powder spraying head moves above the conical surface of the frustum-shaped insulating sample. Step 4: Start the pressurization pump to pressurize the metal microparticle powder storage tank, and force the metal microparticle powder in the storage tank into the powder spraying head through the powder spraying pipe. The powder spraying head sprays the metal microparticle powder into the metal can, and under the action of gravity, it automatically falls and adheres to the conical surface of the frustum-shaped insulation sample. At the same time, start the rotary drive mechanism to drive the combination of the third insulating support rod, the second metal support rod, the frustum-shaped insulation sample and the first metal support rod to rotate synchronously until the metal microparticle powder is evenly adhered to the conical surface of the frustum-shaped insulation sample. Then, turn off the pressurization pump and the rotary drive mechanism. Step 5: Reverse start the third translation drive mechanism to drive the fourth insulating support rod to move out of the metal can until the powder spraying head leaves the conical surface of the frustum-shaped insulating sample and moves back to the initial position; Step Six: Activate the first translation drive mechanism to move the combined support rod consisting of the first insulating support rod and the first metal support rod into the metal can until the needle electrode is moved above the conical surface of the frustum-shaped insulating sample. Step 7: Turn on the first DC power supply and apply voltage between the needle electrode and the second metal support rod. The voltage application time is 10 to 30 minutes until charge injection is completed on the conical surface of the frustum-shaped insulating sample. Then turn off the first DC power supply. Step 8: Reverse start the first translation drive mechanism, which drives the combined support rod consisting of the first insulating support rod and the first metal support rod to move out of the metal can until the needle electrode leaves the conical surface of the frustum-shaped insulating sample and moves back to the initial position. Step 9: Activate the second translation drive mechanism to move the second insulating support rod into the metal tank until the electrostatic probe is moved to the position of the first ring measurement point above the center side of the conical surface of the frustum-shaped insulating sample, and the distance between the electrostatic probe and the conical surface of the frustum-shaped insulating sample is at the set detection distance. Then activate the rotation drive mechanism to drive the combination of the third insulating support rod, the second metal support rod, the frustum-shaped insulating sample and the first metal support rod to rotate synchronously, and complete the charge measurement of the first ring measurement point on the inner side through the electrostatic probe. Step 10: Reverse the second translation drive mechanism to move the electrostatic probe to the location of the second measurement point. Then, start the lifting drive mechanism to move the combination of the third insulating support rod, the second metal support rod, the frustum-shaped insulating sample, and the first metal support rod to rise synchronously until the distance between the electrostatic probe and the conical surface of the frustum-shaped insulating sample returns to the set detection distance. Then, start the rotation drive mechanism again to rotate the combination of the third insulating support rod, the second metal support rod, the frustum-shaped insulating sample, and the first metal support rod synchronously. The charge measurement of the inner second measurement point is completed by the electrostatic probe. Step 11: Repeat steps 9 and 10, following the charge measurement process of the first two rings of measuring points on the center side of the frustum-shaped insulating sample, and complete the charge measurement of all measuring points ring by ring from the inside to the outside; Step 12: After the charge measurement of the first ring of measuring points on the outer side of the frustum-shaped insulating sample is completed, continue to start the second translation drive mechanism in the reverse direction, driving the second insulating support rod to move towards the outside of the metal can until the electrostatic probe leaves the conical surface of the frustum-shaped insulating sample and moves back to the initial position. Step 13: Start the lifting drive mechanism to drive the combination of the third insulating support rod, the second metal support rod, the frustum-shaped insulating sample and the first metal support rod to rise synchronously until the upper end of the first metal support rod contacts the lower end of the high voltage conductor rod; Step Fourteen: Start the second DC power supply and apply voltage between the first metal support rod and the second metal support rod until a surface flashover phenomenon occurs on the surface of the frustum-shaped insulating sample; Step 15: After the surface flashover test is completed, turn off the second DC power supply and start the lifting drive mechanism in reverse. This will cause the combination of the third insulating support rod, the second metal support rod, the frustum-shaped insulating sample, and the first metal support rod to descend synchronously. The upper end of the first metal support rod will disengage from the lower end of the high-voltage conductor rod until the frustum-shaped insulating sample moves back to its initial position.

