Self-closed multistage arc extinguishing circuit lightning arrester

Abstract

The invention discloses a self-closed multistage arc extinguishing circuit lightning arrester, and relates to the technical field of lightning arresters, the self-closed multistage arc extinguishing circuit lightning arrester comprises a composite sleeve, the outer wall of the composite sleeve is provided with radial umbrella skirts which are axially and equidistantly distributed, the top end of the composite sleeve is detachably connected with a lightning receiving diversion block, a high-conductivity graphite block is embedded in the center of the lightning receiving diversion block, and an axial chamber is arranged in the composite sleeve; a composite insulating sphere is arranged in each arc extinguishing chamber, and an opening and closing assembly is arranged at a connection port of each arc extinguishing chamber and the air channel below and used for dynamically preventing high-temperature gas from flowing downwards to the adjacent arc extinguishing chamber during arc extinguishing. According to the invention, improvements are made to solve the problems of weakening of the protection reliability of a multi-stage arc extinguishing structure and the like caused by false triggering of each stage due to high-temperature gas channeling during multiple lightning strokes of an existing lightning arrester in the prior art. The multi-stage arc extinguishing chamber has the advantages that physical isolation of the multi-stage arc extinguishing chamber is achieved through the dynamic locking design of the rotary valve, high-temperature gas is prevented from flowing downwards, it is ensured that the chamber which is not struck by lightning is kept in a standby state, and the multi-lightning-stroke protection efficiency is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lightning arresters, and in particular to a self-closed multi-stage arc extinguishing line lightning arrester. BACKGROUND

[0002] Due to long-term exposure to the natural environment, lightning-induced trip accidents account for a dominant position in various types of faults of overhead transmission lines, and the problem of lightning hazards in mountainous areas and regions with high soil resistivity is particularly serious. The extremely high amplitude overvoltage generated by lightning current far exceeds the insulation tolerance limit of the line, resulting in flashover of insulators, damage to equipment, and permanent insulation damage due to power frequency follow current.

[0003] In the prior art, the current lightning protection system of overhead transmission lines mainly relies on line lightning arresters as core protection devices. As a basic lightning protection measure, lightning arresters intercept direct lightning and shunt lightning current to reduce the risk of conductors. However, in the case of multiple lightning strikes, multiple arc extinguishing units need to be connected in series. However, due to the high-temperature gas channeling and the downward channeling of high-temperature medium along the axial channel in the traditional arc extinguishing chamber, the unstruck chamber is easily triggered to malfunction, resulting in inter-stage interference and affecting the effectiveness of the multiple lightning protection structure.

[0004] To solve the above technical problems, the present application discloses a self-closed multi-stage arc extinguishing line lightning arrester, which has the advantages of physical isolation of multi-stage arc extinguishing chambers by dynamic locking design of rotary valves, blocking of downward channeling of high-temperature gas, ensuring that the unstruck chamber remains in standby state, and significantly improving the multiple lightning protection efficiency. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art and provides a self-closed multi-stage arc extinguishing line lightning arrester to solve the technical problems of existing lightning arresters in the prior art, such as mis-triggering of each stage due to high-temperature gas channeling in multiple lightning strikes, and weakening of the protection reliability of the multi-stage arc extinguishing structure. The present application has the advantages of physical isolation of multi-stage arc extinguishing chambers by dynamic locking design of rotary valves, blocking of downward channeling of high-temperature gas, ensuring that the unstruck chamber remains in standby state, and significantly improving the multiple lightning protection efficiency.

