Ultrahigh-conductivity wire and cable and preparation method thereof

Abstract

The invention relates to the technical field of electric wires and cables, and discloses an ultrahigh-conductivity electric wire and cable and a preparation method thereof. A graphene enhancement layer; a nano composite insulating material layer; an inner semi-conductive layer; a conductive copper strip shielding layer; a silver-plated copper wire woven mesh shielding layer; an intelligent monitoring and protection sheath; the method comprises the following steps: step S01, preparing a superconducting core wire strand; step S02, preparing a nano composite insulating material layer; s03, preparing a shielding layer; step S04, intelligent monitoring and protection sheath preparation; the superconducting core wire strand formed by twisting a plurality of YBCO superconducting material filaments forms a stable structure with excellent conductivity under the precise control of twisting process parameters, so that the resistance is effectively reduced, the loss in the electric energy transmission process is reduced, the electric energy transmission efficiency is improved, high-density current can be borne for stable transmission, and the service life of the cable is prolonged. And the requirement of the modern electrical engineering field on high conductivity of wires and cables is met.

Description

Technical Field

[0001] The present invention relates to the technical field of wires and cables, and in particular to an ultra-high conductive wire and cable. Background Art

[0002] In modern electrical engineering, wires and cables are key carriers of power and signal transmission, and their performance is directly related to the efficiency, safety, and stability of power systems. With the rapid development of science and technology and the increasing demand for energy transmission and utilization, the conductive properties of traditional wires and cables are no longer sufficient for many emerging applications.

[0003] A search revealed Chinese patent number CN103602072A, which discloses a conductive silicone rubber material with electromagnetic shielding properties and its manufacturing method. This patent belongs to the field of organic polymer / metal composite material preparation and chemical processing. Based on a silicone rubber elastomer, this invention utilizes silver-plated nickel powder and silver-plated copper powder to enhance the material's magnetic and electrical conductivity, thereby improving the composite's overall mechanical and electromagnetic shielding properties. The material exhibits excellent electromagnetic shielding performance across the 200 kHz to 10 GHz frequency range, making it suitable for electromagnetic shielding in substations. Its excellent strength and toughness meet the requirements of material installation construction.

[0004] A search revealed Chinese patent number CN110406211A, which discloses a silicone rubber anti-electromagnetic interference insulation fabric and its preparation method. The fabric is composed of a conductive electromagnetic shielding layer and an insulating silicone rubber layer. The silicone rubber layer exhibits excellent insulation, hydrophobicity, and aging resistance, and is commonly used for external insulation of equipment. The insulation fabric acts as an insulator in the vertical direction, while the electromagnetic shielding layer acts as a conductor in the horizontal direction. This multi-layer composite structure achieves both insulation and electromagnetic shielding capabilities, achieving a breakdown strength exceeding 20kV / mm and an electromagnetic shielding effectiveness of 70dB.

[0005] Although the above-mentioned conventional conductor materials such as copper and aluminum have certain conductivity, the power loss is more significant due to the existence of resistance during large-scale power transmission. This not only reduces the efficiency of energy transmission and increases energy costs, but also limits the transmission capacity and coverage of the power system to a certain extent. Especially in long-distance power transmission, high-power transmission and special application scenarios with extremely high requirements for power quality, the shortcomings of the above-mentioned wires and cables are becoming more and more prominent; in addition, in terms of insulating materials, although the above-mentioned insulation technology can meet the insulation requirements under conventional voltage levels, under high voltage, high current and complex environmental conditions, once the nano-composite insulation material layer has problems such as aging and corona discharge, it may not only cause power transmission interruption, but also may cause serious safety accidents. Based on this, the present invention designs an ultra-high conductivity wire and cable to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to provide an ultra-high conductivity wire and cable to solve the problems in the background technology.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: An ultra-high conductivity wire and cable, comprising: Superconducting core strands: Made of multiple strands of YBCO superconducting material filaments twisted together; Graphene reinforcement layer: wrapped around the outside of the superconducting core strand, the graphene content in the graphene reinforcement layer is 5% to 20%, and the thickness of the reinforcement layer is 0.1 mm to 0.5 mm; Nanocomposite insulation material layer: cross-linked polyethylene as the matrix, with nano-silicon dioxide particles and boron nitride particles added; Inner semi-conductive layer: Made of a highly conductive carbon black and polyethylene composite material, with a carbon black content of 20% to 30% and a thickness of 0.05 mm to 0.2 mm, it is coated on the outside of the nanocomposite insulating material layer through an extrusion process at an extrusion temperature of 130 degrees Celsius to 160 degrees Celsius; Conductive copper tape shielding layer: The thickness of the copper tape is 0.1 mm to 0.3 mm and the width is 10 mm to 30 mm; Silver-plated copper wire braided shield: The diameter of the silver-plated copper wire is 0.05 mm to 0.15 mm, the braiding density is greater than 80%, the thickness is 0.3 mm to 0.8 mm, and the braiding angle is 45 degrees to 55 degrees; Intelligent monitoring and protection sheath: based on polyvinyl chloride, with anti-aging additives, wear-resistant additives and flame retardant additives added.

