A series-parallel arc extinguishing and lightning protection device

Abstract

The present invention discloses a series-parallel arc extinguishing and lightning protection device, belonging to the field of arc extinguishing and lightning protection devices. It includes a sealed arc extinguishing unit, an upper-end arc extinguishing unit, and a lower-end arc extinguishing unit. The upper-end arc extinguishing unit is arranged between the top of the insulator string and the top tower pole, the lower-end arc extinguishing unit is arranged between the bottom of the insulator string and the bottom tower pole, and the sealed arc extinguishing unit is arranged in parallel on the insulator string through a screw. Compared with traditional circuit breakers, the novel lightning protection device can instantaneously, integrally, and simultaneously cut off the arc. The impact arc is cut off when it just forms, with an extremely fast arc extinguishing speed. The insulation recovery speed of the liquid medium is faster than that of the valve plate: Since the arc is simultaneously broken in the device, the overall insulation of the medium is restored, and it has anti-reignition properties. After passing through this device, the heat of the arc transfer medium is low, resulting in a low temperature rise of the medium, and thus the probability of thermal breakdown is very low.

Description

Technical Field

[0001] The present invention relates to the field, and in particular to a series-parallel arc extinguishing and lightning protection device. Background Art

[0002] Lightning strikes can cause different forms of damage and destruction to power facilities. Lightning discharges in the power system can cause lightning overvoltage. Lightning overvoltage may damage insulators and transmission lines; the impulse flashover caused by lightning strikes on transmission lines can lead to the flashover of line insulators, and then a large power frequency follow current is generated, damaging the insulator string and fittings, resulting in line accidents; when lightning strikes on transmission lines or lightning conductors, it may cause strand breaks or even fractures, making the transmission work impossible to carry out.

[0003] Existing lightning protection and arc extinguishing devices can make the volt-second characteristics of the active arc extinguishing parallel gap flatter. However, existing lightning protection and arc extinguishing devices can only reduce the wavefront steepness of lightning current and cannot further attenuate the magnitude of lightning current. The ability to attenuate lightning current is limited. Summary of the Invention

[0004] The purpose of the present invention is to provide a series-parallel arc extinguishing and lightning protection device to solve the technical problems of slow arc extinguishing speed and easy trip accidents of existing lightning protection and arc extinguishing devices. The purpose is to improve the reliability of the new lightning protection and arc extinguishing device in protecting insulators. Enhance the arc extinguishing pressure during the arc extinguishing process of the lightning protection and arc extinguishing device, which can not only attenuate the magnitude of lightning current but also extend the discharge time of the arc, avoiding damage to the transmission line caused by excessive instantaneous lightning current amplitude.

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

[0006] A series-parallel arc extinguishing and lightning protection device includes a sealed arc extinguishing unit, an upper end arc extinguishing unit, and a lower end arc extinguishing unit. The upper end arc extinguishing unit is arranged between the top of the insulator string and the top tower pole, and the lower end arc extinguishing unit is arranged between the bottom of the insulator string and the bottom tower pole. The sealed arc extinguishing unit is arranged in parallel on the insulator string through a screw.

[0007] Furthermore, the upper end arc extinguishing unit and the lower end arc extinguishing unit include a sealed arc extinguishing unit, an upper screw, a lower screw, and a silica gel sleeve. The upper screw is fixedly arranged at the top of the sealed arc extinguishing unit and connected to the top tower pole. The lower screw is arranged at the bottom of the sealed arc extinguishing unit and fixed on the bottom tower pole. The silica gel sleeve is sleeved on the sealed arc extinguishing unit.

[0008] Furthermore, the sealed arc extinguishing unit is arranged as a sealed tube. Upper and lower electrodes are respectively arranged at both ends of the sealed tube in a sealed manner. Insulating oil is arranged in the sealed tube, and a skirt is arranged on the side of the sealed tube.

[0009] Furthermore, the sealing tube further comprises 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.

[0010] 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.

[0011] Furthermore, the sealed arc extinguishing unit is configured as a sealed tube, with upper and lower electrode sealing arrangements respectively provided at both ends of the sealed tube, insulating oil provided in the sealed tube, a skirt provided on the side of the sealed tube, and arc extinguishing grids provided at intervals on the inner side of the sealed tube, and the lateral length of the arc extinguishing grid is greater than half the inner diameter of the sealed tube.

