Side-hung adjustable gap lightning protection composite insulator for high-voltage overhead transmission line

Abstract

The application provides a side-hanging adjustable-gap lightning protection composite insulator for high-voltage overhead transmission lines, which is arranged between a conductor and a cross arm of a tower and comprises a suspension type composite insulator body, a lightning protection discharge assembly, an adjustable external series discharge gap assembly, an arc guiding and voltage grading assembly, a mounting and locking assembly and a limiting and anti-swing assembly. The suspension type composite insulator body constitutes a main load bearing path of mechanical suspension load of the conductor. The adjustable external series discharge gap assembly forms an adjustable external series discharge gap distance between an arc striking electrode on the conductor side and a lightning protection side discharge electrode. The arc guiding and voltage grading assembly makes the arc develop in a direction away from the umbrella skirt sheath. The limiting and anti-swing assembly limits the lateral deviation and torsional deviation of the lightning protection discharge assembly, thereby keeping the external series discharge gap distance stable. The application realizes the separation and collaborative control of the mechanical load path, the lightning discharge path and the arc guiding path, and is suitable for 35kV to 220kV and above high-voltage overhead transmission lines.

Description

Technical Field

[0001] This invention relates to the field of power transmission and distribution line insulation and lightning protection technology, specifically to a side-mounted adjustable gap lightning protection composite insulator for high-voltage overhead power transmission lines. Background Technology

[0002] High-voltage overhead transmission lines operate in the open environment for extended periods, where conductors, insulator strings, hardware, and tower crossarms are continuously subjected to the combined effects of lightning strikes, wind deflection, galloping, icing, pollution accumulation, temperature and humidity changes, and mechanical vibration. For 110kV and 220kV high-voltage lines, lightning overvoltages can not only cause insulator flashovers and line tripping, but also lead to problems such as arc burns on end hardware, erosion of composite insulator skirts, conductor surface damage, and concentrated impulse currents on the tower grounding side. Therefore, lightning protection for high-voltage lines needs to simultaneously consider the reliability of mechanical suspension, the safety margin of external insulation, the level of lightning impulse protection, and post-lightning-damage maintenance identification.

[0003] In existing projects, surge arresters, protective gaps, surge protection hardware, or improved insulation configurations are commonly used to enhance lightning protection capabilities. Independent surge arresters offer non-linear discharge capabilities, but typically require additional supports, leads, grounding connections, and installation space. For towers with compact crossarm structures, limited phase-to-phase spacing, complex terrain, or insufficient space for existing line modifications, the placement of independent surge arresters is easily constrained by electrical clearances, ground clearances, wind deflection safety distances, and maintenance space, making construction and modification more challenging.

[0004] Protective gaps provide an air breakdown path under lightning overvoltage, but most common protective gaps are fixed air gaps, making it difficult to simultaneously ensure both lightning impulse protection and power frequency operation safety margin. When the gap distance is too small, it may reduce the insulation margin under normal power frequency operating conditions; when the gap distance is too large, it may not trip preferentially under lightning impulse, causing lightning overvoltage to still randomly flash over along the surface of the composite insulator skirts. Especially in high-altitude, heavily polluted, iced, and significantly misaligned lines, fixed gaps are insufficiently adaptable to field conditions.

[0005] Some surge protection insulators combine the surge arrester unit with the insulator body to reduce installation space. However, if the surge protection unit is located or close to the main load-bearing path of the conductor's mechanical suspension, it may be subjected to additional tensile, bending, or vibration effects caused by the conductor's own weight, wind sway, icing load, galloping impact, and short-circuit electrodynamics during long-term operation. This coupling of mechanical loads with the surge protection function may increase the risk of poor contact of the internal resistor elements, deterioration of seals, or loosening of connections within the surge protection unit.

[0006] Furthermore, existing lightning protection insulators or protective gaps still have shortcomings in discharge path control. Under lightning overvoltage, the electric arc may develop close to the composite insulator skirt sheath or end fittings, causing localized ablation of the skirt, decreased hydrophobicity of the sheath, localized electric field distortion at the ends, and long-term insulation performance degradation. For high-voltage lines, due to the long insulation distance, large structural dimensions, and significant wind deflection and galloping amplitude, the relative position between the side-mounted or external lightning protection structure and the main insulator may change during operation, leading to deviations of the preset external series discharge gap distance from the design value.

[0007] Meanwhile, the long inspection distances and dispersed tower locations of high-voltage overhead lines make fault location after lightning strikes difficult. If the lightning protection unit activates, suffers thermal damage, or fails, inspection personnel cannot promptly determine whether the lightning protection module needs replacement, affecting line maintenance efficiency. Therefore, it is necessary to propose a lightning protection composite insulator structure for high-voltage line suspension points, enabling the separation and coordinated control of mechanical load paths, lightning discharge paths, and arc conduction paths within a limited installation space. Summary of the Invention

[0008] The technical problem to be solved by this application is: within a limited installation space, how to ensure that the lightning protection composite insulator at the suspension point of a high-voltage overhead transmission line simultaneously takes into account the reliability of mechanical suspension, the on-site adjustability of lightning impulse protection level, the directional guidance of the electric arc away from the insulating skirt, the operational stability of the side-mounted structure, and the identifiability of the state after a lightning strike.

