A device for multi-stage attenuation of lightning current intensity and steepness

Abstract

The present invention discloses a device for multi-stage attenuation of lightning current intensity and steepness, belonging to the technical field of lightning protection and arc extinction. It includes a recoil arc extinction unit, a sealed compressed air arc extinction unit, and a sealed arc extinction unit. The recoil arc extinction unit is arranged at the top of the sealed compressed air arc extinction unit and is electrically connected. The sealed arc extinction unit is arranged at the bottom of the sealed compressed air arc extinction unit and is electrically connected. Compressed air is arranged in the sealed compressed air arc extinction unit, and insulating oil is arranged in the sealed arc extinction unit. The present invention cuts off the arc quickly. As soon as the arc discharges in the insulating tube, it is immediately ejected by recoil. When discharging in the liquid, a liquid-electric effect is generated, and an impact pressure wave is quickly formed. The impact arc is immediately cut off when it is just formed, reducing carbon emissions. The liquid medium and gas medium replace the original conductive metal, which is safer and cleaner, can effectively reduce carbon emissions, effectively suppress the residual voltage, and the liquid-electric effect and Pascal effect can quickly cut off the arc and reduce the amplitude of the current.

Description

Technical Field

[0001] The present invention relates to the technical field of lightning protection and arc extinguishing, and in particular to a device for multi-stage attenuation of lightning current intensity and steepness. Background Art

[0002] Zinc oxide lightning arresters installed in parallel with line insulators (in series) can effectively reduce the lightning flashover tripping accident rate and improve the lightning resistance level of AC overhead transmission lines. However, existing zinc oxide lightning arresters have the following problems:

[0003] 1. When the zinc oxide lightning arrester is subjected to impulse voltage, the valve plate will also age under the action of impulse voltage energy.

[0004] 2. Since the zinc oxide lightning arrester cancels the series gap, under the action of the grid operating voltage, its body will flow current. The active component in the current will cause the zinc oxide valve plate to heat up, and then cause the volt-ampere characteristic to change. This is a positive feedback process. The long-term result will cause the zinc oxide valve plate to age and even thermal breakdown.

[0005] 3. If the zinc oxide lightning arrester is damp inside or the insulation performance of the insulating bracket is poor, the power frequency current will increase, the power consumption will increase, and in severe cases, it may cause internal discharge. Summary of the Invention

[0006] The present invention aims to provide a multi-stage device for attenuating lightning current intensity and steepness, resolving the technical problems encountered in the prior art. By replacing the zinc oxide valve disc with a sealed liquid medium, a sealed gas medium, and an open gas medium, the valve disc is prevented from aging and thermal breakdown under the influence of impulse voltage. Furthermore, the high-pressure gas and liquid mediums enhance the pressure within the arc-extinguishing zone during the arc-extinguishing process, enabling rapid arc interruption and preventing damage to transmission lines caused by excessive instantaneous lightning current amplitude.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A multi-stage device for attenuating lightning current intensity and steepness comprises a recoil arc extinguishing unit, a sealed compressed air arc extinguishing unit and a sealed arc extinguishing unit, wherein the recoil arc extinguishing unit is arranged on the top of the sealed compressed air arc extinguishing unit and is electrically connected, the sealed arc extinguishing unit is arranged on the bottom of the sealed compressed air arc extinguishing unit and is electrically connected, compressed air is arranged in the sealed compressed air arc extinguishing unit, and insulating oil is arranged in the sealed arc extinguishing unit.

[0009] Further, the recoil arc extinguishing unit includes a lightning receiving electrode, a recoil tube body, a recoil tube skirt, and a bottom lightning receiving electrode. The lightning receiving electrode is arranged at the top of the recoil tube body, the recoil tube skirt is arranged on the side of the recoil tube body, the inside of the recoil tube body is set as a recoil empty hole, and the bottom lightning receiving electrode is arranged at the low end of the recoil empty hole. Both the lightning receiving electrode and the bottom lightning receiving electrode are graphite electrodes.

[0010] Further, the structure of the sealed compressed air arc extinguishing unit is the same as that of the sealed arc extinguishing unit. The sealed arc extinguishing unit is set as a sealed tube, with an upper electrode and a lower electrode respectively arranged at both ends of the sealed tube in a sealed manner. Insulating oil is arranged inside the sealed tube, and a skirt is arranged on the side of the sealed tube.

[0011] Further, the sealed tube further includes a ceramic tube and a protective shell. The protective shell is arranged outside the ceramic tube, and the skirt is arranged outside the protective shell.

