Zinc oxide lightning arrester with modular structure

Abstract

The invention discloses a zinc oxide lightning arrester with a modular structure, and belongs to the technical field of zinc oxide lightning arresters, and the zinc oxide lightning arrester comprises a silicone rubber jacket assembly, the upper end and the lower end of the silicone rubber jacket assembly are respectively clamped with a first end cap and a second end cap; one end of the bracket is fixedly connected with the outer wall of the second end cap; the insulating sleeve part is fixedly embedded into the silicone rubber jacket assembly and is wrapped by the silicone rubber jacket assembly, an upper electrode and a lower electrode are arranged at the upper end and the lower end of an inner cavity of the insulating sleeve part respectively, and a plurality of nonlinear resistor discs are arranged between the upper electrode and the lower electrode and located in the insulating sleeve part. According to the invention, the dual maintenance convenience that the inner core of the lightning arrester can be pulled out and the shell can be split is realized, when the internal valve plate needs to be overhauled or replaced, the whole insulating sleeve part, the electrode and the valve plate can be integrally pulled out only by dismounting the end cap, the problem that the whole machine needs to be scrapped once the internal valve plate of a traditional product is aged or damped is solved, and the working efficiency is improved. And the whole life cycle operation and maintenance cost is obviously reduced.

Description

Technical Field

[0001] This invention belongs to the technical field of zinc oxide surge arresters, and in particular to a modular zinc oxide surge arrester. Background Technology

[0002] Zinc oxide surge arresters are overvoltage protection devices widely used in power systems. Their core component is a nonlinear resistive element primarily composed of zinc oxide (ZnO). This element exhibits excellent nonlinear volt-ampere characteristics: under normal power frequency voltage, it presents a high-resistivity state, allowing only microampere-level leakage current to flow; when the system is subjected to lightning or switching overvoltage impulses, its resistance rapidly decreases, diverting a large current to ground, thereby limiting the residual voltage on equipment terminals and protecting critical electrical components such as transformers and switchgear from insulation breakdown damage. Due to its advantages such as gapless operation, fast response, large current capacity, and no follow current, zinc oxide surge arresters have become an indispensable protection device in modern power transmission and distribution systems.

[0003] However, existing zinc oxide surge arresters generally employ an integral sealed structure—the nonlinear resistive element is press-fitted into an epoxy fiberglass or ceramic insulating cylinder in one piece, and an external insulating umbrella group is formed by integral injection molding of silicone rubber. Both ends are permanently sealed or welded together with metal end caps. While this structure meets basic operational requirements, it reveals many insurmountable defects in practical applications. For example, because the valve element is permanently sealed within the insulating cylinder and forms an irreversible mechanical-electrical unit with the electrodes and end caps, if any valve element deteriorates due to reasons such as aging under long-term power frequency voltage, thermal damage caused by accumulated energy from multiple lightning strikes, moisture intrusion leading to deterioration after seal failure, or the amplification of minor parameter deviations during manufacturing over long-term operation, the entire surge arrester is considered to have failed. Furthermore, the existing structure does not allow for opening the cylinder for partial inspection or replacement; the entire device must be removed from the line and scrapped. The total life cycle cost (LCC) of equipment remains high; spare parts and components need to be stockpiled at the cost of complete units, tying up a large amount of capital; under the background of large-scale construction of new energy power plants under the "dual carbon" target, this problem will be amplified exponentially. Summary of the Invention

[0004] The purpose of this invention is to provide a modular zinc oxide surge arrester to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a modular zinc oxide surge arrester, comprising: The silicone rubber jacket assembly has a first end cap and a second end cap respectively snapped onto its upper and lower ends; The bracket has one end fixedly connected to the outer wall of the second end cap; An insulating sleeve is fixedly embedded in and wrapped by a silicone rubber outer sleeve assembly. An upper electrode and a lower electrode are respectively provided at the upper and lower ends of the inner cavity of the insulating sleeve. Multiple nonlinear resistors are provided between the upper and lower electrodes and within the insulating sleeve.

[0006] This preferred option also includes: Two wiring bolts are fixedly connected to the first end cap and the second end cap, respectively; Two terminal nuts are respectively adapted to connect to two terminal bolts, so that the two terminal nuts abut against the first end cap and the second end cap respectively.