[0017] The beneficial effects of this invention are: The present invention provides an experimental apparatus and method for simulating flashover of insulating materials with metal particle adhesion. This apparatus can form a predetermined metal particle adhesion layer on the surface of the insulating sample before the flashover test, providing technical support for research on surface flashover characteristics under different metal particle adhesion conditions and broadening the research scope of the apparatus. It also optimizes the configuration of the insulating sample and the sample support structure, meeting the testing requirements for insulating samples with a conical flashover surface. Furthermore, it optimizes the flashover triggering structure, ensuring that the flashover triggering conditions in the experiment are consistent with those in actual applications. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the experimental apparatus for simulating flashover of insulating materials with metal particle adhesion (initial state) of the present invention (view 1, overall). Figure 2 This is a schematic diagram of the structure of the experimental apparatus for simulating flashover of insulating materials with metal particle adhesion (initial state) according to the present invention (view 2, partial). Figure 3 This is a schematic diagram of the structure of the experimental apparatus for simulating flashover of insulating materials (metal particle adhesion) according to the present invention (view 2, partial view). Figure 4 This is a schematic diagram of the structure of the experimental apparatus (charge injection) for simulating flashover of insulating materials by simulating the adhesion of metal particles according to the present invention (view 1, overall). Figure 5 This is a schematic diagram of the structure of the experimental apparatus (charge measurement) for simulating flashover of insulating materials with metal particle adhesion according to the present invention (view 1, overall). Figure 6 This is a schematic diagram of the structure of the experimental apparatus for simulating flashover of insulating materials (surface flashover) that can simulate the adhesion of metal particles according to the present invention (view 1, overall). In the figure, 1—metal can, 2—insulator cover, 3—frustum-shaped insulation sample, 4—first insulation cover, 5—second insulation cover, 6—third insulation cover, 7—observation window, 8—high-voltage guide rod, 9—insulating gas injection port, 10—first DC power supply, 11—first resistor, 12—high-voltage guide post, 13—conductive spring, 14—first insulation support rod, 15—first metal support rod, 16—needle electrode, 17—first translation drive mechanism, 18—electrostatic probe, 19—second insulation support rod, 20—second translation drive mechanism. 21—Second DC power supply, 22—Second resistor, 23—First metal support rod, 24—Second metal support rod, 25—Third insulating support rod, 26—Lifting drive mechanism, 27—Rotation drive mechanism, 28—Carbon brush conductive head, 29—Metal bracket, 30—Powder spraying head, 31—Powder spraying pipe, 32—Pipe joint, 33—Metal microparticle powder storage tank, 34—Pressure pump, 35—Fourth insulating support rod, 36—Third translation drive mechanism. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0020] like Figures 1-6 As shown, an insulating material flashover test device for simulating metal particle adhesion includes a metal can 1, an insulator cover 2, a frustum-shaped insulating sample 3, a charge injection component, a charge measurement component, a sample support and flashover component, and a metal particle adhesion simulation component. The insulator cover 2 is sealed at the top opening of the metal can 1. Four openings are arranged circumferentially in the middle of the side plate of the metal can 1, and a first insulating cover 4, a second insulating cover 5, a third insulating cover 6, and an observation window 7 are respectively fixed in the four openings. The insulating cover 4 is used to mount the charge injection component; the second insulating cover 5 is used to mount the charge measurement component; the third insulating cover 6 is used to mount the metal particle adhesion simulation component; a high-voltage guide rod 8 is vertically fixed at the center of the insulator cover 2; the sample support and flashover component is set between the high-voltage guide rod 8 and the center of the bottom plate of the metal tank 1; the frustum-shaped insulating sample 3 is set on the sample support and flashover component; an insulating gas injection port 9 is provided on the bottom plate of the metal tank 1, and the metal tank 1 is grounded through a wire.

[0021] The conical surface of the frustum-shaped insulating sample 3 faces upward, and several measuring points are marked on the conical surface of the frustum-shaped insulating sample 3.

[0022] The measurement points are distributed radially in multiple rings relative to the center of the frustum-shaped insulating sample 3, and the measurement points on each ring are evenly spaced along the circumference.