[0012] Furthermore, an upper tip electrode is provided at the bottom of the upper electrode, a lower tip electrode is provided 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.

[0013] 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 sealed tube are arranged alternately, and convex piers are arranged between the arc extinguishing grids on the same semicircle. 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.

[0014] Furthermore, the specific working process of the lightning protection device is as follows:

[0015] 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;

[0016] 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.

[0017] Step 3: The Pascal effect enhances the hydroelectric effect. When the arc acts on the insulating oil, a certain part of the static insulating oil undergoes a pressure change, which is then transferred to all directions inside the sealed tube without changing the pressure.

[0018] Step 4: 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, concentrating on impacting and extinguishing the arc channel. Three points on one arc are extinguished, generating an intermittent discharge mode. The breakdown volt-second characteristic becomes flat, reducing both the breakdown starting voltage and the residual voltage value.

[0019] Further, the specific process of Step 2 is as follows: Arc discharge is initiated inside a ceramic tube filled with insulating oil. Part of the insulating oil in the discharge channel is instantaneously vaporized, decomposed, and ionized into 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 cannot be compressed by itself, when liquid-phase discharge occurs in the discharge channel, it exhibits a mechanical effect of power on the outside world, forming a force that impacts the ceramic tube wall in the ceramic tube. Due to the reciprocity of forces, a shock wave is generated in the ceramic tube wall in the insulating oil medium.

[0020] The specific process of Step 3 is as follows: When the impact arc acts on the metal electrode, pressure is applied to the insulating oil inside the ceramic tube. According to Pascal's principle, when a part of the static fluid in a closed container undergoes a pressure change, it will be 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, and this force rebounds after hitting the ceramic tube wall.

[0021] Further, the specific process of Step 4 is as follows: The liquid-electric effect and the Pascal effect cause the pressure inside 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, and the tip elongates the arc length. 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. The medium generates a polarization current during the impact pre-breakdown stage, reducing the breakdown voltage and the breakdown voltage value corresponding to a short time period, making the breakdown volt-second characteristic of the medium become flat. The frequent arc extinguishing and frequent re-ignition mechanisms inhibit the arc intensity and lengthen the arc duration, causing the discharge intensity and steepness to decay significantly at the same time by reducing the intensity of the released destructive energy.

[0022] Induced charges generate Coulomb force inside the sealed insulating tube: Due to electrostatic induction, charges opposite in polarity to the thundercloud are induced inside the insulating tube and accumulate inside the sealed insulating tube. Since the liquid is an incompressible fluid, the charges cannot move freely, and finally an arc chain is formed inside the insulating tube. Coulomb force of mutual repulsion is generated between charges of the same polarity. Also, due to the sealing of the insulating tube, the Coulomb force acts on the tube wall to form a reaction force, truncating the induced charge chain.

[0023] The arc perfusion stage causes the Pascal effect: The Pascal's principle states that: "When a point in an incompressible static fluid is subjected to an external force that generates a pressure increase, this pressure increase is instantaneously transmitted to all points in the static fluid."

[0024] When the impact arc acts on the metal plate, a certain pressure is exerted on the insulating oil 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 is transmitted in all directions without change in magnitude. Then, starting from the discharge channel in the ceramic tube, the insulating oil medium around is impacted with a greater force. This force rebounds after hitting the ceramic tube wall, forming a force directed towards the center of the ceramic tube, achieving the purpose of interrupting the arc.

[0025] After the pre-breakdown of the arc, the liquid-electric effect further enhances the Pascal effect: The insulating tube is filled with an insulating oil medium. When an arc discharge occurs, some of the liquid in the discharge channel is instantaneously vaporized, decomposed, and ionized into a high-temperature plasma and suddenly expands, generating a directional shock pressure wave with a peak pressure of up to 104 - 105 atm. 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 with ultra-high power to the outside world. A force that impacts the ceramic tube wall is formed in the ceramic tube. The ceramic tube wall generates a powerful shock wave in the insulating oil medium, acting on the discharge channel in the form of impulse or shock pressure, impacting the arc and truncating it.

[0026] The peak pressure time is equal to the pre-breakdown time; whether it is an impact arc or a power frequency arc, the time when the change rate of its current and energy with respect to time is the largest is at the pre-breakdown time. The largest change rate will inevitably result in the largest change rate of the arc occupancy volume. At the same time, the liquid is incompressible, and the characteristic of not allowing the arc occupancy is generated, thereby generating the peak value of the arc-extinguishing pressure. At this time, the arc current is extremely weak, and the arc's resistance to interruption pressure is extremely small, forming the asymmetry of the arc-extinguishing pressure.