[0012] Further, the upper electrode includes an upper layer graphite electrode, a middle metal electrode, and a lower layer graphite electrode. The middle metal electrode is fixed at one end of the ceramic tube and the protective shell. The upper layer graphite electrode is arranged above the middle metal electrode, and the lower layer graphite electrode is arranged at the bottom of the middle metal electrode and is arranged inside the ceramic tube. The lower electrode includes an upper end graphite electrode and a bottom metal electrode. The bottom metal electrode is fixed at the other end of the ceramic tube and the protective shell. The upper end graphite electrode is arranged inside the ceramic tube and is connected to the bottom metal electrode.

[0013] Further, the sealed arc extinguishing unit is set as a sealed tube, with an upper electrode and a lower electrode respectively arranged at both ends of the sealed tube in a sealed manner. Insulating oil is arranged inside the sealed tube, a skirt is arranged on the side of the sealed tube, and arc extinguishing grids are arranged at intervals on the inner side of the sealed tube. The transverse length of the arc extinguishing grids is greater than half of the inner diameter of the sealed tube.

[0014] Further, an upper tip electrode is arranged at the bottom of the upper electrode, and a lower tip electrode is arranged at the upper end of the lower electrode. The upper tip electrode and the lower tip electrode are arranged vertically opposite to each other. Both the upper tip electrode and the lower tip electrode are graphite electrodes.

[0015] Further, the arc extinguishing grids are made of insulating materials and are set as a semi-circular structure. The arc extinguishing grids arranged on the inner side walls of the two semi-circles inside the sealed tube are arranged alternately. There are convex piers arranged between the arc extinguishing grids on the same semi-circle. The convex piers on the inner side wall of one semi-circle are arranged opposite to the arc extinguishing grids on the inner side wall of the other semi-circle.

[0016] Further, the specific working process of the device is as follows:

[0017] Step 1: When the overvoltage wave caused by a lightning strike on the line approaches the arc extinguishing device, the air gap above the device is preferentially broken down. The metal electrode draws the arc to the entrance of the device through the action of Coulomb force, and the recoil arc extinguishing unit extinguishes the arc by recoil.

[0018] Step 2: The arc is extinguished by the Pascal effect in the sealed compressed air arc extinguishing unit;

[0019] Step 3: The arc causes the hydroelectric effect and Pascal effect in the sealed arc extinguishing unit to perform double-effect arc extinguishing.

[0020] Furthermore, the specific process of step 2 is that the arc is injected into the sealed compressed air arc extinguishing unit. The air pressure in the sealed compressed air arc extinguishing unit is higher than the standard atmospheric pressure. The density of free electrons is greater than that of air, and the effective movement distance of electrons will become smaller. When the arc acts on the insulating compressed air, a shock wave is generated toward the side wall. After encountering the side, the shock wave rebounds and rushes toward the arc channel, thereby enhancing the insulation of the sealed compressed air arc extinguishing unit and the speed at which the medium recovers quickly, thereby achieving rapid arc interruption.

[0021] Furthermore, the specific process of step 3 is:

[0022] Step 3.1: When an arc discharge is initiated in a sealed tube filled with insulating oil, the hydroelectric effect generates a shock wave that rushes to the side. Arc discharge is triggered in the ceramic tube filled with insulating oil. Part of the insulating oil in the discharge channel is instantly vaporized, decomposed, and ionized into a high-temperature plasma, which suddenly expands, forming a mechanical pressure wave that propagates rapidly outward. However, because the liquid can be regarded as a shock wave transmission medium that cannot be compressed, the liquid-phase discharge in the discharge channel manifests the mechanical effect of power to the outside world, forming a force that impacts the ceramic tube wall. Due to the mutuality of forces, the ceramic tube wall generates a shock wave in the insulating oil medium.

[0023] Step 3.2: The Pascal effect enhances the hydroelectric effect. When the arc acts on the insulating oil, a portion of the static insulating oil undergoes a pressure change, which is transmitted in all directions inside the sealed tube without changing in magnitude. When the impact arc acts on the metal electrode, it applies pressure to the insulating oil in the ceramic tube. According to Pascal's principle, a portion of the static fluid in the closed container undergoes a pressure change, which is transmitted in all directions without changing in magnitude. Starting from the discharge channel inside the ceramic tube, it impacts the surrounding insulating oil medium with a greater force, which rebounds after hitting the ceramic tube wall.

[0024] Step 3.3: Since an arc extinguishing grid is provided inside the sealed tube, the arc length in the sealed tube becomes longer. At the same time, convex piers are provided to increase the surface area of the sealed tube. The shock waves of the liquid-electric effect and the Pascal effect impact the side and then return to impact. The liquid-electric effect and the Pascal effect increase the pressure and temperature inside the ceramic tube, generating a force pointing from the ceramic tube wall to the center. Under this force, the arc moves towards the tip of the arc extinguishing grid. The tip elongates the arc length, and under the blowing of the insulating oil on the arc, the arc temperature decreases, enabling the arc to be extinguished more quickly. The longer the arc formed in the ceramic tube, the greater the force on the ceramic tube wall, and conversely, the greater the impact force for intercepting the arc. The force rebounds after acting on the outer shell, forming a force pointing towards the center of the insulating tube, and concentrating on impacting and extinguishing the arc in the arc channel.