[0006] The present application is achieved by the following technical scheme: The present application discloses a self-closed multi-stage arc extinguishing line lightning arrester, which comprises a composite sleeve with an axial equidistantly distributed radiation umbrella skirt on its outer wall. The top end of the composite sleeve is detachably connected to a lightning attracting and current guiding block, and the center of the lightning attracting and current guiding block is embedded with a high-conductivity graphite block for capturing and directing lightning current. The composite sleeve is provided with an axial chamber inside, and the axial chamber is internally provided with a segmented ceramic insulating tube, an axial air passage and a plurality of arc extinguishing chambers arranged equidistantly along the axial direction. Each arc-extinguishing chamber is provided with a composite insulating sphere, which comprises a melting layer, a sealing layer and insulating oil covered in sequence from outside to inside, the melting layer melts and releases insulating oil in response to thermal shock of lightning current, and the insulating oil is pyrolyzed and gasified to form high-pressure insulating gas to achieve arc-extinguishing by asphyxiation; Each arc-extinguishing chamber is provided with an opening and closing assembly at the connecting port with the lower air passage, which is used to dynamically block the high-temperature gas from flowing downward to the adjacent arc-extinguishing chamber during arc-extinguishing. The arc-extinguishing chamber side wall and the sleeve outer wall are radially penetrated by a pressure relief passage, which is used to release the high-pressure gas generated during arc-extinguishing.

[0007] Further, the inner diameter of the arc-extinguishing chamber is significantly larger than the inner diameter of the air passage, and the outer diameter of the composite insulating sphere is larger than the inner diameter of the air passage, so as to provide a containing space for the composite insulating sphere, and make it stably stay in the chamber in a non-triggering state.

[0008] Further, the opening and closing assembly adopts a coaxial rotary valve structure and is controlled by a trigger.

[0009] Further, the opening and closing assembly comprises a top plate and a bottom plate which are attached to each other, both of which are provided with a plurality of annular arrays of fan-shaped through grooves, and the grooves are overlapped and communicated or misaligned and closed by relative rotation, the trigger comprises a spring, a guide groove and a guide rod, the spring is pre-compressed to make the bottom plate seal the connecting port, the arc-extinguishing gasification pressure drives the bottom plate to move downward and maintain the closed state, and the spring releases to push the bottom plate to move upward after the pressure decays, the guide groove is provided in the arc-extinguishing chamber side wall in a spiral track, and the guide rod and the guide groove cooperate to convert the vertical displacement of the top plate into the rotary motion of the top plate, so that the through grooves are completely overlapped and communicated.

[0010] Further, the bottom plate is fixed with an axially extending fixed shaft, and the top plate is rotatably sleeved on the outer circumferential surface of the fixed shaft.

[0011] Further, the cooperation structure of the guide rod and the spiral guide groove is configured such that when the bottom plate moves downward to the lower limit position, the guide rod reaches the bottom end of the guide groove, the misalignment angle of the through grooves of the top plate and the bottom plate is maximized, and the flow cross section is completely closed, and when the bottom plate moves upward, the guide rod moves along the guide groove to drive the top plate to rotate, so that the through grooves are overlapped to realize the communication with the lower chamber.

[0012] Further, when there is no lightning current passing under normal conditions, the gravity of the composite insulating sphere and the elastic force of the compression spring form a static balance, so that the bottom plate continuously maintains the sealing and pressing state of the connecting port.

[0013] Further, the arc-extinguishing chamber bottom wall is provided with a mounting groove, and the spring is embedded in the mounting groove.

[0014] Further, the bottom plate and the top plate are made of ceramic material with high insulating property, high temperature resistance and wear resistance.

[0015] Furthermore, the melting layer of the composite insulating sphere is composed of a low melting point alloy.

[0016] The present invention has the following advantages: (1) The present invention significantly improves arc extinguishing efficiency and multiple lightning protection capabilities through the combined structure of a composite insulating sphere and an axially series arc extinguishing chamber. The three-layer structure of the composite insulating sphere (melting layer, sealing layer, insulating oil) forms a dynamic response chain when lightning current is injected. The high temperature of the lightning current causes the outer tin alloy melting layer to melt instantly, tearing the sealing layer to release the insulating oil. After the oil contacts the core area of ​​the arc, a cracking reaction occurs, the volume expands, and a high-pressure gas barrier is formed. The arc is extinguished through the asphyxiation effect, thereby improving the arc extinguishing effect.

