A new type of combined arc extinguishing lightning protection device

Abstract

The invention discloses a novel combined arc extinguishing lightning protection device, which belongs to the field of lightning protection arc extinguishing technology, and comprises an end arc extinguishing unit, a sealed arc extinguishing unit and an insulator string, wherein the sealed arc extinguishing unit is arranged in parallel on the insulator string, the end arc extinguishing unit is arranged at the upper end or the lower end of the insulator string, and is electrically connected to the metal parts at the end of the insulator string, when the end arc extinguishing unit is arranged at the upper end of the insulator string, the bottom of the insulator string is grounded, and when the end arc extinguishing unit is arranged at the bottom of the insulator string, the bottom of the end arc extinguishing unit is grounded. The arc extinguishing device of the invention has strong integrity and will not reignite, the arc is cut off as a whole at the same time, not cut off in sections, and at the same time the medium recovery speed tends to infinity and reaches its own limit, so the arc extinguishing speed is fast and will not reignite.

Description

Technical Field

[0001] The invention relates to a field, and in particular to a novel combined arc extinguishing lightning protection device. Background Art

[0002] Lightning strikes can cause various forms of damage and destruction to power facilities. Thundercloud discharges can cause lightning overvoltage in power systems. Lightning overvoltage can damage insulators and transmission lines. When lightning strikes a transmission line, the impulse flashover causes the line insulator to flash over, which in turn generates a large power frequency current, damaging the insulator string and hardware, leading to line accidents. When lightning strikes a transmission line or lightning conductor, it may cause strand breakage or even fracture, making it impossible to carry out power transmission work.

[0003] The existing lightning protection and arc extinguishing devices can make the volt-second characteristics of the active arc extinguishing parallel gap flatter, but the existing lightning protection and arc extinguishing devices can only reduce the steepness of the wave head of the lightning current, cannot completely prevent insulator flashover, have limited ability to attenuate lightning current, and carbon emissions cannot meet ideal standards. Summary of the invention

[0004] The purpose of the present invention is to provide a new type of combined arc extinguishing lightning protection device to solve the technical problems of the limited ability of existing lightning protection arc extinguishing to attenuate the lightning current amplitude and the slow arc extinguishing speed. It can improve the arc extinguishing rate, prevent insulator flashover, reduce the lightning accident rate and tripping rate, improve the stability of power grid operation, and respond to the major demand standards of achieving national carbon peak and carbon neutrality.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A novel combined arc extinguishing lightning protection device comprises an end arc extinguishing unit, a sealed arc extinguishing unit and an insulator string. The sealed arc extinguishing unit is arranged in parallel on the insulator string, the end arc extinguishing unit is arranged at the upper end or the lower end of the insulator string and is electrically connected to the metal piece at the end of the insulator string. When the end arc extinguishing unit is arranged at the upper end of the insulator string, the bottom of the insulator string is grounded, and when the end arc extinguishing unit is arranged at the bottom of the insulator string, the bottom of the end arc extinguishing unit is grounded.

[0007] Furthermore, the end arc extinguishing unit and the sealed arc extinguishing unit are both configured as a sealed tube, upper electrode and lower electrode sealing devices are respectively provided at both ends of the sealed tube, insulating oil is provided in the sealed tube, and a skirt is provided on the side of the sealed tube.

[0008] Furthermore, the sealing tube also includes a ceramic tube and a protective shell, the protective shell is arranged on the outside of the ceramic tube, and the skirt is arranged on the outside of the protective shell.

[0009] Furthermore, the upper electrode includes an upper graphite electrode, an intermediate metal electrode and a lower graphite electrode, the intermediate metal electrode is fixed at one end of the ceramic tube and the protective shell, the upper graphite electrode is arranged on the upper layer of the intermediate metal electrode, the lower graphite electrode is arranged at the bottom of the intermediate metal electrode and is arranged in the ceramic tube, and the lower electrode includes an upper 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 graphite electrode is arranged in the ceramic tube and is connected to the bottom metal electrode.

[0010] Furthermore, the end arc extinguishing unit and the sealed arc extinguishing unit are both configured as a sealed tube, an upper electrode and a lower electrode sealing arrangement are respectively arranged at both ends of the sealed tube, insulating oil is arranged in 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, and the lateral length of the arc extinguishing grid is greater than half of the inner diameter of the sealed tube.

