Green low wind resistance anti-swing overhead bare conductor

Abstract

The present application relates to a kind of green low wind resistance anti-aeroelastic vibration overhead bare conductor, including bearing core and conducting layer, conducting layer is coated in the outside of bearing core, conducting layer is stranded by multiple conducting core, and insulation fiber bundle is filled between bearing core and conducting layer, and at least a part of insulation fiber bundle is from the stranded gap of conducting layer and extends to the outside of the outer surface of conducting layer.By filling insulation fiber bundle between bearing core and conducting layer, vibration energy can be absorbed and dissipated by using the high damping characteristics of the material itself;By extending part of the insulation fiber out of the surface of the conducting layer, the aerodynamic conditions formed by the aeroelastic vibration are destroyed;At the same time, the groove and the convex strip structure on the outer surface of the conducting layer are matched, the wind resistance coefficient is further reduced, and the anti-aeroelastic vibration effect is improved.

Description

Technical Field

[0001] This invention relates to the field of power cable technology, and in particular to a green, low-wind-resistance, anti-galling overhead bare conductor. Background Technology

[0002] Galloping of overhead transmission lines is one of the most serious hazards in the operation of transmission lines. Low-frequency, high-amplitude self-excited vibrations of conductors under wind loads can lead to conductor strand breakage, hardware damage, tower damage, and even major accidents such as line tripping and tower collapse.

[0003] Currently, the main technical means to prevent conductor galloping fall into two categories: external auxiliary devices and conductor body improvements. External auxiliary devices include phase-to-phase spacers, anti-galloping whips, and anti-vibration hammers, but these have problems such as complex installation and construction, high maintenance costs, and additional burden on the line load. Conductor body improvements reduce wind resistance by setting grooves or raised structures on the conductor surface, but it is difficult to target the galloping initiation area for focused control.

[0004] Based on the above-mentioned technical problems, this application proposes a green, low-wind-resistance, anti-galling overhead bare conductor. Summary of the Invention

[0005] The purpose of this invention is to provide a green, low-wind-resistance, anti-galloping overhead bare conductor to solve the technical problems mentioned in the background art. This purpose is achieved through the following technical solution: A green, low-wind-resistance, anti-galling overhead bare conductor includes a carrier core and a conductive layer. The conductive layer covers the outside of the carrier core and is composed of multiple conductive cores twisted together. An insulating fiber bundle is filled between the carrier core and the conductive layer, and at least a portion of the insulating fiber bundle passes through the twisted gaps of the conductive layer and extends beyond the outer surface of the conductive layer.

[0006] Furthermore, the length of the insulating fiber bundle extending beyond the outer surface of the conductive layer is gradually distributed along the axial direction of the bare conductor. The extension length of the insulating fiber bundle is longest in the central region between the two towers and gradually shortens as it approaches the tower connection.

[0007] Furthermore, the insulation fiber bundles in the central area of ​​the two towers extend outwards by 5-10 mm, while those closer to the towers extend outwards by 1-3 mm.

[0008] Furthermore, the insulating fiber bundle is one or a mixture of aramid fiber or PBO fiber, and the surface of the insulating fiber bundle is coated with a weather-resistant coating.

[0009] Furthermore, the bearing core is a steel core, an aluminum-clad steel stranded wire core, or a fiber composite core rod.

[0010] Furthermore, the conductive core is a round aluminum alloy wire, a Z-shaped aluminum alloy wire, or a fan-shaped aluminum alloy wire.

[0011] Furthermore, the outermost conductive core of the conductive layer includes a first conductive core and a second conductive core, and the outer end face of the first conductive core is provided with a groove along the length direction.

[0012] Furthermore, the outermost conductive core of the conductive layer also includes a third conductive core, and the outer end face of the third conductive core is provided with a protrusion along the length direction.

[0013] The technical solutions provided in this application have at least the following technical effects or advantages: 1. By filling the space between the carrier core and the conductive layer with insulating fiber bundles and allowing them to pass through the stranded gaps of the conductive layer, the internal damping energy dissipation and external aerodynamic disturbance functions are integrated into the bare conductor, reducing the installation of external auxiliary devices and saving installation and maintenance costs.