[0009] To solve the above-mentioned technical problems, this application provides the following technical solution: A side-mounted adjustable gap lightning protection composite insulator for high-voltage overhead transmission lines is installed between the conductor and the tower crossarm. It includes a suspended composite insulator body, a lightning protection discharge assembly, an adjustable external series discharge gap assembly, an arc-guiding voltage equalization assembly, a mounting and locking assembly, and a limiting anti-sway assembly. The suspended composite insulator body includes an insulating core rod, a shed sheath covering the outside of the insulating core rod, an upper end fitting at the upper end of the insulating core rod, and a lower end fitting at the lower end of the insulating core rod. The suspended composite insulator body connects the conductor and the tower crossarm, forming the main load-bearing path for the conductor's mechanical suspension load. The lightning protection discharge assembly is side-mounted on one side of the suspended composite insulator body and connected to the upper end fitting, the tower crossarm, the crossarm connecting fitting, or the grounding connector via the mounting and locking assembly. The lightning protection discharge assembly is located outside the main load-bearing path of the conductor's mechanical suspension load. An adjustable external series discharge gap assembly is installed between the conductor-side hardware and the lightning protection discharge assembly. It includes a conductor-side arc-initiating electrode, a lightning protection-side discharge electrode, and an adjustable gap bracket. The conductor-side arc-initiating electrode and the lightning protection-side discharge electrode form an external series discharge gap distance d, which can be adjusted according to the line voltage level, altitude, pollution level, icing conditions, or on-site installation errors. An arc-guiding voltage equalization assembly works in conjunction with the adjustable external series discharge gap assembly. It includes an arc-guiding edge structure that extends or offsets away from the shed sheath, causing the arc formed under lightning overvoltage to propagate away from the shed sheath. A limiting anti-sway assembly is connected between the suspended composite insulator body or its end hardware and the lightning protection discharge assembly or installation locking assembly. It limits the lateral or torsional displacement of the lightning protection discharge assembly relative to the suspended composite insulator body to maintain the stability of the external series discharge gap distance d.

[0010] Furthermore, the lightning protection and discharge assembly includes an insulating jacket, a metal oxide resistor array disposed inside the insulating jacket, conductive end caps disposed at both ends of the metal oxide resistor array, an elastic clamping element, a sealing element, and a lightning protection assembly skirt. The metal oxide resistor array is in a non-linear conducting state under the action of lightning overvoltage.

[0011] Furthermore, the lightning protection and discharge components are arranged in parallel, eccentrically, unilaterally, or symmetrically on both sides along the axial direction of the suspended composite insulator body, and there is a predetermined lateral distance between the lightning protection and discharge components and the suspended composite insulator body.

[0012] Furthermore, the main load-bearing path consists of, in sequence, a conductor, a suspension clamp or tension clamp, a lower fitting, an insulating core rod, an upper fitting, and a tower crossarm, with the lightning protection and discharge assembly located outside the main load-bearing path.

[0013] Furthermore, the adjustable external series discharge gap assembly includes a sliding groove, a positioning hole, a limiting tooth groove, a scale mark, and a locking component. The discharge electrode on the lightning protection side can move along the sliding groove and be locked in a preset position by the positioning hole, the limiting tooth groove, or the locking component to change the external series discharge gap distance d.

[0014] Furthermore, the scale markings include a base voltage level setting and an environmental correction setting. The base voltage level setting is used to indicate the recommended gap position corresponding to voltage levels of 35kV, 66kV, 110kV, and 220kV. The environmental correction setting is used to correct the recommended gap position based on altitude, pollution level, icing conditions, or on-site installation deviations.

[0015] Furthermore, the locking component includes one or more of the following: double nuts, spring washers, anti-loosening washers, toothed locking surfaces, anti-loosening pins, or anti-loosening pressure plates, which cooperate with the anti-loosening structure to prevent the discharge electrode on the lightning protection side from shifting position relative to the adjusting bracket under wind deflection, galloping, icing, or vibration conditions.

[0016] Furthermore, the arc-initiating electrode on the conductor side is one of a ball-shaped electrode, an arc-shaped electrode, a horn-shaped electrode, a ring-shaped electrode, or a rod-shaped electrode, and the discharge electrode on the lightning protection side is one of a ball-shaped electrode, a hemispherical electrode, a conical-spherical combination electrode, a bent rod-shaped electrode, or an arc-shaped arc-conducting electrode.

