Lightning protection overhead insulated cable

Abstract

The invention provides a lightning-proof overhead insulated cable, which relates to the technical field of insulated cables and comprises an insulated cable mechanism, an outer protection mechanism and a mounting mechanism. The insulated cable mechanism comprises an outer sheath, a first insulation sleeve, a second insulation sleeve, a buffer strip, a first insulation filling material, a flame-retardant sleeve, an inner sheath, an extrusion strip, a wire core body, a steel core strip and a second insulation filling material, the inner wall of the outer sheath is connected with the outer wall of the first insulation sleeve, and the second insulation sleeve is arranged on the inner wall of the first insulation sleeve. According to the invention, high-performance basic protection is provided through the insulated cable mechanism, adjustable enhancement and lightning protection functions are realized through the outer protection mechanism, wire clamp fixation, outer protection connection and grounding discharge are completed through the installation mechanism, and the lightning protection capability, the structural stability and the installation and maintenance convenience of the overhead insulated cable are remarkably improved through the synergistic effect of the three parts.

Description

A lightning-proof overhead insulated cable Technical Field

[0001] This invention relates to the field of insulated cable technology, and in particular to a lightning-proof overhead insulated cable. Background Technology

[0002] Overhead insulated cables refer to overhead conductors with an added insulation layer and protective sheath. They combine the advantages of traditional bare overhead conductors and underground power cables. Due to their high power supply reliability, good safety, and small space occupation, they have been widely used in urban power distribution networks, rural power grid renovation, and various overhead transmission lines. Compared with traditional bare overhead conductors, overhead insulated cables, through the outer insulation layer, effectively reduce phase-to-phase short-circuit faults caused by factors such as tree contact or foreign object contact, significantly improving power supply safety. They can also be installed on existing poles, or even along walls or through bushes, offering advantages such as convenient installation and maintenance, and lower overall cost.

[0003] However, overhead insulated cables face two major technical challenges during long-term operation: First, there is the problem of lightning strikes causing wire breakage. Because the outer layer of the cable is covered with insulating material, lightning current cannot be discharged through the surface of the insulator like bare conductors during a lightning strike. This leads to the accumulation of lightning overvoltage. When the voltage exceeds the insulation layer's withstand strength, it will cause the insulation layer to break down and trigger a power frequency follow current arc that burns out the conductor. Statistics show that its lightning strike breakage rate is much higher than that of bare conductors of the same voltage level. Second, there is the problem of wear at the fixing points. Overhead cables are suspended from poles or building supports by fixing devices such as hooks, clamps, and binding wires. During long-term operation, they are affected by factors such as wind vibration, thermal expansion and contraction, and conductor creep. Continuous friction occurs between the cable sheath and the fixing device at the fixing points, causing the sheath to gradually wear down and become thinner. In severe cases, the internal insulation layer or even the conductor may be exposed, leading to leakage or short circuit faults. In existing technologies, lightning protection typically employs parallel surge arresters, external arc-proof hardware, or current-conducting grooves in the insulation layer. However, these methods suffer from drawbacks such as high cost, fixed installation locations, and inability to adapt to on-site adjustments. Wear at fixed points is mitigated by increasing the sheath wall thickness, wrapping protective tape, or using wear-resistant materials. However, these methods are often cumbersome to operate, prone to aging and detachment, and cannot achieve long-term reliable protection. Summary of the Invention

[0004] To address the technical problems of existing overhead insulated cables, such as insufficient lightning protection, high lightning breakage rate, easy wear of sheaths at fixing points, and complex installation of existing lightning protection devices that cannot simultaneously provide local reinforcement and lightning protection functions, this invention provides a lightning-proof overhead insulated cable.