[0025] This scheme has three-stage arc extinguishing or more. Several structures among the recoil arc extinguishing unit, the sealed compressed air arc extinguishing unit, and the sealed arc extinguishing unit can be combined with each other. However, the recoil arc extinguishing unit needs to be set at the top, and the sealed compressed air arc extinguishing unit can also be set at the bottom, and a screw is set at the bottom for grounding.

[0026] This scheme undergoes three-stage arc extinguishing:

[0027] The arc undergoes recoil restricted by the tube wall at the first stage: When the overvoltage wave caused by lightning striking the line approaches the arc extinguishing device, the air gap above the device is preferentially broken down. The metal electrode draws the arc to the device entrance through the action of Coulomb force, and the external arc enters the insulating tube (the inside of the tube is a gas medium) under the action of the metal electrode 1. Since the inner diameter of the insulating tube is much smaller than the arc diameter, the arc is restricted by the insulating tube wall, and the arc column diameter is forced to decrease, resulting in a smaller cross-sectional area of the entire arc conduction and an increase in arc resistance. According to the power calculation formula: P = I 2 ×R, it can be seen that the arc power also increases, causing the heat and temperature inside the tube to rise. When the pressure inside the insulating tube is greater than the pressure outside the tube, a directional arc pressure explosion effect from the inside to the outside is generated, and the pressure explosion effect causes the arc to be discharged: on the one hand, the arc inside the tube is quickly emptied; on the other hand, the external arc cavity effect blocks the injection of external arc energy.

[0028] The arc causes the Pascal effect at the second stage: When the arc enters the second stage after the first-stage recoil effect, the arc is poured into the second stage of the insulating tube, and the air pressure in the second stage of the insulating tube is higher than the standard atmospheric pressure. Since the pressure in the second stage is greater, the density of free electrons is greater, and the effective moving distance of the electrons will become smaller, which enhances the insulation and the speed of rapid dielectric recovery in the second stage, achieving the purpose of quickly intercepting the arc.

[0029] The electric arc causes the liquid-electric effect and Pascal's effect at the third stage: The electric arc enters the third stage of the insulating tube through the metal electrode. The electric arc discharges in the insulating tube containing liquid. Part of the liquid in the discharge channel is instantly vaporized, decomposed, and ionized into a high-temperature plasma and suddenly expands, forming a mechanical pressure wave that rapidly propagates outward. However, since the liquid can be regarded as a shock wave transmission medium that will not be compressed by itself, when liquid-phase discharge occurs in the discharge channel, it exhibits a mechanical effect of ultra-high power on the outside world, forming an impact force in the insulating tube, acting on the discharge channel in the form of impulse or impact pressure, impacting the electric arc and truncating it.

[0030] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0031] The present invention can quickly truncate the electric arc. The electric arc is immediately ejected by the recoil when discharging in the insulating tube. The liquid-electric effect is generated during the discharge in the liquid, and an impact pressure wave is quickly formed. The electric arc is truncated immediately when it is just formed, reducing carbon emissions. The liquid medium and gas medium replace the original conductive metal, which is safer and cleaner, can effectively reduce carbon emissions, and can effectively suppress the residual voltage - the liquid-electric effect and Pascal's effect can quickly truncate the electric arc, reduce the amplitude of the current, and avoid the huge residual voltage caused by the discharge of lightning current, which may damage the power equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic structural diagram of the device of the present invention;

[0033] Figure 2 It is a schematic structural diagram of the first sealed arc extinguishing unit of the present invention;

[0034] Figure 3 It is a schematic structural diagram of the second sealed arc extinguishing unit of the present invention;

[0035] Figure 4 It is a schematic structural diagram of the high-pressure sealing structure of the sealed tube of the present invention;

[0036] Figure 5 It is a schematic structural diagram of the external reinforcement structure of the sealed tube of the present invention.

[0037] In the drawings, A - recoil arc extinguishing unit, B - sealed compressed air arc extinguishing unit, C - sealed arc extinguishing unit, D - bottom screw, 1 - upper electrode, 2 - insulating oil, 3 - ceramic tube, 4 - skirt, 5 - protective housing, 6 - lower electrode, 7 - electric arc, 8 - upper tip electrode, 9 - arc extinguishing grid, 10 - convex pier, 11 - lower tip electrode. DETAILED DESCRIPTION OF THE INVENTION

[0038] To make the objectives, technical solutions and advantages of the present invention more clear and understandable, the following preferred embodiments are given with reference to the accompanying drawings for further detailed description of the present invention. However, it should be noted that many details listed in the specification are only for enabling the reader to have a thorough understanding of one or more aspects of the present invention, and these aspects of the present invention can be implemented even without these specific details.