[0023] The charge injection assembly includes a first DC power supply 10, a first resistor 11, a high-voltage guide post 12, a conductive spring 13, a first insulating support rod 14, a first metal support rod 15, a needle electrode 16, and a first translational drive mechanism 17. The positive terminal of the first DC power supply 10 is connected to one end of the first resistor 11 via a wire, and the other end of the first resistor 11 is connected to the high-voltage guide post 12 via a wire. The high-voltage guide post 12 is horizontally fixedly mounted on the first insulating cover 4, with one end of the high-voltage guide post 12 located outside the metal can 1 and the other end located inside the metal can 1. The negative terminal of the first DC power supply 10 is grounded via a wire. The first insulating support rod 14 and the first metal support rod 15 are connected to the first insulating support rod 16. The rod 15 is coaxially fixed as a combined support rod, which horizontally seals through the first insulating cover 4. The combined support rod has axial movement freedom relative to the first insulating cover 4. One end of the first metal support rod 15 in the combined support rod always extends into the metal can 1. The needle electrode 16 is vertically fixed to the end of the first metal support rod 15 located inside the metal can 1. One end of the conductive spring 13 is fixed to the end of the high-voltage guide post 12 located inside the metal can 1, and the other end of the conductive spring 13 is conductively engaged with the first metal support rod 15. The first translation drive mechanism 17 is located outside the metal can 1, and the first insulating support rod 14 in the combined support rod is connected to the first translation drive mechanism 17.

[0024] The charge measurement assembly includes an electrostatic probe 18, a second insulating support rod 19, and a second translation drive mechanism 20; the second insulating support rod 19 horizontally seals through the second insulating cover 5, and the second insulating support rod 19 has axial movement freedom relative to the second insulating cover 5; the electrostatic probe 18 is vertically fixed to the end of the second insulating support rod 19 located inside the metal tank 1; the second translation drive mechanism 20 is located outside the metal tank 1, and the other end of the second insulating support rod 19 is connected to the second translation drive mechanism 20.

[0025] The sample support and flashover assembly includes a second DC power supply 21, a second resistor 22, a first metal sample support rod 23, a second metal sample support rod 24, a third insulating support rod 25, a lifting drive mechanism 26, a rotary drive mechanism 27, a carbon brush conductive head 28, and a metal bracket 29. The positive terminal of the second DC power supply 21 is connected to one end of the second resistor 22 via a wire, and the other end of the second resistor 22 is connected to the high-voltage conductor 8 at the center of the insulator cover 2 via a wire. The lifting drive mechanism 26 and the rotary drive mechanism 27 are located outside the metal tank 1, and the rotary drive mechanism 27 is mounted on the lifting drive mechanism 26. The third insulating support rod 25 vertically and sealedly passes through the metal tank. The bottom plate of tank 1 has a third insulating support rod 25 whose lower end is connected to a rotary drive mechanism 27, and the upper end of the third insulating support rod 25 is screwed to the lower end of a vertically set second metal support rod 24. The upper end of the second metal support rod 24 is screwed to the center of the lower surface of the frustum-shaped insulating sample 3, and the center of the upper surface of the frustum-shaped insulating sample 3 is screwed to the lower end of a vertically set first metal support rod 23. The upper end of the first metal support rod 23 is located directly below the high-voltage guide rod 8. The metal bracket 29 is fixedly installed on the upper surface of the bottom plate of the metal tank 1, and the carbon brush conductive head 28 is fixedly installed on the top of the metal bracket 29. The carbon brush conductive head 28 and the second metal support rod 24 are in sliding contact.

[0026] The metal particle adhesion simulation component includes a powder spraying head 30, a powder spraying pipe 31, a pipe connector 32, a metal particle powder storage tank 33, a pressure pump 34, a fourth insulating support rod 35, and a third translation drive mechanism 36. The fourth insulating support rod 35 horizontally and sealed through the third insulating cover 6, and the fourth insulating support rod 35 has axial movement freedom relative to the third insulating cover 6. The powder spraying head 30 is fixedly mounted above the end of the fourth insulating support rod 35 located inside the metal tank 1, and the nozzle of the powder spraying head 30 faces upward. The third translation drive mechanism 36 is located outside the metal tank 1, and the other end of the fourth insulating support rod 35 is connected to the third translation drive mechanism 36. The powder spraying pipe 31 horizontally and sealed through the third insulating cover 6, one end of the powder spraying pipe 31 located inside the metal tank 1 is connected to the powder spraying head 30, and the other end of the powder spraying pipe 31 located inside the metal tank 1 is connected to the metal particle powder storage tank 33 through the pipe connector 32. The pressure pump 34 is connected to the metal particle powder storage tank 33.