[0005] The technical solution provided by this invention is as follows: This invention provides a lightning-proof overhead insulated cable, comprising an insulated cable mechanism, an outer sheath mechanism, and an installation mechanism; the insulated cable mechanism includes an outer sheath, a first insulating sleeve, a second insulating sleeve, a buffer strip, a first insulating filler material, a flame-retardant sleeve, an inner sheath, an extrusion strip, a conductor body, a steel core strip, and a second insulating filler material; the inner wall of the outer sheath is connected to the outer wall of the first insulating sleeve, the inner wall of the first insulating sleeve is provided with a second insulating sleeve, the inner wall of the second insulating sleeve is connected to the outer wall of the flame-retardant sleeve, the inner wall of the flame-retardant sleeve is connected to the outer wall of the inner sheath, and the inner wall of the inner sheath is connected to a conductor body; the inner wall of the inner sheath is also connected to... The outer sheath mechanism includes a steel core bar; it comprises a spiral bar, an inner liner bar, slip rings, sliding balls, mounting rings, and mounting blocks; there are two sets of the outer sheath mechanism, which are fitted onto the outer wall of the insulated cable mechanism; the inner wall of the spiral bar is connected to the inner liner bar, and both ends of the spiral bar are connected to slip rings. Sliding balls are circumferentially embedded on one side of the inner wall of each slip ring, and mounting rings are connected to one end of each slip ring. Mounting blocks are connected to both the upper and lower ends of each mounting ring; the mounting mechanism includes a first retaining ring, a second retaining ring, a pressure ring, a pressure block, mounting bolts, a sealing gasket, and an anti-friction ring; the mounting mechanism is installed between the two sets of outer sheath mechanisms and is used to connect the two sets of outer sheath mechanisms.

[0006] The beneficial effects of the technical solution provided by the embodiments of the present invention include at least the following: the insulated cable mechanism achieves high-performance basic protection for the cable body; the outer sheath resists environmental erosion; the first and second insulating sleeves constitute double main insulation; the buffer strip absorbs impact energy through elastic deformation when subjected to external force, preventing the insulation layer from cracking; the flame-retardant sleeve self-extinguishes when exposed to fire, improving fire safety; the extrusion strip isolates the wire cores from each other, avoiding contact short circuits; the steel core strip forms a high tensile strength reinforcing core, making the sag smaller when erected with large spans; and the filling material wraps the internal components into a whole, ensuring insulation and preventing wear.

[0007] The high-strength aluminum alloy strip in the inner layer of the spiral improves the bending and compressive strength at the fixing point, effectively preventing cable damage due to wind vibration or long-term stress. The outer layer of semi-conductive polymer material can evenly distribute the electric field around the fixing point during lightning overvoltage, avoiding excessive electric field concentration that could lead to insulation breakdown, thus significantly reducing the probability of lightning flashover. The inner lining strip is pre-coated with a water-soluble temporary lubricating layer, enabling it to slide when wet and self-lock after drying. It provides high-friction fixing when dry, and forms a lubricating interface after water spraying, allowing it to slide easily to the predetermined position. After the water evaporates, it returns to high-friction permanent fixing, allowing the outer sheath mechanism to be flexibly adjusted according to the site distance. When the span is large, multiple sets can be arranged sequentially. Slip rings and sliding balls ensure smooth movement and precise positioning.

[0008] Using the installation mechanism as a fixed base, the clamps can be directly fixed to the outside of the installation mechanism, realizing the connection of the outer protective mechanism, cable fixing, and lightning protection grounding. The first and second clamping rings clamp the cable in half, which can be fixed by the clamps. The anti-friction ring prevents the cable from being scratched, and the sealing gasket is corrosion-resistant. The two outer protective mechanisms are connected by pressing the installation ring with the pressure ring. The pressure block and the installation block are bolted together, with balanced force and no loosening. The installation block is made of metal, which can be easily connected to the pole grounding wire, providing a safe discharge channel for lightning current and further ensuring the safety of the line. Multiple sets of outer protective mechanisms maintain structural continuity through a shared installation mechanism, ensuring the integrity of the protection at the fixed points of the entire line. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 is a schematic diagram of the overall structure of a lightning protection overhead insulated cable provided in an embodiment of the present invention.

[0011] Figure 2 is a schematic diagram of the insulation cable mechanism of an overhead insulated cable for lightning protection provided in an embodiment of the present invention.

[0012] Figure 3 is a schematic diagram of the connection structure between the two outer sheath mechanisms and the installation mechanism of a lightning protection overhead insulated cable provided in an embodiment of the present invention.

[0013] Figure 4 is a schematic diagram of the structure of two outer sheaths of a lightning protection overhead insulated cable wound around the outer wall of the insulated cable mechanism according to an embodiment of the present invention.

[0014] Figure 5 is a schematic diagram of the outer sheath mechanism of a lightning protection overhead insulated cable provided in an embodiment of the present invention.

[0015] Figure 6 is a cross-sectional view of two slip rings of an overhead insulated cable for lightning protection provided in an embodiment of the present invention.

[0016] Figure 7 is a structural diagram of an installation mechanism for a lightning protection overhead insulated cable provided in an embodiment of the present invention.

[0017] Figure 8 is a cross-sectional view of an installation mechanism for a lightning protection overhead insulated cable provided in an embodiment of the present invention.