[0011] Furthermore, an upper tip electrode is arranged at the bottom of the upper electrode, a lower tip electrode is arranged at the upper end of the lower electrode, the upper tip electrode and the lower tip electrode are relatively vertically arranged, and both the upper tip electrode and the lower tip electrode are graphite electrodes.

[0012] Furthermore, the arc extinguishing grid is made of insulating material, and the arc extinguishing grid is arranged as a semicircular structure. The arc extinguishing grids arranged on the inner walls of the two semicircles in the sealing tube are arranged alternately, and convex piers are arranged between the arc extinguishing grids on the same semicircle, and the convex piers on the inner wall of one semicircle are arranged opposite to the arc extinguishing grid on the inner wall of the other semicircle.

[0013] The specific working process of the lightning protection device is:

[0014] Step 1: When lightning strikes a tower or transmission line, the fully sealed liquid arrester discharges before the insulator string, and the lightning arc is injected into the insulating tube inside the arrester;

[0015] Step 2: 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 a ceramic tube filled with insulating oil. Part of the insulating oil in the discharge channel is instantly vaporized, decomposed, and ionized into high-temperature plasma and 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 will not be compressed itself, when liquid phase discharge is carried out in the discharge channel, it exhibits the mechanical effect of power to the outside world, and forms a force that impacts the ceramic tube wall in the ceramic tube. Due to the mutuality of force, the ceramic tube wall generates a shock wave in the insulating oil medium. At the same time, the pressure peak time point is the same as the pre-breakdown time point. Whether it is impact or power frequency flashover, the maximum change rate time is at the pre-breakdown time. The maximum change rate will inevitably produce the maximum arc occupation volume change rate. At the same time, the liquid has the characteristic of not allowing arc occupation due to its incompressibility, thereby generating a pressure peak. At this time, the arc current is extremely weak, and the arc anti-interruption pressure is extremely small, forming an asymmetric advantage of arc extinguishing pressure. In addition, an intermittent discharge mode is generated, and the frequent arc extinguishing and frequent reignition mechanisms suppress the arc intensity and prolong the arc duration, so that the discharge intensity and steepness are greatly attenuated at the same time, and the intensity of destructive energy release is reduced.

[0016] Step 3: The Pascal effect enhances the liquid-electric effect. When the arc acts on the insulating oil, a part of the static insulating oil 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 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, which rebounds after hitting the ceramic tube wall.

[0017] Step 4: As an arc extinguishing grid 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 is 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, concentrating on the arc channel for impact and arc extinguishing. Two points on one arc are extinguished, resulting in an intermittent discharge mode, and the breakdown volt-second characteristic becomes gentle, thereby reducing the breakdown starting voltage and the residual voltage value.

[0018] The hydroelectric effect and Pascal effect increase the pressure and temperature inside 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 lengthens the arc. Under the blowing of the insulating oil on the arc, the arc temperature decreases, causing the arc to extinguish 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 to cut off the arc. The force rebounds after acting on the outer shell, forming a force directed to the center of the insulating tube. The dielectric generates a polarization current in the impact pre-breakdown stage, which reduces the breakdown voltage and the breakdown voltage value corresponding to a short period of time, making the dielectric's corresponding breakdown volt-second characteristic become gentle. The frequent arc extinguishing and frequent reignition mechanisms suppress the arc intensity and prolong the arc duration, causing the discharge intensity and steepness to be greatly attenuated at the same time, thereby reducing the intensity of the destructive energy release.

[0019] Coulomb force produces pressure: Lightning current will generate an induced arc before breaking through the gap, forming an induced charge chain. The induced charge chain in the air is composed of many charges of the same polarity. Due to the interaction of charges of the same polarity, a large Coulomb force will be generated, that is, the induced arc generates a Coulomb force of opposite attraction, and this Coulomb force ensures that the arc enters the arc extinguishing device smoothly. In the sealed space of the insulating tube, the effect of the Coulomb force is manifested as the pressure breaking effect on the arc and the squeezing of the liquid. The liquid filled in the insulating tube cannot be compressed, so the pressure in the sealed space continues to increase. As the pressure continues to increase, the temperature continues to rise, resulting in faster movement of charges, which will generate greater pressure and pressure, and this pressure reserves energy for breaking and extinguishing the arc. Insulating oil is a strongly polarized medium. In the impact pre-breakdown stage, polarization current will be generated, which will reduce the breakdown voltage, which is equivalent to reducing the breakdown voltage value corresponding to a short period of time, making the corresponding breakdown volt-second characteristic of the insulating oil medium become gentle, reducing the breakdown starting voltage while also reducing the residual pressure value.