[0007] This preferred option also includes: The upper end cap is detachably installed on the top of the insulating sleeve fitting, and a pull ring is fixed on the top surface of the upper end cap; The lower base plate is detachably installed at the bottom of the insulating sleeve, so that the lower base plate and the upper end cover can be detachably encapsulated in the insulating sleeve.

[0008] In this preferred embodiment, the top surface of the upper electrode abuts against the inner wall of the upper end cap, causing the upper electrode to be pressed downward against the top of the inner cavity of the insulating sleeve, and the bottom surface of the lower electrode abuts against the inner wall of the lower base plate, causing the lower electrode to be pressed upward against the bottom of the inner cavity of the insulating sleeve.

[0009] This preferred option also includes: The first external thread is machined on the outer circumferential wall of the upper end cap; The first internal thread is machined on the inner wall of the top end of the insulating sleeve fitting. The first external thread and the first internal thread are adapted to each other so that the upper end cap is threadedly connected to the top end of the insulating sleeve fitting. The second external thread is machined on the bottom outer wall of the insulating sleeve fitting; The second internal thread is machined on the inner wall of the lower base plate. The second external thread and the second internal thread are adapted to each other, so that the lower base plate and the insulating sleeve are threadedly connected.

[0010] In a preferred embodiment, the silicone rubber outer casing assembly includes a silicone rubber insulating cylinder and multiple silicone rubber umbrella groups that are equidistantly connected from top to bottom. The upper and lower ends of the silicone rubber insulating cylinder are respectively secured by a first end cap and a second end cap. The silicone rubber insulating cylinder and the silicone rubber umbrella groups are symmetrically cut along the center line to create a cut-and-joint portion.

[0011] This preferred option also includes: Multiple independent valve plate module groups are connected end to end in the insulating sleeve fitting, and the upper and lower electrodes clamp multiple independent valve plate module groups in a centripetal manner.

[0012] In this preferred embodiment, each of the independent valve plate module groups includes an encapsulated insulating cylinder, a detachable encapsulated top cover ring mounted on the top of the encapsulated insulating cylinder, multiple nonlinear resistor plates encapsulated in the encapsulated insulating cylinder, a cross plate integrally connected to the middle of the top surface of the encapsulated top cover ring, and a standard interface disposed on the top surface of the cross plate.

[0013] This preferred option also includes: A cooling component is provided on the silicone rubber umbrella group and clamps the two adjacent cut joints that are cut, so that the cut silicone rubber umbrella group is fastened by the cooling component. The cooling configuration includes two independent cooling chamber side tubes symmetrically arranged on both sides of the silicone rubber umbrella group. Each cooling chamber side tube has an injection port and a drain port on the upper and lower parts of its outer wall, respectively. Both cooling chamber side pipes are connected to the silicone rubber umbrella group by fasteners.

[0014] In a preferred embodiment, the fastener includes two clamps symmetrically arranged vertically. Each clamp includes two semi-circular rods hinged together by a clamp pin, an extension rod integrally connected to one end of each semi-circular rod, a latch hinged to one of the extension rods, and a locking slot opened in the other extension rod. The inner wall of each cooling chamber side tube is integrally formed with an umbrella blade slot for the silicone rubber umbrella group to be fitted and inserted.

[0015] Compared with the prior art, the technical effects and advantages of the present invention are as follows: This modular zinc oxide surge arrester employs a silicone rubber jacket assembly with first and second end caps respectively snapped onto its upper and lower ends. A bracket is fixedly connected to the second end cap, and an insulating sleeve is embedded and encased within the silicone rubber jacket assembly. Upper and lower electrodes are positioned at the upper and lower ends of the insulating sleeve's inner cavity, with multiple nonlinear resistors arranged between them. This overall layout achieves physical separation and functional decoupling between the core internal conductive path and the external insulation protection structure of the surge arrester. The insulating sleeve, which bears the electrical function, and its internal valve plate assembly are completely encapsulated within the detachable silicone rubber jacket assembly. The end caps only serve axial limiting and external sealing functions, without participating in internal electrode compression or electrical connection. Therefore, during equipment operation, the nonlinear resistors rapidly conduct and discharge current under lightning strikes, with the current path stably passing through the upper electrode → nonlinear resistor → lower electrode. The silicone rubber jacket assembly focuses on providing external insulation, flashover protection, and mechanical protection; the two components function independently and without interference.