[0018] Reference numerals: 1. Insulated cable mechanism; 101. Outer sheath; 102. First insulating sleeve; 103. Second insulating sleeve; 104. Buffer strip; 105. First insulating filler material; 106. Flame-retardant sleeve; 107. Inner sheath; 108. Extrusion strip; 109. Core body; 110. Steel core strip; 111. Second insulating filler material; 2. Outer sheath mechanism; 201. Spiral strip; 202. Inner lining strip; 203. Slip ring; 204. Sliding ball; 205. Mounting ring; 206. Mounting block; 3. Mounting mechanism; 301. First retaining ring; 302. Second retaining ring; 303. Pressure ring; 304. Pressure block; 305. Mounting bolt; 306. Sealing gasket; 307. Anti-friction ring.

[0019] As shown in the figure, specific structures and devices are marked in the figure to clearly illustrate the structure of the embodiments of the present invention. However, this is only for illustrative purposes and is not intended to limit the present invention to this specific structure, device and environment. Those skilled in the art can adjust or modify these devices and environments according to specific needs. Detailed Implementation

[0020] The technical solutions of the present invention will now be described with reference to the accompanying drawings. It should be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some well-known technologies. Furthermore, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0021] As shown in Figures 1 to 8, an embodiment of the present invention provides a lightning protection overhead insulated cable, including an insulated cable mechanism 1, an outer sheath mechanism 2, and an installation mechanism 3. The insulated cable mechanism 1 includes an outer sheath 101, a first insulating sleeve 102, a second insulating sleeve 103, a buffer strip 104, a first insulating filler material 105, a flame-retardant sleeve 106, an inner sheath 107, an extrusion strip 108, a conductor body 109, a steel core strip 110, and a second insulating filler material 111. The inner wall of the outer sheath 101 is connected to the outer wall of the first insulating sleeve 102. The inner wall of the first insulating sleeve 102 is provided with the second insulating sleeve 103. The inner wall of the second insulating sleeve 103 is connected to the outer wall of the flame-retardant sleeve 106. The inner wall of the flame-retardant sleeve 106 is connected to the outer wall of the inner sheath 107. The inner sheath 107 is connected to the wire core body 109, and the inner wall of the inner sheath 107 is connected to the steel core strip 110. The outer sheath mechanism 2 includes a spiral strip 201, an inner lining strip 202, a slip ring 203, a sliding ball 204, a mounting ring 205, and a mounting block 206. There are two sets of outer sheath mechanisms 2, which are fitted onto the outer wall of the insulated cable mechanism 1. The inner wall of the spiral strip 201 is connected to the inner lining strip 202. Both ends of the spiral strip 201 are connected to slip rings 203. The two slip rings 203 are respectively fitted onto the outer wall of the outer sheath 101. A sliding ball 204 is circumferentially embedded on one side of the inner wall of the slip ring 203. One end of the two slip rings 203 is connected to the mounting ring 205. The upper and lower ends of the mounting ring 205 are connected to the mounting block 206. The mounting mechanism 3 includes a first retaining ring 301 and a second retaining ring 306. 02, pressure ring 303, pressure block 304, mounting bolt 305, sealing gasket 306, and anti-friction ring 307; It should be noted that the insulated cable mechanism 1, as the cable body, achieves insulation, buffering, flame retardancy, and tensile reinforcement through a multi-layer structure. The outer sheath 101 is made of weather-resistant material to protect the interior from ultraviolet radiation and environmental corrosion. The first insulating sleeve 102 and the second insulating sleeve 103 together provide reliable main insulation. The six buffer strips 104 sandwiched between them are made of elastic rubber composite material, which can absorb mechanical stress when the cable is squeezed or bent, prevent damage to the insulation layer, and fix the position of the buffer strips 104 through the first insulating filler material 105 to ensure structural stability. The flame-retardant sleeve 106 is in close contact with the inner wall of the second insulating sleeve 103 and is made of halogen-free material. The flame-retardant polyolefin is self-extinguishing when exposed to fire, preventing the spread of flames. The inner sheath 107 encloses the core area, and the four core bodies 109 are separated by four inclined extrusion strips 108 inside, preventing short circuits caused by contact between the cores. At the same time, the inclined sides of the extrusion strips 108 can accommodate the slight displacement of the cores, providing a buffer. Five steel core strips 110 are twisted together at the center, which greatly improves the overall tensile strength of the cable and is suitable for long-span overhead laying. The second insulating filler material 111 fills all the gaps inside the inner sheath 107 to ensure the relative fixation and insulation of the cores and steel cores. The outer sheath mechanism 2 is sleeved on the outside of the insulated cable mechanism 1. The spiral strips 201 of each set of outer sheath mechanism 2 wrap around the cable, and the inner lining strips 202 on its inner wall are in contact with the cable outer sheath 101.Spiral strip 201 consists of an inner high-strength aluminum alloy reinforcing core and an outer semi-conductive polymer material coating layer. The main function of this semi-conductive layer is to uniformly fix the electric field near the point of lightning overvoltage when it acts on the cable, avoiding excessive electric field concentration that could lead to insulation breakdown, thereby reducing the risk of lightning-induced wire breakage. Slip ring 203 is fitted onto the cable and is a metal conductive joint made of copper or galvanized steel. The sliding balls 204 on its inner wall allow the outer sheath mechanism 2 to move along the cable axial direction. The cable is easily movable and can be adjusted to a predetermined fixing point during installation. The mounting ring 205 and mounting block 206 are used to connect to the mounting mechanism 3. The mounting mechanism 3 connects the two sets of outer protective mechanisms 2 and fixes them to the cable. The first retaining ring 301 and the second retaining ring 302 combine to form a ring to clamp the cable. The anti-friction ring 307 on the inner wall prevents damage to the cable surface, and the sealing gasket 306 ensures a waterproof seal at the connection point. This achieves a combination of high-performance cable body and adjustable external protection, significantly improving the overhead cable's lightning protection capability and the durability of the fixing point.