[0039] Embodiment 1:

[0040] As Figure 1-2 shown, a device for multi-stage attenuation of lightning current intensity and steepness includes a recoil arc extinguishing unit A, a sealed compressed air arc extinguishing unit B, and a sealed arc extinguishing unit C. The recoil arc extinguishing unit A is arranged on the top of the sealed compressed air arc extinguishing unit B and is electrically connected. The sealed arc extinguishing unit C is arranged at the bottom of the sealed compressed air arc extinguishing unit B and is electrically connected. Compressed air is arranged in the sealed compressed air arc extinguishing unit B, and insulating oil 2 is arranged in the sealed arc extinguishing unit C. The insulating oil 2 can also be set to other insulating liquid media, and the air in the sealed compressed air arc extinguishing unit B is dry and clean compressed air with a pressure of about 3 atmospheres or more.

[0041] The recoil arc extinguishing unit A, the sealed compressed air arc extinguishing unit B, and the sealed arc extinguishing unit C are integrally arranged. The overall outer shell is set as an integral round tube, and then a skirt is arranged on the outside of the round tube. Then both the sealed compressed air arc extinguishing unit B and the sealed arc extinguishing unit C are sealed and can withstand the corresponding fixed pressure of the beautiful phoenix device.

[0042] In this embodiment, the recoil arc extinguishing unit A includes a lightning receiving electrode, a recoil tube body, a recoil tube skirt, and a bottom lightning receiving electrode. The lightning receiving electrode is arranged at the top of the recoil tube body, the recoil tube skirt is arranged on the side of the recoil tube body, a recoil empty hole is arranged inside the recoil tube body, and a bottom lightning receiving electrode is arranged at the low end of the recoil empty hole. Both the lightning receiving electrode and the bottom lightning receiving electrode are graphite electrodes.

[0043] By setting a graphite electrode at the lightning receiving place, the service life can be effectively improved.

[0044] Graphite electrodes have good electrical conductivity and can easily introduce the arc into the recoil tube: Graphite is a non-metallic material, and its electrical conductivity is 100 times higher than that of ordinary non-metallic ores. Each carbon atom in graphite is connected to three other carbon atoms around it, arranged in a honeycomb-like multiple hexagons. Since each carbon atom will release an electron and those electrons can move freely, graphite belongs to a conductor. Generally speaking, the discharge machining speed of graphite electrodes is 1.5 to 2 times faster than that of copper electrodes as a whole. When lightning strikes the transmission line, the graphite electrode can play the role of arc ignition, enabling the arc to smoothly enter the arc extinguishing tube.

[0045] Graphite electrodes have an extremely high melting point, can withstand a larger current, and are not easily deformed: Graphite electrodes have the characteristic of being able to withstand large current conditions. The softening point of copper is around 1000 degrees Celsius and it is easily deformed by heat; while the sublimation temperature of graphite is around 3650 degrees Celsius. The lightning current with an intensity between 5000 amperes and 50,000 amperes generates a lightning strike temperature exceeding 3000 degrees Celsius at its highest. Therefore, metal electrodes are extremely prone to deformation under the action of a large lightning current, generating metal powder, splashing, damaging the structure of the arc extinguishing chamber, and affecting the effect of impulse arc extinguishing. Using graphite electrodes can effectively solve the above problems.

[0046] The loss of graphite electrodes is small: Graphite electrodes have the characteristic of being able to withstand large current conditions. Under the action of a lightning arc, a polarity effect is generated, and some erosion products and carbon particles will adhere to the surface of the electrode to form a protective layer, ensuring that the loss of graphite electrodes during the process of impulse arc extinguishing is extremely small, even "zero loss".

[0047] As Figure 2 shown, the structure of the sealed compressed air arc extinguishing unit B is the same as that of the sealed arc extinguishing unit C. The sealed arc extinguishing unit C is set as a sealed tube, with an upper electrode 1 and a lower electrode 6 respectively provided and sealed at both ends of the sealed tube. Insulating oil 2 is provided inside the sealed tube, and a skirt 4 is provided on the side of the sealed tube. The sealed tube also includes a ceramic tube 3 and a protective shell 5. The protective shell 5 is provided outside the ceramic tube 3, and the skirt 4 is provided outside the protective shell 5.