[0016] This structure achieves dual maintenance convenience for surge arresters: a removable core and a disassembleable outer shell. Firstly, when internal valve plates need repair or replacement, only the end caps need to be removed to extract the entire insulating bushing along with the electrodes and valve plates, without damaging the external silicone rubber umbrella array or requiring high-altitude disassembly. Secondly, the silicone rubber outer shell assembly itself adopts a symmetrical cut structure, combined with the end cap snap-fit ​​method, allowing the external insulation layer to be opened laterally without damage, greatly simplifying on-site installation and replacement procedures. Compared to the prevalent integrated, non-removable zinc oxide surge arresters with integral glue encapsulation, this solution solves the problem of traditional products requiring complete scrapping once the internal valve plates age or become damp, significantly reducing the overall lifecycle maintenance cost. Simultaneously, because the insulating bushing is independent of the external silicone rubber layer, its internal electric field distribution is unaffected by the umbrella array shape or contamination, resulting in more uniform potential control and improved operational reliability. In summary, this technology fundamentally transforms zinc oxide surge arresters from "closed, one-time devices" to "open, maintainable systems," achieving comprehensive benefits such as convenient installation, efficient maintenance, reliable operation, and extended lifespan. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the disassembly structure of the first end cap of the present invention; Figure 3 This is a schematic diagram of the split structure of the upper and lower electrodes of the present invention; Figure 4 This is a schematic diagram of the independent valve plate module assembly of the present invention in the state after being removed from the insulating sleeve. Figure 5 This is a schematic diagram of the disassembled structure of the independent valve plate module assembly of the present invention; Figure 6 This is a schematic diagram of the cooling configuration component of the present invention.

[0019] Explanation of reference numerals in the attached figures: In the diagram: 1. Silicone rubber outer sleeve assembly; 2. Silicone rubber insulating middle cylinder; 3. Silicone rubber umbrella cluster; 4. First end cap; 5. Terminal nut; 6. Terminal bolt; 7. Cooling configuration component; 8. Cooling chamber side pipe; 9. Second end cap; 10. Bracket; 11. Pull ring; 12. Upper end cover; 13. Insulating sleeve fitting; 14. Lower base plate; 15. Upper electrode; 16. Lower electrode; 17. First external thread; 18. First internal thread; 19. Second external thread ; 20. Second internal thread; 21. Independent valve plate module group; 22. Encapsulated insulating cylinder; 23. Encapsulated top cover ring; 24. Nonlinear resistor plate; 25. Third external thread; 26. Third internal thread; 27. Cross plate; 28. Standard interface; 29. ​​Injection port; 30. Drain port; 31. Umbrella plate slot; 32. Semi-circular hoop; 33. Hoop pin; 34. Locking bayonet; 35. Lock; 36. Extension rod; 37. Cut-off joint. Detailed Implementation

[0020] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0021] Unless otherwise defined, the directions mentioned herein, such as up, down, left, right, front, back, inside, and outside, are based on the directions shown in the figures of this invention, and are explained here together.

[0022] This embodiment provides, for example Figures 1 to 6 The modular zinc oxide surge arrester shown includes: The silicone rubber outer casing assembly 1 has a first end cap 4 and a second end cap 9 respectively snapped onto its upper and lower ends; The bracket 10 has one end fixedly connected to the outer wall of the second end cap 9. The bracket 10 is directly fixed to the outer wall of the second end cap, avoiding drilling holes or bonding metal brackets to the silicone rubber material. This ensures mechanical strength and prevents the outer jacket from cracking or the seal from failing due to stress concentration. An insulating sleeve 13 is fixedly embedded in and wrapped by a silicone rubber outer sleeve assembly 1. An upper electrode 15 and a lower electrode 16 are respectively provided at the upper and lower ends of the inner cavity of the insulating sleeve 13. A plurality of nonlinear resistors 24 are provided between the upper electrode 15 and the lower electrode 16 and within the insulating sleeve 13.