[0022] There are six buffer strips 104, which are distributed around the outer wall of the second insulating sleeve 103. The six buffer strips 104 are located inside the first insulating sleeve 102 and the second insulating sleeve 103. The first insulating filler material 105 is connected to the outer wall of the six buffer strips 104 between the first insulating sleeve 102 and the second insulating sleeve 103. It should be noted that the six buffer strips 104 are evenly distributed circumferentially between the outer wall of the second insulating sleeve 103 and the inner wall of the first insulating sleeve 102, forming a cage-like support structure. When the cable is subjected to external pressure or bending, the buffer strips 104 undergo elastic deformation to absorb impact energy and prevent stress concentration from causing the insulation layer to break. At the same time, the even distribution ensures that the cable has consistent compressive strength in all directions. The first insulating filler material 105 fills the area around the buffer strips 104, firmly embedding the buffer strips 104 between the first and second insulating sleeves 103, preventing them from shifting or falling off during long-term operation, and ensuring the durability of the buffering effect.

[0023] There are four extrusion strips 108, with their sides angled. Each strip connects to the inner wall of the inner sheath 107. There are also four conductor bodies 109. The four extrusion strips 108 compress the conductor bodies 109, preventing them from contacting each other. The four extrusion strips 108 extend in a cross shape towards the center, using the inner wall of the inner sheath 107 as a base. Their angled sides abut against the outer edges of the conductor bodies 109. The extrusion strips 108 are made of elastic rubber composite material, possessing flexibility to adapt to minute displacements of the conductor while maintaining positioning pressure and preventing contact. The angled design allows the extrusion strips 108 to generate an inward component force when the conductor is subjected to radial force, more stably constraining the conductor to a predetermined position. This isolation method avoids the risk of insulation breakdown between conductors and eliminates the need for additional insulating partitions, simplifying the internal structure and improving space utilization.

[0024] There are five steel core bars 110, which are twisted together to improve the overall strength of the insulated cable mechanism 1. The inner sheath 107 is filled with a second insulating filler material 111 at the outside of the four extrusion bars 108, the four conductor bodies 109, and the five steel core bars 110. It should be noted that the five steel core bars 110 are twisted together to form a central reinforcing core, which can withstand the long-term tension and wind vibration of the overhead line. The second insulating filler material 111 tightly fills all the gaps in the inner sheath 107, wrapping the conductor bodies 109, the extrusion bars 108, and the steel core bars 110 into a whole, which not only provides insulation and isolation but also prevents friction caused by relative movement of internal components.

[0025] The first insulating sleeve 102 and the second insulating sleeve 103 are made of cross-linked polyethylene material; the first insulating filler material 105 and the second insulating filler material 111 are made of flame-retardant polypropylene foam material; the buffer strip 104 and the extrusion strip 108 are made of rubber composite material; the flame-retardant sleeve 106 is made of halogen-free flame-retardant polyolefin material. It should be noted that cross-linked polyethylene has excellent insulation resistance, heat resistance and anti-aging ability; the flame-retardant polypropylene foam material has low density, good insulation and is not easily burned when exposed to fire. After filling, it can reduce the weight of the cable and provide auxiliary flame retardancy. The buffer strip 104 and the extrusion strip 108 have high elasticity and fatigue resistance, ensuring the buffering effect under long-term dynamic load. The flame-retardant sleeve 106 is wrapped inside the insulation layer. Even if the outer sheath 101 is ignited, the flame-retardant sleeve 106 can prevent the flame from spreading inward, protect the integrity of the conductor, and improve the power supply reliability in the event of a fire.

