An intelligent tethered cable with a circumferential heat flow directing layer and a method of making the same

Abstract

The application discloses an intelligent tethered cable with a circumferential heat flow guide layer and a preparation method thereof, and the cable comprises a power transmission unit, a distributed sensing optical fiber unit, a wrapped heat-conducting insulation pad layer, a circular double-layer load-bearing armor layer and a circumferential heat flow guide layer formed by multi-head multi-channel co-extrusion, the thermal conductivity of the circumferential heat flow guide layer is greater than or equal to 5 W / (m*K) in a long axis end area A and less than or equal to 0.5 W / (m*K) in a short axis end area B, the circumferential temperature difference is compressed to less than or equal to ±3 DEG C by conductor Joule heat under normal conditions, an edge controller adjusts and controls electric heating power in a closed loop according to distributed optical fiber sensing information and combines with meteorological prediction to perform feedforward compensation. The application realizes the cooperation of passive heat guidance and active electric heating control, effectively solves the contradiction that the oval cross-section cable is difficult to achieve both drag reduction and ice prevention, and the comprehensive electric heating energy consumption is reduced by 15% to 25%.

Description

Technical Field

[0001] This invention relates to the field of special cables and intelligent control technology, specifically to a self-sensing intelligent thermal management mooring cable for overhead laying sections in high-altitude cableways and ground mooring systems in strong wind and cold environments, and its preparation method. Background Technology

[0002] When moored cables operate in high-altitude cableways and ground mooring systems in windy and cold environments, they face the dual challenges of aerodynamic drag and thermal management. Circular cross-section moored cables have a drag coefficient as high as 1.0~1.2, and the wind load generated under strong winds leads to heavy support loads, high foundation costs, high cable tension, and high fatigue risk. To reduce wind resistance, the industry has experimented with using elliptical cross-section outer sheaths, which can reduce the drag coefficient to below 0.6. However, elliptical cross-section cables suffer from severe circumferential temperature differences in strong wind environments: the airflow accelerates at the long axis end (windward side), resulting in rapid heat dissipation and a low surface temperature, while the airflow is gentler at the short axis end (leeward side), leading to slow heat dissipation and a high surface temperature. This circumferential temperature difference can reach 5℃~8℃, causing localized icing, energy waste, and the risk of insulation thermal aging.

[0003] In existing technologies, distributed fiber optic temperature measurement solutions mainly adopt an open-loop monitoring and alarm architecture. This means that after sensing the temperature, an alarm signal is output, and the decision to initiate de-icing is made manually. The lack of closed-loop coupling between fiber optic sensing and electrothermal execution leads to delayed icing location identification, the coexistence of localized icing and excessive energy consumption in ice-free areas, and reliance on manual inspection for de-icing decisions. Furthermore, existing technologies exhibit inherent contradictions between the drag reduction and anti-icing requirements of circular and elliptical cross-sections; no solution can simultaneously achieve low wind resistance, temperature uniformity, and low-energy-consumption anti-icing. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that the existing elliptical cross-section tethered cables have problems such as large circumferential temperature difference between the long axis end and the short axis end, inability to sense the icing state in real time, difficulty in achieving both thermal management and aerodynamic drag reduction, and the existing distributed optical fiber temperature measurement scheme is an open-loop architecture, lacking automatic closed-loop control capability.

[0005] The technical solution adopted by this invention to solve its technical problem is: an intelligent tethered cable with a circumferential heat flow guiding layer, comprising a power transmission unit, a distributed sensing fiber optic unit, a circular double-layer load-bearing armor layer, a circumferential heat flow guiding layer, a segmented controllable electrothermal layer, and an elliptical aerodynamic drag-reducing outer sheath. The circumferential heat flow guiding layer covers the outer side of the circular double-layer load-bearing armor layer, with an elliptical outer surface and a circular inner surface. Its circumferential thermal conductivity is non-uniformly distributed, with high thermal conductivity materials placed in low-temperature regions where heat dissipation is fast and low thermal conductivity materials placed in high-temperature regions where heat dissipation is slow. The segmented controllable electrothermal layer is divided into several independent control sections along the cable axis. An edge controller is connected to the distributed sensing fiber optic unit, and calculates and distributes the electrothermal power of each section in real time based on temperature distribution, strain distribution, and vibration spectrum.