[0008] Preferably, the superconducting core strand further comprises superconducting material filaments having a diameter ranging from 0.05 mm to 0.2 mm, a stranding pitch of 10 mm to 100 mm, a stranding tension controlled at 10 Newtons to 50 Newtons, and a stranding speed of 10 m / min to 30 m / min; The graphene enhancement layer is formed by chemical vapor deposition or solution coating at a deposition temperature of 800 to 1000 degrees Celsius or a coating temperature of 60 to 100 degrees Celsius, and is cured at a temperature of 200 to 300 degrees Celsius for a time of 10 to 30 minutes. The nanocomposite insulating material layer further comprises nano-silicon dioxide with a particle size of 10 to 50 nanometers and an addition amount of 5% to 15%, the boron nitride with a particle size of 5 to 30 nanometers and an addition amount of 3% to 10%, the thickness of the nanocomposite insulating material layer is 1 to 5 mm, and the breakdown strength is greater than 20 kilovolts per millimeter; The conductive copper tape shielding layer is wrapped around the outer side of the inner semi-conductive layer in a spiral winding manner, with a winding angle of 30 degrees to 60 degrees, and the copper tapes are overlapped with each other, with an overlap width of 2 mm to 5 mm; The intelligent monitoring and protection sheath also includes an anti-aging additive content of 0.5% to 2%, a wear-resistant additive content of 0.3% to 1.5%, and a flame retardant additive content of 1% to 3%, and the sheath layer thickness is 1 mm to 3 mm; optical fiber sensors and micro-nano sensors are evenly dispersed in the sheath layer, and the arrangement spacing of the optical fiber sensors is 10 cm to 50 cm, and the arrangement spacing of the micro-nano sensors is 20 cm to 60 cm.

[0009] Preferably, the nanocomposite insulating material layer is prepared by melt blending in a twin-screw extruder, the extrusion temperature is 150 degrees Celsius to 200 degrees Celsius, the screw speed is 30 rpm to 60 rpm, and the inner semi-conductive layer and the nanocomposite insulating material layer are treated with plasma or a chemical coupling agent.

[0010] Preferably, the preparation material of the intelligent monitoring and protection sheath also includes a lubricant with a mass fraction of 0.1% to 0.5%.

[0011] Preferably, the method comprises the following steps: Step S01, preparing a superconducting core strand, wherein superconducting material filaments are twisted into a superconducting core strand, and the twisting pitch, tension, and speed are controlled within a predetermined range; a graphene reinforcement layer is wrapped around the outer side of the superconducting core strand by chemical vapor deposition or solution coating, and a curing treatment is performed after deposition or coating; Step S02, preparing a nanocomposite insulating material layer, surface-modifying nano-silicon dioxide particles and boron nitride particles; melt-blending the modified nanoparticles with a cross-linked polyethylene matrix in a twin-screw extruder to form a nanocomposite insulating material; and coating the insulating material on the outside of the conductor layer through an extrusion process at an extrusion temperature of 160°C to 210°C, using water cooling at a cooling water temperature of 10°C to 20°C, and a cooling rate of 5 meters per minute to 10 meters per minute. Step S03, preparing a shielding layer; Step S04: intelligent monitoring and protective sheath preparation.

[0012] Preferably, the step S03, preparing the shielding layer, further comprises the following steps: Step S031, preparing the inner semi-conductive layer, uniformly mixing highly conductive carbon black and polyethylene composite material, extruding the mixture through an extruder and coating the outer side of the nanocomposite insulating material layer at an extrusion temperature of 130 degrees Celsius to 160 degrees Celsius; Step S032, preparing a conductive copper tape shielding layer, wrapping the copper tape around the outer side of the inner semi-conductive layer in a spiral winding manner, and controlling the thickness, width, winding angle and overlap width of the copper tape to be within a predetermined range; Step S033: preparing a silver-plated copper wire braided mesh shielding layer, using a braiding machine to weave the silver-plated copper wire into a mesh, controlling the braiding angle and density within a predetermined range, and the braiding speed at 10 to 30 meters per minute; The step S04 also includes the following steps: uniformly mixing the polyvinyl chloride substrate with an anti-aging additive, a wear-resistant additive, a flame retardant additive, and a lubricant; extruding the mixed sheath material through an extruder and coating the outer side of the shielding layer, the extrusion temperature is 160 degrees Celsius to 200 degrees Celsius, the cooling method is water cooling, the cooling water temperature is 15 degrees Celsius to 25 degrees Celsius, and the cooling rate is 8 meters per minute to 15 meters per minute; during the extrusion process of the sheath layer, the optical fiber sensor and the micro-nano sensor are uniformly dispersed in the sheath layer by implantation, and the sensor implantation depth is one-third to one-half of the thickness of the sheath layer.