[0017] Furthermore, the arc guiding voltage equalization assembly also includes a first voltage equalization ring disposed near the upper fitting and a second voltage equalization ring disposed near the lower fitting. The arc guiding edge structure is located outside the discharge path between the arc-initiating electrode on the conductor side and the discharge electrode on the lightning protection side, and cooperates with the first voltage equalization ring, the second voltage equalization ring, the arc-initiating electrode on the conductor side or the discharge electrode on the lightning protection side to form an electric field equalization region, so that the local field strength at the outer series discharge gap is higher than the local field strength near the surface of the umbrella skirt sheath.

[0018] Furthermore, the limiting anti-sway component includes one or more of the following: an insulating limiting rod, a buffer pad, an anti-sway clamp, an elastic limiting component, or a flexible insulating pull strip. One end of the limiting anti-sway component is connected to the suspended composite insulator body or its end fittings, and the other end is connected to the lightning protection discharge component or the installation locking component. It is used to limit the variation range of the maximum lateral offset, maximum torsional angle, or external series discharge gap distance d of the lightning protection discharge component relative to the suspended composite insulator body.

[0019] Furthermore, the installation locking assembly includes one or more of the following: connecting clamp, insulating support arm, connecting ear plate, bolt tightening unit, clamp locking unit, limiting clamp, anti-loosening nut, anti-reverse washer or pre-tightening component. The lightning protection discharge assembly is a replaceable structure. After the installation locking assembly is loosened, the lightning protection discharge assembly can be disassembled without disassembling the suspended composite insulator body.

[0020] Furthermore, it also includes a status identification component, which is installed at the lightning protection discharge component, the installation locking component, or the grounding connection. The status identification component includes at least one of the following: a thermal disconnector, a mechanical flip-card indicator, a color indicator, an action counter, a remote status terminal, or a wireless status acquisition module, for displaying or remotely transmitting the lightning strike action, abnormal heating, internal damage, or failure status of the lightning protection discharge component.

[0021] This application has the following beneficial effects: Because the lightning protection and discharge assembly is mounted on one side of the suspended composite insulator body and is not located in the main load-bearing path of the conductor's mechanical suspension load, the tensile and bending effects caused by the conductor's self-weight, wind sway, icing load, and galloping impact are mainly borne by the suspended composite insulator body. The lightning protection and discharge assembly basically does not bear the above mechanical loads. Therefore, the risk of the lightning protection and discharge assembly deteriorating due to long-term stress, poor contact of the resistor element, or loosening of the connector is reduced, and the functional separation of the mechanical load path and the lightning discharge path is achieved.

[0022] Because of the adjustable external series discharge gap assembly, the distance d between the discharge electrode on the lightning protection side and the arc-starting electrode on the conductor side can be changed by moving the discharge electrode on the lightning protection side along the adjustable bracket. This allows the lightning impulse protection level to be adjusted according to the insulation coordination requirements of lines of different voltage levels, so that the lightning impulse protection level matches the power frequency insulation safety margin.

[0023] Furthermore, because the scale markings include basic voltage level settings and environmental correction settings, the recommended gap position can be corrected based on factors such as changes in air density at high altitudes, heavily polluted environments, icing conditions, and on-site installation deviations. This improves the on-site adaptability of high-voltage line lightning protection parameters.

[0024] Furthermore, since the arc equalization component is provided with an arc edge structure that extends or is offset away from the umbrella skirt sheath, and forms an electric field equalization region in cooperation with the first equalization ring and the second equalization ring, the local field strength at the outer series discharge gap is higher than the local field strength near the surface of the umbrella skirt sheath. Therefore, the discharge channel is preferentially formed at the outer series discharge gap, and the arc develops in the direction away from the umbrella skirt sheath, reducing the risk of umbrella skirt ablation and insulation degradation.

[0025] Furthermore, since the limiting anti-sway component is connected between the suspended composite insulator body and the lightning protection discharge component, it can limit the lateral and torsional displacement of the lightning protection discharge component under wind deflection, galloping, icing and vibration conditions. Therefore, the distance d of the external series discharge gap is kept within the preset error range, ensuring the stability of the preset lightning discharge path.

[0026] Furthermore, since the locking components enable detachable connections and the lightning protection discharge components are replaceable, modular replacement can be performed when the lightning protection discharge components are activated or fail, without disassembling the suspended composite insulator body. With the status recognition components, the corresponding status can be displayed or remote identification information can be transmitted after a lightning strike or fault, assisting inspection personnel in locating faulty towers and phases. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention installed at the suspension position of a high-voltage overhead transmission line; Figure 2 This is a schematic diagram of the structure of the suspended composite insulator body of the present invention; Figure 3 This is a cross-sectional structural diagram of the lightning protection and discharge assembly of the present invention; Figure 4 This is a schematic diagram of the adjustable external series discharge gap assembly of the present invention; Figure 5 This is a schematic diagram of the arc-guiding voltage equalization component of the present invention; Figure 6 This is a partially enlarged schematic diagram of the installation of the locking assembly and the limiting anti-sway assembly of the present invention; Figure 7 This is a schematic diagram of the lightning discharge state of a line when the lightning protection composite insulator of this invention is not installed; Figure 8 A schematic diagram of the lightning discharge state of the line after installing the lightning protection composite insulator of the present invention; Figure 9 This is a comparison diagram of the high-voltage line lightning protection mechanism and structural advantages of the present invention.