[0014] 2. Since conductor galloping usually begins at the lowest point of the sag between towers, extending longer insulation fibers in the central area between the two towers maximizes the aerodynamic turbulence effect, while shortening the insulation fibers in the high-tension area near the towers reduces aerodynamic impact, significantly improving the targeting and effectiveness of anti-galloping measures.

[0015] 3. By filling the space between the load-bearing core and the conductive layer with insulating fiber bundles, the high damping properties of the material itself can be used to absorb and dissipate vibration energy; by extending some of the insulating fibers out of the outer surface of the conductive layer, the aerodynamic conditions formed by galloping are disrupted; at the same time, the groove and convex structure on the outer surface of the conductive layer further reduces the wind resistance coefficient and improves the anti-galloping effect.

[0016] 4. By extending the insulating fiber bundles out of the conductive layer and combining them with the surface groove and protrusion design, the wind load on the bare conductor can be effectively reduced. Under the same working conditions, the design strength requirements of the tower can be reduced accordingly, saving the amount of steel used in the line project and the investment in foundation construction, which is in line with the green and low-carbon development direction. Attached Figure Description

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

[0018] Figure 1 This is a schematic diagram of the overhead bare conductor structure according to an embodiment of this application.

[0019] Reference numerals: 1. Carrier core; 2. Conductive layer; 20. Conductive core; 201. First conductive core; 202. Second conductive core; 2021. Groove; 203. Third conductive core; 3. Insulating fiber bundle; 31. Exposed fiber section. Detailed Implementation

[0020] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0021] like Figure 1 The diagram shows a green, low-wind-resistance, anti-galling overhead bare conductor, which is erected between towers along the line direction. The bare conductor includes a carrying core 1 and a conductive layer 2. The conductive layer 2 covers the outside of the carrying core 1 and is formed by multiple conductive cores 20 twisted around the carrying core 1. Insulating fiber bundles 3 are filled between the carrying core 1 and the conductive layer 2, and at least a portion of the insulating fiber bundles 3 protrudes from the twisting gaps of the conductive layer 2 and extends beyond the outer surface of the conductive layer 2, forming exposed fiber sections 31.

[0022] In the above structure, the insulating fiber bundle 3 forms a damping buffer layer between the bearing core 1 and the conductive layer 2, which can absorb and dissipate the vibration energy of the conductor. Furthermore, the exposed fiber section 31 extending from the outer surface of the conductive layer 2 can interfere with the flow field around the conductor surface, disrupting the aerodynamic stability conditions required for galloping. This achieves highly efficient anti-galloping functionality without adding external auxiliary devices, significantly reducing line construction and maintenance costs.

[0023] like Figure 1 As shown, the load-bearing core 1 is located at the center of the bare conductor and serves as the main load-bearing component of the bare conductor. The load-bearing core 1 can be any one of steel core, aluminum-clad steel stranded core, or fiber composite core rod.

[0024] The load-bearing core 1 is preferably a steel core, specifically galvanized steel strand. The cross-sectional shape of the steel core is circular, and its nominal diameter is determined according to the overall specifications of the conductor. Using a steel core as the load-bearing core has the advantages of high strength and low cost, and is suitable for transmission lines with long spans and heavy loads.

[0025] In another embodiment of this application, the carrying core 1 may be an aluminum-clad steel stranded core, which is composed of multiple aluminum-clad steel single wires stranded together. The steel core of the aluminum-clad steel single wire is covered with an aluminum layer, and the thickness of the aluminum layer is not less than 5% of the diameter of the single wire. The aluminum-clad steel stranded core combines the high strength of the steel core with the conductivity of the aluminum layer, and can partially undertake the conductive function, which is beneficial to improving the overall current carrying capacity of the conductor.

[0026] In another embodiment of this application, the carrier core 1 can be selected as a fiber composite core, specifically a carbon fiber reinforced resin matrix composite core or a glass fiber reinforced resin matrix composite core. Fiber composite cores have advantages such as light weight, high strength, high temperature resistance, and low coefficient of linear expansion, effectively reducing conductor sag and increasing the transmission capacity of the line. A spirally wound fiber reinforcement layer can be provided on the outer surface of the fiber composite core to improve the bonding force between the carrier core 1 and the conductive layer 2.