[0020] The shock wave is generated by the liquid-electric effect: after the arc enters the sealed pipe, it discharges in the insulating tube filled with liquid medium. Part of the liquid in the discharge channel is instantly vaporized, decomposed, and ionized into high-temperature plasma and suddenly expands. The volume of the expanded gas is 1800 times the volume of the liquid, forming a mechanical pressure wave that propagates rapidly outward. However, since the liquid can be regarded as a shock wave transmission medium that will not be compressed by itself, and the arc itself exerts a space-occupying pressure on the liquid, when the liquid phase discharge is carried out in the discharge channel, it exhibits an ultra-high-power mechanical effect to the outside world. A force that impacts the inner wall of the pipe is formed in the insulating tube. Due to the interaction of forces, the wall of the insulating tube generates a strong shock wave in the liquid medium, which acts on the discharge channel in the form of impulse or impact pressure, and the arc is instantly crushed and extinguished as a whole. At the moment the arc is extinguished, it is equivalent to leaving a fracture space inside the channel. Because the speed of medium recovery tends to infinity and the medium strength is very high, the medium is instantly fully restored, changing from conductivity to dielectricity. The peak pressure time is at the pre-breakdown time. Whether it is an impact or a power frequency flashover, the maximum change rate is in the pre-breakdown time. The maximum change rate will inevitably result in the maximum arc occupation volume change rate. At the same time, the liquid has the characteristic of not allowing arc occupation due to its incompressibility, which produces a pressure peak. At this time, the arc current is extremely weak, and the arc anti-interruption pressure is extremely small, forming an asymmetric advantage of arc extinguishing pressure.

[0021] In addition, the rapid arc extinguishing capability produces an intermittent discharge mode. The frequent arc extinguishing and frequent reignition mechanism suppresses the arc intensity and prolongs the arc duration, causing the discharge intensity and steepness to decay significantly at the same time, thereby ensuring the safety, durability and reliability of the lightning protection device by reducing the intensity of destructive energy release.

[0022] The Pascal effect further enhances the Coulomb force and the hydroelectric effect: The Pascal principle states that "when any point in an incompressible static fluid is subjected to an external force and the pressure increases, this pressure increase is instantly transmitted to all points in the static fluid", that is, the pressure is equal to the applied pressure divided by the area under force.

[0023] The Coulomb force between the charges and the impact arc act on the metal electrode, exerting a certain pressure on the liquid medium in the insulating tube. According to Pascal's principle, the pressure change of a part of the static fluid in a closed container will be transmitted in all directions without changing in magnitude. Starting from the discharge channel in the insulating tube, the surrounding liquid medium is impacted with a greater force. After hitting the insulating tube wall, the force rebounds to form a force pointing to the center of the insulating tube, further enhancing the Coulomb force and the impact pressure generated in the liquid-electric effect. The dual pressure sources are jointly amplified to achieve the purpose of cutting off the arc. And the longer the arc in the insulating tube, the greater the force on the insulating tube wall, and conversely the greater the impact pressure to cut off the arc.

[0024] The present invention has the following beneficial effects due to the adoption of the above technical solution:

[0025] (1) The arc extinguishing device of the present invention has strong integrity and will not reignite. The arc is cut off as a whole at the same time, not in sections. At the same time, the medium recovery speed tends to infinity and reaches its own limit. Therefore, the arc extinguishing speed is fast and will not reignite.

[0026] (2) The arc is cut off quickly. The arc enters the insulating tube through the conductive electrode, and the heat transferred to the liquid medium is very low, which greatly reduces the temperature rise rate of the liquid medium and greatly reduces the probability of thermal breakdown of the medium. Under the condition of multiple pulse lightning strikes, this characteristic will not inject large arc energy into the medium, thus protecting the device structure from damage, greatly improving the reliability of the device, and blocking the possibility of damage to the structure caused by the heat accumulation effect of multiple pulse lightning strikes. The arc discharges in the liquid to produce a liquid-electric effect, quickly forming an impact pressure wave, and the impact arc is immediately cut off when it is just formed.