[0026] Spiral bar 201 is made of a multi-layer composite structure, including an inner reinforcing core material and an outer functional coating layer. The reinforcing core material is a high-strength aluminum alloy strip, which provides mechanical reinforcement. The functional coating layer is made of a semi-conductive polymer material, which is used to uniformly distribute the electric field under lightning overvoltage and achieve lightning protection. It should be noted that the inner layer of spiral bar 201 is made of high-strength aluminum alloy strip, which is lightweight and high-strength. When wrapped around the outside of the cable, it can significantly improve the bending and compressive strength at the fixing point and prevent fatigue damage to the cable under long-term wind vibration. The semi-conductive layer can guide the lightning current to the two-end installation mechanism 3 and discharge it to the ground through the grounding device, thereby protecting the main insulation of the cable.

[0027] The inner liner 202 is made of a water-activated lubricating coating, and its inner surface has a temporary lubricating layer. In a dry state, this temporary lubricating layer has a sufficient coefficient of friction to maintain the relative fixation of the spiral strip 201 and the insulated cable mechanism 1. Upon contact with water, it dissolves to form a lubricating interface, reducing sliding friction and facilitating the movement and adjustment of the spiral strip 201 along the cable axis. After the water evaporates, the lubricating layer disappears, and the inner liner 202 directly contacts the cable outer sheath 101, restoring a high-friction state and achieving tight fixation. It should be noted that the inner liner 202 uses water-soluble materials such as polyvinyl alcohol, and its inner surface is pre-coated with a very thin temporary lubricating layer. Before cable installation, the spiral strip 201 can maintain its relative position with the cable by utilizing the dry, high-friction properties of the lubricating layer, preventing it from shifting during transportation. During on-site installation, construction personnel only need to wipe it with a damp cloth or spray a small amount of water onto the spiral strip 201. The temporary lubricating layer quickly dissolves, forming a water film lubrication interface between the inner liner strip 202 and the cable outer sheath 101. The coefficient of friction drops sharply, allowing the spiral strip 201 to easily slide along the cable to the predetermined fixing point. After adjustment, as the water evaporates naturally, the lubricating layer completely disappears, and the inner liner strip 202 directly contacts the cable outer sheath 101, achieving permanent and tight fixing by relying on the material's own high coefficient of friction.

[0028] The mounting mechanism 3 is installed between the two sets of outer sheath mechanisms 2. The mounting mechanism 3 connects the two sets of outer sheath mechanisms 2. Both the first retaining ring 301 and the second retaining ring 302 are arc-shaped, forming a complete ring. The first retaining ring 301 and the second retaining ring 302 are engaged with the outer wall of the insulated cable mechanism 1. Anti-friction rings 307 are connected to the inner walls of both the first retaining ring 301 and the second retaining ring 302. Multiple anti-friction rings 307 are connected to the outer wall of the insulated cable mechanism 1. Sealing gaskets 306 are connected to the upper and lower parts of one side of the first retaining ring 301 and the other side of the second retaining ring 302. Two sealing gaskets 306 contact each other to seal the connection between the first retaining ring 301 and the second retaining ring 302. It should be noted that the mounting mechanism 3, as a component connecting the two sets of outer sheath mechanisms 2, allows the first retaining ring 301 and the second retaining ring 302 to be easily fastened onto the cable on-site. After assembly, they are tightened with bolts. The inner wall anti-friction ring 307 is made of wear-resistant polymer material and is in direct contact with the cable outer sheath 101 to prevent the cable from being scratched when the first retaining ring 301 and the second retaining ring 302 slide. At the same time, the anti-friction ring 307 has a certain degree of elasticity, which can compensate for the small gaps between the first retaining ring 301 and the second retaining ring 302 and the cable, ensuring uniform clamping force. The sealing gasket 306 is set on the upper and lower sides of the retaining ring mating surface. When the first retaining ring 301 and the second retaining ring 302 are closed, the upper and lower sealing gaskets 306 press against each other to form two sealing lines, effectively preventing rainwater and moisture from entering the interior along the gaps in the retaining rings and avoiding corrosion at the cable fixing point. The installation mechanism 3 is connected to the installation ring 205 of the outer sheath mechanism 2 through the pressure ring 303 and the pressure block 304, so as to reliably fix the two sets of outer sheath mechanisms 2 to the designated section of the cable. During installation, the wire clamp can be directly fixed to the outside of the installation mechanism 3 and connected to the wire clamp through the installation ring 205 or the installation block 206, thereby realizing the reliable fixing of the cable and the tower.

