Trapezoidal double-pole arc-extinguishing lightning protection device without air gap

Abstract

The application discloses a trapezoidal double-pole arc-extinguishing lightning protection device without air gap, which mainly comprises an arc-extinguishing body, an upper electrode and a lower electrode; the upper and lower ends of the arc-extinguishing body are respectively installed at the two ends of an insulator string through connecting fittings; the arc-extinguishing body is hollow inside and is longitudinally provided with a plurality of insulating partitions, so that a plurality of independent backflushing arc-extinguishing cavities are formed inside the arc-extinguishing body; one backflushing device is arranged in each backflushing arc-extinguishing cavity, and the backflushing devices are arranged in a stepped spiral mode inside the arc-extinguishing body, and the backflushing opening directions of every two adjacent backflushing devices are opposite; wall electrodes are arranged on the insulating partitions between every two adjacent backflushing devices, one surface of the wall electrode is connected with the top of the backflushing device below, and the other surface of the wall electrode is connected with the bottom of the backflushing device above; and the two end heads of the backflushing devices at the upper and lower ends of the arc-extinguishing body are respectively connected with the upper electrode and the lower electrode, so that the lightning protection effect is good.

Description

Technical Field

[0001] This invention pertains to lightning protection devices for overhead power transmission and distribution lines, and specifically relates to a trapezoidal bipolar arc-extinguishing lightning protection device without an air gap. Background Technology

[0002] Lightning strikes can cause various forms of damage and destruction to power facilities. Thundercloud discharges can induce lightning overvoltages in power systems. Common overvoltages in overhead lines include those caused by lightning strikes near the transmission line through electromagnetic induction and those caused by direct lightning strikes on the conductors. Lightning-induced overvoltages can damage insulators and transmission lines. Lightning-induced flashover discharges in insulators can cause burns and detachment of porcelain surfaces or network cracks in glass insulators, significantly reducing insulation strength. Lightning strikes on transmission lines or lightning protection wires can cause broken strands or even breakage, rendering power transmission impossible.

[0003] Lightning protection for transmission lines has always been a crucial aspect of power sector lightning protection efforts, as lightning faults remain a significant factor affecting power grid safety. When lightning strikes a transmission line, the resulting flashover causes insulator flashover, leading to substantial power frequency follow current, damaging insulator strings and fittings, and ultimately resulting in line accidents. Power sectors typically address this by installing surge protectors on transmission lines.

[0004] During their ongoing research, the applicant and related inventors discovered the following problems with existing surge protectors: 1) Insufficient arc extinguishing capability, with the arc extinguishing energy of the device always affecting the flashover arc energy; 2) Low arc extinguishing sensitivity, with the arc extinguishing device failing to operate under low-temperature arc conditions; 3) Poor durability, as most arc extinguishing devices require gas-generating materials to provide arc extinguishing conditions, resulting in unnecessary consumption in extreme environments; 4) Influenced by the operating mode, resulting in poor arc extinguishing and lightning protection effects. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a trapezoidal bipolar arc-extinguishing lightning protection device without air gaps, which has better effectiveness and durability.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A trapezoidal bipolar arc-extinguishing lightning protection device without air gap mainly consists of an arc-extinguishing body, an upper electrode, and a lower electrode. The upper electrode is fixedly installed on the top of the arc-extinguishing body, and the lower electrode is fixedly installed on the bottom of the arc-extinguishing body. The upper and lower ends of the arc-extinguishing body are respectively connected to the two ends of an insulator string via connecting hardware to form a reliable electrical connection. The arc-extinguishing body has openings at both the upper and lower ends, is hollow inside, and has several insulating partitions arranged along the longitudinal direction of the arc-extinguishing body, forming several independent backflushing arc-extinguishing cavities inside the arc-extinguishing body. A [missing information - likely a device or component] is placed in each backflushing arc-extinguishing cavity. Each recoil device is arranged in a stepped spiral pattern inside the arc-extinguishing body, and the recoil openings of adjacent recoil devices face opposite directions (i.e., the recoil devices inside the arc-extinguishing body are arranged in the same direction at intervals). A wall electrode is provided on the insulating partition between adjacent recoil devices, and one side of the wall electrode is connected to the top of the recoil device below, and the other side is connected to the bottom of the recoil device above. The top of the recoil device at the top of the arc-extinguishing body is connected to the upper electrode, and the bottom of the recoil device at the bottom of the arc-extinguishing body is connected to the lower electrode.