[0027] like Figure 1 As shown, the conductive layer 2 is formed by multiple conductive cores 20 concentrically twisted around the carrier core 1. The conductive layer 2 can be a single-layer structure, or a double-layer or multi-layer structure, depending on the current carrying capacity and voltage level of the conductor. The twisting direction of the conductive layer 2 can be left-handed or right-handed, and the twisting directions between adjacent layers are opposite to ensure the overall stability of the conductor structure.

[0028] In some embodiments of this application, the conductive layer 2 consists of an inner layer and an outer layer. The inner layer is formed by stranding 6 to 12 conductive cores 20, and the outer layer is formed by stranding 10 to 18 conductive cores 20. The stranding pitch ratio of the inner layer is 10 to 16, and the stranding pitch ratio of the outer layer is 8 to 14. The stranding pitch ratio refers to the ratio of the stranding pitch to the outer diameter of the stranded layer. This ratio affects the flexibility of the conductor and the size of the stranding gap. A smaller pitch ratio results in a larger stranding gap, which is beneficial for the insulating fiber bundles 3 to pass through.

[0029] The conductive core 20 can be any one of round aluminum alloy wire, Z-shaped aluminum alloy wire, or fan-shaped aluminum alloy wire. Round aluminum alloy wire is simple to process and has a mature stranding technology, making it suitable for conventional transmission lines. Z-shaped aluminum alloy wire has a Z-shaped cross-section; when adjacent conductive cores are stranded, the interlocking of the Z-shaped structure forms a tight stranded layer, which improves the fill factor and surface smoothness of the conductive layer 2, and reduces conductor wind resistance. Fan-shaped aluminum alloy wire has a fan-shaped cross-section; multiple fan-shaped wires are combined to form a complete annular conductive layer, resulting in a high fill factor, making it suitable for large-section conductors.

[0030] The aluminum alloy profile is made of aluminum-magnesium-silicon alloy or aluminum-zirconium alloy, with a conductivity of 52.5% IACS to 60% IACS and a tensile strength of 250 MPa to 350 MPa. Compared with ordinary hard aluminum wire, aluminum alloy profile has higher strength and better heat resistance, which is beneficial to improving the transmission capacity and service life of the conductor.

[0031] like Figure 1 As shown, the insulating fiber bundle 3 fills the annular space between the carrier core 1 and the conductive layer 2, and at least some of the fibers extend out from the twisted gaps of the conductive core 20 to the outer surface of the conductive layer 2.

[0032] The insulating fiber bundle 3 is made of insulating high-damping fiber material. The insulating fiber bundle 3 can be made of either aramid fiber or PBO fiber, or a mixture of both. Aramid fiber has high strength, high modulus, good damping characteristics, and excellent insulation properties, with a density of approximately 1.44 g / cm³. 3 With a tensile strength exceeding 3000 MPa and an elongation at break of approximately 2.5% to 4.0%, PBO fibers effectively absorb and dissipate vibrational energy. PBO fibers exhibit even higher strength and modulus, with a tensile strength reaching 5800 MPa and a modulus exceeding 280 GPa. They also possess excellent heat resistance, with a long-term service temperature up to 250℃. Blending PBO fibers with aramid fibers in a specific ratio can improve the overall strength and weather resistance of the fiber bundle while maintaining damping performance.

[0033] Preferably, the surface of the insulating fiber bundle 3 is coated with a weather-resistant coating, which is a fluoropolymer coating or a silicone resin coating, with a coating thickness of 0.02 mm to 0.05 mm. Specifically, the fluoropolymer coating can be made of polytetrafluoroethylene (PTFE), fluorinated ethylene propylene copolymer (FEP), or polyvinylidene fluoride (PVDF). These coatings have excellent resistance to ultraviolet aging, chemical corrosion, and hydrophobic properties, effectively protecting the insulating fiber bundle 3 from ultraviolet radiation and rain during long-term outdoor use. The silicone resin coating has good flexibility and high and low temperature resistance, remaining stable within a temperature range of -60℃ to 200℃, and also exhibits excellent hydrophobicity and self-cleaning properties.