[0048] The upper electrode 1 includes an upper layer graphite electrode, a middle metal electrode, and a lower layer graphite electrode. The middle metal electrode is fixed at one end of the ceramic tube 3 and the protective shell 5. The upper layer graphite electrode is provided above the middle metal electrode, and the lower layer graphite electrode is provided at the bottom of the middle metal electrode and is provided inside the ceramic tube 3. The lower electrode 6 includes an upper end graphite electrode and a bottom metal electrode. The bottom metal electrode is fixed at the other end of the ceramic tube 3 and the protective shell 5. The upper end graphite electrode is provided inside the ceramic tube 3 and is connected to the bottom metal electrode.

[0049] When the overvoltage wave caused by a lightning strike on the line approaches the arc extinguishing device, the air gap above the device is preferentially broken down, and the metal electrode draws the arc to the entrance of the device through the action of Coulomb force. The external arc enters the insulating tube under the action of the metal electrode 1; the arc is restricted by the wall of the insulating tube, resulting in a smaller cross-sectional area of the arc conduction, an increase in the arc power, an increase in the heat and temperature inside the tube, and a directional arc pressure explosion effect from the inside out. The pressure explosion effect causes the arc to be discharged outside the tube.

[0050] Example 2:

[0051] The difference between this example and Example 1 is that, as Figure 3As shown in the figure, the sealed arc extinguishing unit C is set as a sealed tube. The upper electrode 1 and the lower electrode 6 are respectively and hermetically arranged at both ends of the sealed tube. Insulating oil 2 is arranged inside the sealed tube. A skirt 4 is arranged on the side of the sealed tube. Arc extinguishing grids 9 are arranged at intervals on the inner side of the sealed tube. The transverse length of the arc extinguishing grid 9 is greater than half of the inner diameter of the sealed tube. A upper tip electrode 8 is arranged at the bottom of the upper electrode 1, and a lower tip electrode 11 is arranged at the upper end of the lower electrode 6. The upper tip electrode 8 and the lower tip electrode 11 are arranged vertically opposite to each other. Both the upper tip electrode 8 and the lower tip electrode 11 are graphite electrodes.

[0052] In this embodiment, the arc extinguishing grid 9 is made of insulating material. The arc extinguishing grid 9 is set as a semi-circular structure. The arc extinguishing grids 9 arranged on the inner side walls of the two semi-circles inside the sealed tube are arranged alternately. Protrusions 10 are arranged between the arc extinguishing grids 9 on the same semi-circle. The protrusions 10 on the inner side wall of one semi-circle are arranged opposite to the arc extinguishing grids 9 on the inner side wall of the other semi-circle.

[0053] The liquid-electric effect and the Pascal effect cause the pressure in the ceramic tube to increase and the temperature to rise, generating a force pointing from the ceramic tube wall to the center. Under this force, the arc moves towards the tip of the arc extinguishing grid. The tip elongates the length of the arc, and with the blowing of the insulating oil on the arc, the arc temperature decreases, enabling the arc to be extinguished more quickly. The longer the arc formed in the ceramic tube, the greater the force on the ceramic tube wall, and conversely, the greater the impact force for intercepting the arc, thus completing arc extinguishing.

[0054] The specific working process of the device is as follows:

[0055] Step 1: When the overvoltage wave caused by lightning striking the line approaches the arc extinguishing device, the air gap above the device is preferentially broken down. The metal electrode uses the Coulomb force to draw the arc to the entrance of the device, and the recoil arc extinguishing unit A extinguishes the arc by recoil.

[0056] When the overvoltage wave caused by lightning striking the line approaches the arc extinguishing device, the air gap above the device is preferentially broken down. The metal electrode uses the Coulomb force to draw the arc to the entrance of the device. The external arc enters the insulating tube (the inside of the tube is a gas medium) under the action of the metal electrode 1; since the inner diameter of the insulating tube is much smaller than the arc diameter, the arc is restricted by the wall of the insulating tube, and the diameter of the arc column is forced to decrease, resulting in a smaller cross-sectional area of the entire arc conduction and an increase in the arc resistance. According to the power calculation formula: P = I 2 ×R, it can be seen that the arc power also increases, causing the heat and temperature inside the tube to rise. When the pressure inside the insulating tube is greater than the pressure outside the tube, a directional arc explosion effect from the inside to the outside is generated. The explosion effect causes the arc to be discharged: on the one hand, the arc inside the tube is quickly emptied; on the other hand, the external arc cavity effect blocks the injection of external arc energy.