[0008] In this invention, the backflush devices are arranged in a spiral stepped pattern, and each backflush injection arc-extinguishing chamber contains only one backflush device, which can sequentially backflush and extinguish the arc. Furthermore, the wall electrodes can limit the flashover path of the arc. Simultaneously, by setting the backflush openings of adjacent backflush devices in opposite directions, this invention can effectively backflush and extinguish the arc regardless of whether the lightning arc flashes from top to bottom or bottom to top.

[0009] The present invention further explains that the recoil device mainly consists of a recoil tube and a lightning arrester; one end of the recoil tube is open and the lightning arrester is fixedly installed at the other end, making the recoil device a semi-closed tube with a hollow interior, an open end, and a closed end; the lightning arrester is connected to the adjacent wall electrode.

[0010] The present invention further illustrates that the opening of the recoil tube is provided with an arc guide ring; the arc guide ring is connected to the adjacent wall electrode.

[0011] The present invention further illustrates that the cross-section of the arc-extinguishing body has a honeycomb structure.

[0012] The present invention further illustrates that the outer surface of the arc-extinguishing and lightning protection arc-extinguishing device is provided with several skirts. The addition of skirts to the outer surface of the device structure enhances the creepage distance and prevents arc discharge along the surface.

[0013] The present invention further illustrates that the wall electrode is an arc-guiding electrode sheet or a compression arc-extinguishing tube. The compression arc-extinguishing tube contains an arc-guiding ball. The compression arc-extinguishing tube is made of ceramic.

[0014] The present invention further explains that the inner wall of the arc-extinguishing body is mainly composed of high-strength, high-pressure-resistant non-conductive materials, such as alloy ceramics, rare earth ceramics, graphene-ceramic composite materials, organic ceramics, and other non-conductive materials; the insulating partition material is a high-strength, high-pressure-resistant non-conductive material, such as synthetic silicone rubber, rare earth glass, graphene glass, and other non-conductive materials; and the wall electrode material is a highly conductive metal or non-metal, such as copper, aluminum, tungsten, nickel, iron, graphite, and other materials.

[0015] The technical principle underlying this invention is as follows:

[0016] This arc-extinguishing lightning protection device is connected in parallel next to the insulator string, with a flashover air channel in the middle. Through insulation coordination, the lightning overvoltage generated when lightning strikes the tower or lightning protection wire will preferentially break down the parallel channel protecting the insulator string, and the resulting arc will enter the trapezoidal bipolar arc-extinguishing lightning protection device without air gap.

[0017] An electric arc is a plasma exhibiting elastic deformation. When it enters the recoil device through the arc guide ring, its density, velocity, and temperature increase due to the confinement of the recoil tube wall at the beginning of the tube, leading to an increase in internal pressure and ultimately a pressure burst effect. The arc impacts the lightning arrester at the bottom of the recoil tube, where it experiences a reverse elastic force. Most of the arc's trajectory changes 180°. The rebounding arc, with even greater velocity, density, and pressure, creates a cavity effect at the inlet, causing the arc at the recoil tube port to be interrupted. The remaining arc, due to the Coulomb force of the wall electrodes, enters the next recoil tube, repeating the process.

[0018] The recoil tube in this patent is a narrow injection channel, which is the only channel through which the electric arc enters the device. Various physical changes occur during the injection process.

[0019] 1. The arc plasma undergoes elastic deformation. When the arc plasma enters the recoil tube inlet, its physical shape changes first, from a thick arc to an extremely thin arc, and the radial pressure is converted into axial pressure. Due to the narrow tube recoil effect, the ejection velocity increases during arc recoil.

[0020] 2. The arc temperature rise effect is amplified. As the arc becomes thinner, its cross-sectional area decreases, according to the formula... The arc resistance will increase significantly. Since lightning arcs are often used as a constant current source in practical applications, according to the formula... It can be seen that although the impact time is only a few microseconds, the overall energy will be enhanced and the recoil tube internal temperature will rise.

[0021] Arc radiation, convection, and conduction are the three ways energy is lost. Because the heat cannot be released in a closed pipe, i.e., an externally blocked environment, the arc is blocked. It only generates heat and does not dissipate heat, thus causing a blocking temperature rise, which makes the temperature inside the pipe continue to rise.