[0006] Furthermore, the circumferential heat flow guiding layer is integrally formed using a multi-head, multi-channel co-extrusion die head process, with at least two extruders arranged circumferentially, and multiple independent channels built into the die head corresponding to multiple circumferential heat conduction zones.

[0007] Furthermore, in the circumferential heat flow guiding layer, the thermal conductivity of region A at both ends of the long axis is ≥5W / (m·K), the thermal conductivity of region B at both ends of the short axis is ≤0.5W / (m·K), and the thermal conductivity of the transition region C is 1~3W / (m·K); under normal operating conditions, the circumferential temperature difference on the cable surface is compressed to ≤±3℃ by utilizing the Joule heating of the conductor.

[0008] Furthermore, the segmented controllable heating layer is a strip-shaped self-limiting polymer PTC heating material or a flexible graphene composite heating film; the edge controller is also used to monitor the real-time resistance changes of each segment, and when the resistance of a certain segment deviates from the nominal value by more than a preset threshold, an early warning signal for aging or damage of the heating layer is generated.

[0009] Furthermore, a phase change heat dissipation microtube array is also provided, which is fixed on the outer surface of the circular double-layer load-bearing armor layer and located at both ends of the long axis, with at least one at each end, and the tube is encapsulated with a phase change material with a melting point of 55℃~65℃.

[0010] Furthermore, the ratio of the major axis to the minor axis of the elliptical aerodynamic drag-reducing outer sheath is 1.3 to 1.6, and axial guide ribs are provided on the outer surfaces at both ends of the major axis. The cross-section of the guide ribs is arc-shaped, which smoothly transitions with the surface of the sheath, and the outer sheath and the guide ribs are integrally extruded.

[0011] Furthermore, a thermally conductive insulating pad is provided, which is filled between the power transmission unit and the circular double-layer load-bearing armor layer. The pad is made of boron nitride-filled polyimide film composite material. The power transmission unit is provided with a copper wire shielding layer, which is also used to share part of the axial tensile force.

[0012] Furthermore, the edge controller communicates with the weather forecast server to obtain weather forecast data of the environment where the cable is located within a preset time period, and accordingly applies heating power to the low-temperature area before the ambient temperature drops to the freezing threshold, forming feedforward compensation; the edge controller also performs closed-loop correction based on the real-time feedback data of the distributed sensing fiber unit to realize composite control of feedforward and feedback.

[0013] Furthermore, an anti-icing coating is provided on the surface of the elliptical aerodynamic drag-reducing outer sheath, which is a composite structure of fluorosilane-modified silica nanoparticles as the bottom layer and graphene microsheets as the surface layer.

[0014] Furthermore, the distributed sensing fiber unit contains at least two sensing fibers, which are redundantly configured; the edge controller periodically sends self-test pulse signals to each sensing fiber, judges the health status of the fiber based on the echo signal, and switches to the backup fiber when fiber performance degradation is detected.

[0015] Furthermore, the present invention also provides a method for preparing the above-mentioned tethered cable, comprising the following steps: stranding conductors or co-extruding and cross-linking medium-voltage three layers to form a power transmission unit; inserting optical fibers into a stainless steel loose tube and sealing it with water-resistant fiber grease to form a sensing optical fiber unit; stranding three power transmission units into a cable and embedding them into the optical fiber unit, then wrapping it with a thermally conductive insulating pad; providing a double-layer reverse spiral continuous armor without joints for steel wires; co-extruding a circumferential heat flow guiding layer using a multi-head, multi-channel co-extrusion process; laying a segmented controllable electrothermal layer and laser etching to isolate the lead-out electrodes; and extruding an elliptical pneumatic drag-reducing outer sheath using a shaped die.

[0016] The beneficial effects of this invention are: (1) The present invention uses the counterintuitive design of the circumferential heat flow guiding layer to actively supplement heat in the low temperature area and to prevent excessive heat concentration in the high temperature area. By using the Joule heat of the conductor under normal operating conditions, the circumferential temperature difference is compressed from 5~8℃ to ≤±3℃, which significantly reduces the start-up frequency of the electric heating layer and reduces the overall energy consumption by 15%~25%.