[0027] (3) The residual voltage is extremely low. When the arc discharges through the pipeline, the initial breakdown voltage will be reduced by the distance between the upper and lower conductive electrodes. Once the breakdown occurs, the voltage will quickly drop to the arc voltage drop, so the residual voltage is very low. At the same time, the insulating oil is a highly polarized medium. In the impact pre-breakdown stage, polarization current will be generated, which will reduce the breakdown voltage, which is equivalent to reducing the breakdown voltage value corresponding to a short period of time, making the corresponding breakdown volt-second characteristic of the insulating oil medium become gentle, reducing the breakdown starting voltage and the residual voltage value.

[0028] (4) Effectively protect against direct lightning overvoltage. When the pilot channel of lightning discharge hits the conductor, tower or other buildings of the transmission line, the arc extinguishing method based on the Pascal principle can reduce the overvoltage amplitude and prolong the discharge time, thus avoiding damage to equipment and devices caused by direct lightning overvoltage.

[0029] (5) Avoid electromagnetic induction overvoltage from damaging equipment. During lightning discharge, a transient strong electromagnetic field is generated in the space around the discharge channel, generating a higher electromagnetic induction electromotive force that interferes with signal lines and even damages equipment. The arc extinguishing method based on the Pascal principle cuts off the arc through the recoil force, which not only delays the arc discharge time, but also reduces the steepness of the lightning wave. It avoids the harm of induced electromagnetic overvoltage to power electronic components, communication signals, etc.

[0030] (6) Environmental protection and good economic performance. Liquid medium replaces the previous valve plate. The production of traditional lightning arresters requires smelting and sintering, which has very strict process requirements. Repeated sintering leads to a large amount of carbon emissions. The combined device can greatly reduce the carbon emission content, which meets the national major demand standards for carbon peak and carbon neutrality. In addition, the device has a simple production structure and good economic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the structure of the first device of the present invention;

[0032] Figure 2 It is a schematic diagram of the structure of the second device of the present invention;

[0033] Figure 3 This is a schematic diagram of the structure of the first sealed arc extinguishing unit of the present invention;

[0034] Figure 4 It is a schematic diagram of the structure of the second sealed arc extinguishing unit of the present invention;

[0035] Figure 5 It is a schematic diagram of the high-pressure sealing structure of the sealed arc extinguishing unit of the present invention;

[0036] Figure 6 It is a schematic diagram of the external reinforcement structure of the sealed arc extinguishing unit of the present invention.

[0037] In the accompanying drawings, A-end arc extinguishing unit, B-sealed arc extinguishing unit, C-insulator string, D-grounding wire, 1-upper electrode, 2-insulating oil, 3-ceramic tube, 4-skirt, 5-protective casing, 6-lower electrode, 7-arc, 8-upper tip electrode, 9-arc extinguishing grid, 10-convex pier, 11-lower tip electrode. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are only for the purpose of 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] like Figure 1 and Figure 3-4 As shown, a new type of combined arc extinguishing lightning protection device includes an end arc extinguishing unit A, a sealed arc extinguishing unit B and an insulator string C. The sealed arc extinguishing unit B is arranged in parallel on the insulator string C, the end arc extinguishing unit A is arranged at the upper end of the insulator string C, and is electrically connected to the metal part at the end of the insulator string C. The bottom of the insulator string C is grounded. The arc enters from one end of the series insulator device, and the basic arc will be completely cut off at this stage and will not reignite. If there is still an arc that has not been completely cut off after the arc is extinguished at this stage, it will also be completely cut off through the parallel device with the insulator string, and the remaining arc energy will enter the ground through the grounding channel of the conductive electrode, which greatly protects the safety of the insulator.

[0041] In this embodiment, the end arc extinguishing unit A and the sealed arc extinguishing unit B are both configured as a sealed tube, an upper electrode 1 and a lower electrode 6 are respectively provided at both ends of the sealed tube for sealing, insulating oil 2 is provided in 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 on the outside of the ceramic tube 3, and the skirt 4 is provided on the outside of the protective shell 5.

[0042] The upper electrode 1 includes an upper graphite electrode, an intermediate metal electrode and a lower graphite electrode. The intermediate metal electrode is fixed at one end of the ceramic tube 3 and the protective shell 5, the upper graphite electrode is arranged on the upper layer of the intermediate metal electrode, and the lower graphite electrode is arranged at the bottom of the intermediate metal electrode and arranged in the ceramic tube 3. The lower electrode 6 includes an upper 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, and the upper graphite electrode is arranged in the ceramic tube 3 and connected to the bottom metal electrode.