[0028] Reference numerals: 1. Suspended composite insulator body; 2. Insulating core rod; 3. Sheath; 4. Upper fitting; 5. Lower fitting; 6. Lightning protection discharge assembly; 7. Insulating outer jacket; 8. Metal oxide resistor assembly; 9. Conductive end cap; 10. Elastic clamping element; 11. Sealing element; 12. Lightning protection assembly sheath; 13. Adjustable external series discharge gap assembly; 14. Conductor-side arc-starting electrode; 15. Lightning protection-side discharge electrode; 16. Adjustable distance bracket; 17. Sliding groove; 18. Locking element; 19. Scale markings; 20. Arc-guiding voltage equalization assembly; 21. 22. First equalizing ring; 23. Second equalizing ring; 24. Guide arc edge structure; 25. Mounting and locking assembly; 26. Connecting clamp; 27. Insulating support arm; 28. Connecting ear plate; 29. ​​Bolt tightening unit; 30. Anti-loosening nut; 31. Status recognition assembly; 32. Thermal release device; 33. Mechanical flip-card indicator; 34. Action counter; 35. Remote status terminal; 36. Limiting and anti-sway assembly; 37. Insulating limiting rod; 38. Buffer pad; 39. Anti-sway clamp; 40. Conductor; 41. Tower crossarm; 42. Suspension clamp or tension clamp. Detailed Implementation

[0029] To make the technical problems, technical solutions and advantages of this application clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments.

[0030] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0031] like Figure 1 and Figure 2 As shown, the side-mounted adjustable gap lightning protection composite insulator of this application is installed between the conductor 39 and the crossarm 40 of the high-voltage overhead transmission line. The suspended composite insulator body 1 is connected to the crossarm 40, hanging ring or connecting plate of the tower through the upper hardware 4, and to the suspension clamp or tension clamp 41 through the lower hardware 5, thereby bearing the mechanical suspension load of the conductor 39 and the external insulation function to the ground. The suspended composite insulator body 1 includes an insulating core rod 2, a shed sheath 3 covering the outside of the insulating core rod 2, an upper hardware 4 set at the upper end of the insulating core rod 2, and a lower hardware 5 set at the lower end of the insulating core rod 2. The insulating core rod 2, as the main load-bearing component, is used to bear the mechanical load under conductor suspension, wind sway, icing, galloping and short-circuit electrodynamic forces. The shed sheath 3 covers the outside of the insulating core rod 2 and is used to form the creepage distance and pollution flashover resistance capability that meet the external insulation requirements of the high-voltage overhead transmission line. The upper fitting 4 is used to connect the tower crossarm 40, hanging ring, connecting plate, or other tower side fittings. The lower fitting 5 is used to connect the suspension clamp or tension clamp 41.

[0032] like Figure 3As shown, the lightning protection discharge assembly 6 is disposed on one side of the suspended composite insulator body 1, preferably in a side-mounted parallel arrangement. The lightning protection discharge assembly 6 includes an insulating jacket 7, a metal oxide resistor sheet group 8 disposed inside the insulating jacket 7, conductive end caps 9 disposed at both ends of the metal oxide resistor sheet group 8, an elastic clamping member 10, a sealing member 11, and a lightning protection assembly skirt 12. The metal oxide resistor sheet group 8 is stacked along the axial direction of the lightning protection discharge assembly 6, and is used to be in a non-linear conducting state under the action of lightning overvoltage to discharge lightning current and limit the overvoltage at both ends of the suspended composite insulator body 1. The lightning protection discharge assembly 6 is connected to the upper hardware 4, the tower crossarm 40, the crossarm connecting hardware, or the grounding connection member through the installation locking assembly 24, so that it forms an electrical connection with the grounding side of the tower, but it is not located on the main mechanical load path from the conductor 39 to the tower crossarm 40. Thus, the suspended composite insulator body 1 bears the main load of the conductor suspension, and the lightning protection discharge assembly 6 mainly undertakes the function of lightning current discharge. The lightning protection discharge assembly 6 can be side-mounted, eccentrically mounted, arranged on one side, or arranged symmetrically on both sides along the axial direction of the suspended composite insulator body 1, and there is a predetermined lateral distance between the lightning protection discharge assembly 6 and the suspended composite insulator body 1.