[0027] The medium generates a polarization current during the impact pre-breakdown stage; this reduces the breakdown voltage, which is equivalent to reducing the breakdown voltage value corresponding to a short time period, making the breakdown volt-second characteristic of the medium become flatter. It reduces both the breakdown starting voltage and the residual voltage value.

[0028] Due to the adoption of the above technical solutions, the present invention has the following beneficial effects:

[0029] Compared with traditional circuit breakers, the new lightning protection device can instantaneously, integrally, and simultaneously cut off the electric arc. The impact electric arc is cut off when it just forms, with an extremely fast arc extinguishing speed. The insulation recovery speed of the liquid medium is faster than that of the varistor. Since the electric arc is simultaneously broken in the device, the overall insulation of the medium is restored, and it has anti-reignition properties. After passing through this device, the heat transfer medium of the electric arc has a low temperature, resulting in a reduced temperature rise of the medium, and thus the probability of thermal breakdown is very low. In a multi-pulse lightning strike environment, the arc extinguishing structure will not be damaged due to the thermal accumulation effect. By adjusting the electrode distance, the control of the breakdown distance is completed, thereby reducing the initial value of the arc breakdown voltage and making the residual voltage of the device extremely low. The fast arc extinguishing ability generates an intermittent discharge mode. The frequent arc extinguishing and frequent reignition mechanisms suppress the arc intensity and lengthen the arc duration, causing the discharge intensity and steepness to decay significantly at the same time. By reducing the intensity of the released destructive energy, the safety, durability, and reliability of the lightning protection device are ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic structural diagram of the present invention;

[0031] Figure 2 is the end arc extinguishing unit of the present invention;

[0032] Figure 3 is a schematic structural diagram of the first sealed arc extinguishing unit of the present invention;

[0033] Figure 4 is a schematic structural diagram of the second sealed arc extinguishing unit of the present invention;

[0034] Figure 5 is a schematic structural diagram of the high-pressure sealing structure of the sealed tube of the present invention;

[0035] Figure 6 is a schematic structural diagram of the external reinforcement structure of the sealed tube of the present invention.

[0036] In the drawings, A - sealed arc extinguishing unit, B - upper end arc extinguishing unit, C - lower end arc extinguishing unit, 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, 12 - upper screw, 13 - lower screw, 14 - silica gel sleeve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] To make the objectives, technical solutions, and advantages of the present invention clearer and more 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.

[0038] Example 1:

[0039] As Figures 1-3 shown, a series - parallel arc extinguishing and lightning protection device includes a sealed arc extinguishing unit A, an upper - end arc extinguishing unit B, and a lower - end arc extinguishing unit C. The upper - end arc extinguishing unit B is arranged between the top of the insulator string and the top tower pole, the lower - end arc extinguishing unit C is arranged between the bottom of the insulator string and the bottom tower pole, and the sealed arc extinguishing unit A is arranged in parallel on the insulator string through a screw. The upper - end arc extinguishing unit B and the lower - end arc extinguishing unit C include a sealed arc extinguishing unit A, an upper screw 12, a lower screw 13, and a silica gel sleeve 14. The upper screw 12 is fixedly arranged on the top of the sealed arc extinguishing unit A and is connected to the top tower pole, the lower screw 13 is arranged at the bottom of the sealed arc extinguishing unit A and is fixed on the bottom tower pole, and the silica gel sleeve 14 is sleeved on the sealed arc extinguishing unit A.

[0040] By setting the arc extinguishing points at three points, a frequent arc extinguishing and frequent re - ignition mechanism can be realized, which inhibits the arc intensity and lengthens the arc duration, so that the discharge intensity and steepness are simultaneously greatly attenuated, and the safety, durability, and reliability of the lightning protection device are avoided by reducing the release intensity of the destructive energy.

[0041] The pressure peak time is equal to the pre - breakdown time. Whether it is an impulse arc or a power - frequency arc, the time when the change rate of its current and energy with time is the largest is at the pre - breakdown time. The largest change rate will inevitably result in the largest change rate of the arc occupancy volume. At the same time, the liquid is incompressible, and the characteristic of not allowing the arc occupancy is generated, thereby generating the peak value of the arc extinguishing pressure. At this time, the arc current is extremely weak, and the arc breaking resistance pressure is extremely small, forming the asymmetry of the arc extinguishing pressure.

