Detection system and method for motion characteristics of metal particles

Abstract

The invention discloses a metal particle motion characteristic detection system and method, and relates to the technical field of metal particle motion detection.The system comprises an alternating current voltage source, a vibration table, a camera and a defect model, the defect model comprises a first electrode and a second electrode which are oppositely arranged, and the second electrode is of a bowl-shaped structure and used for containing metal particles; the alternating-current voltage source is used for applying alternating-current voltage to the first electrode; the vibration table is used for driving the second electrode to vibrate; and the camera is used for shooting videos and / or images of the metal particles so as to analyze the motion characteristics of the metal particles under different electric fields and / or different vibration conditions through the videos and / or images of the metal particles. According to the method, the actually acquired videos and / or images of the metal particles under different electric fields and / or different vibration conditions are analyzed, so that the motion characteristic analysis result of the metal particles is more accurate, and accurate data support is provided for potential safety hazards caused by the metal particles moving freely in GIS equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of metal particle motion detection, and in particular to a detection system and method for metal particle motion characteristics. Background Art

[0002] Gas Insulated Switchgear (GIS) has the advantages of compact structure, environmental friendliness and high reliability, and is widely used in power systems. As its use increases, GIS equipment has been experiencing failures. At present, the operation of GIS equipment is still affected by metal particle defects, and insulation failures of GIS equipment caused by free metal particle defects have occurred many times. These metal particles have different shapes such as slender lines, spiral lines, flakes, spheres and powders. Their main sources are: mechanical wear during the production and assembly of GIS equipment; mechanical vibration during the transportation of GIS equipment; switching actions during the operation of GIS equipment, etc.

[0003] The metal particles that can move freely inside the GIS equipment are a major safety hazard for GIS equipment. In particular, the motion characteristics of submillimeter particles are the main way to affect the insulation strength of GIS, and the motion characteristics of particles are determined by their stress conditions. The type of external voltage, the shape of the insulator, the shape of the particles, etc. will change the electric field around the metal particles. The change in the electric field causes the stress conditions of the metal particles to change, which in turn causes differences in the motion behavior of the metal particles. However, the motion characteristics of metal particles are currently studied by simulation calculation. However, for some metal particles, such as 10mm long particles, the dielectrophoretic force is 10% of the Coulomb force, which indicates that the metal particles cannot be set as point charges to simplify the simulation model of GIS equipment combined with freely moving metal particles. Moreover, compared with regular metal particles such as spheres, the motion of irregular metal particles such as linear particles is complex. This is mainly due to the irregular shape of the ends of the linear particles. The shapes of the metal particles that can move freely in GIS equipment are often irregular. Therefore, there are large errors in the calculation results of simulation calculations. Summary of the invention

[0004] The technical problem to be solved by the present invention is to address the deficiencies of the prior art and specifically provide a detection system and method for the motion characteristics of metal particles, as follows:

[0005] 1) In the first aspect, the present invention provides a detection system for the motion characteristics of metal particles, and the specific technical scheme is as follows:

[0006] It includes an AC voltage source, a vibration table, a camera and a defect model, wherein the defect model includes a first electrode and a second electrode arranged opposite to each other, wherein the second electrode is a bowl-shaped structure for placing metal particles;

[0007] The AC voltage source is used to apply an AC voltage to the first electrode;

[0008] The vibration table is used to drive the second electrode to vibrate;

[0009] The camera is used to capture videos and / or images of metal particles, so as to analyze the movement characteristics of the metal particles under different electric fields and / or different vibration conditions through the videos and / or images of the metal particles.

[0010] The beneficial effects of the metal particle motion characteristic detection system provided by the present invention are as follows:

[0011] It is possible to truly obtain videos and / or images of metal particles under different electric fields and / or different vibration conditions, and analyze the movement characteristics of metal particles under different electric fields and / or different vibration conditions through the videos and / or images of metal particles, so that the analysis results of the movement characteristics of metal particles are more accurate, and provide accurate data support for the safety hazards caused by freely moving metal particles in GIS equipment.