[0017] (2) The present invention uses the communication connection between the edge controller and the meteorological forecast server to pre-apply heating power to the low temperature area before the ambient temperature drops to the icing threshold, forming feedforward compensation. Combined with the real-time feedback signal of the distributed optical fiber, closed-loop correction is performed, realizing the coordinated control of advanced anti-icing and precise de-icing, and shortening the icing response time to less than 30 seconds.

[0018] (3) This invention improves the sensing reliability of the cable throughout its entire life cycle by periodically detecting the health status of the optical fiber and automatically switching to the backup optical fiber when the performance deteriorates through the redundant configuration and self-testing function of the distributed sensing optical fiber unit; and realizes automatic diagnosis and early warning of aging and damage of the electrothermal layer through online monitoring of the resistance of the electrothermal layer, thereby reducing the operation and maintenance cost.

[0019] (4) The present invention provides a complete preparation method, which adopts a multi-head multi-channel co-extrusion process to form a circumferential heat flow guiding layer in one step. The process is simple and the partitioning is precise, which is suitable for industrial-scale production. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a schematic diagram of the cable cross-section structure of the present invention.

[0022] Figure 2 This is a schematic diagram of the circumferential partitioning of the circumferential heat flow guiding layer of the present invention.

[0023] Figure 3 This is a block diagram of the edge controller control logic of the present invention.

[0024] Explanation of reference numerals in the attached figures: 100. Power transmission unit; 110. Conductor; 120. Cross-linked polyethylene insulation layer; 130. Copper wire shielding layer; 200. Distributed sensing fiber optic unit; 300. Communication fiber optic unit; 400. Wrapped thermally conductive insulating pad; 500. Circular double-layer load-bearing armor layer; 600. Phase change heat dissipation microtube array; 700. Circumferential heat flow guiding layer; 710. High thermal conductivity material in area A; 720. Low thermal conductivity material in area B; 730. Medium thermal conductivity material in area C; 800. Segmented controllable electrothermal layer; 900. Elliptical aerodynamic drag-reducing outer sheath; 910. Guide rib; 1000. Surface anti-icing coating; 1100. Edge controller. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] like Figure 1 , Figure 2 and Figure 3As shown, the present invention discloses an intelligent tethered cable with a circumferential heat flow guiding layer, comprising, from the inside out, a power transmission unit 100, a distributed sensing optical fiber unit 200, a communication optical fiber unit 300, a wrapped thermally conductive insulating pad 400, a circular double-layer load-bearing armor layer 500, a phase change heat dissipation microtube array 600, a circumferential heat flow guiding layer 700, a segmented controllable electric heating layer 800, an elliptical aerodynamic drag-reducing outer sheath 900, and a surface anti-icing coating 1000.

[0028] The power transmission unit 100 is located in the innermost layer of the cable, and uses one or more stranded copper or high-strength aluminum alloy conductors 110 with a nominal cross-section of 50~400mm². The outermost layer of conductor 110 has no splices, and the entire conductor has no intermediate joints to avoid stress concentration and breakage at joints in moored scenarios. The rated voltage is selected according to the application scenario: ≤1kV can be selected for ground mooring systems, and 10~35kV can be selected for high-altitude cableways. In medium-voltage paths, a semi-conductive conductor shielding layer, a cross-linked polyethylene insulation layer 120, and a semi-conductive insulation shielding layer are sequentially set outside conductor 110, and a copper wire shielding layer 130 is set on the outermost layer. The copper wire is loosely wound and the copper tape is tied tightly in the opposite direction. The copper wire shielding layer 130 not only provides electromagnetic shielding and fault current carrying capacity, but also can share part of the axial tensile force under moored conditions, improving the overall tensile strength of the cable.