[0033] like Figure 4As shown, the adjustable external series discharge gap assembly 13 is disposed between the conductor-side hardware and the lightning protection discharge assembly 6. The adjustable external series discharge gap assembly 13 includes a conductor-side arc-starting electrode 14, a lightning protection-side discharge electrode 15, an adjustable distance bracket 16, a sliding groove 17, a positioning hole, a limiting tooth groove, a scale mark 19, a locking element 18, and an anti-loosening structure. The conductor-side arc-starting electrode 14 is fixed to the lower end hardware 5, a suspension clamp or a tension clamp 41, or the conductor-side hardware. The lightning protection-side discharge electrode 15 is electrically connected to the lower conductive end cap 9 of the lightning protection discharge assembly 6 and can move along the sliding groove 17 on the adjustable distance bracket 16 to change the external series discharge gap distance d between the conductor-side arc-starting electrode 14 and the lightning protection-side discharge electrode 15. During adjustment, first select the base voltage level setting based on the line's rated voltage, then select the environmental correction setting based on altitude, pollution level, icing conditions, or on-site installation deviations. Finally, fix the lightning protection side discharge electrode 15 in the set position using the positioning hole, limit tooth groove, locking element 18, and anti-loosening structure. The scale markings 19 include base voltage level settings and environmental correction settings. The base voltage level setting indicates the recommended gap position corresponding to 35kV, 66kV, 110kV, and 220kV voltage levels. The environmental correction setting is used to correct the recommended gap position based on altitude, pollution level, icing conditions, or on-site installation deviations. The locking element 18 includes one or more of the following: double nuts, spring washers, anti-rebound washers, toothed locking surfaces, anti-loosening pins, or anti-loosening pressure plates. These components, in conjunction with the anti-loosening structure, prevent the lightning protection side discharge electrode 15 from shifting relative to the adjusting bracket 16 under wind deflection, galloping, icing, or vibration conditions. The conductor-side arc-starting electrode 14 can be one of a ball-shaped electrode, an arc-shaped electrode, a horn-shaped electrode, a ring-shaped electrode, or a rod-shaped electrode, while the lightning protection-side discharge electrode 15 can be one of a ball-shaped electrode, a hemispherical electrode, a conical-spherical combination electrode, a bent rod-shaped electrode, or an arc-shaped arc-guided electrode.

[0034] During normal operation, the adjustable external series discharge gap assembly 13 remains in an insulated state, and the lightning protection discharge assembly 6 is not directly connected to the main load-bearing path of the conductor mechanical suspension. When the line is struck by lightning or a lightning overvoltage occurs, the external series discharge gap between the conductor-side arc-starting electrode 14 and the lightning protection-side discharge electrode 15 breaks down first. The lightning current enters the lightning protection discharge assembly 6 through the conductor 39, suspension clamp or tension clamp 41, conductor-side arc-starting electrode 14, external series discharge gap, and lightning protection-side discharge electrode 15, and is then discharged to the grounding side through the upper hardware 4, grounding connector, tower crossarm 40, or tower grounding system.

[0035] like Figure 5As shown, the arc-guiding voltage equalization assembly 20 includes a first voltage equalization ring 21, a second voltage equalization ring 22, and an arc-guiding edge structure 23. The first voltage equalization ring 21 is located near the upper fitting 4 and is used to improve the electric field distribution near the upper end of the suspended composite insulator body 1 and the upper end of the lightning protection discharge assembly 6. The second voltage equalization ring 22 is located near the lower fitting 5 and is used to improve the electric field distribution near the lower end of the suspended composite insulator body 1 and the conductor-side arc-guiding electrode 14. The arc-guiding edge structure 23 is located near the outer series discharge gap and extends or is offset away from the side away from the shed sheath 3. The arc-guiding edge structure 23 is located outside the discharge path between the conductor-side arc-initiating electrode 14 and the lightning protection-side discharge electrode 15. It works with the first equalizing ring 21, the second equalizing ring 22, the conductor-side arc-initiating electrode 14, or the lightning protection-side discharge electrode 15 to form an electric field equalization region. This makes the local field strength at the outer series discharge gap higher than the local field strength near the surface of the umbrella skirt sheath 3. As a result, under the action of lightning overvoltage, the induced discharge channel is preferentially formed at the outer series discharge gap, and the arc is guided away from the umbrella skirt sheath 3.

[0036] like Figure 6 As shown, the mounting and locking assembly 24 includes a connecting clamp 25, an insulating support arm 26, a connecting lug 27, a bolt tightening unit 28, and a lock nut 29. The connecting clamp 25 is used to fix the assembly to the upper hardware 4, the tower crossarm 40, or adjacent hanging point hardware. The insulating support arm 26 is used to support the lightning protection discharge assembly 6 and maintain its side-mounted position. The connecting lug 27 and the bolt tightening unit 28 are used to achieve a detachable connection. The lock nut 29 is used to resist loosening caused by long-term vibration. The mounting and locking assembly 24 may also include one or more of the following: a clamp locking unit, a limiting clamp, a backstop washer, or a pre-tightening component. The lightning protection discharge assembly 6 is a replaceable structure; the lightning protection discharge assembly 6 can be disassembled after the mounting and locking assembly 24 is loosened without disassembling the suspended composite insulator body 1.