[0043] The insulating tube filled with insulating oil is made of high-hardness, high-temperature and high-pressure resistant inorganic non-metallic material and is cylindrical; the insulating tube is tightly connected to the composite insulation to fix the insulating tube and the umbrella skirt; the closed space inside the insulating tube is filled with insulating oil and is the area of ​​arc elastic collision.

[0044] When lightning strikes a pole tower or transmission line, the fully sealed liquid arrester discharges before the insulator string, and the lightning arc is poured into the insulating tube inside the arrester, generating a liquid-electric effect, forming a powerful shock wave, which acts on the discharge channel in the form of impulse or impact pressure to cut off the arc. At the same time, when the arc enters the insulating tube, it applies a certain pressure to the liquid in the insulating tube. According to Pascal's principle, the pressure change of a part of the static fluid in the closed container will be transmitted in all directions without changing the size, which will inevitably generate a greater force on the inner wall of the insulating tube. This force rebounds after acting on the outer shell, forming a force pointing to the center of the insulating tube, thereby achieving the purpose of cutting off the arc.

[0045] By setting up graphite electrodes at the lightning connection point, the service life can be effectively improved. Graphite electrodes have good conductivity and are easy to introduce arcs into the recoil tube: graphite is a non-metallic material, and the conductivity of graphite is 100 times higher than that of general non-metallic minerals. Each carbon atom in graphite is connected to three other carbon atoms around it, arranged in multiple honeycomb hexagons. Since each carbon atom releases an electron, those electrons can move freely, so graphite is 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 initiation, allowing the arc to enter the arc extinguishing tube smoothly.

[0046] Graphite electrodes have a very high melting point, can withstand greater currents, and are not easily deformed: Graphite electrodes have the characteristics of being able to withstand high current conditions. The softening point of copper is around 1000 degrees, and it is easy to deform due to heat; while the sublimation temperature of graphite is around 3650 degrees. The lightning strike temperature generated by a lightning current with an intensity between 5000 amperes and 50,000 amperes is as high as 3000 degrees. Therefore, metal electrodes are very easy to deform under the action of high lightning currents, produce metal powder, splash, damage the structure of the arc extinguishing chamber, and affect the effect of recoil arc extinguishing. The use of graphite electrodes can effectively solve the above problems.

[0047] Graphite electrodes have low losses: Graphite electrodes have the characteristic of being able to withstand large current conditions. Under the action of lightning arcs, a polarity effect is produced, and some eroded materials and carbon particles will adhere to the surface of the electrode to form a protective layer, ensuring that the graphite electrode has extremely small losses during the recoil arc extinguishing process, or even "zero loss".

[0048] like Figure 4 As shown, this structure is different from the above structure. The end arc extinguishing unit A and the sealed arc extinguishing unit B are both set as a sealed tube. The upper electrode 1 and the lower electrode 6 are sealed at both ends of the sealed tube. Insulating oil 2 is set in the sealed tube. The side of the sealed tube is provided with a skirt 4. The inner side of the sealed tube is provided with an arc extinguishing grid 9 at intervals. The horizontal length of the arc extinguishing grid 9 is greater than half of the inner diameter of the sealed tube. An upper tip electrode 8 is set at the bottom of the upper electrode 1, and a lower tip electrode 11 is set at the upper end of the lower electrode 6. The upper tip electrode 8 and the lower tip electrode 11 are relatively vertically arranged. The upper tip electrode 8 and the lower tip electrode 11 are both graphite electrodes.

[0049] In this embodiment, the arc extinguishing grid 9 is made of insulating material, and the arc extinguishing grid 9 is arranged as a semicircular structure. The arc extinguishing grids 9 arranged on the inner walls of the two semicircles in the sealed tube are arranged alternately, and convex piers 10 are arranged between the arc extinguishing grids 9 on the same semicircle, and the convex piers 10 on the inner wall of one semicircle are arranged opposite to the arc extinguishing grid 9 on the inner wall of the other semicircle.

[0050] The hydroelectric effect and Pascal effect increase the pressure and temperature inside the ceramic tube, generating a force directed from the ceramic tube wall toward the center. Under this force, the arc moves toward the tip of the arc extinguishing grid, which lengthens the arc. Under the blowing of the insulating oil on the arc, the arc temperature decreases, causing the arc to extinguish 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 to cut off the arc, thus completing the arc extinguishing.