[0012] Based on the above solution, the detection system of the motion characteristics of metal particles of the present invention can also be improved as follows.

[0013] Furthermore, it also includes a fill light, which is used to provide fill light when the camera shoots videos and / or images of metal particles.

[0014] Furthermore, the first electrode is a spherical electrode.

[0015] Furthermore, the vibration table is used to drive the second electrode to perform sinusoidal vibration in the vertical direction.

[0016] 2) In the second aspect, the present invention also provides a method for detecting the motion characteristics of metal particles, and the specific technical solution is as follows:

[0017] A detection system for the motion characteristics of metal particles is used, wherein the detection system for the motion characteristics of metal particles includes an AC voltage source, a vibration table, a camera, and a defect model, wherein the defect model includes a first electrode and a second electrode arranged opposite to each other, wherein the second electrode is a bowl-shaped structure for placing metal particles;

[0018] Methods include:

[0019] After placing the metal particles in the second electrode, applying an AC voltage to the first electrode through an AC voltage source and / or driving the second electrode to vibrate through a vibration table, and taking a video and / or image of the metal particles with a camera;

[0020] Based on the video and / or image of the metal particles, the movement characteristics of the metal particles under different electric fields and / or different vibration conditions are analyzed.

[0021] Based on the above solution, the method for detecting the motion characteristics of metal particles of the present invention can be improved as follows.

[0022] Furthermore, the detection system for the motion characteristics of metal particles also includes a fill light, and the fill light is used to provide fill light when the camera captures the video and / or image of the metal particles.

[0023] Furthermore, the first electrode is a spherical electrode.

[0024] Further, driving the second electrode to vibrate by using the vibration table includes: driving the second electrode to perform sinusoidal vibration in a vertical direction by using the vibration table.

[0025] Furthermore, the camera is a macro camera.

[0026] It should be noted that the beneficial effects achieved by the technical solution of the second aspect of the present invention and the corresponding possible implementation methods can be found in the above-mentioned technical effects of the first aspect and its corresponding possible implementation methods, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments of the present invention:

[0028] Figure 1 A schematic diagram of the structure of a detection system for the motion characteristics of metal particles according to an embodiment of the present invention;

[0029] Figure 2 The figure is a flow chart of a method for detecting the motion characteristics of metal particles according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0031] The technical solution of the present invention and how the technical solution of the present invention solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below in conjunction with the accompanying drawings.

[0032] like Figure 1As shown, a detection system for the motion characteristics of metal particles according to an embodiment of the present invention includes an AC voltage source, a vibration table, a camera, and a defect model. The defect model includes a first electrode 1 and a second electrode 2 that are arranged opposite to each other. The second electrode 2 is a bowl-shaped structure for placing metal particles 4.

[0033] The first electrode 1 is a spherical electrode, and other structures of the first electrode 1 may also be selected according to actual conditions, and the vibration platform is used to drive the second electrode 2 to perform sinusoidal vibration in the vertical direction. The camera is a macro camera.

[0034] The AC voltage source is used to apply an AC voltage to the first electrode 1; the high voltage source includes a voltage regulator and a transformer, which are used to increase the AC high voltage for the first electrode 1 of the defect model.

[0035] The defect model further includes a metal rod, which is connected to the end of the first electrode 1 away from the second electrode 2, and the metal rod is in the vertical direction. The specific connection method can be welding or:

[0036] A threaded rod is connected to one end of the first electrode 1 away from the second electrode 2, a thread matching the threaded rod is provided at one end of the metal rod, and then a matching nut is first fixed on the threaded rod, and then the threaded rod is connected through the nut. The first electrode 1 and the threaded rod can be integrally formed or separately provided.

[0037] The vibration table is used to drive the second electrode 2 to vibrate. Specifically, the vibration table surface 3 of the vibration table is rigidly connected to the second electrode 2 by bolts, and the power amplifier is used to power the vibration table, and the vibration amplitude and frequency of the vibration table are changed by adjusting the output mode.