[0034] like Figure 1 As shown, insulating fiber bundles 3 fill the space between the outer periphery of the bearing core 1 and the inner periphery of the conductive layer 2. The filling form can be multiple independent fiber bundles distributed along the outer periphery of the bearing core 1, or a fiber braided layer wrapped around the outer periphery of the bearing core 1. The length of the insulating fiber bundles 3 extending beyond the outer surface of the conductive layer 2 is gradually distributed along the axial direction of the bare conductor. Specifically, the extension length of the insulating fiber bundles 3 is longest in the central region between the two towers (i.e., the region where the lowest point of sag is located), and gradually shortens as it approaches the tower connection point (i.e., the conductor suspension point).

[0035] In some embodiments of this application, the extension length of the insulating fiber bundle 3 in the central region of the two towers is 5mm to 10mm, preferably 6mm to 8mm; the extension length of the insulating fiber bundle 3 near the towers is 1mm to 3mm, preferably 1.5mm to 2.5mm.

[0036] Conductor galloping typically begins at the lowest point of the sag between towers (i.e., the central area). Extending longer insulating fiber bundles in this area maximizes aerodynamic turbulence, effectively suppressing and maintaining galloping. In the high-tension area near the tower, conductor amplitude is relatively small; shortening the fiber bundle extension length reduces unnecessary wind load and aerodynamic impact, lowering wind resistance. Through these targeted designs, conductor lifespan is extended while ensuring anti-galloping effectiveness.

[0037] like Figure 1 As shown, in a preferred embodiment of this application, the outermost conductive core of the conductive layer 2 includes a first conductive core 201 and a second conductive core 202, and the outer end face of the second conductive core 202 is provided with a groove 2021 along the length direction.

[0038] In some embodiments of this application, the first conductive cores 201 are evenly distributed at intervals on the circumference of the outermost layer of the conductive layer 2, and a second conductive core 202 is disposed between two adjacent first conductive cores 201. That is, in the circumferential direction of the outermost layer, the first conductive cores 201 and the second conductive cores 202 are arranged alternately, and adjacent first conductive cores 201 and second conductive cores 202 are in close contact. A groove 2021 is disposed on the radial outer end face of the second conductive core 202, and the groove 2021 extends continuously along the length direction of the second conductive core 202. The cross-sectional shape of the groove 2021 is arc-shaped, V-shaped, or rectangular, and the depth of the groove 2021 is 0.3mm~0.6mm; the width of the groove 2021 is 0.8mm~1.5mm.

[0039] When airflow flows along the surface of the conductor, the groove 2021 can guide the boundary layer airflow to generate micro-vortices, causing the separation point of the airflow on the surface of the conductor to move backward, thereby reducing the low-pressure area on the leeward side of the conductor and effectively reducing the wind resistance coefficient.

[0040] like Figure 1 As shown, in a preferred embodiment of this application, the outermost conductive core of the conductive layer 2 further includes a third conductive core 203, and the outer end face of the third conductive core 203 is provided with a protrusion along the length direction. The third conductive cores 203 are evenly distributed on the circumference of the outermost layer of the conductive layer 2. The protrusion is provided on the radial outer end face of the third conductive core 203, and the protrusion extends continuously along the length direction of the third conductive core 203. The protrusion causes the third conductive core 203 to protrude from the outer surface of the bare wire, which can further disturb the airflow boundary layer and cooperate with the groove 2021 to form a non-uniform roughness distribution on the surface of the wire along the circumferential direction. When the wire twists, the difference in aerodynamic characteristics at different circumferential positions produces an aerodynamic damping effect, thereby suppressing the occurrence and development of galloping.

[0041] Through the synergistic effect of the above-mentioned multiple surface structures, good aerodynamic stability can be maintained under different wind attack angles and wind speeds, significantly reducing the probability of conductor galloping.

[0042] The technical principles and beneficial effects of this application will be explained below in conjunction with the actual working conditions of the conductor.

[0043] The insulating fiber bundles 3 fill the space between the carrying core 1 and the conductive layer 2, effectively creating multiple micro-dampers inside the conductor. When the conductor vibrates under wind excitation, a relative displacement occurs between the carrying core 1 and the conductive layer 2. The insulating fiber bundles 3 convert the mechanical energy of the vibration into heat energy and dissipate it through friction between the fibers, friction between the fibers and the conductive core 20, and the elastic deformation of the fibers themselves, thus playing a role in damping and vibration reduction. Since the distribution of the insulating fiber bundles 3 covers the entire length of the conductor, it can dampen and dissipate energy throughout the entire propagation of the galloping energy, effectively suppressing the accumulation of amplitude.