[0023] This embodiment also includes: Two wiring bolts 6 are fixedly connected to the first end cap 4 and the second end cap 9, respectively; Two terminal nuts 5 are respectively fitted to two terminal bolts 6, so that the two terminal nuts 5 abut against the first end cap 4 and the second end cap 9 respectively. Moving the electrical connection point to the surface of the end caps avoids direct drilling and welding on the silicone rubber jacket or insulating sleeve, maintaining the integrity of the main insulation structure while providing a highly conductive, low-contact-resistance connection interface. During operation, lightning current or power frequency leakage current is stably conducted through the terminal nut 5 → terminal bolt 6 → end cap → electrode path, resulting in uniform pressure on the contact surface and strong oxidation resistance. Compared with the existing technology that often uses crimped terminals or welded leads, this design significantly improves the convenience of field wiring and the ability to repeatedly disassemble and reassemble, while avoiding poor contact, localized overheating, or even flashover faults caused by welding heat damage or loose crimping. It achieves the beneficial effects of reliable connection, convenient maintenance, and adaptability to various installation scenarios.

[0024] This embodiment also includes: The upper end cover 12 is detachably installed on the top of the insulating sleeve 13, and a pull ring 11 is fixed on the top surface of the upper end cover 12. The lower base plate 14 is detachably mounted on the bottom of the insulating sleeve 13, allowing the lower base plate 14 and the upper end cover 12 to detachably encapsulate the insulating sleeve 13. The upper end cover 12 and the lower base plate 14 not only provide mechanical encapsulation but also serve as reaction force support surfaces for electrode clamping, while the pull ring 11 provides a dedicated force point during maintenance. During operation, this structure ensures a dry and clean microenvironment inside the insulating sleeve 13; during maintenance, the valve plate assembly can be pulled out entirely by simply unscrewing the upper and lower end covers, eliminating the need for piece-by-piece disassembly. Compared to traditional surge arresters where electrodes are directly welded or riveted to both ends of the cylinder, making it impossible to replace internal components individually, this solution achieves a modular operation and maintenance mode of "core-shell separation," significantly shortening power outage maintenance time, reducing the risk of manual operation, and achieving high maintainability and high system availability.

[0025] In this embodiment, the top surface of the upper electrode 15 abuts against the inner wall of the upper end cover 12, causing the upper electrode 15 to be pressed downwards against the top of the inner cavity of the insulating sleeve 13. The bottom surface of the lower electrode 16 abuts against the inner wall of the lower base plate 14, causing the lower electrode 16 to be pressed upwards against the bottom of the inner cavity of the insulating sleeve 13. When the upper end cover 12 and the lower base plate 14 are tightened by threads, their inner walls apply a reverse thrust to the electrodes, thereby stably clamping the intermediate nonlinear resistor 24 or independent valve plate module group 21 within a constant pressure range (typically 5–15 MPa). This pressure is crucial for the ZnO valve plate to maintain low contact resistance and prevent partial discharge and thermal instability. Compared with the prior art, which relies on springs or internal pads to provide pressure and is prone to failure due to aging and loosening, this design utilizes the end cover's own structure to achieve "self-loading clamping," resulting in stable pressure, no moving parts, long service life, and automatic reproduction of the original clamping state during reassembly after each maintenance, effectively ensuring the electrical consistency and thermal stability of the surge arrester during long-term operation.

[0026] This embodiment also includes: The first external thread 17 is machined on the peripheral outer wall of the upper end cap 12; The first internal thread 18 is machined on the inner wall of the top end of the insulating sleeve 13. The first external thread 17 and the first internal thread 18 are adapted to each other so that the upper end cap 12 is threadedly connected to the top end of the insulating sleeve 13. The second external thread 19 is machined on the bottom outer wall of the insulating sleeve 13; The second internal thread 20 is machined on the inner wall of the lower base plate 14. The second external thread 19 and the second internal thread 20 are adapted to each other, enabling the lower base plate 14 and the insulating sleeve 13 to be threadedly connected. The design of matching first external threads 17 / first internal threads 18 and second external threads 19 / second internal threads 20 between the upper end cover 12, the insulating sleeve 13, and the lower base plate 14 allows the core unit to be packaged using a fully threaded connection. This utilizes a precision thread pair to achieve a reversible connection with high coaxiality and high sealing performance, simultaneously completing mechanical locking, electrode clamping, and gas-tight sealing during tightening. During operation, the threaded connection can withstand transportation vibrations, seismic loads, and thermal expansion and contraction stress without loosening; during maintenance, only a conventional wrench is needed for disassembly and assembly, without the need for special tools. Compared with existing technologies that use flange bolt connections (which involve many parts and are heavy) or adhesive sealing (which is irreversible), this solution significantly simplifies the structure, reduces weight, and ensures good sealing performance even after multiple disassemblies and reassemblies, achieving a comprehensive effect of lightweight, high reliability, and full life-cycle maintainability.