[0022] 3. The pressure explosion effect increases dramatically. As the temperature gradually rises, the accumulation of the electric arc increases, which further exacerbates the pressure explosion effect, making the arc ejection force even greater.

[0023] When the electric arc enters the recoil device from the lightning arrester, because the recoil tube is very narrow, the large lightning arc will transform into a slender arc upon entering the recoil tube, filling the entire tube. The tube exerts a force on the arc, eventually creating a compression burst effect, blocking the passage of subsequent arcs and severing the arc. A small portion of the arc, due to the Coulomb force of the arc guide ring and arc guide components, enters the next recoil tube, repeating the above process.

[0024] Compared with multi-chamber

[0025] (1) Durability comparison. The gas-generating material added to the multi-chamber requires baking under high temperature conditions to generate gas. Therefore, the gas-generating material in the multi-chamber arc extinguishing device is consumed under high temperature conditions, resulting in poor durability of the multi-chamber. However, the injection material used in this invention does not have consumption factors and does not need to be extinguished through the gas generation mechanism. Therefore, this invention has better durability.

[0026] (2) Comparison of arc extinguishing effects. In a multi-chamber, the condensation electrode effect is generated when the electric arc passes between two adjacent electrodes. That is, the temperature of the electric arc is lower under the adjacent electrodes. The low temperature of the electric arc bakes the gas-generating material, resulting in poor gas generation. The contradiction between the condensation electrode effect and the high temperature baking gas generation to form arc extinguishing results in poor arc extinguishing effect. However, the present invention adopts the narrow tube injection mechanism, where the electric arc collision generates huge arc extinguishing energy. By utilizing the energy of the electric arc itself and the collision arc extinguishing, the arc extinguishing effect is excellent.

[0027] (3) Comparison of arc extinguishing sensitivity. Based on the above durability and arc extinguishing effect, the durability of the multi-chamber is affected by high temperature, and the gas generation is affected by the electrode condensation effect, that is, the low temperature arc baking ability is extremely low. The contradiction between the condensation effect and the high temperature baking gas generation forms the arc extinguishing effect. When a small arc passes through, the arc extinguishing effect is not good. Only when a larger arc passes through can the multi-chamber operate correctly. However, the flow of a large arc will cause the relay protection to operate, that is, there will be a tripping accident. Therefore, the arc extinguishing sensitivity of the multi-chamber is not ideal. In contrast, regardless of whether a large arc or a small arc exists, as long as the arc enters the invention, the injection mechanism will be generated, and the sensitivity is high.

[0028] (4) Comparison of operating modes. According to the above sensitivity analysis, the operation of multi-chamber systems is affected by external factors such as system operating mode and short-circuit current, and there is an arc extinguishing blind zone, which makes it very difficult to match the lightning protection of multi-chamber systems; while the present invention is not affected by external factors such as system operating mode and short-circuit current.

[0029] The advantages of this invention are as follows:

[0030] (1) Constrain and control the arc path, ensuring that the arc is consistent with the arc extinguishing channel, thus eliminating the hazards of arc drift;

[0031] (2) The recoil devices in the multiple recoil injection arc extinguishing chambers act on the arc to achieve mutual isolation between different arc segments. The arc is cut off at the lightning arrester in each recoil component, making it difficult for the arc to reignite.

[0032] (3) The wall electrodes inside the partition outside the backflushing arc extinguishing cavity can effectively disperse the arc energy, making the arc smaller and smaller;

[0033] (4) The backflushing device in the backflushing injection arc extinguishing chamber is not affected by temperature and electrodynamics during the arc extinguishing process;

[0034] (5) The electric arc is extinguished in the impact arc extinguishing section and the power frequency arc building channel is destroyed, and the relay protection device is not detected;

[0035] (6) Trapezoidal bipolar arc-extinguishing lightning protection device without air gap has a wide range of applications and is not affected by conductor layout, tower type, or polarity effect.