[0038] Optionally, the other end of the metal rod is connected to a non-metallic plate, and the non-metallic plate is fixedly connected to the vibration table through multiple non-metallic rods. When the vibration table drives the second electrode 2 to vibrate, the first electrode 1 vibrates synchronously to ensure that the relative position between the first electrode 1 and the second electrode 2 remains unchanged.

[0039] The camera is used to capture videos and / or images of the metal particles 4, so as to analyze the motion characteristics of the metal particles under different electric fields and / or different vibration conditions through the videos and / or images of the metal particles 4. Specifically:

[0040] 1) Use an electronic balance to measure 1mm, 30 mesh (550μm) and 1000 mesh (13μm) metal particles, a total of 0.1g, and place them in the second electrode 2, and gather them in the center of the concave surface of the second electrode 2 to form a pile of metal particles. First, gradually increase the AC voltage applied to the first electrode 1 without vibration, observe its initial movement process with a macro camera, and record the values ​​of the initial jump voltage and the stable jump voltage, where the initial jump voltage refers to: the voltage at which the metal particles are observed to move for the first time during the gradual application of the AC voltage, and the stable jump voltage is defined as: under such a voltage, the metal particles can maintain stable jumps without applying other forces. Then, the vibration table is powered by a power amplifier, and a vertical steady-state vibration is applied to the defect model. The vibration amplitude is gradually increased at vibration frequencies such as 100Hz, 500Hz and 1000Hz, and the motion characteristics of metal particles of different particle sizes are investigated at vibration amplitudes of 1Vpp, 2Vpp, 3Vpp, 4Vpp and 5Vpp.

[0041] The particle size of metal particles has a great influence on the initial jump voltage and the stable jump voltage. From the perspective of average AC voltage, when the number of metal particles is 0.1g, metal particles with a particle size of 30 mesh are the easiest to jump, followed by metal particles with a particle size of 1mm, and metal particles with a particle size of 1000 mesh are the most difficult to jump. From the analysis of the force on the metal particles, the smaller the particle size of the metal particles, the greater the combined force of gravity, electric field force, Coulomb force and van der Waals force they bear relative to the metal particles themselves. Therefore, smaller dust particles will be easier to jump and have a larger diffusion radius.

[0042] The test results show that it is most difficult for metal particles with a particle size of 1000 mesh to jump, which is caused by the nature of the metal particles themselves. It should be clear that the above force analysis is aimed at a dust pile with a "pyramid" structure, and it is assumed that the force conditions between any two dust particles are similar. But in fact, due to the different ways of obtaining metal particles in practice, the metal particles used in the experiment rarely have a uniform and stable structure. The internal structure of the powder pile may be adhered, resulting in different internal forces. There may even be a certain number of powder piles with stable structures that are tightly combined to form a "large metal particle" that is loose but has been formed. In addition, too small powder itself is easy to adhere to the aluminum bottom electrode, making it difficult to jump.

[0043] The test results show that under different vibration conditions, metal particles of three different particle sizes behave stably and have the following characteristics: (1) The vibration amplitude will affect the movement of metal particles. The larger the vibration amplitude, the lower the initial jump voltage and stable jump voltage of the metal particles. However, the sensitivity of metal particles of different particle sizes is different. For 1mm metal particles, the decrease of their initial jump voltage and stable jump voltage is more obvious; for 30-mesh metal particles, their initial jump voltage has little correlation with the vibration amplitude, but their stable jump voltage decreases with the increase of vibration amplitude, and the vibration frequency has almost no effect; for 1000-mesh metal particles, their initial jump voltage and stable jump voltage decrease are more obvious. (2) The vibration frequency has little effect on the initial jump voltage and stable jump voltage of metal particles, and the 1mm metal particles have a slight upward trend.