[0027] In this embodiment, the first translation drive mechanism 17, the second translation drive mechanism 20, the lifting drive mechanism 26, and the third translation drive mechanism 36 all adopt motor-driven nut slider guide rail mechanism, and the rotary drive mechanism 27 directly adopts electric motor; a total of 29 rings of measurement points are marked on the conical surface of the frustum-shaped insulating sample 3, with 80 measurement points on each ring, so that the total number of measurement points on the conical surface of the frustum-shaped insulating sample 3 is 2320.

[0028] A flashover test method for insulating materials, employing the aforementioned flashover test apparatus for insulating materials capable of simulating the adhesion of metal particles, includes the following steps: Step 1: Open the insulator cover 2, first fix the frustum-shaped insulation sample 3 at the upper end of the second metal support rod 24, then fix the first metal support rod 23 at the upper end of the frustum-shaped insulation sample 3, and then close the insulator cover 2. Step 2: Insulating gas is injected into the metal tank 1 through the insulating gas injection port 9 until the gas pressure reaches the set value, and then the insulating gas injection port 9 is closed. Step 3: Activate the third translation drive mechanism 36 to drive the fourth insulating support rod 35 to move into the metal tank 1 until the powder spraying head 30 moves to above the conical surface of the frustum-shaped insulating sample 3. Step 4: Start the pressurization pump 34 to pressurize the metal microparticle powder storage tank 33, and force the metal microparticle powder in the metal microparticle powder storage tank 33 into the powder spraying head 30 through the powder spraying pipe 31. The powder spraying head 30 sprays the metal microparticle powder into the metal tank 1, and under the action of gravity, it automatically falls and adheres to the conical surface of the frustum-shaped insulating sample 3. At the same time, start the rotary drive mechanism 27 to drive the combination of the third insulating support rod 25, the second metal support rod 24, the frustum-shaped insulating sample 3 and the first metal support rod 23 to rotate synchronously until the metal microparticle powder is evenly adhered to the conical surface of the frustum-shaped insulating sample 3. Then, turn off the pressurization pump 34 and the rotary drive mechanism 27. Step 5: Reverse start the third translation drive mechanism 36, which drives the fourth insulating support rod 35 to move out of the metal tank 1 until the powder spraying head 30 leaves the conical surface of the frustum-shaped insulating sample 3 and moves back to the initial position. Step 6: Activate the first translation drive mechanism 17 to drive the combined support rod consisting of the first insulating support rod 14 and the first metal support rod 15 to move into the metal can 1 until the needle electrode 16 is moved above the conical surface of the frustum-shaped insulating sample 3. Step 7: Turn on the first DC power supply 10, apply voltage between the needle electrode 16 and the second metal support rod 24, and apply the voltage for 10 to 30 minutes until charge injection is completed on the conical surface of the frustum-shaped insulating sample 3. Then turn off the first DC power supply 10. Step 8: Reverse start the first translation drive mechanism 17, which drives the combined support rod consisting of the first insulating support rod 14 and the first metal support rod 15 to move to the outside of the metal can 1 until the needle electrode 16 moves away from the conical surface of the frustum-shaped insulating sample 3 and moves back to the initial position. Step 9: Activate the second translation drive mechanism 20 to move the second insulating support rod 19 into the metal tank 1 until the electrostatic probe 18 is moved to the position of the first ring measurement point above the center side of the conical surface of the frustum-shaped insulating sample 3, and the distance between the electrostatic probe 18 and the conical surface of the frustum-shaped insulating sample 3 is at the set detection distance. Then activate the rotation drive mechanism 27 to drive the combination of the third insulating support rod 25, the second metal support rod 24, the frustum-shaped insulating sample 3 and the first metal support rod 23 to rotate synchronously, and complete the charge measurement of the inner first ring measurement point through the electrostatic probe 18. Step 10: Reverse start the second translation drive mechanism 20 to move the electrostatic probe 18 to the position of the second ring measurement point. Then start the lifting drive mechanism 26 to drive the combination of the third insulating support rod 25, the second metal support rod 24, the frustum-shaped insulating sample 3 and the first metal support rod 23 to rise synchronously until the distance between the electrostatic probe 18 and the conical surface of the frustum-shaped insulating sample 3 is restored to the set detection distance. Then start the rotation drive mechanism 27 again to drive the combination of the third insulating support rod 25, the second metal support rod 24, the frustum-shaped insulating sample 3 and the first metal support rod 23 to rotate synchronously. The charge measurement of the inner second ring measurement point is completed by the electrostatic probe 18. Step 11: Repeat steps 9 and 10, following the charge measurement process of the first two rings of measuring points on the center side of the frustum-shaped insulating sample 3, and complete the charge measurement of all measuring points ring by ring from the inside to the outside; Step 12: After the charge measurement of the first ring of measuring points on the outer side of the frustum-shaped insulating sample 3 is completed, the second translation drive mechanism 20 is started in reverse to drive the second insulating support rod 19 to move to the outside of the metal can 1 until the electrostatic probe 18 leaves the conical surface of the frustum-shaped insulating sample 3 and moves back to the initial position. Step 13: Start the lifting drive mechanism 26 to drive the assembly of the third insulating support rod 25, the second metal support rod 24, the frustum-shaped insulating sample 3 and the first metal support rod 23 to rise synchronously until the upper end of the first metal support rod 23 contacts the lower end of the high voltage guide rod 8. Step Fourteen: Start the second DC power supply 21 and apply voltage between the first metal support rod 23 and the second metal support rod 24 until a surface flashover phenomenon occurs on the surface of the frustum-shaped insulating sample 3. Step 15: After the surface flashover test is completed, turn off the second DC power supply 21 and start the lifting drive mechanism 26 in reverse. This will cause the combination of the third insulating support rod 25, the second metal support rod 24, the frustum-shaped insulating sample 3 and the first metal support rod 23 to descend synchronously. The upper end of the first metal support rod 23 will disengage from the lower end of the high voltage guide rod 8 until the frustum-shaped insulating sample 3 moves back to its initial position.