[0029] Both ends of the first retaining ring 301 and both ends of the second retaining ring 302 are connected to pressure rings 303. The pressure rings 303 on one side of the first retaining ring 301 and the pressure rings 303 on one side of the second retaining ring 302 press against the outer wall of the mounting ring 205 on one side of one of the outer protective mechanisms 2. The pressure rings 303 on the other side of the first retaining ring 301 and the pressure rings 303 on the other side of the second retaining ring 302 press against the outer wall of the mounting ring 205 on the other side of the other outer protective mechanism 2. The two symmetrical pressure rings 303 form a complete ring, connecting the two outer protective mechanisms 2. It should be noted that the pressure rings 303 are force transmission bridges between the mounting mechanism 3 and the outer protective mechanism 2. Each retaining ring has pressure rings 303 at both ends. With a pressure ring 303, when the two retaining rings are closed, the two pressure rings 303 at the same end symmetrically close together to form a complete ring, which tightly presses against the outer edge of the mounting ring 205 of the outer sheath mechanism 2. This crimping method converts the clamping force of the mounting mechanism 3 into axial pressure on the mounting ring 205, thereby firmly connecting the two sets of outer sheath mechanisms 2 together and preventing them from sliding on the cable. The inner diameter of the pressure ring 303 is slightly smaller than the outer diameter of the mounting ring 205 to ensure that sufficient pre-tightening force is generated after crimping. Even if the cable is subjected to wind vibration or thermal expansion and contraction, the two sets of outer sheath mechanisms 2 can remain relatively fixed, so that the spiral strip 201 at the fixing point is always in the correct position and continues to play a role in reinforcement and lightning protection.

[0030] Multiple pressure rings 303 are connected to pressure blocks 304 at their upper and lower ends. Two pressure blocks 304 at the same height on two pressure rings 303 are symmetrically arranged on both sides of the corresponding mounting block 206. The two pressure blocks 304 and the mounting block 206 have coaxial bolt holes. The mounting bolts 305 pass through one of the pressure blocks 304, the mounting block 206 and the other pressure block 304 in sequence to fasten the three together, thereby fixing the two outer protective mechanisms 2 and the mounting mechanism 3 into one unit.

[0031] It should be noted that the bolt connection between the pressure block 304 and the mounting block 206 is the key to achieving final fixation. Each pressure ring 303 has a pressure block 304 at both its upper and lower ends. When the two pressure rings 303 are closed, the upper and lower pairs of pressure blocks 304 are located on both sides of the mounting ring 205 and the two mounting blocks 206 respectively. The mounting bolts 305 pass laterally through a pair of pressure blocks 304 and the middle mounting block 206, locking the three together. The mounting block 206 can be made of metal to facilitate connection with the grounding wire. The lightning current guided by the spiral strip 201 is introduced into the tower grounding system through the mounting mechanism 3 to achieve lightning protection grounding. The outer protective mechanism 2 and the mounting mechanism 3 form a whole and are firmly attached to the cable fixing point, which not only protects the cable from abrasion but also provides a reliable lightning protection discharge path.

[0032] Working principle: In the insulated cable structure 1, the outer sheath 101 directly withstands environmental erosion such as ultraviolet rays, wind and sand, and rainwater, protecting the internal structure. The first insulating sleeve 102 and the second insulating sleeve 103 ensure the long-term safe operation of the cable under rated voltage. When the cable is squeezed or bent by external force, the six buffer strips 104 undergo elastic deformation to absorb impact energy and prevent the insulation layer from cracking due to stress concentration. The first insulating filler material 105 is embedded and fixed to ensure the long-term stability of the buffer structure. The flame-retardant sleeve 106 improves the fire safety of the cable. The four extrusion strips 108 on the inner wall of the inner sheath 107 apply radial pressure to the four core bodies 109, isolating them from each other and avoiding contact short circuits. The five stranded steel core strips 110 form a high tensile strength reinforcing core to withstand long-term overhead tension, making the sag smaller and the safety distance to the ground larger when the span is large. The second insulating filler material 111 fills the internal gaps of the inner sheath 107, wrapping the extrusion strips 108, core bodies 109 and steel core strips 110 into a whole, ensuring insulation and preventing internal wear.