[0044] From the perspective of movement characteristics, (1) for 1mm metal particles, their initial movement process is characterized by the standard "initial jump" and "stable jump" when there is no vibration. However, after vibration is applied, the stable jump stage can be divided into the early horizontal large jump and the later vertical large jump. (2) For 30-mesh metal particles, the measurement of their initial jump is more difficult than that of 1mm metal particles. This is because the boundary between the two stages becomes less obvious after the particle size of the metal particles becomes smaller. When vibration is applied and pressure is applied to above PDIV, a small large jump in the horizontal range can be clearly observed, and the falling position of the metal particles is in the center of the bottom electrode. (3) For 1000-mesh metal particles, their movement characteristics are characterized by "cutting off the top" at the end of the powder pile. As the voltage continues to increase, a small, tightly bound powder pile is gradually exposed. It is worth noting that for metal particles with smaller particle sizes, the effect of high-amplitude vibration can be reflected when no voltage is applied.

[0045] From the relationship between vibration and motion process, the most prominent feature is the periodic motion of metal particles. In the experiment, most metal particles can be observed to have obvious "jump-rest" cyclic reciprocating motion, which is related to the energy conversion between metal particles. At a voltage less than the PDIV of metal particle defects, one or several metal particles will become activated metal particles due to the energy obtained by external vibration. The activated metal particles release energy through displacement and further distort the electric field. In addition, the impact of the activated metal particles on the peripheral metal particles causes more metal particles to start moving. However, since the voltage is lower than the PDIV at this time, and although the energy of vibration can cause one or several metal particles to initially jump, such mechanical energy is not enough to maintain the long-term and large-scale jumping of more metal particles, so such movement is not self-sustaining and will stop after a period of time. Subsequently, after a period of rest, one or several metal particles will again become activated metal particles due to the energy obtained by external vibration, and the above process will be repeated. In the periodic motion, the jumping time and the resting time are related to multiple factors such as the number of metal particles and the particle size of metal particles. They change with the change of working conditions and have a certain randomness. The runout may be a small horizontal movement or a large vertical movement.

[0046] 2) Use an electronic balance to measure 0.01g, 0.1g and 1g of 30-mesh (550μm) metal particles, respectively, and place them on the bottom electrode of the defect model and gather them in the center of the concave surface to form a pile of metal particles. First, gradually increase the voltage under vibration-free conditions, observe its initial movement process with a macro camera, and record the values ​​of the initial jump voltage and the stable jump voltage. Then, use a power amplifier and a vibration table to apply vertical steady-state vibration to the defect model, gradually increase the vibration amplitude at vibration frequencies such as 100Hz, 500Hz and 1000Hz, and examine the motion characteristics of metal particles at 1Vpp, 2Vpp, 3Vpp, 4Vpp and 5Vpp.

[0047] The test results show that the number of metal particles has a certain influence on the initial jump voltage and the stable jump voltage. From the perspective of average voltage, the more metal particles there are, the smaller the initial jump voltage is, but the correlation of the stable jump voltage is general. From the perspective of energy, as mentioned above, for a pile of metal particles with a larger mass, the small movement of individual metal particles is more obvious. This is because under the same energy state, compared with a pile of metal particles with a smaller mass, a single metal particle has a smaller impact on the whole. In more cases, due to the large proportion of energy of a single metal particle, a powder pile with a smaller mass will skip the small movement and directly enter the stable jump, that is, in such a powder pile, a metal particle can easily drive other metal particles to move when it jumps, making the initial jump voltage and the stable jump voltage tend to be the same, which leads to a higher initial jump voltage. The stable jump voltage is more related to the properties of the metal particles themselves, and the number of metal particles has little effect on it. When different vibrations are applied, the three different numbers of metal particles behave stably, with the following characteristics:

[0048] The vibration amplitude will affect the movement of metal particles. The larger the vibration amplitude, the lower the initial jump voltage and stable jump voltage of metal particles. However, the sensitivity of different numbers of metal particles is different. The more metal particles there are, the smaller the impact of the vibration amplitude. The vibration frequency has little effect on the initial jump voltage and stable jump voltage of metal particles, and an upward trend was occasionally measured in the test.