[0017] (2) The present invention solves the risk of false triggering caused by the downward flow of high-temperature gas by setting an opening and closing component and realizing the dynamic locking and conduction of the arc extinguishing chamber through pure mechanical linkage. When the arc is extinguished, the high pressure generated by the gasification of the insulating oil pushes the bottom plate downward, compresses the spring and maintains the staggered locking state of the fan-shaped grooves of the top and bottom plates, and physically isolates the adjacent chambers. After the chamber pressure decays, the spring releases the stored energy to drive the bottom plate upward, and the guide rod converts the vertical displacement into rotation of the top plate along the spiral groove, so that the fan-shaped grooves completely overlap the conduction channel. The whole process does not require external energy or electronic control components, relies on the arc extinguishing energy for self-drive, adapts to the passive environment of the overhead line, and maximizes the flow cross-section after reset, ensuring a low-resistance injection path for subsequent lightning current. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the cross-sectional structure of the sleeve of the present invention; Figure 3 For the present invention Figure 2 A local enlarged structural diagram of point A; Figure 4 For the present invention Figure 3 A schematic diagram of the partially enlarged structure at point B; Figure 5 This is a schematic structural diagram of the opening and closing assembly of the present invention; Figure 6 For the present invention Figure 3 A schematic diagram of the partially enlarged structure at point C; Figure 7 This is a schematic cross-sectional view of the structure of the segmented ceramic insulating tube of the present invention; Figure 8 For the present invention Figure 7 A schematic diagram of the local enlarged structure at D; Figure 9 It is a schematic diagram of the entire object of the present invention; Figure 10 It is a schematic diagram of the actual pressure relief channel of the present invention.

[0019] In the figure: 1. Composite sleeve; 2. Radial umbrella skirt; 3. Lightning conductor block; 4. Graphite block; 5. Axial chamber; 6. Segmented ceramic insulating tube; 7. Air channel; 8. Arc extinguishing chamber; 9. Composite insulating sphere; 10. Pressure relief channel; 11. Opening and closing assembly; 12. Trigger; 13. Mounting groove; 901. Melting layer; 902. Sealing layer; 903. Insulating oil; 111. Bottom plate; 112. Top plate; 113. Fixed shaft; 114. Through slot; 121. Spring; 122. Guide rod; 123. Guide slot. DETAILED DESCRIPTION

[0020] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented based on the technical solution of the present invention, and a detailed implementation method and specific operation process are given. However, the scope of protection of the present invention is not limited to the following embodiment. In the description of the present invention, words indicating directions or positional relationships such as "front", "rear", "left", and "right" are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, it should not be understood as a limitation on the present invention.

[0021] The embodiment discloses a self-enclosed multi-stage arc extinguishing line arrester, such as Figures 1-8 As shown, it includes a composite sleeve 1 and radial sheds 2 arranged on the outer wall of the sleeve, and the sheds are equidistantly distributed along the axial direction of the sleeve; the top of the sleeve is detachably connected to a lightning termination block 3, which is made of copper-aluminum alloy. In addition, a replaceable high-conductivity graphite block 4 is embedded in the center of the lightning termination block 3, which utilizes the high conductivity and arc erosion resistance of graphite to achieve directional guidance of lightning current.

[0022] like Figure 2 and Figure 3 As shown, an axial chamber 5 is provided inside the sleeve, and a segmented ceramic insulating tube 6 is embedded in the cavity as the main insulating channel. The insulating cavity is longitudinally provided with multi-stage air channels 7 and an arc extinguishing chamber 8. The ceramic material provides stable dielectric strength and high temperature resistance.

