Conductor structure, quad-bundle low windage conductor and method of construction

Abstract

The embodiment of the application provides a conductor structure, a four-split low-wind-pressure conductor and a construction method, wherein the conductor structure comprises a reinforcing core, an aluminum wire layer and aerodynamic grooves, and the aluminum wire layer is arranged around the reinforcing core. A plurality of aerodynamic grooves are arranged at intervals in the aluminum wire layer around the reinforcing core, and each aerodynamic groove extends in the axial direction. The application sets the aerodynamic grooves on the conductor structure, uses the "early transition" mode, can induce the laminar boundary layer with weak original kinetic energy to become the high-energy turbulent boundary layer, and can delay the airflow separation point to the leeward side. The fluid dynamics effect directly reduces the wake area and reduces the pressure difference resistance of the conductor. Ultimately, the wind load of the conductor is reduced in the macroscopic aspect, so that the wind vibration is inhibited, the stability of the conductor is improved, and the situations of the tower strength overrun and fatigue damage are avoided.

Description

Technical Field

[0001] This application relates to the field of overhead transmission line technology, and in particular to a conductor structure, a four-split low wind pressure conductor, and a construction method. Background Technology

[0002] In ultra-high voltage and extra-high voltage power transmission projects, four-split conductors are the mainstream choice. However, traditional four-split conductors have the drawback of high drag coefficient. Because the outermost layer of traditional conductors is made of circular single strands twisted together, there are deep "troughs" on the surface, which causes boundary layer separation to occur prematurely when air flows over the surface, and the drag coefficient Cd is usually between 1.1 and 1.2.

[0003] In areas with high winds, the wind resistance at traditional conductors is relatively large, which can easily lead to towers exceeding strength limits and fatigue damage. Summary of the Invention

[0004] In view of this, this application aims to provide a conductor structure, a four-split low wind pressure conductor, and a construction method to solve the problem of high wind resistance in related technologies, which easily leads to tower strength exceeding limits and fatigue damage.

[0005] In a first aspect, this application provides a conductor structure, including a reinforcing core, an aluminum wire layer, and pneumatic grooves, with the aluminum wire layer surrounding the reinforcing core. A plurality of pneumatic grooves are spaced apart around the reinforcing core on the aluminum wire layer, each pneumatic groove extending axially.

[0006] In one possible implementation, the pneumatic groove includes an arcuate section and an extension section, the extension section being located at at least one end of the arcuate section and extending in a direction away from the reinforcing core.

[0007] In one possible implementation, the pneumatic groove includes an opening and a bottom, with the free ends of two extensions forming the opening of the pneumatic groove and the arc-shaped segment forming the bottom of the pneumatic groove.

[0008] In one possible implementation, the width of the slot is w, and the depth between the slot and the bottom of the slot is h, satisfying: 2.8≤w / h≤3.2.

[0009] In one possible implementation, the diameter of the outer contour of the aluminum wire layer is D, which satisfies: 1.5%≤h / D≤2.2%.

[0010] In one possible implementation, four pneumatic grooves are non-uniformly distributed around the reinforcing core.

[0011] In one possible implementation, the aluminum wire layer comprises aluminum single wires.

[0012] In one possible implementation, the aluminum single wire includes a wire body, a portion of which protrudes to form a convex portion. A concave portion is provided in the wire body, and the concave portion is disposed opposite to the convex portion. A plurality of aluminum single wires are wound around a reinforcing core, with the convex portion of one aluminum single wire located within the concave portion of another aluminum single wire in adjacent aluminum single wires.

[0013] In one possible implementation, there is a stranding gap between adjacent aluminum wires, the stranding gap being less than 0.05 mm.

[0014] In one possible implementation, the conductor structure further includes a drag-reducing coating disposed on the side of the aluminum wire layer away from the reinforcing core.

[0015] Secondly, this application provides a four-split low wind pressure conductor, including the conductor structure and vibration damping spacer provided in any of the above embodiments, wherein the vibration damping spacer is disposed between adjacent conductor structures.

[0016] In one possible implementation, the four wire structures are arranged in an equilateral quadrilateral.

[0017] In one possible implementation, the spacing between adjacent wire structures in the horizontal direction is Sh, and the spacing between adjacent wire structures in the vertical direction is Sv, satisfying: 1.1≤Sh / Sv≤1.25.

[0018] Thirdly, this application provides a construction method for a four-split low-wind-pressure conductor, including: Obtain historical environmental parameters for the target route area; Adjust the structural parameters of the aerodynamic grooves in the conductor structure based on historical environmental parameters and wind speed Reynolds number. Assemble the conductor structure and vibration damping spacers according to the preset spacing.