[0027] In this embodiment, the silicone rubber outer casing assembly 1 includes a silicone rubber insulating cylinder 2 and multiple silicone rubber umbrella groups 3 fixedly connected at equal intervals from top to bottom. The upper and lower ends of the silicone rubber insulating cylinder 2 are respectively secured by a first end cap 4 and a second end cap 9. The silicone rubber insulating cylinder 2 and the silicone rubber umbrella groups 3 are symmetrically cut along the center line, creating a split joint 37. This facilitates the disassembly of the silicone rubber insulating cylinder 2 and the silicone rubber umbrella groups 3 when the first end cap 4 and the second end cap 9 are removed, thereby allowing the removal of the middle insulating sleeve component 13. The two halves of the outer casing can be opened laterally after the end caps are removed, exposing the internal insulating sleeve component 13, thus allowing for internal maintenance without axially pulling out the entire machine. During operation, the split joint 37 in the closed state is axially pressed and sealed by the end caps, maintaining complete external insulation performance; during maintenance, the outer casing can be opened for direct inspection or replacement of internal components. Compared with existing one-piece silicone rubber jacket surge arresters that are integrally molded or injection molded, this design completely solves the industry problem of "non-removable outer shell and inaccessible interior". It is especially suitable for indoor switch cabinets with limited space or densely arranged new energy substations, achieving unprecedented on-site maintainability and installation flexibility.

[0028] This embodiment also includes: Multiple independent valve plate module groups 21 are connected end-to-end within the insulating sleeve fitting 13, with the upper electrode 15 and lower electrode 16 concentrically clamping multiple independent valve plate module groups 21. Each independent valve plate module group 21 is a standardized functional unit with unified electrical parameters and mechanical interfaces, and the total reference voltage is linearly superimposed after being connected in series. During operation, lightning current flows through each module sequentially, and the energy is evenly distributed; when a module ages or is damaged, only that unit needs to be replaced. Compared with the "black box" structure of existing technologies that directly stack and press all valve plates into a single cylinder, this solution achieves traceability, replaceability, and upgradeability at the valve plate level. It not only reduces the types of spare parts inventory but also supports future upgrades to the equipment protection level by replacing high-performance modules, achieving advanced effects of product flexibility, intelligent operation and maintenance, and asset life extension.

[0029] In this embodiment, each independent valve plate module group 21 includes an encapsulated insulating cylinder 22, a detachable encapsulated top cover ring 23 mounted on the top of the encapsulated insulating cylinder 22, multiple nonlinear resistor plates 24 encapsulated in the encapsulated insulating cylinder 22, a cross plate 27 integrally connected to the middle of the top surface of the encapsulated top cover ring 23, and a standard interface 28 disposed on the top surface of the cross plate 27. Each encapsulated insulating cylinder 22 has a wiring conduit connected to the standard interface 28 on its bottom surface. A third external thread 25 is provided on the top periphery of the encapsulated insulating cylinder 22, and a third internal thread 26 is provided on the inner wall of the encapsulated top cover ring 23, which is thread-fitted to the third external thread 25. The encapsulation structure isolates external moisture intrusion, the cross plate 27 enhances the top rigidity and guides uniform pressure distribution, and the standard interface 28 ensures automatic alignment and insertion between modules. During operation, this design effectively suppresses fluctuations in contact resistance between modules and local electric field concentration; when replacing, the new module can be "plug and play" without the need for matching or adjustment. Compared with the complex process of on-site assembly, pressing, and testing of existing bulk valve plates, this solution extends factory-level precision to the on-site maintenance process, significantly improving replacement efficiency and operational consistency, and achieving a high-quality maintenance effect of "factory prefabrication, quick on-site replacement, and performance like new".