[0057] Step 2: The arc extinguishes itself by the Pascal effect within the sealed compressed air arc extinguishing unit B. The arc is injected into the sealed compressed air arc extinguishing unit B, where the air pressure is higher than standard atmospheric pressure. The density of free electrons is greater than that of air, reducing the effective distance electrons can travel. When the arc strikes the insulating compressed air, it generates a shock wave that bounces toward the sidewalls. Upon encountering the sidewalls, the shock wave rebounds toward the arc channel, enhancing the insulation of the sealed compressed air arc extinguishing unit B and expediting dielectric recovery, thereby rapidly interrupting the arc.

[0058] Step 3: The arc causes the hydroelectric effect and the Pascal effect in the sealed arc extinguishing unit C to perform double-effect arc extinguishing.

[0059] Step 3.1: When an arc discharge is initiated in a sealed tube filled with insulating oil, the liquid-electric effect generates a shock wave that rushes to the side, inducing an arc discharge in the ceramic tube filled with insulating oil. Part of the insulating oil in the discharge channel is instantly vaporized, decomposed, and ionized into a high-temperature plasma, which suddenly expands, forming a mechanical pressure wave that propagates rapidly outward. However, since the liquid can be regarded as a shock wave transmission medium that cannot be compressed itself, when liquid-phase discharge occurs in the discharge channel, it exhibits the mechanical effect of power to the outside world, forming a force that impacts the ceramic tube wall in the ceramic tube. Due to the mutuality of forces, the ceramic tube wall generates a shock wave in the insulating oil medium.

[0060] Step 3.2: The Pascal effect enhances the hydroelectric effect. When the arc acts on the insulating oil 2, a certain part of the static insulating oil 2 undergoes a pressure change, which is transmitted in all directions inside the sealed tube without changing in magnitude. When the impact arc acts on the metal electrode, it applies pressure to the insulating oil in the ceramic tube. According to the Pascal principle, a certain part of the static fluid in the closed container undergoes a pressure change, which is transmitted in all directions without changing in magnitude. Starting from the discharge channel in the ceramic tube, it impacts the surrounding insulating oil medium with a greater force, which rebounds after hitting the ceramic tube wall.

[0061] Step 3.3: Since an arc extinguishing grid 9 is provided in the sealed tube, the length of the arc in the sealed tube becomes longer, and at the same time, the convex pier 10 is provided to increase the surface area of the sealed tube. The shock waves of the hydro-electric effect and the Pascal effect hit the side and then return to impact. The hydro-electric effect and the Pascal effect increase the pressure and temperature in the ceramic tube, generating a force directed from the ceramic tube wall to the center. Under this force, the arc moves toward the tip of the arc extinguishing grid, and the tip stretches the length of the arc. Under the blowing of the insulating oil on the arc, the arc temperature is reduced, so that the arc is extinguished more quickly. The longer the arc formed in the ceramic tube, the greater the force on the ceramic tube wall. Conversely, the impact force to cut off the arc is also greater. The force rebounds after acting on the outer shell, forming a force directed to the center of the insulating tube, which concentrates on the arc channel to impact and extinguish the arc.

[0062] A high-pressure sealing structure and an external reinforcement structure are provided inside the sealed arc extinguishing unit, such as Figure 4-5 shown.

[0063] The high-pressure sealing structure includes a plastic sleeve 21, a stainless steel washer 22, an O-ring 23, a steel sleeve 24, a sealing silica gel 25, and an extrusion fixing block 26. The electrode is nested inside the sealing silica gel 25. The sealing silica gel 25 is hermetically arranged at both ends of the ceramic tube. The steel sleeve 24 is fastened on the outside of the joint of the sealing silica gel 25 and the ceramic tube. The plastic sleeve 21 is sleeved on the outside of the steel sleeve 24 and the ceramic tube. The stainless steel washer 22 is placed at the front end of the electrode. The O-ring 23 is arranged between the contact of the sealing silica gel 25 and the ceramic tube. The extrusion fixing block 26 is arranged on the outside of the sealing silica gel 25. A bolt hole 27 is provided on the extrusion fixing block 26, and the bolt hole 27 is in contact with the stainless steel washer 22. The sealing silica gel 25 is set as a "T"-shaped structure silica gel, and the bottom of the "T"-shaped structure silica gel is set as a spherical concave structure.

[0064] The outer shell is made of a plastic insulating material, aiming to fix the ceramic tube; the steel sleeves are installed at both ends of the ceramic tube to fix the ends of the ceramic tube and prevent the generated high-intensity pressure from mechanically deforming the ceramic tube; the semi-circular silica gel wraps the upper and lower electrodes. When the upper and lower electrodes extinguish the arc in a narrow space with a small area, pressure dispersion occurs. Wrapping the electrodes with semi-circular silica gel can focus the pressure wave, increasing the pressure in the arc extinguishing channel by several times and effectively intercepting the arc. A thrust is generated by the screw on the stainless steel washer and silica gel combination, making it closely cooperate with the O-ring and the ceramic tube to achieve the purpose of high-pressure sealing, well preventing the leakage of high-intensity pressure and ensuring that the generated high-intensity pressure acts on the arc maximally.