[0023] Specifically, the air channel 7 is a central axis hole that axially penetrates the segmented ceramic insulating tube 6, and the arc extinguishing chambers 8 are distributed in the axial direction of the air channel 7 in an equidistant manner, and all arc extinguishing chambers 8 are interconnected with the air channel 7; it should be noted that the inner diameter of the arc extinguishing chamber 8 is significantly larger than the inner diameter of the air channel 7, and a composite insulating sphere 9 is placed in each arc extinguishing chamber 8; the outer diameter of the sphere is designed to be larger than the inner diameter of the air channel 7, thereby ensuring that the composite insulating sphere 9 is completely confined to the internal space of the arc extinguishing chamber 8.

[0024] like Figure 3 and Figure 4As shown, the composite insulating sphere 9 adopts a three-layer composite structure, which specifically includes a melting layer 901, a sealing layer 902, and insulating oil 903. The melting layer 901, as the outermost layer, is made of high-temperature fusible material, such as low-melting-point alloy or special polymer, and directly responds to the thermal shock of lightning current. The sealing layer 902 is nested inside the melting layer 901 to form an airtight barrier, ensuring that the internal insulating oil 903 does not leak out.

[0025] The insulating oil 903 is encapsulated in the core area inside the sealing layer 902 and expands and drives the arc-extinguishing medium to diffuse at high temperature to achieve rapid arc extinction.

[0026] Through the above arrangement, after the lightning current is efficiently guided through the graphite block 4, high temperature is excited in the air channel 7 and high-speed injection of the arc-extinguishing chamber 8 along the axial air channel 7 is achieved, directly wrapping the surface of the upper composite insulating sphere 9; which causes the tin alloy melting layer 901 of the surface layer of the composite insulating sphere 9 to rapidly melt and tear the sealing layer 902, and instantaneously release the encapsulated insulating oil 903.

[0027] After the insulating oil 903 contacts the arc core area or the high-temperature cavity wall, a cracking reaction occurs, the volume expands to form high-pressure insulating gas, and suffocation arc extinction is achieved.

[0028] In addition, in this embodiment, to effectively release the high-pressure insulating gas in the air channel 7, a directional pressure relief channel 10 is provided on the side wall of the arc-extinguishing chamber 8. The channel is arranged in a radial manner through the outer wall of the sleeve, ensuring that when the chamber pressure is high, high-pressure gas can be discharged at high speed along the pressure relief channel 10.

[0029] It should be noted that the outlet end of the pressure relief channel 10 is integrated with a conical valve core type one-way valve (not shown in the figure). When the chamber pressure exceeds the preset threshold, the valve is driven by high-pressure gas to open the valve core, achieving directional high-speed discharge of high-temperature insulating gas. Under normal pressure-free state, the one-way valve maintains airtight locking under the action of spring pre-tightening force, blocking the intrusion of impurities such as dust and moisture from the outside into the arc-extinguishing chamber 8, ensuring the chemical stability of the insulating oil 903 and the standby state of the composite insulating sphere 9, thereby improving the reliability of multiple lightning strike protection.

[0030] However, considering that in actual use, after the lightning current is directed through the graphite block 4, high temperature is excited in the air channel 7 and high-speed injection of the arc-extinguishing chamber 8 along the axial channel is achieved, triggering the melting of the melting layer 901 of the upper composite insulating sphere 9 and releasing the insulating oil 903; if the high-pressure and high-temperature insulating gas generated by the cracking and gasification of the oil body is not effectively blocked, it will flow down to the adjacent arc-extinguishing chamber 8 along the axial air channel 7; the high-temperature medium acts on the lower composite insulating sphere 9 through the dual paths of thermal radiation conduction and forced convection, causing the tin alloy melting layer 901 of the lower composite insulating sphere 9 to unexpectedly melt, leading to the premature activation of the arc-extinguishing unit, and causing structural failure of the multiple lightning strike protection capability.