[0042] In this embodiment, the sealed arc extinguishing unit A is set as a sealed tube. Upper electrodes 1 and lower electrodes 6 are respectively and hermetically arranged at both ends of the sealed tube. Insulating oil 2 is arranged inside the sealed tube, and a skirt 4 is arranged 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 arranged outside the ceramic tube 3, and the skirt 4 is arranged outside the protective shell 5.

[0043] The upper electrode 1 includes an upper - layer graphite electrode, a middle - layer metal electrode, and a lower - layer graphite electrode. The middle - layer metal electrode is fixed at one end of the ceramic tube 3 and the protective shell 5. The upper - layer graphite electrode is arranged above the middle - layer metal electrode, the lower - layer graphite electrode is arranged at the bottom of the middle - layer metal electrode and is arranged inside the ceramic tube 3. The lower electrode 6 includes an upper - end graphite electrode and a bottom - layer metal electrode. The bottom - layer metal electrode is fixed at the other end of the ceramic tube 3 and the protective shell 5. The upper - end graphite electrode is arranged inside the ceramic tube 3 and is connected to the bottom - layer metal electrode.

[0044] The insulating tube filled with insulating oil is made of an inorganic non-metallic material with high hardness, high temperature resistance and high pressure resistance, and is cylindrical; the insulating tube is tightly connected to the composite insulation, playing a role in fixing the insulating tube and the umbrella skirt; the closed space inside the insulating tube is filled with insulating oil, which is the area of elastic collision of the arc.

[0045] When the lightning strikes the tower or the transmission line, the fully enclosed liquid lightning arrester discharges prior to the insulator string, and the lightning arc is poured into the insulating tube inside the lightning arrester, generating a liquid-electric effect to form 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, a certain pressure is applied to the liquid inside the insulating 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 insulating tube. This acting force rebounds after acting on the outer shell, forming an acting force directed towards the center of the insulating tube, achieving the purpose of cutting off the arc.

[0046] By setting the lightning-receiving place as a graphite electrode, the service life can be effectively improved. The graphite electrode has good electrical conductivity and is easy to introduce the arc into the recoil tube: Graphite is a non-metallic material, and the electrical conductivity of graphite is 100 times higher than that of general 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 the graphite electrode is 1.5 to 2 times faster than that of the copper electrode as a whole. When the lightning strikes the transmission line, the graphite electrode can play an arc-initiating role, enabling the arc to smoothly enter the arc extinguishing tube.

[0047] The melting point of the graphite electrode is extremely high, it can withstand a larger current and is not easy to deform: The graphite electrode has the characteristic of being able to withstand large 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 current with an intensity between 5000 amperes and 50,000 amperes generates a lightning temperature of up to over 3000 degrees. Therefore, the metal electrode is extremely easy to deform under the action of the large lightning current, generating metal powder, splashing, damaging the structure of the arc extinguishing chamber, and affecting the recoil arc extinguishing effect, while using the graphite electrode can effectively solve the above problems.

[0048] The loss of the graphite electrode is small: The graphite electrode has the characteristic of being able to withstand large current conditions. Under the action of the 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 the graphite electrode during the recoil arc extinguishing process is extremely small, even "zero loss".

[0049] Example 2:

[0050] Such as Figure 4As shown, this embodiment differs from Example 1 in that the sealed arc-extinguishing unit A is configured as a sealed tube, with an upper electrode 1 and a lower electrode 6 sealed at each end. Insulating oil 2 is provided within the sealed tube, and a skirt 4 is provided on the side of the sealed tube. Arc-extinguishing grates 9 are spaced apart on the inner side of the sealed tube, and the lateral length of the arc-extinguishing grates 9 is greater than half the inner diameter of the sealed tube. An upper tip electrode 8 is provided at the bottom of the upper electrode 1, and a lower tip electrode 11 is provided at the upper end of the lower electrode 6. The upper tip electrode 8 and the lower tip electrode 11 are arranged vertically relative to each other, and both the upper tip electrode 8 and the lower tip electrode 11 are graphite electrodes.

[0051] In this embodiment, the arc extinguishing grid 9 is made of insulating material and 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. 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.