[0065] When the device is struck by lightning, a liquid-electric effect is generated, forming a powerful impact pressure wave, which acts on the discharge channel in the form of impulse or impact pressure to intercept the arc. At the same time, a certain pressure is applied to the arc extinguishing liquid in the ceramic tube. According to Pascal's principle, the pressure change occurring in a certain part of the static fluid in a closed container will be transmitted unchanged in all directions, and a greater acting force will surely be generated on the inner wall of the ceramic tube. This acting force rebounds after acting on the outer shell, forming an acting force directed towards the center of the ceramic tube, achieving the purpose of intercepting the arc, reducing the amplitude of the current, decreasing the steepness of the lightning wave, and prolonging the discharge time of the arc, effectively extinguishing the arc with a simple structure and good sealing performance.

[0066] The external reinforcement structure includes a top cover plate 31, an insulating screw 33, a bottom cover plate 34, and an insulating coating 35. The top cover plate 31 is arranged on the top of the high-pressure sealing device, and the bottom

[0067] The component cover plate 34 is arranged at the bottom of the high-voltage sealing device. The insulating screw 33 passes through the top cover plate 31 and the bottom cover plate 34 and is fixedly arranged. The insulating coating 35 is arranged on the outside of the high-voltage sealing device. The top cover plate 31 and the bottom cover plate 34 respectively abut against and fix the extrusion block 26. At the same time, the top cover plate 31 and the bottom cover plate 34 are provided with screw holes. The fixing effect is better, enabling the entire arc extinguishing device to withstand greater pressure.

[0068] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A device for multi-stage attenuation of lightning current intensity and steepness, characterized in that: It includes a recoil arc extinguishing unit (A), a sealed compressed air arc extinguishing unit (B), and a sealed arc extinguishing unit (C). The recoil arc extinguishing unit (A) is arranged on the top of the sealed compressed air arc extinguishing unit (B) and is electrically connected. The sealed arc extinguishing unit (C) is arranged at the bottom of the sealed compressed air arc extinguishing unit (B) and is electrically connected. Compressed air is provided inside the sealed compressed air arc extinguishing unit (B), and insulating oil (2) is provided inside the sealed arc extinguishing unit (C). The sealed arc extinguishing unit (C) is arranged as a sealed tube. An upper electrode (1) and a lower electrode (6) are respectively and hermetically arranged at both ends of the sealed tube. Insulating oil (2) is provided inside the sealed tube. A skirt (4) is arranged on the side of the sealed tube. Arc extinguishing grids (9) are arranged at intervals on the inner side of the sealed tube. The transverse length of the arc extinguishing grid (9) is greater than half of the inner diameter of the sealed tube. The arc extinguishing grid (9) is made of insulating material and is arranged in a semi-circular structure. The arc extinguishing grids (9) arranged on the inner side walls of the two semi-circles inside the sealed tube are arranged alternately. Protrusions (10) are arranged between the arc extinguishing grids (9) on the same semi-circle. The protrusions (10) on the inner side wall of one semi-circle are arranged opposite to the arc extinguishing grids (9) on the inner side wall of the other semi-circle. An upper tip electrode (8) is arranged at the bottom of the upper electrode (1). A lower tip electrode (11) is arranged at the upper end of the lower electrode (6). The upper tip electrode (8) and the lower tip electrode (11) are arranged vertically opposite to each other. Both the upper tip electrode (8) and the lower tip electrode (11) are graphite electrodes.

2. The device for multi-stage attenuation of lightning current intensity and steepness according to claim 1, characterized in that: The recoil arc extinguishing unit (A) includes a lightning receiving electrode, a recoil tube body, a recoil tube skirt, and a bottom lightning receiving electrode. The lightning receiving electrode is arranged at the top of the recoil tube body. The recoil tube skirt is arranged on the side of the recoil tube body. The inside of the recoil tube body is set as a recoil hole. A bottom lightning receiving electrode is arranged at the low end of the recoil hole. Both the lightning receiving electrode and the bottom lightning receiving electrode are graphite electrodes.

3. A device for multi - stage attenuation of lightning current intensity and steepness according to claim 1, characterized in that: The structure of the sealed compressed air arc extinguishing unit (B) is the same as that of the sealed arc extinguishing unit (C). The sealed arc extinguishing unit (C) is arranged as a sealed tube. An upper electrode (1) and a lower electrode (6) are respectively and hermetically arranged at both ends of the sealed tube. Insulating oil (2) is provided inside the sealed tube. A skirt (4) is arranged on the side of the sealed tube. The sealed tube also includes a ceramic tube (3) and a protective housing (5). The protective housing (5) is arranged outside the ceramic tube (3). The skirt (4) is arranged outside the protective housing (5).