[0031] Therefore, in the present embodiment, as shown in Figure 2 , Figure 3 , Figure 5 and Figure 6 , to solve the risk of the lower composite insulation sphere 9 being unexpectedly melted due to the high-temperature insulation gas of the upper arc-extinguishing chamber 8 leaking downward, an opening and closing assembly 11 is arranged at the connecting port of each arc-extinguishing chamber 8 and the lower air passage 7, which ensures that the upper and lower arc-extinguishing chambers 8 can be blocked when the high-pressure insulation gas is generated by the melting of the upper composite insulation sphere 9, so as to avoid the high-temperature gas entering the lower arc-extinguishing chamber 8 and causing the lower composite insulation sphere 9 to be prematurely melted, thereby leading to the structural failure of the multiple lightning strike protection capability.

[0032] Specifically, the opening and closing assembly 11 adopts a coaxial rotary valve structure, and includes a top plate 112, a bottom plate 111, a fixed shaft 113, and a through groove 114. The bottom plate 111 is inside the arc-extinguishing chamber 8 and covers the connecting port of the arc-extinguishing chamber 8 and the lower air passage 7, thereby achieving the physical isolation of the adjacent arc-extinguishing chambers 8. The fixed shaft 113 is vertically fixed at the center of the bottom plate 111 and is concentric with each other. The top plate 112 is rotatably sleeved outside the fixed shaft 113. Optionally, the top plate 112 can be rotatably sleeved outside the fixed shaft 113 through a bearing or a clamping groove structure, and is limited in the axial direction. The top plate 112 is above the bottom plate 111, and the facing surfaces of the top plate 112 and the bottom plate 111 are mutually adhered and mirror-polished, thereby ensuring the sliding sealing property.

[0033] Based on the high-temperature sealing and insulation requirements of the lightning arrester opening and closing assembly 11, the bottom plate 111 and the top plate 112 need to adopt advanced ceramic materials with high insulation, high temperature resistance and wear resistance.

[0034] As shown in Figure 5 , the top plate 112 and the bottom plate 111 are both provided with multiple groups of fan-shaped through grooves 114, which are uniformly distributed along the circumferential ring array and are within the range of the connecting port of the arc-extinguishing chamber 8 and the lower air passage 7. When the through grooves 114 on the top plate 112 and the bottom plate 111 are staggered up and down, the through grooves 114 are closed, and when the through grooves 114 on the top plate 112 and the bottom plate 111 overlap with each other, the through grooves 114 are opened.

[0035] As shown in Figure 2 , Figure 3 , Figure 5 , Figure 6 , Figure 7 and Figure 8 , the top plate 112 is rotated by the trigger 12 to realize the complete overlap of the double-plate grooves, and the flow area is maximized in the open state, thereby accurately controlling the on-off of the high-temperature gas between the chambers.

[0036] The trigger 12 adopts a pneumatic and mechanical cooperative driving structure, and comprises a spring 121, a guide groove 123 and a guide rod 122. An inner recessed mounting groove 13 is arranged on the bottom wall of the arc extinguishing chamber 8, and the spring 121 is embedded in the groove and has a top end in contact with the bottom plate 111 and applying a supporting force. Under normal circumstances, the composite insulating ball 9 is above the top plate, the gravity of the composite insulating ball 9 and the elastic force of the compressed spring form a static balance, the gravity of the composite insulating ball 9 causes the spring 121 to be compressed, forcing the bottom plate 111 to be tightly attached to the bottom wall of the chamber, and the connecting port is completely blocked. When the lightning current is injected to cause the ball to melt and gasify, the gasification pressure pushes the bottom plate 111 to move downward, and the spring 121 remains compressed, and the locking state is still maintained (the closure is maintained through the groove 114), and the high pressure of the gasification of the ball itself is used to strengthen the sealing and block the risk of downward channeling of the high-temperature gas. After the arc extinguishing is completed and the chamber pressure is reduced, the spring 121 releases the stored energy to drive the bottom plate 111 to move upward, the linear motion is converted into rotary motion of the top plate 112 through cooperation of the guide rod 122 and the guide groove 123, the upper and lower through grooves 114 are completely overlapped, the flow area is expanded, and the communication with the lower chamber is realized, and the next lightning protection is prepared.