[0030] This embodiment also includes: Cooling configuration 7 is disposed on silicone rubber umbrella group 3 and fastens and clamps two adjacent cut joints 37 that are cut, so that the cut silicone rubber umbrella group 3 is fastened by cooling configuration 7. The cooling configuration component 7 includes two independent cooling chamber side pipes 8 symmetrically arranged on both sides of the silicone rubber umbrella group 3. Each cooling chamber side pipe 8 has an injection port 29 and a drain port 30 respectively on the upper and lower parts of its outer wall. Both cooling chamber side pipes 8 are connected to the silicone rubber umbrella group 3 via fasteners. The cooling chamber side pipes 8 are in close contact with the silicone rubber material, transferring the heat generated by the internal valve plates to the coolant within the chamber through heat conduction, forming a heat exchange circuit. Under conditions of continuously high power frequency voltage or frequent lightning strikes, traditional surge arresters are prone to excessive temperature rise of the valve plates due to poor heat dissipation, accelerating aging or even thermal collapse. This solution effectively controls temperature rise through a liquid cooling mechanism. Compared to existing surge arresters that rely solely on natural convection for heat dissipation, this design significantly improves heat load carrying capacity, making it particularly suitable for harsh environments such as high altitude, high temperature, or high pollution, achieving high thermal stability, long lifespan, and high environmental adaptability.

[0031] In this embodiment, the fastener includes two clamps symmetrically arranged vertically. Each clamp includes two semi-circular clamp rods 32 hinged together by clamp pins 33, an extension rod 36 integrally connected to one end of each semi-circular clamp rod 32, a latch 35 hinged in one of the extension rods 36, and a locking slot 34 opened in the other extension rod 36. When the two semi-circular clamp rods 32 are clamped around the periphery of the silicone rubber insulating cylinder 2 and located between two adjacent silicone rubber umbrella groups 3, the latch 35 is pried open and engaged into the locking slot 34, so that the latch 35 locks the two semi-circular clamp rods 32 around the periphery of the silicone rubber insulating cylinder 2. The inner wall of each cooling chamber side pipe 8 is integrally formed with umbrella blade slots 31 for the silicone rubber umbrella groups 3 to be fitted and inserted. The cooling chamber side pipe 8 has a chamber for holding coolant. The design of the cooling chamber side pipe 8 can not only lock the two cut silicone rubber umbrella groups 3, but also help the silicone rubber umbrella groups 3 and the silicone rubber insulating cylinder 2 to dissipate heat and cool down. The outer walls of the two semi-circular hoops 32 are fixedly connected to the inner walls of the cooling chamber side pipes 8. After the semi-circular hoops 32 clamp the silicone rubber insulating cylinder 2, tool-free quick locking is achieved through the engagement of the latches 35 and locking slots 34; the umbrella-shaped slots 31 ensure precise fitting between the cooling chamber side pipes 8 and the silicone rubber umbrella group 3, preventing slippage. During operation, this structure resists loosening caused by wind vibration and thermal deformation, while maintaining the sealing of the cooling chamber; during maintenance, it can be unlocked and disassembled with one hand. Compared with the existing method of using bolts to fasten the cooling device, this solution avoids drilling holes or applying concentrated stress to the silicone rubber, preventing material tearing, while significantly improving installation efficiency, achieving a synergistic optimization effect of mechanical reliability, efficient thermal management, and extremely simple operation.

[0032] Working principle When the power system is struck by lightning or experiences an operational overvoltage, the line-to-ground voltage of this modular zinc oxide surge arrester instantly rises, exceeding the system's rated voltage. The nonlinear resistor 24 inside the arrester exhibits excellent volt-ampere characteristics: under normal power frequency voltage, it is in a high-resistance state (microampere-level leakage current) and almost non-conductive; once the voltage exceeds its reference voltage, its resistance drops sharply, rapidly transitioning from high resistance to low resistance. The overvoltage energy is channeled to the grounding system via the path of upper electrode 15 → multiple independent valve module groups 21 → lower electrode 16, through the connecting bolt 6 and connecting nut 5, safely discharging the surge current and limiting the residual voltage on the equipment terminals, protecting downstream electrical equipment. After the overvoltage disappears, the system voltage returns to normal, the nonlinear resistor automatically returns to the high-resistance state, and the arrester re-enters a "standby" state, with only a small leakage current flowing through it.