[0049] Among them, the shape and particle size of the metal particles, the applied AC voltage value, the vibration amplitude and vibration frequency, etc. can be set according to actual conditions.

[0050] The macro camera is placed next to the defect model. To facilitate observation, the shooting direction of the camera is at a certain angle to the horizontal plane where the metal particles are located.

[0051] Optionally, a fill light is also included, which is used to provide fill light when the camera captures videos and / or images of metal particles. Specifically, the fill light is also set beside the defect model and aimed at the location of the metal particles to enhance the brightness within the imaging field of view.

[0052] The detection system for the motion characteristics of metal particles also includes a computer device. The vibration table in the detection system for the motion characteristics of metal particles is used to simulate the vibration process of the GIS equipment during operation, and a video is collected through a macro camera. The computer device preprocesses each video frame in the video of the metal particles. In the preprocessed video frame, the position and size of the particles are detected using a threshold segmentation algorithm, an edge detection algorithm, and a matching algorithm. After the metal particles are detected, the motion trajectory of each particle is continuously tracked, which can be specifically achieved through an SPT algorithm. The characteristic information of each metal particle, such as speed and acceleration, is extracted from the tracked motion trajectory. By analyzing multiple videos, the speed and acceleration of each metal particle at different vibration amplitudes and vibration frequencies can be quantified.

[0053] Optionally, by analyzing the metal particles during the operation of the GIS equipment, a first functional relationship of how the shape, particle size and number of the metal particles change with the operating time can be quantified. By using the first functional relationship and combining the speed and acceleration of each metal particle at different vibration amplitudes and vibration frequencies, a second functional relationship of how the shape, particle size, number, speed, acceleration and direction of the metal particles change with the operating time under different vibration conditions can be quantified. When the operating time and vibration conditions of the GIS equipment are known, the shape, particle size and number of the metal particles can be inferred by using the first functional relationship, and the speed and acceleration of each metal particle can be inferred by using the second functional relationship. The shape, particle size, number, speed and acceleration of the metal particles are added to a simulation model of the GIS equipment combined with freely moving metal particles, thereby accurately calculating simulation calculation results such as the electric field distribution of the GIS equipment. The risk of insulation failure can be accurately determined from the simulation calculation results, so that the GIS equipment can be shut down, replaced or other measures can be taken in time to ensure the safe and stable operation of the power grid where the GIS equipment is located.

[0054] Optionally, in the above technical solution, a reflective sticker is set on the vibration table surface 3, and one end of the optical fiber is aligned with the reflective sticker at a distance of less than 5 mm. The optical fiber can be fixed on the defect model and vibrate synchronously with the defect model. At this time, it can be ensured that the distance between one end of the optical fiber and the reflective sticker does not change. A laser is transmitted to the reflective sticker through the optical fiber by a laser, and the light reflected by the reflective sticker is transmitted to a spectrometer through the optical fiber. The spectrometer generates a spectrum of the light reflected by the reflective sticker, and analyzes the spectrum to obtain a curve of the spectrum peak value changing with the frequency. According to the change of the spectrum peak value, the actual vibration frequency of the vibration table is determined.

[0055] like Figure 2As shown, a method for detecting the motion characteristics of metal particles according to an embodiment of the present invention uses a detection system for the motion characteristics of metal particles, wherein the detection system for the motion characteristics of metal particles includes an AC voltage source, a vibration table, a camera, and a defect model, wherein the defect model includes a first electrode 1 and a second electrode 2 that are arranged opposite to each other, wherein the second electrode 2 is a bowl-shaped structure for placing metal particles 4;

[0056] Methods include:

[0057] S1. After placing the metal particles 4 in the second electrode 2, applying an AC voltage to the first electrode 1 through an AC voltage source and / or driving the second electrode 2 to vibrate through a vibration table, and taking a video and / or image of the metal particles with a camera;

[0058] S2. Analyze the motion characteristics of the metal particles under different electric fields and / or different vibration conditions based on the video and / or image of the metal particles.