[0037] The anti-sway limiting component 35 is disposed between the suspended composite insulator body 1 and the lightning protection discharge component 6, and includes an insulating limiting rod 36, a buffer pad 37, and an anti-sway clamp 38. The anti-sway limiting component 35 may also include one or more of an elastic limiting element or a flexible insulating pull strip. One end of the anti-sway limiting component 35 is connected to the suspended composite insulator body 1 or its end fittings, and the other end is connected to the lightning protection discharge component 6 or the mounting locking component 24. Under conditions of line wind deflection, conductor galloping, uneven icing, or vibration, the anti-sway limiting component 35 can limit the lateral swing and torsional displacement of the lightning protection discharge component 6 relative to the suspended composite insulator body 1, and limit the variation range of the maximum lateral displacement, the maximum torsional angle, or the external series discharge gap distance d, so that the external series discharge gap distance d is kept within a preset error range under conditions of wind deflection, galloping, icing, or vibration.

[0038] The status identification component 30 can be installed at the top, side, or grounding connection of the surge protection and discharge component 6, and includes a thermal disconnector 31, a mechanical flip-card indicator 32, an action counter 33, and a remote status terminal 34. The status identification component 30 may also include at least one of a color indicator or a wireless status acquisition module. When the surge protection and discharge component 6 experiences a lightning strike, continuous abnormal current, internal moisture damage, or thermal failure, the thermal disconnector 31 can trigger the mechanical flip-card indicator 32 or the color indicator to activate. The action counter 33 records the number of actions. The remote status terminal 34 can be connected to an online monitoring system, enabling inspection personnel to identify actions and fault states through ground inspections, drone inspections, or remote platforms.

[0039] like Figure 9 As shown, the structural advantage of this application lies in the coordinated separation of the three paths. Without this application, lightning overvoltages can easily form random flashovers along the surface of the composite insulator skirt sheath 3, with the arc close to the skirt sheath 3 and the end fittings, posing a risk of skirt ablation and insulation degradation. With this application, the mechanical load path is borne by the conductor 39, suspension clamp or tension clamp 41, lower end fitting 5, insulating core rod 2, upper end fitting 4, and tower crossarm 40, with the lightning protection discharge assembly 6 located outside this path. The lightning discharge path is borne by the conductor-side arc-initiating electrode 14, the external series discharge gap, the lightning protection-side discharge electrode 15, the lightning protection discharge assembly 6, and the grounding connector. The arc guiding path is controlled by the arc-equalizing assembly 20, causing the arc to develop from the external series discharge gap to the side away from the skirt sheath 3.

[0040] Example 1: Application of suspension string lightning protection for 110kV high-voltage overhead transmission lines In this embodiment, the suspended composite insulator body 1 is installed between the crossarm 40 and the conductor 39 of the 110kV line tower. The lightning protection discharge assembly 6 is installed side-mounted in parallel along one side of the suspended composite insulator body 1. During construction, the suspended composite insulator body 1 is installed first, so that it forms the main load-bearing path for the mechanical suspension of the conductor through the upper hardware 4 and the lower hardware 5; then, the lightning protection discharge assembly 6 is fixed to the upper hardware 4, the crossarm connecting hardware, or the grounding connection near the locking assembly 24, so that the lightning protection discharge assembly 6 forms an electrical connection with the grounding side of the tower. When installing the adjustable external series discharge gap assembly 13, the conductor-side arc-starting electrode 14 is fixed to the lower hardware 5, the suspension clamp, or the conductor-side hardware, and the lightning protection-side discharge electrode 15 is electrically connected to the lower conductive end cap 9 of the lightning protection discharge assembly 6. When adjusting the distance d of the external series discharge gap, the base voltage level is selected based on the insulation coordination requirements of the 110kV line, and the environmental correction level is selected in conjunction with the site altitude, pollution level, icing conditions, and installation deviation. Then, the locking element 18 is tightened and the anti-loosening structure is checked. During operation, when the line is struck by lightning or experiences a lightning overvoltage, the external series discharge gap breaks down preferentially. The lightning current enters the lightning protection discharge assembly 6 along the preset lightning discharge path and is discharged to the grounding side of the tower. The arc equalization component 20 keeps the arc away from the umbrella skirt sheath 3, and the limiting anti-sway component 35 restricts the swaying of the lightning protection discharge assembly 6, keeping the distance d of the external series discharge gap stable.