[0052] 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. As the insulating oil blows 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 in turn, the greater the impact force to cut off the arc, completing the arc extinguishing.

[0053] The specific working process of the lightning protection device is:

[0054] Step 1: When lightning strikes a tower or transmission line, the fully sealed liquid arrester discharges before the insulator string, and the lightning arc flows into the insulating tube inside the arrester. When the lightning strikes the three-point sealed arc extinguishing unit A, an arc is formed because the insulation strength is lower than that of the insulator string.

[0055] Step 2: When an arc discharge is triggered in a sealed tube filled with insulating oil, the liquid-electric effect generates a shock wave that rushes to the side. When an 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 a high-temperature plasma that 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, the mechanical effect of power is exhibited 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;

[0056] Step 3: The Pascal effect enhances the liquid-electric effect. When the arc acts on the insulating oil 2 and a pressure change occurs in a certain part of the static insulating oil 2, it will be transmitted to all directions inside the sealed tube without changing in magnitude. When the impact arc acts on the metal electrode and applies pressure to the insulating oil inside the ceramic tube, according to Pascal's principle, when a pressure change occurs in a certain part of the static fluid in a closed container, it will be transmitted to all directions without changing in magnitude. Then, starting from the discharge channel inside the ceramic tube, it impacts the surrounding insulating oil medium with a greater force, and this force rebounds after hitting the ceramic tube wall.

[0057] Step 4: Since there is an arc extinguishing grid 9 inside the sealed tube, the length of the arc in the sealed tube becomes longer. 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 return and impact after hitting the side, concentrating on the arc channel for arc extinguishing. Arc extinguishing is carried out at three points on one arc, generating an intermittent discharge mode, making the breakdown volt-second characteristic become flat, reducing the breakdown inception voltage and the residual voltage value at the same time.

[0058] 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, and the tip elongates the length of the arc. With the blowing of the insulating oil on the arc, the arc temperature decreases, making the arc 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 for intercepting the arc. The force rebounds after acting on the outer shell, forming a force pointing towards the center of the insulating tube. The medium generates a polarization current during the impact pre-breakdown stage, reducing the breakdown voltage and the breakdown voltage value corresponding to a short time period, making the breakdown volt-second characteristic of the medium become flat. The frequent arc extinguishing and frequent reignition mechanisms inhibit the arc intensity and lengthen the arc duration, significantly attenuating the discharge intensity and steepness simultaneously by reducing the release intensity of the destructive energy.

[0059] A high-pressure sealing structure and an external reinforcement structure are provided inside the sealed arc extinguishing unit, as Figures 5-6 shown.

[0060] The high-pressure sealing structure includes a plastic sleeve 21, a stainless-steel washer 22, an O-ring 23, a steel sleeve 24, sealing silicone 25, and an extrusion fixing block 26. The electrode is nested within the sealing silicone 25. The sealing silicone 25 is hermetically arranged 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 washer 22 is placed at the front end of the electrode. The O-ring 23 is arranged between the contact of the sealing silicone 25 and the ceramic tube. The extrusion fixing block 26 is arranged on the outside of the sealing silicone 25. There is a bolt hole 27 on the extrusion fixing block 26, and the bolt hole 27 is in contact with the stainless-steel washer 22. The sealing silicone 25 is set as a "T"-shaped structure silicone, and the bottom of the "T"-shaped structure silicone is set as a spherical concave structure.

[0061] The outer shell is made of a plastic insulating material for the purpose of fixing 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 silicone wraps around the upper and lower electrodes. In the narrow space when the upper and lower electrodes extinguish the arc, the area is small and pressure dispersion occurs. Wrapping the electrodes with semi-circular silicone can focus the pressure wave, increasing the pressure in the arc extinguishing channel by several times and effectively blocking the electric arc. A thrust is generated by the screw on the stainless-steel washer and silicone 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 electric arc maximally.

[0062] When the device is struck by lightning, a liquid-electric effect is generated, forming a powerful impact pressure wave that acts on the discharge channel in the form of impulse or impact pressure to cut off the electric 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 in all directions without change in magnitude, 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 cutting off the electric arc, reducing the amplitude of the current, decreasing the steepness of the lightning wave, and prolonging the discharge time of the electric arc, effectively extinguishing the arc, with a simple structure and good sealing performance.

[0063] 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 at the top of the high-pressure sealing device, and the bot

[0064] 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.