[0051] The specific working process of the lightning protection device is:

[0052] Step 1: When lightning strikes a tower or transmission line, the fully sealed liquid lightning arrester discharges before the insulator string, and the lightning arc is injected into the insulating tube inside the lightning arrester.

[0053] Step 2: 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 a ceramic tube filled with insulating oil. Part of the insulating oil in the discharge channel is instantly vaporized, decomposed, and ionized into high-temperature plasma and 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 will not be compressed itself, when liquid phase discharge is carried out in the discharge channel, it exhibits the mechanical effect of power to the outside world, and forms a force that impacts the ceramic tube wall in the ceramic tube. Due to the mutuality of force, the ceramic tube wall generates a shock wave in the insulating oil medium. At the same time, the pressure peak time point is the same as the pre-breakdown time point. Whether it is impact or power frequency flashover, the maximum change rate time is at the pre-breakdown time. The maximum change rate will inevitably produce the maximum arc occupation volume change rate. At the same time, the liquid has the characteristic of not allowing arc occupation due to its incompressibility, thereby generating a pressure peak. At this time, the arc current is extremely weak, and the arc anti-interruption pressure is extremely small, forming an asymmetric advantage of arc extinguishing pressure. In addition, an intermittent discharge mode is generated, and the frequent arc extinguishing and frequent reignition mechanisms suppress the arc intensity and prolong the arc duration, so that the discharge intensity and steepness are greatly attenuated at the same time, and the intensity of destructive energy release is reduced.

[0054] Step 3: The Pascal effect enhances the liquid-electric effect. When the arc acts on the insulating oil, a part of the static insulating oil 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 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, which rebounds after hitting the ceramic tube wall.

[0055] Step 4: As an arc extinguishing grid 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 is 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, concentrating on the arc channel for impact and arc extinguishing. Two points on one arc are extinguished, resulting in an intermittent discharge mode, and the breakdown volt-second characteristic becomes gentle, thereby reducing the breakdown starting voltage and the residual voltage value.

[0056] The hydroelectric effect and Pascal effect increase the pressure and temperature inside 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 lengthens the arc. Under the blowing of the insulating oil on the arc, the arc temperature decreases, causing the arc to extinguish 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 to cut off the arc. The force rebounds after acting on the outer shell, forming a force directed to the center of the insulating tube. The dielectric generates a polarization current in the impact pre-breakdown stage, which reduces the breakdown voltage and the breakdown voltage value corresponding to a short period of time, making the dielectric's corresponding breakdown volt-second characteristic become gentle. The frequent arc extinguishing and frequent reignition mechanisms suppress the arc intensity and prolong the arc duration, causing the discharge intensity and steepness to be greatly attenuated at the same time, thereby reducing the intensity of the destructive energy release.

[0057] Embodiment 2:

[0058] like Figure 2 As shown, this embodiment is different from Embodiment 1 in that the end arc extinguishing unit A is installed at the bottom of the insulator string C, and the bottom of the end arc extinguishing unit A is directly grounded, and then the top of the end arc extinguishing unit A is also connected to one end of the sealed arc extinguishing unit B. When a lightning strike occurs, the lightning arc first passes through the top of the insulator string C through the sealed arc extinguishing unit B and then to the end arc extinguishing unit A, achieving breakdown at two locations, and also achieving arc extinguishing at two locations, achieving arc extinguishing at two points on one channel at the same time.

[0059] When lightning current strikes the line, the liquid arc extinguishing device introduces the arc into it through insulation coordination, preventing the arc from passing through the insulator and causing flashover. The arc is extinguished quickly and efficiently through a series-parallel combination, greatly protecting the safety of the transmission line and insulators.

[0060] The shed of the liquid arc extinguishing lightning protection device introduced above can also be removed, which is divided into two types: removing the shed and retaining the shed. Removing the shed further shortens the flashover distance, making the external flashover distance smaller than the internal flashover distance, guiding the arc to smoothly enter the arc extinguishing pipe, and further ensuring the safety of the transmission line and insulators.

[0061] The sealed arc extinguishing unit is provided with a high-pressure sealing structure and an external reinforcement structure, such as Figure 5-6 shown.