[0041] Example 2: Lightning protection application at the suspension point of tension string or jumper for 220kV high-voltage overhead transmission lines In this embodiment, the suspended composite insulator body 1 can be configured with appropriate length, creepage distance, and end fitting structure according to the insulation level and mechanical load requirements of the 220kV line. The lightning protection discharge assembly 6 can be a metal oxide resistor sheet group 8 adapted to the lightning energy absorption requirements of the 220kV line, and is side-mounted on one side of the suspended composite insulator body 1 by the installation locking assembly 24. The adjustable external series discharge gap assembly 13 is configured with a larger basic gap adjustment range through the sliding groove 17, positioning hole, limiting tooth groove, and scale mark 19, and is modified according to environmental conditions such as high altitude, icing, or heavy pollution. The first equalizing ring 21, the second equalizing ring 22, and the arc guiding edge structure 23 of the arc guiding voltage equalizing assembly 20 can be configured in position and size according to the electric field distribution requirements at the end of the 220kV line to ensure that the external series discharge gap breaks down preferentially and guides the arc away from the umbrella skirt sheath 3. At the suspension point of the tension string or jumper, conductor swing, jumper swing and wind deflection may cause relative displacement of the external lightning protection structure. The limiting anti-sway component 35 limits the lateral and torsional displacement of the lightning protection discharge component 6 through the insulating limiting rod 36, buffer pad 37 or anti-sway clamp 38, so that the distance d of the external series discharge gap is kept within the preset error range.

[0042] Example 3: Lightning protection upgrade of high-voltage lines with status recognition and modular replacement functions This embodiment is applicable to lightning protection upgrades in areas with frequent lightning strikes, mountainous lines, heavily polluted lines, or important transmission channels. The lightning protection discharge component 6 adopts a replaceable structure and is fixed to one side of the suspended composite insulator body 1 by the installation locking component 24. During the upgrade, it is not necessary to change the main load-bearing path of the suspended composite insulator body 1 that bears the mechanical suspension load of the conductor; only the lightning protection discharge component 6, the adjustable external series discharge gap component 13, the arc guiding voltage equalization component 20, and the limiting anti-sway component 35 need to be added to its side. When the status identification component 30 displays a lightning strike action, thermal detachment, or fault status, maintenance personnel can determine the faulty tower and phase through ground inspection, drone inspection, or remote information transmission. During replacement, the lightning protection discharge component 6 can be disassembled and a new module replaced by loosening the installation locking component 24; there is no need to completely disassemble the suspended composite insulator body 1. The status identification component 30 serves as an auxiliary operation and maintenance structure, without altering the core technical solution of this application, which achieves three-path separation and coordinated control through side-mounted non-main load-bearing arrangement, adjustable external series discharge gap, directional arc equalization and limit anti-sway.

[0043] In this application, the suspended composite insulator body 1 bears the entire mechanical suspension load of the conductor 39, while the lightning protection discharge component 6 is side-mounted and does not bear this load; the adjustable external series discharge gap component 13 provides an adjustable external series discharge gap distance d, which, together with the arc guiding voltage equalization component 20, directs the arc away from the umbrella skirt sheath 3; the limiting anti-sway component 35 maintains a stable gap distance under wind deflection, galloping, icing, and vibration conditions; the installation locking component 24 and the status recognition component 30 facilitate modular replacement and post-lightning strike inspection and positioning. The above components work together to achieve the separation and stable control of the mechanical load path, the lightning discharge path, and the arc guiding path.

[0044] The above description is the preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principles described in this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A side-mounted adjustable gap lightning protection composite insulator for high-voltage overhead transmission lines, installed between the conductor and the crossarm of the tower, characterized in that... include: The suspended composite insulator body (1) includes an insulating core rod (2), a shed sheath (3) covering the outside of the insulating core rod (2), an upper end fitting (4) set at the upper end of the insulating core rod (2), and a lower end fitting (5) set at the lower end of the insulating core rod (2). The suspended composite insulator body (1) is connected between the conductor and the tower crossarm, forming the main load-bearing path for the mechanical suspension load of the conductor. The lightning protection discharge assembly (6) is mounted on one side of the suspended composite insulator body (1) and connected to the upper hardware (4), tower crossarm (40), crossarm connecting hardware or grounding connector by means of the installation locking assembly (24). The lightning protection discharge assembly (6) is located outside the main load-bearing path of the mechanical suspension load of the conductor. An adjustable external series discharge gap assembly (13) is disposed between the conductor-side fittings and the lightning protection discharge assembly (6), including a conductor-side arc-starting electrode (14), a lightning protection-side discharge electrode (15), and an adjustable distance bracket (16). An external series discharge gap distance d is formed between the conductor-side arc-starting electrode (14) and the lightning protection-side discharge electrode (15). The external series discharge gap distance d can be adjusted according to the line voltage level, altitude, pollution level, icing conditions, or on-site installation error. The arc equalization assembly (20) is configured in conjunction with the adjustable external series discharge gap assembly (13), and includes an arc edge structure (23). The arc edge structure (23) extends or is offset toward the side away from the umbrella skirt sheath (3), so that the arc formed under the action of lightning overvoltage develops in the direction away from the umbrella skirt sheath (3). The limiting anti-sway component (35) is connected between the suspended composite insulator body (1) or its end fittings and the lightning protection discharge component (6) or the mounting locking component (24) to limit the lateral or torsional offset of the lightning protection discharge component (6) relative to the suspended composite insulator body (1) in order to maintain the stability of the external series discharge gap distance d.