[0033] Modular structure installation and maintenance: Multiple independent valve plate module groups 21 are connected end to end and installed into the inner cavity of the insulating sleeve fitting 13. The upper electrode 15 is placed at the top and the lower electrode 16 is placed at the bottom. The upper end cover 12 is tightened to the top of the insulating sleeve fitting 13 through the first external thread 17 and the first internal thread 18. The lower base plate 14 is tightened to the bottom of the insulating sleeve fitting 13 through the second external thread 19 and the second internal thread 20. The pull ring 11 on the top surface of the upper end cover 12 is easy to pull out.

[0034] The assembled insulating sleeve 13 is inserted into the silicone rubber outer sleeve assembly 1, which is composed of silicone rubber insulating middle cylinder 2 and multiple silicone rubber umbrella groups 3. The silicone rubber outer sleeve assembly 1 is symmetrically cut into two halves along the center line (forming a split joint 37) to facilitate wrapping the internal components. The first end cap 4 and the second end cap 9 are used to clamp the upper and lower ends of the silicone rubber outer sleeve assembly 1 respectively to achieve axial fixation and sealing.

[0035] The wiring bolt 6 is fixed to the first end cap 4 and the second end cap 9. The external lead is connected by the wiring nut 5. The bracket 10 is fixed to the outer wall of the second end cap 9 to support the entire surge arrester on the bracket or frame. The cooling configuration component 7 is installed at the cut seam of the adjacent silicone rubber umbrella group 3. The silicone rubber insulating cylinder 2 is held tightly by the semi-circular hoop 32 and locked by the locking buckle 35 and the locking slot 34. Coolant can be injected into the inner cavity of the cooling chamber side pipe 8 (through the injection port 29). Heat is conducted to the coolant through the silicone rubber material and circulated for heat dissipation through the drain port 30, improving the long-term thermal stability.

[0036] Replacement / Maintenance after Fault: Disconnect the system power, remove the wiring nut 5, remove the external lead, loosen the first end cap 4 and the second end cap 9, open the lock 35 of the cooling configuration 7, remove the semi-circular hoop 32, open the cut silicone rubber outer sleeve assembly 1 to both sides along the cut joint 37 to expose the internal insulating sleeve 13, use the pull ring 11 to pull out the entire insulating sleeve 13 assembly, unscrew the upper end cap 12 and the lower base plate 14, and take out the internal independent valve plate module group 21. If the performance of a certain module deteriorates (such as abnormal leakage current), only the independent valve plate module group 21 needs to be replaced (it is composed of an encapsulated insulating cylinder 22 + an encapsulated upper cover ring 23 + a nonlinear resistor 24, and can be replaced as a whole). The new module is quickly assembled through the third external thread 25 and the third internal thread 26, and the standard interface 28 is automatically aligned and connected with the adjacent module.

[0037] Reassembly after replacement: Reinstall the upper cover 12 and the lower base plate 14, ensure that the electrodes are properly pressed, put the insulating sleeve 13 back into the silicone rubber outer sleeve assembly 1, close and cut the outer sleeve, install and lock the cooling configuration 7, restore the wiring, and perform insulation resistance, DC reference voltage and leakage current tests. After confirming that the performance is qualified, put it into operation.

[0038] Therefore, the entire system can be replaced without scrapping it, and only the faulty valve plate module can be replaced, which greatly reduces the operation and maintenance costs. By increasing or decreasing the number of independent valve plate module groups 21, different voltage levels can be adapted. The cooling chamber side pipe 8 integrates liquid cooling channels to improve thermal stability.

[0039] It should be noted that, in this document, relational terms such as "one" and "two" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the phrase "comprising an element defined as..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0040] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A modular zinc oxide surge arrester, characterized in that, include: The silicone rubber outer casing assembly (1) has a first end cap (4) and a second end cap (9) respectively snapped onto its upper and lower ends. The bracket (10) is fixedly connected at one end to the outer wall of the second end cap (9); An insulating sleeve (13) is fixedly embedded in a silicone rubber outer sleeve assembly (1) and is wrapped by the silicone rubber outer sleeve assembly (1). An upper electrode (15) and a lower electrode (16) are respectively provided at the upper and lower ends of the inner cavity of the insulating sleeve (13). A plurality of nonlinear resistors (24) are provided between the upper electrode (15) and the lower electrode (16) and located in the insulating sleeve (13).

2. The modular zinc oxide surge arrester according to claim 1, characterized in that, Also includes: Two wiring bolts (6) are fixedly connected to the first end cap (4) and the second end cap (9) respectively; Two terminal nuts (5) are adapted to and connected to two terminal bolts (6) respectively, so that the two terminal nuts (5) abut against the first end cap (4) and the second end cap (9) respectively.