[0062] The high-pressure sealing structure includes a plastic sleeve 21, a stainless steel gasket 22, an O-ring 23, a steel sleeve 24, a sealing silicone 25 and an extrusion fixing block 26. The electrode is nested in the sealing silicone 25. The sealing silicone 25 is sealed at both ends of the ceramic tube. The steel sleeve 24 is fastened to the outside of the connection between the sealing silicone 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 gasket 22 is padded at the front end of the electrode, and the O-ring 23 is arranged between the contact between the sealing silicone 25 and the ceramic tube. The extrusion fixing block 26 is arranged on the outside of the sealing silicone 25, and a bolt hole 27 is arranged on the extrusion fixing block 26. The bolt hole 27 is arranged in contact with the stainless steel gasket 22. The sealing silicone 25 is set as a "T"-shaped structural silicone, and the bottom of the "T"-shaped structural silicone is set as a spherical concave structure.

[0063] The shell is made of plastic insulating material to fix the ceramic tube; the steel sleeve is installed at both ends of the ceramic tube to fix the ends of the ceramic tube to prevent the high-intensity pressure from mechanically deforming the ceramic tube; the semi-arc-shaped silicone wraps the upper and lower electrodes. When the upper and lower electrodes extinguish the arc, the narrow space and small area produce pressure dispersion. The semi-arc-shaped silicone wraps the electrodes to focus the pressure wave, increase the pressure of the arc extinguishing channel by several times, and effectively block the arc. The screw generates thrust to the stainless steel gasket and silicone assembly, so that it cooperates closely with the O-ring and the ceramic tube to achieve the purpose of high-pressure sealing, which well prevents the leakage of high-intensity pressure and can ensure that the generated high-intensity pressure acts on the arc to the maximum extent.

[0064] When the device is struck by lightning, a liquid-electric effect is generated, forming a strong shock pressure wave, which acts on the discharge channel in the form of impulse or shock pressure to cut off 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 of a part of the static fluid in the closed container will be transmitted in all directions without changing the size, which will inevitably produce a greater force on the inner wall of the ceramic tube. This force rebounds after acting on the outer shell, forming a force pointing to the center of the ceramic tube, so as to cut off the arc, reduce the amplitude of the current, reduce the steepness of the lightning wave, and prolong the discharge time of the arc. It effectively extinguishes the arc, has a simple structure, and has good sealing performance.

[0065] The external reinforcement structure includes a top cover plate 31, an insulating screw 33, a bottom cover plate 34 and an insulating covering layer 35. The top cover plate 31 is arranged on the top of the high-pressure sealing device, and the bottom cover plate 34 is arranged on the top of the high-pressure sealing device.

[0066] The top 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 covering layer 35 is arranged on the outside of the high-voltage sealing device, the top cover plate 31 and the bottom cover plate 34 respectively support the extrusion fixing block 26, and the top cover plate 31 and the bottom cover plate 34 are provided with screw holes. The fixing effect is better, so that the entire arc extinguishing device can withstand greater pressure.

[0067] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A new type of combined arc extinguishing lightning protection device, characterized in that: The invention comprises an end arc extinguishing unit (A), a sealed arc extinguishing unit (B) and an insulator string (C), wherein the sealed arc extinguishing unit (B) is arranged in parallel on the insulator string (C), the end arc extinguishing unit (A) is arranged at the upper end or the lower end of the insulator string (C), and is electrically connected to the metal piece at the end of the insulator string (C); when the end arc extinguishing unit (A) is arranged at the upper end of the insulator string (C), the bottom of the insulator string (C) is grounded; when the end arc extinguishing unit (A) is arranged at the bottom of the insulator string (C), the bottom of the end arc extinguishing unit (A) is grounded; An 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 relatively vertically arranged, and both the upper tip electrode (8) and the lower tip electrode (11) are graphite electrodes. The end arc extinguishing unit (A) and the sealed arc extinguishing unit (B) are both arranged as a sealed tube, an upper electrode (1) and a lower electrode (6) are respectively arranged at both ends of the sealed tube for sealing, insulating oil (2) is arranged in 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, and 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 the arc extinguishing grid (9) is arranged in a semicircular structure. The arc extinguishing grids (9) arranged on the inner side walls of the two semicircles in the sealed tube are arranged alternately, and a convex pier (10) is arranged between the arc extinguishing grids (9) on the same semicircle, and the convex pier (10) on the inner side wall of one semicircle is arranged opposite to the arc extinguishing grid (9) on the inner side wall of the other semicircle; The specific working process of the lightning protection device is: Step 1: When lightning strikes a tower or transmission line, the fully sealed liquid arrester discharges before the insulator string, and the lightning arc is injected into the insulating tube inside the arrester; Step 2: 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; Step 3: The Pascal effect enhances the liquid-electric effect. When the arc acts on the insulating oil (2), when a certain part of the static insulating oil (2) undergoes a pressure change, the pressure will be transmitted to all directions inside the sealed tube without changing in magnitude. Step 4: 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 liquid-electric effect and the Pascal effect impact the side and then return to impact, and the arc channel is concentratedly impacted and extinguished. Two points on one arc are extinguished, and an intermittent discharge mode is generated. The breakdown volt-second characteristic becomes gentle, which reduces the breakdown starting voltage and also reduces the residual voltage value.