2. The side-mounted adjustable gap lightning protection composite insulator according to claim 1, characterized in that, The lightning protection and discharge assembly (6) includes an insulating jacket (7), a metal oxide resistor sheet group (8) disposed inside the insulating jacket (7), conductive end caps (9) disposed at both ends of the metal oxide resistor sheet group (8), an elastic clamping member (10), a sealing member (11), and a lightning protection assembly skirt (12). The metal oxide resistor sheet group (8) is in a non-linear conducting state under the action of lightning overvoltage.

3. The side-mounted adjustable gap lightning protection composite insulator according to claim 1, characterized in that, The lightning protection discharge assembly (6) is arranged in parallel, eccentrically, on one side, or symmetrically on both sides along the axial direction of the suspended composite insulator body (1), and there is a predetermined lateral distance between the lightning protection discharge assembly (6) and the suspended composite insulator body (1).

4. The side-mounted adjustable gap lightning protection composite insulator according to claim 1, characterized in that, The main load-bearing path consists of conductor (39), suspension clamp or tension clamp (41), lower end fitting (5), insulating core rod (2), upper end fitting (4) and tower crossarm (40), and the lightning protection discharge assembly (6) is located outside the main load-bearing path.

5. The side-mounted adjustable gap lightning protection composite insulator according to claim 1, characterized in that, The adjustable external series discharge gap assembly (13) includes a sliding groove (17), a positioning hole, a limiting tooth groove, a scale mark (19), and a locking member (18). The lightning protection side discharge electrode (15) can move along the sliding groove (17) and be locked in a preset position by the positioning hole, the limiting tooth groove, or the locking member (18) to change the distance d of the external series discharge gap.

6. The side-mounted adjustable gap lightning protection composite insulator according to claim 5, characterized in that, The scale markings (19) include a base voltage level setting and an environmental correction setting. The base voltage level setting is used to indicate the recommended gap position corresponding to voltage levels of 35kV, 66kV, 110kV, and 220kV. The environmental correction setting is used to correct the recommended gap position according to altitude, pollution level, icing conditions, or on-site installation deviation.

7. The side-mounted adjustable gap lightning protection composite insulator according to claim 5, characterized in that, The locking component (18) includes one or more of the following: double nuts, spring washers, anti-loosening washers, toothed locking surfaces, anti-loosening pins, or anti-loosening pressure plates, which cooperate with the anti-loosening structure to prevent the lightning protection side discharge electrode (15) from shifting position relative to the adjusting bracket (16) under wind deflection, galloping, icing, or vibration conditions.

8. The side-mounted adjustable gap lightning protection composite insulator according to claim 5, characterized in that, The conductor-side arc-starting electrode (14) is one of a ball-head electrode, an arc-shaped electrode, a horn-shaped electrode, a ring electrode, or a rod-shaped electrode, and the lightning protection-side discharge electrode (15) is one of a ball-shaped electrode, a hemispherical electrode, a conical-spherical combination electrode, a bent rod-shaped electrode, or an arc-shaped arc-guided electrode.

9. The side-mounted adjustable gap lightning protection composite insulator according to claim 1, characterized in that, The arc equalization assembly (20) further includes a first equalization ring (21) disposed near the upper fitting (4) and a second equalization ring (22) disposed near the lower fitting (5). The arc edge structure (23) is located outside the discharge path between the conductor-side arc-initiating electrode (14) and the lightning protection-side discharge electrode (15), and forms an electric field equalization region in conjunction with the first equalization ring (21), the second equalization ring (22), the conductor-side arc-initiating electrode (14) or the lightning protection-side discharge electrode (15), so that the local field strength at the outer series discharge gap is higher than the local field strength near the surface of the umbrella skirt sheath (3).

10. The side-mounted adjustable gap lightning protection composite insulator according to claim 1, characterized in that, The limiting anti-sway component (35) includes one or more of the following: an insulating limiting rod (36), a buffer pad (37), an anti-sway clamp (38), an elastic limiting component, or a flexible insulating pull strip. One end of the limiting anti-sway component (35) is connected to the suspended composite insulator body (1) or its end fittings, and the other end is connected to the lightning protection discharge component (6) or the installation locking component (24). It is used to limit the maximum lateral offset, maximum torsional angle, or variation range of the external series discharge gap distance d of the lightning protection discharge component (6) relative to the suspended composite insulator body (1).

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