[0029] As needed, the above experimental process can be repeated, with the difference being that the type and adhesion thickness of the metal microparticle powder, the type and pressure of the insulating gas inside the metal tank 1 can be changed to verify the influence of different types and adhesion thicknesses of metal microparticle powder, and different types and pressures of the insulating gas environment on the surface flashover characteristics of the insulating medium.

[0030] The solutions in the embodiments are not intended to limit the scope of protection of the present invention. All equivalent implementations or modifications that do not depart from the present invention are included in the scope of protection of the present invention.

Claims

1. An experimental apparatus for simulating flashover of insulating materials by simulating the adhesion of metal particles, characterized in that: The device includes a metal can, an insulator cover, a frustum-shaped insulating sample, a charge injection assembly, a charge measurement assembly, a sample support and flashover assembly, and a metal particle adhesion simulation assembly. The insulator cover is sealed at the top opening of the metal can. Four openings are arranged circumferentially in the middle of the side plate of the metal can, each fixed with a first insulating cover, a second insulating cover, a third insulating cover, and an observation window. The first insulating cover is used to mount the charge injection assembly; the second insulating cover is used to mount the charge measurement assembly; and the third insulating cover is used to mount the metal particle adhesion simulation assembly. A high-voltage guide rod is vertically fixed at the center of the insulator cover. The sample support and flashover assembly is positioned between the high-voltage guide rod and the center of the bottom plate of the metal can. The frustum-shaped insulating sample is mounted on the sample support and flashover assembly. An insulating gas injection port is provided on the bottom plate of the metal can, and the metal can is grounded via a conductor.

2. The experimental apparatus for simulating flashover of insulating materials by simulating the adhesion of metal particles according to claim 1, characterized in that: The conical surface of the frustum-shaped insulating sample faces upward, and several measuring points are marked on the conical surface of the frustum-shaped insulating sample.

3. The experimental apparatus for simulating flashover of insulating materials by simulating the adhesion of metal particles according to claim 2, characterized in that: The measurement points are distributed radially in multiple rings relative to the center of the frustum-shaped insulating sample, and the measurement points on each ring are evenly spaced along the circumference.