4. A device for multi-stage attenuation of lightning current intensity and steepness according to claim 3, characterized in that: The upper electrode (1) includes an upper layer graphite electrode, a middle metal electrode, and a lower layer graphite electrode. The middle metal electrode is fixed at one end of the ceramic tube (3) and the protective housing (5). The upper layer graphite electrode is arranged on the upper layer of the middle metal electrode. The lower layer graphite electrode is arranged at the bottom of the middle metal electrode and is arranged inside the ceramic tube (3). The lower electrode (6) includes an upper end graphite electrode and a bottom metal electrode. The bottom metal electrode is fixed at the other end of the ceramic tube (3) and the protective housing (5). The upper end graphite electrode is arranged inside the ceramic tube (3) and is connected to the bottom metal electrode.

5. A device for multi-stage attenuation of lightning current intensity and steepness according to claim 1, characterized in that, The specific working process of the device is as follows: Step 1: When the overvoltage wave caused by the lightning strike approaches the arc extinguishing device, the air gap above the device is broken down first. The metal electrode draws the arc to the device entrance through the Coulomb force, and the recoil arc extinguishing unit (A) extinguishes the arc by recoil. Step 2: The arc is extinguished by the Pascal effect in the sealed compressed air arc extinguishing unit (B); Step 3: The arc causes the hydroelectric effect and Pascal effect in the sealed arc extinguishing unit (C) to perform double-effect arc extinguishing.

6. The device for multi-stage attenuation of lightning current intensity and steepness according to claim 5, characterized in that: The specific process of step 2 is that the arc is injected into the sealed compressed air arc extinguishing unit (B). The air pressure in the sealed compressed air arc extinguishing unit (B) is higher than the standard atmospheric pressure. The density of free electrons is greater than that of air, and the effective movement distance of electrons will become smaller. When the arc acts on the insulating compressed air, a shock wave is generated toward the side wall. After encountering the side, the shock wave rebounds and rushes toward the arc channel, enhancing the insulation of the sealed compressed air arc extinguishing unit (B) and the speed at which the medium recovers quickly, thereby achieving rapid arc interruption.

7. The device for multi-stage attenuation of lightning current intensity and steepness according to claim 5, characterized in that ,The specific process of step 3 is: Step 3.1: When an arc discharge is initiated in a sealed tube filled with insulating oil, the hydroelectric effect generates a shock wave that rushes to the side. Arc discharge is triggered in the ceramic tube filled with insulating oil. Part of the insulating oil in the discharge channel is instantly vaporized, decomposed, and ionized into a high-temperature plasma, which suddenly expands, forming a mechanical pressure wave that propagates rapidly outward. However, because the liquid can be regarded as a shock wave transmission medium that cannot be compressed, the liquid-phase discharge in the discharge channel manifests the mechanical effect of power to the outside world, forming a force that impacts the ceramic tube wall. Due to the mutuality of forces, the ceramic tube wall generates a shock wave in the insulating oil medium. Step 3.2: The Pascal effect enhances the hydroelectric effect. When the arc acts on the insulating oil (2), a certain part of the static insulating oil (2) undergoes a pressure change, which is transmitted to all directions inside the sealed tube without changing in magnitude. When the impact arc acts on the metal electrode, it applies pressure to the insulating oil in the ceramic tube. According to the Pascal principle, a certain part of the static fluid in the closed container undergoes a pressure change, which is transmitted to all directions without changing in magnitude. Starting from the discharge channel in the ceramic tube, it impacts the surrounding insulating oil medium with a greater force, and this force rebounds after hitting the ceramic tube wall. Step 3.3: Since an arc extinguishing grid (9) is provided in the sealed tube, the length of the arc in the sealed tube becomes longer, and at the same time, a convex pier (10) is provided to increase the surface area of the sealed tube. The shock waves of the hydro-electric effect and the Pascal effect impact the side and then return to impact. The hydro-electric effect and the Pascal effect increase the pressure and temperature in the ceramic tube, generating a force directed from the ceramic tube wall to the center. Under this force, the arc moves toward the tip of the arc extinguishing grid, and the tip stretches the length of the arc. Under the blowing of the insulating oil on the arc, the arc temperature is reduced, so that the arc is extinguished more quickly. The longer the arc formed in the ceramic tube, the greater the force on the ceramic tube wall. In turn, the impact force to cut off the arc is also greater. The force rebounds after acting on the outer shell, forming a force directed to the center of the insulating tube, and the arc channel is concentrated to impact and extinguish the arc.

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