[0019] Compared with the prior art, the beneficial effects of this application are: In this application, by setting axially extending aerodynamic grooves on the surface of the conductor structure, a controllable surface roughness or turbulence element is introduced. The aerodynamic grooves disrupt the stability of the laminar boundary layer, inducing it to transition from laminar to turbulent flow earlier. Although the turbulent boundary layer increases surface friction drag slightly, its most significant characteristic is that the fluid particles near the wall have greater momentum and more intense energy exchange, giving the turbulent boundary layer stronger kinetic energy to resist the downstream adverse pressure gradient.

[0020] This invention, by setting aerodynamic grooves on the conductor structure and utilizing an "early transition" method, can induce the originally weak laminar boundary layer to transform into a high-energy turbulent boundary layer (turbulent boundary layer has higher kinetic energy and stronger resistance to separation). This can delay the airflow separation point to the leeward side. This hydrodynamic effect directly reduces the wake region and lowers the pressure drag of the conductor. Ultimately, this manifests macroscopically as a reduction in the wind load (i.e., wind resistance Fw) on the conductor, thereby suppressing wind vibration and improving the stability of the conductor. This also helps to prevent tower strength exceeding limits and avoid fatigue damage.

[0021] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic cross-sectional view of the conductor structure provided in an embodiment of this application; Figure 2 A partial cross-sectional view of a wire structure provided in one embodiment of this application; Figure 3 A schematic diagram of the structure of a four-split low-pressure conductor provided in one embodiment of this application; Figure 4 A flowchart illustrating a construction method for a four-split low-pressure conductor provided in one embodiment of this application.

[0024] Explanation of reference numerals in the attached figures: 1. Conductor structure, 11-strength core, 12 aluminum wire layers, 121 raised portion, 122 recessed portion, 123 twisted gap. 13 Pneumatic groove, 131 Arc-shaped section, 132 Extension section, 14. Drag-reducing coating, 2. Low wind pressure conductor, 21. Vibration damping spacer. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0027] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0028] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0029] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0030] Firstly, this application provides a wire structure 1, such as... Figure 1 and Figure 2 As shown, the structure includes a reinforcing core 11, an aluminum wire layer 12, and pneumatic grooves 13, with the aluminum wire layer 12 surrounding the reinforcing core 11. A plurality of pneumatic grooves 13 are spaced apart around the reinforcing core 11 on the aluminum wire layer 12, each pneumatic groove 13 extending axially.

[0031] The conductor structure 1 provided in this application has a reinforcing core 11 located at its center. An aluminum wire layer 12 is wound around the periphery of the reinforcing core 11. Specifically, the reinforcing core 11 is cylindrical, and the aluminum wire layer 12 is annular, with the aluminum wire layer 12 wrapped around the outer periphery of the reinforcing core 11. The reinforcing core 11 is a high-strength steel core.

[0032] Specifically, the reinforcing core 11 is the load-bearing element of the conductor, typically made of high-strength materials (such as galvanized steel wire, aluminum-clad steel wire, or carbon fiber composites). The reinforcing core 11 primarily bears mechanical loads, resists conductor galloping and fatigue, and supports the outer aluminum wire layer 12. Specifically, the reinforcing core 11 is mainly responsible for bearing the weight of the conductor itself, the weight of icing, and the tension transmitted to the line by external wind loads. This ensures that the conductor will not break under strong winds or icing conditions. Due to the drag-reducing and wind-vibration-suppressing design (such as the aerodynamic groove 13), the reinforcing core 11 provides sufficient rigidity to prevent fatigue damage to the conductor caused by frequent vibrations under strong winds. It provides a solid supporting foundation for the stranded multi-layered aluminum alloy single wire, ensuring the stability of the conductor's cross-sectional shape.

[0033] The aluminum wire layer 12 not only primarily performs electrical functions but also shapes the aerodynamic form. Specifically, the aluminum wire layer 12 has multiple spaced-apart aerodynamic grooves 13, meaning that the multiple aerodynamic grooves 13 are independent of each other. Each aerodynamic groove 13 extends along the length of the conductor structure 1.

[0034] According to the principles of fluid mechanics, the wind resistance Fw received by the conductor is expressed as:

[0035] In the formula: Fw represents wind resistance, which is the wind load on the guideline, measured in Newtons (N).

[0036] ρ is the fluid density, specifically the density of air, typically taken as 1.225 kg / m³. 3 .

[0037] V represents the wind speed, specifically the wind speed near the guide line, measured in meters per second (m / s).