[0029] The distributed sensing fiber optic unit 200 uses multimode fiber (62.5 / 125μm), encapsulated in a 1.5mm inner diameter stainless steel loose tube, and filled with water-blocking fiber grease. The end is connected to a three-in-one demodulation module combining Raman time-domain reflectometry, Brillouin time-domain reflectometry, and phase-sensitive time-domain reflectometry to achieve distributed measurement of temperature (±1℃), strain (±20με), and vibration (0~100Hz), with a spatial resolution ≤1m. In this embodiment, two sensing fibers are configured for redundancy. The edge controller 1100 periodically sends self-test pulse signals to each sensing fiber, judging the fiber's health status based on the attenuation of the echo signal. When performance degradation of a fiber is detected, it automatically switches to the backup fiber, ensuring the continuity of sensing data throughout its entire lifecycle.

[0030] The communication fiber optic unit 300 uses single-mode fiber, is encapsulated in an independent stainless steel loose tube, and is filled with water-blocking fiber grease. It is used for uplink transmission of sensor data and is physically isolated from the sensor fiber to ensure communication reliability.

[0031] Three power transmission units 100 are arranged in a triangular twisted configuration, with distributed sensing fiber optic units 200 and communication fiber optic units 300 embedded in the gaps. The remaining gaps are filled with polypropylene filler strips with steel wire rope cores. The cable core is wrapped with a 0.2~0.5mm thick boron nitride-filled polyimide film and non-woven fabric composite material to form a thermally conductive and insulating pad 400 with an overlap rate of ≥25%, achieving the functions of thermal conductivity (λ≥2W / (m·K)), insulation, and stress absorption during cable formation.

[0032] The circular double-layer load-bearing armor layer 500 is constructed from double-layer reverse spiral winding of steel wire, providing the cable with axial tensile and torsional load-bearing capacity. The inner layer of steel wire is wound in a reverse spiral with a pitch of 8 times the outer diameter; the outer layer of steel wire is wound in a reverse spiral (opposite to the inner layer) with a pitch of 12 times the outer diameter. Z-shaped steel wire is preferred, with a corner radius ≥0.3mm. The Z-shaped interlocking significantly improves torsional stiffness, while the overall circular cross-section ensures dynamic bending flexibility in moored scenarios. After armoring, the circular cross-section is maintained, with a roundness deviation ≤0.3mm.

[0033] The phase change heat dissipation microtube array 600 is only arranged at both ends of the long axis (area A), fixed to the outer surface of the armor layer 500, located between the armor layer 500 and the circumferential heat flow guiding layer 700. Each end has at least one microtube, using a metal tube with an outer diameter of 2-3 mm, encapsulating a phase change material (preferably paraffin-based phase change material) with a melting point of 55-65℃. The melting point of the phase change material is higher than the normal operating temperature, triggering melting and heat absorption only in de-icing mode. In de-icing mode, when the high thermal conductivity material 710 in area A rapidly conducts heat inward, the phase change microtube absorbs pulsed heat, limiting the inner core temperature to below 70℃. When the electrothermal pulse enters its intermittent period, the phase change material re-solidifies, preparing for the next heat absorption.

[0034] like Figure 2 As shown, the circumferential heat flow guiding layer 700 is the core feature layer of the cable, filling the outer side of the armor layer 500 and the inner side of the heating layer 800. Its outer surface is elliptical (fitting the inner wall of the heating layer 800 and the outer sheath 900), and its inner surface is circular (fitting the outer wall of the armor layer 500). The circumferential heat flow guiding layer 700 is integrally formed using a multi-head, multi-channel co-extrusion die process. Several extruders are arranged circumferentially, and the die has multiple independent channels corresponding to multiple circumferential heat conduction zones. After each channel exits independently, they are fused together to form the final product. A typical configuration consists of three extruders and eight flow channels forming three thermally conductive zones: Zone A (both ends of the long axis, high thermal conductivity, λ≥5W / (m·K), boron nitride or graphene-modified silicone), Zone B (both ends of the short axis, low thermal conductivity, λ≤0.5W / (m·K), microporous polyurethane elastomer), and Zone C (transition zone, medium thermal conductivity, λ=1~3W / (m·K), conventional thermally conductive silicone). This design employs a counterintuitive approach: in the low-temperature Zone A, high thermal conductivity material 710 actively guides internal heat to the surface to compensate for temperature drops; in the high-temperature Zone B, low thermal conductivity material 720 prevents excessive heat concentration; and in Zone C, medium thermal conductivity material 730 facilitates temperature transition. Under normal operating conditions, the circumferential temperature difference can be reduced from 5~8℃ to ≤±3℃ solely through the redistribution of Joule heat in the circumferential heat flow guiding layer 700, resulting in a 15%~25% reduction in overall electrothermal energy consumption compared to a uniform heat conduction scheme.