4. The experimental apparatus for simulating flashover of insulating materials by simulating the adhesion of metal particles according to claim 1, characterized in that: The charge injection assembly includes a first DC power supply, a first resistor, a high-voltage guide post, a conductive spring, a first insulating support rod, a first metal support rod, a needle electrode, and a first translational drive mechanism. The positive terminal of the first DC power supply is connected to one end of the first resistor via a wire, and the other end of the first resistor is connected to the high-voltage guide post via a wire. The high-voltage guide post is horizontally fixedly mounted on the first insulating cover, with one end located outside the metal can and the other end located inside the metal can. The negative terminal of the first DC power supply is grounded via a wire. The first insulating support rod and the first metal support rod are coaxially fixed together. The combined support rod is horizontally sealed through the first insulating cover and has axial movement freedom relative to the first insulating cover. One end of the first metal support rod in the combined support rod always extends into the interior of the metal can. The needle electrode is vertically fixed to the end of the first metal support rod located inside the metal can. One end of the conductive spring is fixed to the end of the high-voltage guide column located inside the metal can, and the other end of the conductive spring is electrically connected to the first metal support rod. The first translation drive mechanism is located outside the metal can, and the first insulating support rod in the combined support rod is connected to the first translation drive mechanism.

5. The experimental apparatus for simulating flashover of insulating materials by simulating the adhesion of metal particles according to claim 1, characterized in that: The charge measurement assembly includes an electrostatic probe, a second insulating support rod, and a second translation drive mechanism; the second insulating support rod horizontally seals through the second insulating cover and has axial movement freedom relative to the second insulating cover; the electrostatic probe is vertically fixed to the end of the second insulating support rod located inside the metal can; the second translation drive mechanism is located outside the metal can, and the other end of the second insulating support rod is connected to the second translation drive mechanism.

6. The experimental apparatus for simulating flashover of insulating materials by simulating the adhesion of metal particles according to claim 1, characterized in that: The sample support and flashover assembly includes a second DC power supply, a second resistor, a first metal sample support rod, a second metal sample support rod, a third insulating support rod, a lifting drive mechanism, a rotary drive mechanism, a carbon brush conductive head, and a metal bracket. The positive terminal of the second DC power supply is connected to one end of the second resistor via a wire, and the other end of the second resistor is connected to a high-voltage conductor rod at the center of the insulator cover via a wire. The lifting drive mechanism and the rotary drive mechanism are located outside the metal tank, with the rotary drive mechanism mounted on the lifting drive mechanism. The third insulating support rod vertically and sealedly passes through the bottom plate of the metal tank. The lower end of the third insulating support rod is connected to the rotary drive mechanism, and the upper end of the third insulating support rod is screwed and fixed to the lower end of the vertically set second metal support rod. The upper end of the second metal support rod is screwed and fixed to the center of the lower surface of the frustum-shaped insulating sample, and the center of the upper surface of the frustum-shaped insulating sample is screwed and fixed to the lower end of the vertically set first metal support rod. The upper end of the first metal support rod is located directly below the high-voltage guide rod. The metal bracket is fixedly installed on the upper surface of the bottom plate of the metal tank, and the carbon brush conductive head is fixedly installed on the top of the metal bracket. The carbon brush conductive head slides and contacts the second metal support rod.

7. The experimental apparatus for simulating flashover of insulating materials by simulating the adhesion of metal particles according to claim 1, characterized in that: The metal particle adhesion simulation component includes a powder spraying head, a powder spraying pipe, a pipe connector, a metal particle powder storage tank, a pressure pump, a fourth insulating support rod, and a third translation drive mechanism. The fourth insulating support rod horizontally and sealed through the third insulating cover, and the fourth insulating support rod has axial movement freedom relative to the third insulating cover. The powder spraying head is fixed above the end of the fourth insulating support rod located inside the metal tank, with the nozzle of the powder spraying head facing upwards. The third translation drive mechanism is located outside the metal tank, and the other end of the fourth insulating support rod is connected to the third translation drive mechanism. The powder spraying pipe horizontally and sealed through the third insulating cover, with one end of the powder spraying pipe located inside the metal tank connected to the powder spraying head, and the other end of the powder spraying pipe located inside the metal tank connected to the metal particle powder storage tank through a pipe connector. The pressure pump is connected to the metal particle powder storage tank.