[0036] (7) Effectively prevents flashover problems of lightning protection devices, reduces the tripping rate of power equipment due to lightning strikes, protects power facilities, improves the reliability of the power grid, and is conducive to safe power production. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the installation structure of the trapezoidal bipolar arc-extinguishing lightning protection device of the present invention;

[0038] Figure 2 This is a partial unfolded view of the internal structure of the trapezoidal bipolar arc-extinguishing lightning protection device of the present invention;

[0039] Figure 3 This is a schematic diagram of the cross-sectional structure of the trapezoidal bipolar arc-extinguishing lightning protection device of the present invention;

[0040] Figure 4 This is a schematic diagram of the recoil device structure of the present invention.

[0041] The labels in the above figures and their corresponding component names are as follows:

[0042] 1-Arc extinguishing body, 2-Upper electrode, 3-Lower electrode, 4-Insulating partition, 5-Recoil injection arc extinguishing cavity, 6-Recoil device, 7-Wall electrode, 8-Skirt, 61-Recoil tube, 62-Lightning arrester, 611-Arc guiding ring. Detailed Implementation

[0043] The following detailed, non-limiting description of the technical solution of the present invention is provided in conjunction with preferred embodiments and accompanying drawings.

[0044] Example 1:

[0045] like Figure 2-4 As shown, a trapezoidal bipolar arc-extinguishing lightning protection device without air gap mainly consists of an arc-extinguishing body 1, an upper electrode 2, and a lower electrode 3. The upper electrode 2 is fixedly installed on the top of the arc-extinguishing body 1, and the lower electrode 3 is fixedly installed on the bottom of the arc-extinguishing body 1. The upper and lower ends of the arc-extinguishing body 1 are respectively installed at both ends of an insulator string through connecting hardware to form a reliable electrical connection. The arc-extinguishing body 1 has openings at both the upper and lower ends and is hollow inside. Several insulating partitions 4 are arranged along the longitudinal direction of the arc-extinguishing body 1, so that several independent back-flow injection arc-extinguishing cavities 5 are formed inside the arc-extinguishing body 1. Each of the arc-extinguishing chambers 5 is equipped with a backflushing device 6, which is arranged in a stepped spiral pattern inside the arc-extinguishing body 1. The backflushing openings of adjacent backflushing devices 6 are in opposite directions. A wall electrode 7 is provided on the insulating partition 4 between adjacent backflushing devices 6. One side of the wall electrode 7 is connected to the top of the lower backflushing device, and the other side is connected to the bottom of the upper backflushing device. The top of the uppermost backflushing device in the arc-extinguishing body 1 is connected to the upper electrode 2, and the bottom of the lowermost backflushing device in the arc-extinguishing body 1 is connected to the lower electrode 3.

[0046] The recoil device 6 mainly consists of a recoil tube 61 and a lightning arrester 62; one end of the recoil tube 61 is open and the other end is fixedly installed with the lightning arrester 62, making the recoil device 6 a semi-closed tube with a hollow interior, one open end and the other closed end; the lightning arrester 62 is connected to the adjacent wall electrode 7.

[0047] The opening of the recoil tube 61 is provided with an arc guide ring 611; the arc guide ring 611 is connected to the adjacent wall electrode 7.

[0048] The cross-section of the arc-extinguishing body 1 has a honeycomb structure.

[0049] The wall electrode 7 mentioned above is an arc-guided electrode sheet.

[0050] Example 2:

[0051] The difference between this embodiment and embodiment 1 is that the outer surface of the arc extinguishing body 1 is provided with several skirts 8.

[0052] Example 3:

[0053] The difference between this embodiment and Embodiment 1 is that the wall electrode described herein uses a compression arc-extinguishing tube.

[0054] Example 4:

[0055] The difference between this embodiment and embodiment 3 is that the inside of the compression arc extinguishing tube is provided with an arc guiding ball.

[0056] In practical applications, such as Figure 1 As shown, the trapezoidal bipolar arc-extinguishing lightning protection device without air gap in this embodiment can be connected in parallel next to the insulator string, with a flashover air channel in the middle. Through insulation coordination, the lightning overvoltage generated when lightning strikes the tower or lightning protection wire will preferentially break down the parallel channel to protect the insulator string, and the resulting arc will enter the trapezoidal bipolar arc-extinguishing lightning protection device without air gap.