2. A novel combined arc extinguishing lightning protection device according to claim 1, characterized in that: The end arc extinguishing unit (A) and the sealed arc extinguishing unit (B) are both arranged as a sealed tube, an upper electrode (1) and a lower electrode (6) are respectively arranged at both ends of the sealed tube for sealing, insulating oil (2) is arranged in the sealed tube, a skirt (4) is arranged on the side of the sealed tube, and the sealed tube also includes a ceramic tube (3) and a protective shell (5), the protective shell (5) is arranged on the outside of the ceramic tube (3), and the skirt (4) is arranged on the outside of the protective shell (5).

3. A novel combined arc extinguishing lightning protection device according to claim 2, characterized in that: The upper electrode (1) comprises an upper graphite electrode, an intermediate metal electrode and a lower graphite electrode, the intermediate metal electrode is fixed to one end of the ceramic tube (3) and the protective shell (5), the upper graphite electrode is arranged on the upper layer of the intermediate metal electrode, the lower graphite electrode is arranged at the bottom of the intermediate metal electrode and is arranged in the ceramic tube (3), and the lower electrode (6) comprises an upper graphite electrode and a bottom metal electrode, the bottom metal electrode is fixed to the other end of the ceramic tube (3) and the protective shell (5), and the upper graphite electrode is arranged in the ceramic tube (3) and is connected to the bottom metal electrode.

4. A novel combined arc extinguishing lightning protection device according to claim 1, characterized in that: The specific process of step 2 is as follows: an arc discharge is initiated in a ceramic tube filled with insulating oil, and part of the insulating oil in the discharge channel is instantly vaporized, decomposed, and ionized into high-temperature plasma and 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 will not be compressed by itself, when liquid phase discharge is performed in the discharge channel, the mechanical effect of power is exhibited to the outside world, and a force that impacts the ceramic tube wall is formed in the ceramic tube. Due to the mutuality of force, the ceramic tube wall generates a shock wave in the insulating oil medium, and at the same time, the pressure peak time point is consistent with the pre-shock wave. The time point of the breakdown is the same, no matter it is an impact or a power frequency flashover, the maximum change rate time is in the pre-breakdown time. The maximum change rate will inevitably produce the maximum arc occupation volume change rate. At the same time, the liquid has the characteristic of incompressibility that does not allow arc occupation, thereby generating a pressure peak. At this time, the arc current is extremely weak, and the arc anti-interruption pressure is extremely small, forming an asymmetric advantage of arc extinguishing pressure. In addition, an intermittent discharge mode, frequent arc extinguishing and frequent reignition mechanism are generated, which suppresses the arc intensity and prolongs the arc duration, so that the discharge intensity and steepness are greatly attenuated at the same time, thereby reducing the intensity of destructive energy release.

5. A novel combined arc extinguishing lightning protection device according to claim 4, characterized in that: The specific process of step 3 is as follows: 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 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, and the force rebounds after hitting the ceramic tube wall.

6. A novel combined arc extinguishing lightning protection device according to claim 5, characterized in that: The specific process of step 4 is that the hydraulic 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 lengthens the length of the arc. Under the blowing of the insulating oil on the arc, the arc temperature decreases, 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 greater the impact force to cut off the arc. The force rebounds after acting on the outer shell, forming a force directed to the center of the insulating tube. The medium generates a polarization current in the impact pre-breakdown stage, which reduces the breakdown voltage and reduces the breakdown voltage value corresponding to a short period of time, so that the medium's corresponding breakdown volt-second characteristic becomes gentle, and the frequent arc extinguishing and frequent reignition mechanisms suppress the arc intensity and prolong the arc duration, so that the discharge intensity and steepness are greatly attenuated at the same time, thereby reducing the intensity of destructive energy release.

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