[0035] The segmented controllable heating layer 800 is laid on the elliptical outer surface of the circumferential heat flow guiding layer 700. The heating layer 800 is divided into several independently controllable sections along the cable axis. The section length is selected from 3 to 50 meters depending on the application scenario. Adjacent sections are separated by laser-etched 5-30 mm insulation barriers, with independent electrodes leading out. The optional paths for the heating layer 800 include: Path A is a carbon black polyolefin composite self-regulating polymer (PTC), suitable for anti-icing mode and long-pulse de-icing; Path B is a graphene composite heating film formed by calendering graphene microsheets and a -50℃ resistant elastomer, with a serpentine conductive path laser-etched on the surface, providing fast thermal response and suitable for short-pulse rapid de-icing. The edge controller 1100 also periodically monitors the real-time resistance changes of each section. When the resistance of a section deviates from the nominal value by more than a preset threshold, an aging or damage warning signal for that section's heating layer is automatically generated, prompting maintenance.

[0036] The elliptical aerodynamic drag-reducing outer sheath 900 is made of TPU material that is -50℃ resistant, tear-resistant, and UV-resistant. It is formed by a shaped extrusion die, with a major axis to minor axis ratio of 1.3~1.6 and a drag coefficient Cd≤0.6. Axial guide ribs 910 are provided on the outer surface of both ends of the major axis of the outer sheath 900. The guide ribs 910 have an arc-shaped cross-section (3mm wide at the bottom and 1.5mm high), smoothly transitioning with the sheath surface and integrally extruded with the outer sheath 900. Under wind action, the guide ribs 910 generate aerodynamic torque, causing the cable to rotate until the major axis is aligned with the wind direction, suitable for mooring scenarios with stable prevailing winds.

[0037] The surface anti-icing coating 1000 is applied to the outer surface of the elliptical aerodynamic drag-reducing outer sheath 900. It is a composite structure of fluorosilane-modified silica nanoparticles as the bottom layer and graphene microplate as the surface layer. The contact angle is ≥150° and the solar light absorption rate is ≥90%.

[0038] like Figure 3 As shown, the edge controller 1100 is deployed in a cable end or intermediate junction box, connected to the distributed sensing fiber optic unit 200 via optical fiber, electrically connected to the electrodes of each segment of the segmented controllable electrothermal layer 800, and simultaneously communicates with the weather forecast server via a wireless network. The core control logic of the edge controller 1100 is as follows: First, the temperature distribution, strain distribution, and vibration spectrum along the cable are acquired in real time using distributed sensing fiber optic units 200. A one-dimensional discretized heat conduction equation combined with a regularization method is used to reconstruct the thermo-mechanical coupling field along the cable, identifying the icing location and equivalent ice load.

[0039] Secondly, the edge controller 1100 communicates with the weather forecast server to obtain weather forecast data such as wind speed, temperature, and humidity of the environment where the cable is located within a preset time period (e.g., the next 6 hours). When the weather forecast data indicates that the ambient temperature is about to drop to the icing threshold, the edge controller 1100 pre-applies heating power to the predicted low-temperature area before icing occurs, forming feedforward compensation to keep the surface temperature of the area above the freezing point, thus achieving proactive anti-icing.

[0040] Next, closed-loop correction is performed based on the real-time feedback data from the distributed sensing fiber optic unit 200, and the final power allocation command is formed by combining the feedforward command and the feedback measurement results. The operating modes include: standby mode (power 5W / m when the minimum temperature is >2℃ and there is no ice load), anti-icing mode (power 10~40W / m when the minimum temperature is ≤2℃, linearly adjustable within the -5℃~+2℃ range), and de-icing mode (power 40~100W / m when the strain increment is >200με or the vibration peak exceeds the threshold for 30 seconds, single duration ≤30 minutes, interval between two adjacent de-icing operations ≥2 hours). In de-icing mode, non-uniform ice load is eliminated through rapid heating, and the aerodynamic shape of the cable recovers and wind resistance drops sharply after the ice layer falls off, assisting in vibration attenuation and achieving active suppression of galloping vibration.