[0013] Preferably, the curing treatment of the graphene enhancement layer adopts a staged heating process. In the first stage, the temperature is raised to 150 degrees Celsius at a rate of 5 degrees Celsius per minute and kept warm for 5 minutes; in the second stage, the temperature is raised to the target curing temperature at a rate of 3 degrees Celsius per minute.

[0014] Preferably, during the spiral winding process of the conductive copper tape shielding layer, ultrasonic welding treatment is applied to the edge of the copper tape, the welding frequency is 20 kHz to 40 kHz, and the welding pressure is 0.2 MPa to 0.5 MPa.

[0015] Preferably, during the preparation of the nanocomposite insulating material layer, the surface modification degree of the nano-silicon dioxide particles and the boron nitride particles is adjusted by controlling the amount of the modifying agent and the modification time.

[0016] Preferably, after the nanocomposite insulating material layer is extruded, the surface of the nanocomposite insulating material layer is subjected to corona treatment, with a treatment voltage of 10 kV to 15 kV, an electrode spacing of 1 mm to 3 mm, and a treatment time of 30 seconds to 90 seconds.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention adopts a superconducting core strand formed by twisting multiple strands of YBCO superconducting material filaments. Under the precise control of the twisting process parameters, a stable structure with excellent conductive performance is formed, which effectively reduces the resistance and the loss during the power transmission process, improves the efficiency of power transmission, and can carry high-density current for stable transmission, meeting the demand for high conductivity of wires and cables in the field of modern electrical engineering.

[0018] 2. The present invention tightly wraps the superconducting core strands with a graphene reinforcement layer. The unique two-dimensional nanostructure and excellent thermal conductivity of graphene enable it to effectively conduct and dissipate heat, ensuring the stable operation of the superconducting core strands, avoiding superconducting performance degradation or failure due to overheating, and improving the reliability and durability of the cable system. At the same time, the boron nitride particles in the nanocomposite insulating material layer also enhance the thermal conductivity of the nanocomposite insulating material layer, accelerate heat conduction and dissipation, and reduce the increase in the operating temperature of the nanocomposite insulating material layer.

[0019] 3. The present invention, through the twisting process of the superconducting core strands, makes the strands have good mechanical strength and flexibility, can adapt to complex laying environments and mechanical stresses, such as stretching, bending, torsion and other mechanical stresses that may be encountered during cable laying, as well as reliability in use under different geographical conditions and climatic environments, thereby improving the service life and stability of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the overall structure of the ultra-high conductive wire and cable of the present invention; Figure 2 This is a diagram showing the composition of the ultra-high conductive wire and cable of the present invention; Figure 3 This is a flow chart of the steps of the method for preparing the ultra-high conductive wire and cable of the present invention; Figure 4 Flow chart of the steps for preparing the shielding layer of the present invention.