[0037] Specifically, the guide groove 123 is processed in a spiral trajectory on the side wall of the arc extinguishing chamber 8, and the structure satisfies that the spiral trajectory extends upward from the bottom of the chamber while expanding a specific arc length in the circumferential direction. The guide rod 122 is rigidly fixed to the outer circumference of the top plate 112, and the free end of the guide rod 122 is embedded in the guide groove 123. When the bottom plate 111 is driven to move downward to the lower limit of the arc extinguishing chamber 8, the guide rod 122 reaches the bottom end of the spiral trajectory of the guide groove 123, at this time, the dislocation angle of the through groove 114 between the top plate 112 and the bottom plate 111 reaches the maximum value, and the flow cross section is completely closed. When the spring 121 releases the acting force, the bottom plate 111 drives the top plate 112 to move upward synchronously, the guide rod 122 moves along the spiral groove to convert the vertical displacement into the rotation angle of the top plate 112, so that the upper and lower through grooves 114 are completely overlapped, and the maximum flow cross section is opened.

[0038] The principle of the present application is as follows: in the present application, the lightning current is first captured by the lightning current guide block 3 at the top end of the composite sleeve 1, and is directed to the axial chamber 5 by using the high conductivity and arc ablation resistance of graphite, and is injected at high speed along the central axis hole of the segmented ceramic insulating tube 6, so as to excite high temperature and enter the primary arc extinguishing chamber 8, and the high temperature wraps the first layer of composite insulating sphere 9, the low melting point alloy melting layer 901 on the surface layer of the first layer of composite insulating sphere 9 is instantaneously melted, the inner sealing layer 902 is torn, the core insulating oil 903 is released, the oil body is cracked and gasified after contacting the arc or the high temperature cavity wall, the volume is expanded to form high pressure insulating gas, the primary arc extinguishing is realized by the asphyxiation effect, the high pressure gas generated by the arc extinguishing pushes the bottom plate 111 of the opening and closing assembly 11 to move downward, compresses the bottom spring 121, at this time, the top plate 112 and the bottom plate 111 are in a dislocation state at the fan-shaped through groove 114, the air channel 7 is kept closed, the gasification pressure synchronously strengthens the sealing fit of the bottom plate 111 and the bottom wall of the chamber, blocks the path of the high temperature gas flowing downward to the lower layer arc extinguishing chamber 8, avoids the unintended activation of the lower layer composite insulating sphere 9, maintains the standby state of the lower layer sphere, when the arc extinguishing is completed and the chamber pressure decays, the spring 121 releases the stored energy, pushes the bottom plate 111 to move upward, the guide rod 122 fixed to the top plate 112 moves along the spiral guide groove 123 on the side wall of the arc extinguishing chamber 8, converts the vertical displacement into the rotation angle of the top plate 112, makes the top plate 112 and the bottom plate 111 completely overlap, opens the flow cross section, at this time, the primary arc extinguishing chamber 8 and the lower layer air channel 7 are restored to be in communication, the lower layer composite insulating sphere 9 enters the standby state, and prepares for subsequent lightning protection.

[0039] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A self-enclosed multi-stage arc-extinguishing line arrester, comprising a composite sleeve (1), the outer wall of which is provided with radial sheds (2) distributed axially and equidistantly, characterized in that: The top end of the composite sleeve (1) is detachably connected to a lightning conductor block (3), and a high-conductivity graphite block (4) is embedded in the center of the lightning conductor block (3) for capturing and directionally guiding lightning current; An axial chamber (5) is provided in the composite sleeve (1), a segmented ceramic insulating tube (6) is built into the axial chamber (5), and a penetrating axial air passage (7) and a plurality of arc extinguishing chambers (8) are provided in the segmented ceramic insulating tube (6). A composite insulating sphere (9) is provided in each arc extinguishing chamber (8), the composite insulating sphere (9) comprising a melting layer (901), a sealing layer (902), and insulating oil (903) sequentially coated from the outside to the inside, the melting layer (901) melts and releases the insulating oil (903) in response to thermal shock of lightning current, and the insulating oil (903) is pyrolyzed and gasified at high temperature to form high-voltage insulating gas to achieve arc extinguishing by asphyxiation; An opening and closing assembly (11) is provided at the connection between each arc extinguishing chamber (8) and the air passage (7) below, and is used to dynamically block high-temperature gas from flowing downward to the adjacent arc extinguishing chamber (8) during arc extinguishing. A pressure relief channel (10) is radially passed through the side wall of the arc extinguishing chamber (8) and the outer wall of the sleeve, and is used to release the high-pressure gas generated by arc extinguishing.