8. A flashover test method for insulating materials, employing the flashover test apparatus for insulating materials capable of simulating the adhesion of metal particles as described in claim 1, characterized in that, Includes the following steps: Step 1: Open the insulator cover, first fix the frustum-shaped insulation sample at the upper end of the second metal support rod, then fix the first metal support rod at the upper end of the frustum-shaped insulation sample, and then close the insulator cover. Step 2: Insulating gas is injected into the metal canister through the insulating gas injection port until the gas pressure reaches the set value, and then the insulating gas injection port is closed. Step 3: Activate the third translation drive mechanism to move the fourth insulating support rod into the metal can until the powder spraying head moves above the conical surface of the frustum-shaped insulating sample. Step 4: Start the pressurization pump to pressurize the metal microparticle powder storage tank, and force the metal microparticle powder in the storage tank into the powder spraying head through the powder spraying pipe. The powder spraying head sprays the metal microparticle powder into the metal can, and under the action of gravity, it automatically falls and adheres to the conical surface of the frustum-shaped insulation sample. At the same time, start the rotary drive mechanism to drive the combination of the third insulating support rod, the second metal support rod, the frustum-shaped insulation sample and the first metal support rod to rotate synchronously until the metal microparticle powder is evenly adhered to the conical surface of the frustum-shaped insulation sample. Then, turn off the pressurization pump and the rotary drive mechanism. Step 5: Reverse start the third translation drive mechanism to drive the fourth insulating support rod to move out of the metal can until the powder spraying head leaves the conical surface of the frustum-shaped insulating sample and moves back to the initial position; Step Six: Activate the first translation drive mechanism to move the combined support rod consisting of the first insulating support rod and the first metal support rod into the metal can until the needle electrode is moved above the conical surface of the frustum-shaped insulating sample. Step 7: Turn on the first DC power supply and apply voltage between the needle electrode and the second metal support rod. The voltage application time is 10 to 30 minutes until charge injection is completed on the conical surface of the frustum-shaped insulating sample. Then turn off the first DC power supply. Step 8: Reverse start the first translation drive mechanism, which drives the combined support rod consisting of the first insulating support rod and the first metal support rod to move out of the metal can until the needle electrode leaves the conical surface of the frustum-shaped insulating sample and moves back to the initial position. Step 9: Activate the second translation drive mechanism to move the second insulating support rod into the metal tank until the electrostatic probe is moved to the position of the first ring measurement point above the center side of the conical surface of the frustum-shaped insulating sample, and the distance between the electrostatic probe and the conical surface of the frustum-shaped insulating sample is at the set detection distance. Then activate the rotation drive mechanism to drive the combination of the third insulating support rod, the second metal support rod, the frustum-shaped insulating sample and the first metal support rod to rotate synchronously, and complete the charge measurement of the first ring measurement point on the inner side through the electrostatic probe. Step 10: Reverse the second translation drive mechanism to move the electrostatic probe to the location of the second measurement point. Then, start the lifting drive mechanism to move the combination of the third insulating support rod, the second metal support rod, the frustum-shaped insulating sample, and the first metal support rod to rise synchronously until the distance between the electrostatic probe and the conical surface of the frustum-shaped insulating sample returns to the set detection distance. Then, start the rotation drive mechanism again to rotate the combination of the third insulating support rod, the second metal support rod, the frustum-shaped insulating sample, and the first metal support rod synchronously. The charge measurement of the inner second measurement point is completed by the electrostatic probe. Step 11: Repeat steps 9 and 10, following the charge measurement process of the first two rings of measuring points on the center side of the frustum-shaped insulating sample, and complete the charge measurement of all measuring points ring by ring from the inside out; Step 12: After the charge measurement of the first ring of measuring points on the outer side of the frustum-shaped insulating sample is completed, continue to start the second translation drive mechanism in the reverse direction, driving the second insulating support rod to move towards the outside of the metal can until the electrostatic probe leaves the conical surface of the frustum-shaped insulating sample and moves back to the initial position. Step 13: Start the lifting drive mechanism to drive the combination of the third insulating support rod, the second metal support rod, the frustum-shaped insulating sample and the first metal support rod to rise synchronously until the upper end of the first metal support rod contacts the lower end of the high voltage conductor rod; Step Fourteen: Start the second DC power supply and apply voltage between the first metal support rod and the second metal support rod until a surface flashover phenomenon occurs on the surface of the frustum-shaped insulating sample; Step 15: After the surface flashover test is completed, turn off the second DC power supply and start the lifting drive mechanism in reverse. This will cause the combination of the third insulating support rod, the second metal support rod, the frustum-shaped insulating sample, and the first metal support rod to descend synchronously. The upper end of the first metal support rod will disengage from the lower end of the high-voltage conductor rod until the frustum-shaped insulating sample moves back to its initial position.

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