[0038] Cd is the resistance coefficient, a dimensionless coefficient that depends on the cross-sectional shape, surface roughness, and Reynolds number of the conductor. For cylindrical conductors, it is typically taken as around 1.0.

[0039] D is the diameter of the conductor, referring to the outer diameter of the conductor, in meters (m).

[0040] L represents the length of the conductor, specifically the length of the windward section of the conductor, measured in meters (m).

[0041] Based on the aforementioned formula, it can be seen that, under the condition that environmental factors (air density ρ, wind speed V) and conductor specifications (diameter D, length L) remain unchanged, the key to reducing wind resistance lies in reducing the drag coefficient Cd. The size of Cd mainly depends on the size of the wake region behind the object. When the wake region is larger, the pressure difference between the front and rear is greater (i.e., the pressure drag is greater), and the Cd value is higher.

[0042] When the surface of a conventional conductor is not grooved, a laminar boundary layer forms on the surface. The laminar boundary layer has a small velocity gradient and is relatively weak in resisting the adverse pressure gradient.

[0043] This application introduces a controllable surface roughness or turbulence element by setting an axially extending aerodynamic groove 13 on the surface of the conductor structure 1. The aerodynamic groove 13 disrupts the stability of the laminar boundary layer, inducing it to transition from laminar to turbulent flow earlier. Although the turbulent boundary layer increases surface friction drag slightly, its most significant characteristic is that the fluid micro-elements near the wall have greater momentum and more intense energy exchange, giving the turbulent boundary layer stronger kinetic energy to resist the downstream adverse pressure gradient.

[0044] This invention, by setting aerodynamic grooves 13 on the conductor structure 1, utilizes an "early transition" method to induce the originally weak laminar boundary layer to transform into a high-energy turbulent boundary layer (turbulent boundary layer has higher kinetic energy and stronger anti-separation ability). This can delay the airflow separation point to the leeward side. This hydrodynamic effect directly reduces the wake region and lowers the pressure drag of the conductor. Ultimately, macroscopically, this manifests as a reduction in the wind load (i.e., wind resistance Fw) on the conductor, thereby suppressing wind vibration and improving the stability of the conductor. This also helps to avoid situations such as tower strength exceeding limits and fatigue damage.

[0045] In one possible implementation, such as Figure 1 As shown, the pneumatic groove 13 includes an arc-shaped section 131 and an extension section 132. The extension section 132 is located at at least one end of the arc-shaped section 131 and extends in a direction away from the reinforcing core 11.

[0046] In this embodiment, the pneumatic groove 13 includes an arc-shaped segment 131, which is used to adapt to the outer contour surface of the reinforcing core 11. Since the reinforcing core 11 is cylindrical, by providing the arc-shaped segment 131, the distance between the arc-shaped segment 131 and the reinforcing core 11 can be kept relatively consistent. Optionally, the cross-section of the arc-shaped segment 131 is a parabolic arc.

[0047] Specifically, the number of extension segments 132 is one or two. When there is one extension segment 132, the extension segment 132 and the arc segment 131 form an "L"-shaped groove structure. When there are two extension segments 132, the extension segment 132 and the arc segment 131 form a "U"-shaped groove structure.

[0048] In one possible implementation, the pneumatic groove 13 includes a groove opening and a groove bottom, with the free ends of two extensions 132 forming the groove opening of the pneumatic groove 13 and the arc-shaped segment 131 forming the groove bottom of the pneumatic groove 13.

[0049] In one possible implementation, the width of the slot is w, and the depth between the slot and the bottom of the slot is h, satisfying: 2.8≤w / h≤3.2.

[0050] Preferably, the width w of the groove is three times the groove depth h.

[0051] In one possible implementation, the diameter of the outer contour of the aluminum wire layer 12 is D, which satisfies: 1.5%≤h / D≤2.2%.

[0052] In one possible implementation, such as Figure 1 As shown, four pneumatic grooves 13 are non-uniformly distributed around the reinforcing core 11.

[0053] In this embodiment, the four pneumatic grooves 13 are not uniformly distributed and are located at 42~48° and 132~138° relative to the horizontal central axis in the clockwise and counterclockwise directions, respectively.

[0054] Preferably, the four pneumatic grooves 13 are symmetrically arranged at a position offset by 45° from the windward centerline.

[0055] Preferably, the center points of the four pneumatic grooves 13 are located at 40°, 140°, 220°, and 320° of the circumferential cross-section of the conductor.

[0056] In one possible implementation, the aluminum wire layer 12 comprises aluminum single wires.

[0057] In this embodiment, the aluminum single wire is an aluminum alloy single wire structure.