[0044] The insulating fiber bundles 3 extending from the outer surface of the conductive layer 2 disrupt the original smooth cylindrical flow boundary conditions on the conductor surface. When the airflow passes over the protruding fibers, the fibers generate minute vibrations and deflections under the action of the airflow, continuously disturbing the boundary layer flow on the conductor surface, inhibiting the orderly shedding of vortices, and causing the aerodynamic forces on the conductor surface to no longer change periodically, thereby disrupting the aerodynamic conditions formed by the galloping motion.

[0045] The gradual distribution of fiber extension length along the axial direction fully considers the differences in aerodynamic and tension characteristics between different sections of the two towers. In the central region between the two towers, where the sag is lowest, the conductor tension is minimal and the amplitude is maximum. This is also the region where galloping is most likely to begin and develop. Extending longer fiber bundles here provides the strongest aerodynamic turbulence effect. In the high-tension region near the towers, the conductor amplitude is smaller. Extending shorter fiber bundles here provides the necessary turbulence while reducing excessive interference with the flow field around the conductor, thus avoiding additional wind-induced vibrations.

[0046] By integrating damping energy dissipation and aerodynamic turbulence functions into the bare conductor, the need for external auxiliary devices such as anti-galloping spacers and turbulence lines is eliminated, simplifying the line structure and saving installation and maintenance costs. Through a targeted axially tapered extension length design, the anti-galloping effect is precisely matched to the actual needs of each section of the conductor, achieving optimal anti-galloping performance with minimal additional wind resistance.

[0047] The surface microstructures such as grooves and convex strips are directly formed during the drawing or stranding process of the conductive core, without the need for additional materials or increasing the weight of the conductor. At the same time, the wind load is reduced, and the design strength requirements of the tower can be reduced accordingly under the same working conditions, saving the amount of steel used in the line project and the investment in foundation construction, which is in line with the green and low-carbon development direction.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A green, low-wind-resistance, anti-galloping overhead bare conductor, comprising a carrier core and a conductive layer, wherein the conductive layer covers the outside of the carrier core, and the conductive layer is formed by stranding multiple conductive cores, characterized in that, An insulating fiber bundle is filled between the carrier core and the conductive layer, and at least a portion of the insulating fiber bundle passes through the twisted gaps of the conductive layer and extends beyond the outer surface of the conductive layer.

2. The green, low-wind-resistance, anti-galloping overhead bare conductor according to claim 1, characterized in that, The length of the insulating fiber bundle extending beyond the outer surface of the conductive layer is gradually distributed along the axial direction of the bare conductor. The extension length of the insulating fiber bundle is the longest in the central region between the two towers and gradually shortens as it approaches the tower connection.

3. The green, low-wind-resistance, anti-galloping overhead bare conductor according to claim 2, characterized in that, The insulation fiber bundles in the central area of ​​the two towers extend 5-10 mm, while those closer to the towers extend 1-3 mm.

4. The green, low-wind-resistance, anti-galloping overhead bare conductor according to claim 1, characterized in that, The insulating fiber bundle is one or a mixture of aramid fiber and PBO fiber, and the surface of the insulating fiber bundle is coated with a weather-resistant coating.

5. A green, low-wind-resistance, anti-galloping overhead bare conductor according to claim 1, characterized in that, The bearing core is a steel core, an aluminum-clad steel stranded wire core, or a fiber composite core rod.

6. A green, low-wind-resistance, anti-galloping overhead bare conductor according to claim 1, characterized in that, The conductive core is a round aluminum alloy wire, a Z-shaped aluminum alloy wire, or a fan-shaped aluminum alloy wire.

7. A green, low-wind-resistance, anti-galling overhead bare conductor according to claim 1, characterized in that, The outermost conductive core of the conductive layer includes a first conductive core and a second conductive core, and the outer end face of the first conductive core is provided with a groove along the length direction.

8. A green, low-wind-resistance, anti-galloping overhead bare conductor according to claim 7, characterized in that, The outermost conductive core of the conductive layer also includes a third conductive core, and the outer end face of the third conductive core is provided with a protrusion along the length direction.

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