[0033] The outer sheath mechanism 2 is installed outside the insulated cable mechanism 1 for local reinforcement and lightning protection at the fixing point. The spiral strip 201 of each set of outer sheath mechanism 2 has a multi-layer composite structure: the inner layer is a high-strength aluminum alloy reinforcing core material to improve the bending and compressive strength of the fixing point; the outer layer is a semi-conductive polymer material to uniformly distribute the lightning electric field and conduct the lightning current to both ends. The inner surface of the inner liner 202 is pre-coated with a temporary lubricating layer: when dry, it maintains high friction with the cable outer sheath 101 for fixation; after water is sprayed on site, the lubricating layer dissolves to form a water film, and the friction drops sharply, allowing the spiral strip 201 to slide along the cable to the predetermined position; after the water evaporates, the lubricating layer disappears, and the inner liner 202 directly contacts the outer sheath 101, restoring high friction to achieve permanent fixation. The slip ring 203 is fixed at both ends of the spiral strip 201, and the sliding ball 204 embedded in its inner wall allows the slip ring 203 to move smoothly, and completes the position adjustment in conjunction with the temporary lubricating layer; the mounting ring 205 at one end of the slip ring 203 and the upper and lower mounting blocks 206 are used to connect the mounting mechanism 3.

[0034] The mounting mechanism 3 is installed between the two sets of outer sheath mechanisms 2, connecting and fixing them to the cable. The first retaining ring 301 and the second retaining ring 302 combine to form a complete circular ring to clamp the cable. The inner wall anti-friction ring 307 prevents the cable from being scratched and compensates for gaps to ensure uniform clamping. The upper and lower sealing gaskets 306 on the mating surface press against each other to form two sealing lines to prevent rainwater and moisture from intruding and corroding the fixing point. The pressure rings 303 at both ends close symmetrically after the retaining rings are closed, pressing the outer edge of the mounting ring 205 of the outer sheath mechanism 2, converting the clamping force of the mounting mechanism 3 into axial pressure, so that the two sets of outer sheath mechanisms 2 are firmly connected. Each pressure ring 303 has pressure blocks 304 at both ends. The two symmetrical pressure blocks 304 are located on both sides of the corresponding mounting block 206. The three coaxial bolt holes are tightened by the mounting bolts 305 passing through them in sequence, so that the two outer sheath mechanisms 2 and the mounting mechanism 3 are fixed as one unit.

[0035] Lightning protection: When struck by lightning, the lightning overvoltage acts on the cable. The semi-conductive layer on the outer layer of the spiral bar 201 can improve the electric field distribution at the fixing point, prevent local electric field concentration from causing the main insulation to break down, thereby reducing the probability of lightning flashover and wire breakage.

[0036] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the preferred embodiments, while those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0037] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A lightning-proof overhead insulated cable, characterized in that, The system includes an insulated cable mechanism, an outer sheath mechanism, and an installation mechanism. The insulated cable mechanism includes an outer sheath, a first insulating sleeve, a second insulating sleeve, a buffer strip, a first insulating filler material, a flame-retardant sleeve, an inner sheath, an extrusion strip, a conductor body, a steel core strip, and a second insulating filler material. The outer sheath mechanism includes a spiral strip, an inner liner strip, a slip ring, sliding balls, an installation ring, and an installation block. There are two sets of outer sheath mechanisms, which are fitted onto the outer wall of the insulated cable mechanism. The inner liner strip is made of a water-activated lubricating coating, and its inner surface has a temporary lubricating layer. This temporary lubricating layer is resistant to drying. In its current state, it has a sufficient coefficient of friction to maintain the relative fixation between the spiral strip and the insulated cable mechanism. Upon contact with water, it dissolves to form a lubricating interface, reducing sliding friction and facilitating the spiral strip's axial movement and position adjustment. After the water evaporates, the lubricating layer disappears, and the inner liner strip directly contacts the cable's outer sheath, restoring the high-friction state and achieving tight fixation. The inner wall of the spiral strip is connected to an inner liner strip, and both ends of the spiral strip are connected to slip rings. Sliding balls are circumferentially embedded on one side of the inner wall of each slip ring, and one end of each slip ring is connected to a mounting ring. Mounting blocks are connected to both the upper and lower ends of each mounting ring.