[0058] In one possible implementation, such as Figure 2 As shown, the aluminum single wire has a self-locking irregular shape structure. During the tight twisting process, adjacent aluminum single wires can lock their positions with each other, thereby achieving position locking and improving the overall structural stability of the aluminum wire layer 12.

[0059] Among them, the aluminum wire layer 12 is made of trapezoidal or S-shaped aluminum single wires tightly twisted together, and its filling coefficient is controlled at 0.95-0.98, which can improve the surface flatness of the conductor structure 1 by more than 85% compared with ordinary round wire.

[0060] In one possible implementation, such as Figure 2As shown, the aluminum single wire includes a wire body, a portion of which protrudes to form a protrusion 121. A recess 122 is provided in the wire body, and the recess 122 is disposed opposite to the protrusion 121. Multiple aluminum single wires are wound around a reinforcing core 11, and the protrusion 121 of one aluminum single wire is located within the recess 122 of another aluminum single wire.

[0061] In this embodiment, during the stranding of aluminum single wires, along the direction from the inside out, the protrusion 121 of the outer aluminum single wire of the adjacent aluminum single wire can be embedded into the concave portion 122 of the inner aluminum single wire, so that a self-locking structure is formed between the aluminum single wires to achieve mechanical interlocking.

[0062] In one possible implementation, there is a stranding gap 123 between adjacent aluminum wires, the stranding gap 123 being less than 0.05 mm.

[0063] Furthermore, the inner surface roughness Ra of the pneumatic groove 13 is less than 0.8 μm.

[0064] In one possible implementation, such as Figure 2 As shown, the conductor structure 1 also includes a drag-reducing coating 14, which is disposed on the side of the aluminum wire layer 12 away from the reinforcing core 11.

[0065] In this embodiment, a drag-reducing coating 14 is further provided on the outer side of the aluminum wire layer 12. The drag-reducing coating 14 is used to reduce drag. Specifically, the drag-reducing coating 14 is a hydrophobic drag-reducing composite coating. The drag-reducing coating 14 is composed of a fluorocarbon resin matrix and nano-sized silica filler, and its static contact angle is greater than 150°. The thickness of the drag-reducing coating 14 is 30μm~60μm.

[0066] Secondly, such as Figure 3 As shown, this application provides a four-split low-wind-pressure conductor 2, including the conductor structure 1 and vibration-damping spacers 21 provided in any of the above embodiments. The vibration-damping spacers 21 are disposed between adjacent conductor structures 1. The vibration-damping spacers 21 are used to support and fix the four conductor structures 1. Optionally, the vibration-damping spacers 21 include spacer bars.

[0067] In one possible implementation, the four wire structures 1 are arranged in an equilateral quadrilateral.

[0068] In this embodiment, the four conductor structures 1 present an equilateral rectangular split layout, which can optimize the split interval according to the prevailing wind direction and can use the front row of conductors to "shield" the rear row of conductors.

[0069] In one possible implementation, such as Figure 3 As shown, the spacing between adjacent conductor structures 1 in the horizontal direction is Sh, and the spacing between adjacent conductor structures 1 in the vertical direction is Sv, satisfying: 1.1≤Sh / Sv≤1.25.

[0070] In this embodiment, the spacing between adjacent conductor structures 1 in the horizontal direction is increased compared to the spacing between adjacent conductor structures 1 in the vertical direction, which can reduce the probability of synchronous shedding of the entire conductor by the Karman vortex street.

[0071] Optionally, the horizontal spacing Sh is 300~600mm and the vertical spacing Sv is 400~500mm.

[0072] It is worth noting that this application optimizes the aluminum single-wire structure, resulting in a tightly compressed, irregularly shaped stranded structure. The outermost aluminum wire adopts a self-locking trapezoidal (S-shaped) structure, increasing the fill factor to over 0.95. Furthermore, aerodynamic grooves 13 for inducing turbulence are provided on the conductor structure 1, and longitudinal arc-shaped grooves are set at specific angles (near the windward side) of the sub-conductors to reduce pressure drag by controlling boundary layer transition (laminar to turbulent flow). Simultaneously, the four conductor structures 1 are arranged in a non-equilateral rectangular split layout. The split spacing is optimized for the prevailing wind direction, utilizing the front row of conductors to "shield" the rear row. In other words, this application achieves drag reduction of the four-split low-wind-pressure conductor 2 through a three-pronged approach: wire irregularity, surface micro-nanoization, and asymmetrical arrangement.