[0057] When lightning strikes a transmission line or induces an overvoltage, a lightning current begins to flow through the high-voltage electrode at the flashover high-voltage end of the lightning protection device. The arc can be drawn into the backflush injection arc-extinguishing chamber 5 of the device through the high-voltage electrode. Upon entering the backflush device 6, due to the restriction of the backflush tube wall, the arc's density, velocity, and temperature increase at the beginning of the backflush tube 61, leading to an increase in pressure inside the tube and ultimately a pressure burst effect. The arc impacts the lightning arrester 62 at the bottom of the backflush tube 61. The arc experiences a reverse rebound force at the blocked bottom of the backflush tube, causing most of the arc's direction of travel to change 180°. The rebounding arc, with its greater velocity, density, and pressure, and the cavity effect at the entrance, acts on the external arc, causing the arc at the port of the backflush tube 61 to be truncated. A small portion of the arc, due to the Coulomb force of the wall electrode, enters the next backflush tube, repeating the above process.

[0058] When lightning strikes a tower or the lightning protection wire of a transmission line, causing a flashover at the low-voltage end of the lightning protection device, a lightning current begins to flow through the low-voltage electrode. The electric arc can be drawn into the backflush injection arc-extinguishing chamber 5 of this device through the low-voltage electrode. Because the inner diameter of the backflush pipe device 6 is very small, the large lightning arc will transform into a slender arc when it enters the backflush pipe, filling the entire pipe. The pipe exerts a force on the arc, eventually creating a compression burst effect, blocking the passage of subsequent arcs and severing the arc. The remaining part of the arc enters the next backflush pipe due to the Coulomb force of the arc-guiding ring 611 and the arc-guiding component, repeating the above process.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A trapezoidal bipolar arc-extinguishing lightning protection device without air gap, mainly composed of an arc-extinguishing body (1), an upper electrode (2), and a lower electrode (3); the upper electrode (2) is fixedly installed on the top of the arc-extinguishing body (1), the lower electrode (3) is fixedly installed on the bottom of the arc-extinguishing body (1), and the upper and lower ends of the arc-extinguishing body (1) are respectively installed on the two ends of an insulator string through connecting fittings to form a reliable electrical connection; characterized in that: The arc-extinguishing body (1) has openings at both the top and bottom, is hollow inside, and has several insulating partitions (4) arranged along the longitudinal direction of the arc-extinguishing body (1) to form several independent backflushing injection arc-extinguishing cavities (5) inside the arc-extinguishing body (1); a backflushing device (6) is placed in each backflushing injection arc-extinguishing cavity (5), and the backflushing devices are arranged in a stepped spiral inside the arc-extinguishing body (1), and the backflushing openings of two adjacent backflushing devices are opposite in direction; a wall electrode (7) is provided on the insulating partition (4) between two adjacent backflushing devices (6), and one side of the wall electrode (7) is connected to the top of the backflushing device below, and the other side is connected to the bottom of the backflushing device above; the top of the backflushing device at the top of the arc-extinguishing body (1) is connected to the upper electrode (2), and the bottom of the backflushing device at the bottom of the arc-extinguishing body (1) is connected to the lower electrode (3).

2. The trapezoidal bipolar arc-extinguishing lightning protection device without air gap according to claim 1, characterized in that: The recoil device (6) mainly consists of a recoil tube (61) and a lightning arrester (62); the recoil tube (61) is open at one end and the lightning arrester (62) is fixedly installed at the other end, making the recoil device (6) a semi-closed tube with a hollow interior, an open end, and a closed end; the lightning arrester (62) is connected to the adjacent wall electrode (7).

3. The trapezoidal bipolar arc-extinguishing lightning protection device without air gap according to claim 2, characterized in that: The opening of the recoil tube (61) is provided with an arc guide ring (611); the arc guide ring (611) is connected to the adjacent wall electrode (7).

4. The trapezoidal bipolar arc-extinguishing lightning protection device without air gap according to claim 1, characterized in that: The cross-section of the arc-extinguishing body (1) has a honeycomb structure.

5. The trapezoidal bipolar arc-extinguishing lightning protection device without air gap according to claim 1, characterized in that: The outer surface of the arc-extinguishing body (1) is provided with several skirts (8).

6. The trapezoidal bipolar arc-extinguishing lightning protection device without air gap according to claim 1, characterized in that: The wall electrode (7) is an arc-conducting electrode sheet or a compression arc-extinguishing tube.

7. The trapezoidal bipolar arc-extinguishing lightning protection device without air gap according to claim 6, characterized in that: The compressed arc-extinguishing tube is equipped with an arc-guiding ball inside.

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