3. The modular zinc oxide surge arrester according to claim 2, characterized in that, Also includes: The upper end cap (12) is detachably installed on the top of the insulating sleeve (13), and a pull ring (11) is fixed on the top surface of the upper end cap (12). The lower base plate (14) is detachably installed at the bottom of the insulating sleeve (13), so that the lower base plate (14) and the upper end cover (12) can be detachably encapsulated in the insulating sleeve (13).

4. A modular zinc oxide surge arrester according to claim 3, characterized in that: The top surface of the upper electrode (15) abuts against the inner wall of the upper end cover (12), so that the upper electrode (15) is pressed downward against the top of the inner cavity of the insulating sleeve (13), and the bottom surface of the lower electrode (16) abuts against the inner wall of the lower base plate (14), so that the lower electrode (16) is pressed upward against the bottom of the inner cavity of the insulating sleeve (13).

5. A modular zinc oxide surge arrester according to claim 3, characterized in that, Also includes: The first external thread (17) is machined on the outer circumferential wall of the upper end cap (12); The first internal thread (18) is machined on the inner wall of the top end of the insulating sleeve (13). The first external thread (17) and the first internal thread (18) are adapted to each other so that the upper end cap (12) is threadedly connected to the top end of the insulating sleeve (13). The second external thread (19) is machined on the bottom outer wall of the insulating sleeve (13); The second internal thread (20) is machined on the inner wall of the lower base plate (14). The second external thread (19) and the second internal thread (20) are adapted to make the lower base plate (14) and the insulating sleeve (13) threadedly connected.

6. A modular zinc oxide surge arrester according to claim 5, characterized in that: The silicone rubber outer casing assembly (1) includes a silicone rubber insulating cylinder (2) and a plurality of silicone rubber umbrella groups (3) that are fixedly connected at equal intervals from top to bottom. The upper and lower ends of the silicone rubber insulating cylinder (2) are respectively fastened and covered by a first end cap (4) and a second end cap (9). The silicone rubber insulating cylinder (2) and the silicone rubber umbrella groups (3) are symmetrically cut along the center line to create a cut-and-joint part (37).

7. A modular zinc oxide surge arrester according to claim 6, characterized in that, Also includes: Multiple independent valve plate module groups (21) are arranged end to end in the insulating sleeve (13), and the upper electrode (15) and the lower electrode (16) clamp multiple independent valve plate module groups (21) in a concentric manner.

8. A modular zinc oxide surge arrester according to claim 7, characterized in that: Each of the independent valve plate module groups (21) includes an encapsulation insulating cylinder (22), an encapsulation cover ring (23) detachably mounted on the top of the encapsulation insulating cylinder (22), multiple nonlinear resistor plates (24) encapsulated in the encapsulation insulating cylinder (22), a cross plate (27) integrally connected to the middle of the top surface of the encapsulation cover ring (23), and a standard interface (28) provided on the top surface of the cross plate (27).

9. A modular zinc oxide surge arrester according to claim 6, characterized in that, Also includes: Cooling configuration (7) is provided on silicone rubber umbrella group (3) and clamps the two adjacent cut joints (37) that are cut, so that the cut silicone rubber umbrella group (3) is fastened by cooling configuration (7); The cooling configuration component (7) includes two independent cooling chamber side pipes (8) symmetrically arranged on both sides of the silicone rubber umbrella group (3). Each cooling chamber side pipe (8) has an injection port (29) and a drain port (30) respectively on the upper and lower parts of its outer wall. Both cooling chamber side pipes (8) are connected to the silicone rubber umbrella group (3) by fasteners.

10. A modular zinc oxide surge arrester according to claim 9, characterized in that: The fasteners include two clamps arranged symmetrically on the top and bottom. Each clamp includes two semi-circular clamp rods (32) that are hinged together by clamp pins (33), an extension rod (36) integrally connected to one end of each semi-circular clamp rod (32), a latch (35) hinged in one of the extension rods (36), and a locking slot (34) opened in the other extension rod (36). The inner wall of each cooling chamber side tube (8) is integrally formed with an umbrella blade slot (31) for the silicone rubber umbrella group (3) to be adapted and inserted.

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