[0073] This application induces the boundary layer to transition from laminar to turbulent flow earlier through aerodynamic grooves 13 (turbulent boundary layer has higher kinetic energy and stronger resistance to separation), delaying the separation point to the leeward side, thereby significantly reducing the wake region. Combined with the wake shielding effect generated by the rectangular arrangement, the overall drag coefficient Cd of the entire conductor group can be reduced to 0.75~0.85.

[0074] The low wind pressure conductor 2 provided in this application has the following beneficial effects: Drag reduction performance: Overall wind load is reduced by up to 20%, greatly relieving pressure on towers.

[0075] Anti-icing / hydrophobic: Combined with a superhydrophobic coating, the groove does not accumulate water in rainy or snowy weather, maintaining protection against aerodynamic drag reduction failure.

[0076] Electromagnetic properties: Surface smoothing reduces tip discharge and corona loss by 10%.

[0077] Table 1 Experimental parameters for different wire types

[0078] In summary, this invention reduces the original drag base through "irregular lines", achieves active intervention in the boundary layer through "aerodynamic grooves", and achieves system-level wind force cancellation through "rectangular layout". The three have a significant synergistic gain effect.

[0079] Thirdly, this application provides a construction method for a four-split low-wind-pressure conductor, such as... Figure 4 As shown, it includes: S102, Obtain historical environmental parameters for the target route area; S104, adjust the structural parameters of the aerodynamic groove in the conductor structure according to historical environmental parameters and wind speed Reynolds number; S106, Assemble the conductor structure and vibration damping spacers according to the preset spacing.

[0080] In this embodiment, the target line area is the area where the conductor is planned to be laid. Historical environmental parameters include the historical maximum wind speed and the prevailing wind direction. The groove depth h of the aerodynamic groove in the conductor structure can be adjusted according to the wind speed Reynolds number. During the installation of the four-split conductor, the ratio of the horizontal spacing Sh to the vertical spacing Sv of the conductor structure can be kept within a preset range by adjusting the transverse and longitudinal axis length ratio of the vibration damping spacers.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A conductor structure, characterized in that, include: Reinforced core; An aluminum wire layer surrounds the reinforcing core; Multiple pneumatic grooves are spaced around the reinforcing core on the aluminum wire layer, and each pneumatic groove extends axially.

2. The conductor structure according to claim 1, characterized in that, The pneumatic groove includes: Arc segment; An extension segment is provided at at least one end of the arcuate segment, the extension segment extending in a direction away from the reinforcing core.

3. The conductor structure according to claim 2, characterized in that, The pneumatic groove includes an opening and a bottom; the free ends of the two extended sections form the opening of the pneumatic groove, and the arc-shaped section forms the bottom of the pneumatic groove; wherein, The width of the slot is w, and the depth between the slot and the bottom of the slot is h, satisfying: 2.8 ≤ w / h ≤ 3.2; and / or The diameter of the outer contour of the aluminum wire layer is D, which satisfies: 1.5%≤h / D≤2.2%.

4. The conductor structure according to claim 1, characterized in that, The four pneumatic grooves are non-uniformly distributed around the reinforcing core.

5. The conductor structure according to any one of claims 1 to 4, characterized in that, The aluminum wire layer includes aluminum single wires, and the aluminum single wires include: A line body, a portion of which protrudes to form a convex portion; A recess is provided on the line body, and the recess is disposed opposite to the convex part; Multiple aluminum single wires are wound around the reinforcing core, and the protrusion of one aluminum single wire is located inside the concave part of another aluminum single wire.

6. The conductor structure according to claim 5, characterized in that, There is a stranding gap between adjacent aluminum wires, and the stranding gap is less than 0.05 mm.

7. The conductor structure according to any one of claims 1 to 4, characterized in that, The conductor structure also includes: A drag-reducing coating is applied to the side of the aluminum wire layer opposite to the reinforcing core.

8. A four-split low-wind-pressure conductor, characterized in that, include: The wire structure as described in any one of claims 1 to 7; Vibration damping spacers are disposed between adjacent conductor structures.

9. The four-split low-wind-pressure conductor according to claim 8, characterized in that, The four wire structures are arranged in an equilateral quadrilateral. Wherein, the spacing between adjacent conductor structures in the horizontal direction is Sh, and the spacing between adjacent conductor structures in the vertical direction is Sv, satisfying: 1.1≤Sh / Sv≤1.

25.

10. A construction method for a four-split low-wind-pressure conductor, characterized in that, include: Obtain historical environmental parameters for the target route area; Based on the historical environmental parameters and wind speed Reynolds number, adjust the structural parameters of the aerodynamic groove in the conductor structure; Assemble the conductor structure and vibration damping spacers according to the preset spacing.

Images