[0021] Among them: 1. Superconducting core wire strands; 2. Graphene reinforcement layer; 3. Nanocomposite insulation material layer; 4. Inner semi-conductive layer; 5. Conductive copper tape shielding layer; 6. Silver-plated copper wire braided mesh shielding layer; 7. Intelligent monitoring and protection sheath. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] Example 1; please refer to Figures 1-4In an embodiment of the present invention, an ultra-high conductivity wire and cable is characterized by comprising: a superconducting core strand 1: formed by twisting multiple strands of YBCO superconducting material filaments, the diameter of the superconducting material filaments ranges from 0.05 mm to 0.2 mm, the twisting pitch ranges from 10 mm to 100 mm, the twisting tension is controlled at 10 Newtons to 50 Newtons, and the twisting speed ranges from 10 meters per minute to 30 meters per minute; a graphene reinforcement layer 2: wrapped around the outside of the superconducting core strand 1, the graphene content in the graphene reinforcement layer 2 is 5% to 20%, the thickness of the reinforcement layer is 0.1 mm to 0.5 mm, and the graphene reinforcement layer 2 is formed by chemical vapor deposition or solution coating. The nanocomposite insulating material layer 3 is formed by a deposition temperature of 800 to 1000 degrees Celsius or a coating temperature of 60 to 100 degrees Celsius, and is cured at a temperature of 200 to 300 degrees Celsius for a curing time of 10 to 30 minutes; the nanocomposite insulating material layer 3 is based on cross-linked polyethylene, and nano-silicon dioxide particles and boron nitride particles are added. The nano-silicon dioxide particle size is 10 to 50 nanometers and the addition amount is 5% to 15%. The boron nitride particle size is 5 to 30 nanometers and the addition amount is 3% to 10%. The thickness of the nanocomposite insulating material layer is 1 to 5 mm, and the breakdown strength is greater than 20 kilovolts per millimeter. The inner semi-finished product is characterized by a plurality of layers, a plurality of layers, and a plurality of layers. Conductive layer 4: Made of a highly conductive carbon black and polyethylene composite material with a carbon black content of 20% to 30% and a thickness of 0.05 mm to 0.2 mm, it is extruded onto the outer side of the nanocomposite insulating material layer at an extrusion temperature of 130°C to 160°C. Conductive copper tape shielding layer 5: The copper tape is 0.1 mm to 0.3 mm thick and 10 mm to 30 mm wide, and is spirally wrapped around the outer side of the inner semi-conductive layer 4 at a winding angle of 30 to 60 degrees. The copper tapes overlap with each other, with an overlap width of 2 mm to 5 mm. Silver-plated copper wire braided shielding layer 6: The diameter of the silver-plated copper wire is 0.05 mm to 0. 15 mm, weaving density greater than 80%, thickness of 0.3 mm to 0.8 mm, weaving angle of 45 degrees to 55 degrees; Intelligent monitoring and protection sheath 7: polyvinyl chloride as the base material, adding anti-aging additives, wear-resistant additives and flame retardant additives, of which the anti-aging additive content is 0.5% to 2%, the wear-resistant additive content is 0.3% to 1.5%, the flame retardant additive content is 1% to 3%, and the sheath layer thickness is 1 mm to 3 mm; optical fiber sensors and micro-nano sensors are evenly dispersed in the sheath layer, the arrangement spacing of the optical fiber sensors is 10 cm to 50 cm, and the arrangement spacing of the micro-nano sensors is 20 cm to 60 cm.

[0024] The nanocomposite insulating material layer 3 is prepared by melt blending in a twin-screw extruder at an extrusion temperature of 150°C to 200°C and a screw speed of 30 to 60 rpm. The inner semiconductive layer 4 and the nanocomposite insulating material layer are treated with plasma or a chemical coupling agent. The materials used to prepare the intelligent monitoring and protection sheath 7 also include a lubricant at a mass fraction of 0.1% to 0.5%.

[0025] The working principle of the embodiment of the present invention is: the conductor core strand serves as the main body of power transmission, and its multiple strands of YBCO superconducting material filaments are controlled by the twisting process parameters to form a stable structure with excellent conductive properties, providing a basis for stable transmission of high-density current, while enhancing mechanical strength and flexibility to adapt to complex laying environments and mechanical stress.

[0026] The graphene reinforcement layer tightly wraps around the superconducting core strands. Graphene's unique two-dimensional nanostructure and excellent electrical and mechanical properties ensure a tight bond with the superconducting core strands. During the chemical vapor deposition or solution coating process, the graphene forms a continuous and uniform reinforcement layer, reducing interfacial resistance, facilitating efficient electron transmission and minimizing power transmission losses. Its excellent thermal conductivity effectively conducts and dissipates heat, ensuring stable operation of the superconducting core strands and enhancing the reliability and durability of the cable system.

[0027] The nanocomposite insulation layer is made from a cross-linked polyethylene matrix, with nano-silica and boron nitride particles added, then melt-blended in a twin-screw extruder. The nano-silica particles form a three-dimensional network within the matrix, enhancing the mechanical strength and thermal stability of the nanocomposite insulation layer and ensuring insulation performance in high-voltage environments. The boron nitride particles enhance the thermal conductivity of the nanocomposite insulation layer, accelerating heat transfer and dissipation, reducing operating temperature increases and ensuring long-term reliability.

[0028] The inner semi-conductive layer is made of a highly conductive carbon black and polyethylene composite material, extruded onto the outer surface of the nanocomposite insulation layer. The controlled carbon black content ensures optimal conductivity and evens out the electric field, eliminating surface charge accumulation, reducing the concentrated distribution of electric field intensity, and minimizing corona discharge, thereby increasing the lifespan and reliability of the nanocomposite insulation layer.