2. A self-enclosed multi-stage arc-extinguishing line arrester according to claim 1, characterized in that: The inner diameter of the arc extinguishing chamber (8) is significantly larger than the inner diameter of the air passage (7), and the outer diameter of the composite insulating sphere (9) is larger than the inner diameter of the air passage (7).

3. A self-enclosed multi-stage arc-extinguishing line arrester according to claim 1, characterized in that: The opening and closing component (11) adopts a coaxial rotary valve structure and controls opening and closing via a trigger (12).

4. A self-enclosed multi-stage arc-extinguishing line arrester according to claim 3, characterized in that: The opening and closing assembly (11) includes a top plate (112) and a bottom plate (111) that are fitted together, and both are provided with a plurality of sets of annular array fan-shaped through slots (114), and the slots are overlapped and connected or dislocated and closed by relative rotation. The triggering member (12) includes a spring (121), a guide slot (123) and a guide rod (122). The spring (121) is pre-compressed to make the bottom plate (111) block the connection port, and the arc extinguishing gasification pressure drives the bottom plate (111) to move downward and maintain the locked state. After the pressure decays, the spring (121) is released to push the bottom plate (111) upward. The guide slot (123) is opened on the side wall of the arc extinguishing chamber (8) in a spiral trajectory. The guide rod (122) cooperates with the guide slot (123) to convert the vertical displacement of the top plate (112) into the rotational movement of the top plate (112), so that the through slots (114) are completely overlapped and connected.

5. A self-enclosed multi-stage arc-extinguishing line arrester according to claim 4, characterized in that: An axially extending fixed shaft (113) is fixed at the center of the bottom plate (111), and the top plate (112) is rotatably sleeved on the outer circumferential surface of the fixed shaft (113).

6. A self-enclosed multi-stage arc-extinguishing line arrester according to claim 4, characterized in that: The matching structure of the guide rod (122) and the spiral guide groove (123) is configured such that when the bottom plate (111) moves downward to the lower limit position, the guide rod (122) reaches the bottom end of the guide groove (123), the misalignment angle of the through groove (114) between the top plate (112) and the bottom plate (111) is maximized, and the flow cross section is completely closed; when the bottom plate (111) moves upward, the guide rod (122) moves along the guide groove (123) to drive the top plate (112) to rotate, so that the through groove (114) overlaps, thereby achieving communication with the lower chamber.

7. A self-enclosed multi-stage arc-extinguishing line arrester according to claim 4, characterized in that: Under normal conditions, when no lightning current passes through, the gravity of the composite insulating sphere (9) and the elastic force of the compression spring (121) form a static balance, so that the bottom plate (111) continues to maintain a sealed and pressed state with respect to the connection port.

8. A self-enclosed multi-stage arc-extinguishing line arrester according to claim 4, characterized in that: The bottom wall of the arc extinguishing chamber (8) is provided with a mounting groove (13), and the spring (121) is embedded in the mounting groove (13).

9. A self-enclosed multi-stage arc-extinguishing line arrester according to claim 4, characterized in that: The bottom plate (111) and the top plate (112) are both made of ceramic materials with high insulation, high temperature resistance and wear resistance.

10. The self-enclosed multi-stage arc-extinguishing line arrester according to claim 1, characterized in that: The melting layer (901) of the composite insulating sphere (9) is composed of a low melting point alloy.

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