2. The lightning-proof overhead insulated cable according to claim 1, characterized in that, The inner wall of the outer sheath is connected to the outer wall of the first insulating sleeve. The inner wall of the first insulating sleeve is provided with a second insulating sleeve. The inner wall of the second insulating sleeve is connected to the outer wall of the flame-retardant sleeve. The inner wall of the flame-retardant sleeve is connected to the outer wall of the inner sheath. The inner wall of the inner sheath is connected to a wire core body. The inner wall of the inner sheath is connected to a steel core strip. There are six buffer strips. The six buffer strips are distributed around the outer wall of the second insulating sleeve. The six buffer strips are located inside the first insulating sleeve and the second insulating sleeve. The outer walls of the six buffer strips corresponding to the first insulating sleeve and the second insulating sleeve are connected with a first insulating filler material.

3. The lightning-proof overhead insulated cable according to claim 1, characterized in that, The number of extrusion strips is four, and the two sides of the extrusion strips are set at an angle. The four extrusion strips are respectively connected to the inner wall of the inner sheath. The number of wire core bodies is four. The four extrusion strips extrude four wire core bodies to prevent the wire core bodies from contacting each other.

4. The lightning-proof overhead insulated cable according to claim 1, characterized in that, The number of steel core bars is five, and the five steel core bars are twisted together to improve the overall strength of the insulated cable mechanism. The inner sheath is filled with a second insulating filler material corresponding to the four extrusion bars, the four wire core bodies, and the five steel core bars.

5. A lightning-proof overhead insulated cable according to claim 1, characterized in that, The first insulating sleeve and the second insulating sleeve are made of cross-linked polyethylene material, the first insulating filler material and the second insulating filler material are made of flame-retardant polypropylene foam material, the buffer strip and the extrusion strip are made of rubber composite material, and the flame-retardant sleeve is made of halogen-free flame-retardant polyolefin material.

6. The lightning-proof overhead insulated cable according to claim 1, characterized in that, The spiral strip is made of a multi-layer composite structure, including an inner reinforcing core material and an outer functional coating layer. The reinforcing core material is a high-strength aluminum alloy strip, which is used to provide mechanical reinforcement. The functional coating layer is made of a semi-conductive polymer material, which is used to uniformly distribute the electric field under lightning overvoltage, thereby achieving lightning protection.

7. The lightning-proof overhead insulated cable according to claim 1, characterized in that, The installation mechanism includes a first retaining ring, a second retaining ring, a pressure ring, a pressure block, mounting bolts, a sealing gasket, and an anti-friction ring.

8. A lightning-proof overhead insulated cable according to claim 7, characterized in that, The installation mechanism is installed between the two sets of outer sheath mechanisms. The installation mechanism is used to connect the two sets of outer sheath mechanisms. The first retaining ring and the second retaining ring are both arc-shaped structures. The first retaining ring and the second retaining ring are combined to form a complete ring. The first retaining ring and the second retaining ring are engaged with the outer wall of the insulated cable mechanism. The inner wall of the first retaining ring and the inner wall of the second retaining ring are both connected with anti-friction rings. The inner walls of multiple anti-friction rings are connected to the outer wall of the insulated cable mechanism. Sealing gaskets are connected to the upper and lower parts of one side of the first retaining ring and one side of the second retaining ring. Two of the sealing gaskets are in contact with the other two sealing gaskets to achieve sealing at the connection between the two first retaining rings and the second retaining rings.

9. A lightning-proof overhead insulated cable according to claim 7, characterized in that, Both ends of the first retaining ring and both ends of the second retaining ring are connected to pressure rings. The pressure ring on one side of the first retaining ring and the pressure ring on one side of the second retaining ring are pressed against the outer wall of the mounting ring on one side of one of the outer protective mechanisms. The pressure ring on the other side of the first retaining ring and the pressure ring on the other side of the second retaining ring are pressed against the outer wall of the mounting ring on one side of the other outer protective mechanism. The two symmetrical pressure rings form a complete ring, thereby connecting the two outer protective mechanisms.

10. A lightning-proof overhead insulated cable according to claim 7, characterized in that, Multiple pressure rings are connected to pressure blocks at their upper and lower ends. Two pressure blocks at the same height on two pressure rings are symmetrically arranged on both sides of the corresponding mounting block. The two pressure blocks and the mounting block are provided with bolt holes on the same axis. The mounting bolt passes through one of the pressure blocks, the mounting block and the other pressure block in sequence to fasten the three together, thereby fixing the two outer protective mechanisms and the mounting mechanism into one unit.

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