[0041] The preparation method of this invention includes the following steps: conductor stranding or medium-pressure three-layer co-extrusion cross-linking → optical fiber insertion into stainless steel loose tube, injection of water-resistant fiber grease for sealing → phase change microtube length cutting, cleaning, and temporary sealing of both ends → three power transmission units cabled, stranded, and embedded with optical fiber units and filler strips → wrapping with thermally conductive insulating pads → double-layer steel wire seamless continuous armoring → phase change microtubes fixed at both ends of the long axis of the armor layer → multi-head multi-channel co-extrusion forming of circumferential heat flow guiding layer → electrothermal layer cutting, laser etching, isolation, lead-out electrodes, constant tension longitudinal wrapping on the elliptical outer surface of the circumferential heat flow guiding layer → elliptical pneumatic drag-reducing outer sheath and guide ribs extruded by irregular mold → plasma treatment, spraying silica underlayer for curing, then spraying graphene top layer for curing → factory testing.

[0042] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A smart tethered cable with a circumferential heat flow guiding layer, characterized in that, include: Power transmission unit (100) for transmitting electrical energy; A distributed sensing fiber optic unit (200) is arranged along the cable axis to acquire the temperature distribution, strain distribution, and vibration spectrum along the cable in real time. A circular double-layer load-bearing armor layer (500) covers the outside of the power transmission unit (100) and is composed of double-layer reverse spiral winding of steel wire. A circumferential heat flow guiding layer (700) covers the outside of the circular double-layer load-bearing armor layer (500), with an elliptical outer surface and a circular inner surface. Its circumferential thermal conductivity is non-uniformly distributed, and its distribution trend is towards low-temperature regions with rapid heat dissipation. High thermal conductivity materials are used, and low thermal conductivity materials are used in high-temperature areas where heat dissipation is slow; a segmented controllable electric heating layer (800) is divided into several independent control sections along the cable axis and laid on the elliptical outer surface of the circumferential heat flow guiding layer (700); an elliptical aerodynamic drag-reducing outer sheath (900) is wrapped around the outside of the segmented controllable electric heating layer (800); and an edge controller is connected to the distributed sensing fiber optic unit (200) to calculate and distribute the electric heating power of each section in real time according to the temperature distribution, strain distribution and vibration spectrum.

2. The intelligent tethered cable with a circumferential heat flow guiding layer according to claim 1, characterized in that: The circumferential heat flow guiding layer (700) is integrally formed using a multi-head, multi-channel co-extrusion die head process. At least two extruders are arranged circumferentially, and the die head has multiple independent channels that correspond to multiple circumferential heat conduction zones. The minimum configuration is two extruders with four flow channels to form two heat conduction zones, and the typical configuration is three extruders with eight flow channels to form three heat conduction zones.

3. The intelligent tethered cable with a circumferential heat flow guiding layer according to claim 1, characterized in that: In the circumferential heat flow guiding layer (700), the thermal conductivity of region A at both ends of the long axis is ≥5W / (m·K), the thermal conductivity of region B at both ends of the short axis is ≤0.5W / (m·K), and the thermal conductivity of region C, the transition region between region A and region B, is 1~3W / (m·K). Under normal operating conditions, the circumferential heat flow guiding layer (700) uses the Joule heating of the conductor to compress the circumferential temperature difference on the cable surface to ≤±3℃, and the overall electrothermal energy consumption is reduced by 15%~25% compared with the uniform heat conduction scheme.

4. The intelligent tethered cable with a circumferential heat flow guiding layer according to claim 1, characterized in that: The segmented controllable heating layer (800) is a strip-shaped self-limiting polymer PTC heating material or a flexible graphene composite heating film; the edge controller is also used to monitor the real-time resistance change of each segment, and when the resistance of a certain segment deviates from the nominal value by more than a preset threshold, an aging or damage warning signal of the heating layer of that segment is generated.