[0059] Optionally, in the above technical solution, the detection system for the motion characteristics of metal particles further includes a fill light, and the fill light is used to provide fill light when the camera captures the video and / or image of the metal particles.

[0060] Optionally, in the above technical solution, the first electrode 1 is a spherical electrode.

[0061] Optionally, in the above technical solution, driving the second electrode 2 to vibrate by using a vibration table includes: driving the second electrode 2 to perform sinusoidal vibration in a vertical direction by using the vibration table.

[0062] Optionally, in the above technical solution, the camera is a macro camera.

[0063] In the above embodiments, although the steps are numbered S1, S2, etc., these are only specific embodiments given by the present invention. Those skilled in the art may adjust the execution order of S1, S2, etc. according to actual conditions, which is also within the protection scope of the present invention. It can be understood that in some embodiments, some or all of the above embodiments may be included.

[0064] In addition, the method and system embodiments provided in the above embodiments belong to the same concept, and their specific implementation processes are detailed in the system embodiments, which will not be repeated here.

[0065] The above description is only a preferred embodiment of the present invention and an explanation of the technical principles used. Those skilled in the art should understand that the disclosure scope involved in the present invention is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present invention (but not limited to) by each other.

[0066] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects and represent the definition of a specific order or sequence. The order of use of similar objects can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than the order shown or described.

[0067] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A detection system for the motion characteristics of metal particles, characterized in that: It includes an AC voltage source, a vibration table, a camera and a defect model, wherein the defect model includes a first electrode and a second electrode arranged opposite to each other, wherein the second electrode is a bowl-shaped structure for placing metal particles; The AC voltage source is used to apply an AC voltage to the first electrode; The vibration table is used to drive the second electrode to vibrate; The camera is used to capture videos and / or images of metal particles, so as to analyze the movement characteristics of the metal particles under different electric fields and / or different vibration conditions through the videos and / or images of the metal particles.

2. A detection system for the motion characteristics of metal particles according to claim 1, characterized in that: It also includes a fill light, which is used to provide fill light when the camera captures videos and / or images of metal particles.

3. A detection system for the motion characteristics of metal particles according to claim 1, characterized in that: The first electrode is a spherical electrode.

4. A detection system for the motion characteristics of metal particles according to claim 1, characterized in that: The vibration table is used to drive the second electrode to perform sinusoidal vibration in a vertical direction.

5. A detection system for the motion characteristics of metal particles according to claim 1, characterized in that: The camera is a macro camera.

6. A method for detecting the motion characteristics of metal particles, characterized in that: A detection system for the motion characteristics of metal particles is used, wherein the detection system for the motion characteristics of metal particles includes an AC voltage source, a vibration table, a camera, and a defect model, wherein the defect model includes a first electrode and a second electrode arranged opposite to each other, wherein the second electrode is a bowl-shaped structure for placing metal particles; Methods include: After placing the metal particles in the second electrode, applying an AC voltage to the first electrode through an AC voltage source and / or driving the second electrode to vibrate through a vibration table, and taking a video and / or image of the metal particles with a camera; Based on the video and / or image of the metal particles, the movement characteristics of the metal particles under different electric fields and / or different vibration conditions are analyzed.

7. A method for detecting the motion characteristics of metal particles according to claim 6, characterized in that: The detection system for the motion characteristics of metal particles further comprises a fill light, and the fill light is used to provide fill light when the camera captures the video and / or image of the metal particles.

8. A method for detecting the motion characteristics of metal particles according to claim 6, characterized in that: The first electrode is a spherical electrode.

9. The method for detecting the motion characteristics of metal particles according to claim 6, characterized in that: Driving the second electrode to vibrate by using the vibration table includes: driving the second electrode to perform sinusoidal vibration in a vertical direction by using the vibration table.

10. The method for detecting the motion characteristics of metal particles according to claim 6, characterized in that: The camera is a macro camera.

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