[0065] 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 refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A series-parallel arc extinguishing and lightning protection device, characterized in that: The invention comprises a sealed arc extinguishing unit (A), an upper end arc extinguishing unit (B) and a lower end arc extinguishing unit (C), wherein the upper end arc extinguishing unit (B) is arranged between the top end of the insulator string and the top end tower, and the lower end arc extinguishing unit (C) is arranged between the bottom end of the insulator string and the bottom end tower, and the sealed arc extinguishing unit (A) is arranged in parallel on the insulator string through a screw rod; The sealed arc extinguishing unit (A) is provided as a sealed tube, an upper electrode (1) and a lower electrode (6) are provided at both ends of the sealed tube for sealing, insulating oil (2) is provided in the sealed tube, a skirt (4) is provided on the side of the sealed tube, arc extinguishing grids (9) are provided at intervals on the inner side of the sealed tube, and the transverse length of the arc extinguishing grids (9) is greater than half the inner diameter of the sealed tube; The upper end arc extinguishing unit (B) and the lower end arc extinguishing unit (C) comprise a sealed arc extinguishing unit (A), an upper end screw (12), a lower end screw (13) and a silicone sleeve (14); the upper end screw (12) is fixedly arranged at the top of the sealed arc extinguishing unit (A) and connected to the top tower; the lower end screw (13) is arranged at the bottom of the sealed arc extinguishing unit (A) and fixed on the bottom tower; and the silicone sleeve (14) is sleeved on the sealed arc extinguishing unit (A); The arc extinguishing grid (9) is made of insulating material and 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. A convex pier (10) is arranged between the arc extinguishing grids (9) on the same semicircle. 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.

2. The series-parallel arc extinguishing and lightning protection device according to claim 1, characterized in that: The sealed arc extinguishing unit (A) is configured as a sealed tube, with an upper electrode (1) and a lower electrode (6) 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), wherein 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).

3. The series-parallel arc extinguishing and lightning protection device according to claim 2, wherein: The upper electrode (1) includes 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). The lower electrode (6) includes 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). The upper graphite electrode is arranged in the ceramic tube (3) and is connected to the bottom metal electrode.

4. The series-parallel arc extinguishing and lightning protection device according to claim 1, characterized in that: An upper tip electrode (8) is provided at the bottom of the upper electrode (1), and a lower tip electrode (11) is provided 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.

5. A series-parallel arc extinguishing and lightning protection device according to claim 1, characterized in that: The specific working process of the lightning protection device is: 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; 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. Step 3: The Pascal effect enhances the liquid-electric effect. When the arc acts on the insulating oil (2), when the pressure of a certain part of the static insulating oil (2) changes, it will be transmitted to all directions inside the sealed tube without changing in magnitude; Step 4: Since an arc extinguishing grid (9) is provided inside the sealed tube, the length of the arc in the sealed tube becomes longer. 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, concentrating on the arc channel for arc extinguishing. Three points on one arc are extinguished, generating an intermittent discharge mode. The breakdown volt-second characteristic becomes flat, reducing both the breakdown initiation voltage and the residual voltage value.

6. A series-parallel arc extinguishing and lightning protection device according to claim 5, 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. Part of the insulating oil 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 power on the outside world, forming a force that impacts the ceramic tube wall in the ceramic tube. Due to the reciprocity of forces, a shock wave is generated in the ceramic tube wall in the insulating oil medium; The specific process of Step 3 is as follows: When the impact arc acts on the metal electrode, pressure is applied to the insulating oil in the ceramic tube. According to Pascal's principle, when the pressure of a certain part of the static fluid in a closed container changes, it will be transmitted to all directions without changing in magnitude. Then, 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.

7. A series-parallel arc extinguishing and lightning protection device according to claim 6, characterized in that: The specific process of Step 4 is as follows: The liquid-electric effect and the Pascal effect cause the pressure inside 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, and the tip elongates the length of 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 for intercepting the arc. The force rebounds after acting on the outer shell, forming a force pointing towards the center of the insulating tube. The medium generates a polarization current during the impact pre-breakdown stage, reducing the breakdown voltage and the breakdown voltage value corresponding to a short time period, making the breakdown volt-second characteristic of the medium flat. The mechanism of frequent arc extinguishing and frequent re-ignition suppresses the arc intensity and lengthens the arc duration, causing the discharge intensity and steepness to decay significantly at the same time by reducing the release intensity of the destructive energy.

Images