5. The intelligent tethered cable with a circumferential heat flow guiding layer according to claim 1, characterized in that: It also includes a phase change heat dissipation microtube array (600), which is fixed to the outer surface of the circular double-layer load-bearing armor layer (500) and located at both ends of the long axis, with at least one at each end. The tubes are encapsulated with a phase change material with a melting point of 55°C to 65°C, which is used to absorb inward pulse heat in de-icing mode to protect the inner core of the cable.

6. The intelligent tethered cable with a circumferential heat flow guiding layer according to claim 1, characterized in that: The ratio of the major axis to the minor axis of the elliptical pneumatic drag-reducing outer sheath (900) is 1.3 to 1.

6. Axial guide ribs (910) are provided on the outer surfaces at both ends of the major axis. The cross section of the guide ribs (910) is arc-shaped and smoothly transitions with the surface of the sheath. The outer sheath and the guide ribs (910) are integrally extruded.

7. The intelligent tethered cable with a circumferential heat flow guiding layer according to claim 1, characterized in that: A thermally conductive insulating pad (400) is also provided, which is filled between the power transmission unit (100) and the circular double-layer load-bearing armor layer (500), and is made of boron nitride-filled polyimide film composite material; the power transmission unit (100) is provided with a copper wire shielding layer (130), with the copper wire loosely wound and the copper strip tightly tied in the opposite direction. The copper wire shielding layer (130) is also used to share part of the axial tensile force.

8. The intelligent tethered cable with a circumferential heat flow guiding layer according to claim 1, characterized in that: The edge controller is connected to the weather forecast server to obtain weather forecast data of the environment where the cable is located within a preset time period. Based on this, it applies heating power to the low-temperature area in advance before the ambient temperature drops to the freezing threshold, forming feedforward compensation. The edge controller also performs closed-loop correction based on the real-time feedback data of the distributed sensing fiber unit (200) to realize the composite control of feedforward and feedback.

9. A smart tethered cable with a circumferential heat flow guiding layer according to claim 1, characterized in that: It is also provided with a surface anti-icing coating (1000) coated on the outer surface of the elliptical aerodynamic drag-reducing outer sheath (900). The anti-icing coating (1000) is a composite structure of fluorosilane modified silica nanoparticle bottom layer and graphene microplate surface layer, with a contact angle ≥150° and a solar light absorption rate ≥90%.

10. A method for preparing a smart tethered cable with a circumferential heat flow guiding layer as described in any one of claims 1 to 9, characterized in that... The process includes the following steps: Step a: Prepare a power transmission unit (100) by stranding a single or multiple copper or high-strength aluminum alloy conductors, with no splices on the outermost single filament of the conductor; for medium-voltage paths, a semi-conductive conductor shielding layer, a cross-linked polyethylene insulation layer (120), and a copper wire shielding layer (130) are set in sequence, and an insulation layer is extruded for low-voltage paths; Step b: Prepare a distributed sensing fiber optic unit (200) by inserting multimode optical fibers into a stainless steel loose tube and injecting water-blocking fiber grease to seal both ends; Step c: Strand three power transmission units (100) into a cable in a triangular arrangement, embed a distributed sensing fiber optic unit (200) and a communication fiber optic unit (300) at the edge gaps, and wrap a boron nitride-filled polyimide film composite material to form a wrapped thermally conductive insulating pad layer (400) with an overlap rate ≥25%; Step d: Use steel wire to form a circular double-layer load-bearing armor layer (500) by double-layer reverse spiral winding, with continuous armoring without joints in the steel wire; Step e: A circumferential heat flow guiding layer (700) is formed on the outside of the circular double-layer load-bearing armor layer (500) using a multi-head, multi-channel co-extrusion die process. At least two extruders are arranged circumferentially. The die has multiple independent channels that correspond to multiple heat conduction zones in the circumferential direction. After each channel discharges independently, they are fused at the die outlet. The outer die orifice of the extrusion die is elliptical and the inner die core is circular, directly forming an outer elliptical and inner circular cross section. Step f: A segmented controllable electric heating layer (800) is laid on the elliptical outer surface of the circumferential heat flow guiding layer (700). Independent electrodes are led out after laser etching for insulation separation. Step g: An elliptical pneumatic drag-reducing outer sheath (900) is extruded on the outside of the segmented controllable electric heating layer (800) using a shaped extrusion die.

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