[0029] The conductive copper tape shield is spirally wrapped around the inner semi-conductive layer. Precisely controlled copper tape parameters ensure excellent conductivity and electromagnetic shielding effectiveness. The overlapping copper tapes form a continuous conductive path, effectively shielding against external electromagnetic interference, limiting the cable's internal electromagnetic field and preventing electromagnetic energy leakage.

[0030] The silver-plated copper wire braided shield further enhances the cable's electromagnetic shielding effectiveness. The high conductivity and corrosion resistance of the silver-plated copper wire form a dense, stable conductive shielding layer on the cable surface. The braided structure, with a braid density exceeding 80%, ensures electrical continuity and uniformity of the shield.

[0031] The intelligent monitoring and protection sheath serves as the cable's outermost layer. The polyvinyl chloride (PVC) base is enhanced with anti-aging, wear-resistant, and flame-retardant additives to impart environmental aging resistance, mechanical wear resistance, and flame retardancy, ensuring the cable's long-term operational safety and reliability. Collected parameters are transmitted to the monitoring system for analysis and processing, enabling timely detection of potential faults and abnormalities, providing a basis for cable maintenance and management.

[0032] Example 2: Please refer to Figures 1-4 In an embodiment of the present invention, the method includes the following steps: step S01, preparing a superconducting core strand 1, forming a superconducting core strand 1 by a twisting process of superconducting material filaments, and controlling the twisting pitch, tension and speed within a predetermined range; wrapping a graphene reinforcement layer 2 on the outside of the superconducting core strand 1 by a chemical vapor deposition method or a solution coating method, and performing a curing treatment after deposition or coating; step S02, preparing a nano-composite insulating material layer 3, surface-modifying nano-silicon dioxide particles and boron nitride particles; melt-blending the modified nano-particles with a cross-linked polyethylene matrix in a twin-screw extruder to form a nano-composite insulating material; coating the insulating material on the outside of the conductor layer by an extrusion process, the extrusion temperature is 160 degrees Celsius to 210 degrees Celsius, the cooling method is water cooling, the cooling water temperature is 10 degrees Celsius to 20 degrees Celsius, and the cooling rate is 5 meters per minute to 10 meters per minute; step S03, preparing a shielding layer; step S04, preparing an intelligent monitoring and protection sheath 7.

[0033] Step S03, preparing the shielding layer, further comprising the following steps: Step S031, preparing the inner semi-conductive layer 4, uniformly mixing highly conductive carbon black with a polyethylene composite material, extruding the mixture through an extruder and coating it on the outside of the nanocomposite insulating material layer, at an extrusion temperature of 130 to 160 degrees Celsius; Step S032, preparing the conductive copper tape shielding layer 5, spirally wrapping the copper tape around the outside of the inner semi-conductive layer 4, controlling the thickness, width, winding angle, and overlap width of the copper tape within a predetermined range; Step S033, preparing the silver-plated copper wire braided mesh shielding layer 6, using a braiding machine to weave the silver-plated copper wire into a mesh, controlling the braiding angle and density within a predetermined range, and weaving at a speed of 10 to 30 meters per minute; Step S04 also includes the following steps: uniformly mixing the polyvinyl chloride substrate with anti-aging additives, wear-resistant additives, flame retardant additives and lubricants; extruding the mixed sheath material through an extruder and coating it on the outside of the shielding layer, the extrusion temperature is 160 degrees Celsius to 200 degrees Celsius, the cooling method is water cooling, the cooling water temperature is 15 degrees Celsius to 25 degrees Celsius, and the cooling rate is 8 meters per minute to 15 meters per minute; during the extrusion process of the sheath layer, the optical fiber sensor and the micro-nano sensor are uniformly dispersed in the sheath layer by implantation, and the sensor implantation depth is one-third to one-half of the thickness of the sheath layer.

[0034] The curing process for the graphene-reinforced layer 2 utilizes a staged heating process. In the first stage, the temperature is raised to 150°C at a rate of 5°C / minute and held for 5 minutes. In the second stage, the temperature is raised to the target curing temperature at a rate of 3°C / minute. During the spiral winding of the conductive copper tape shielding layer 5, the edges of the copper tape are ultrasonically welded at a frequency of 20 kHz to 40 kHz and a pressure of 0.2 MPa to 0.5 MPa. During the preparation of the nanocomposite insulating material layer, the degree of surface modification of the nano-silicon dioxide and boron nitride particles is adjusted by controlling the amount of modifier and the modification time. After extrusion of the nanocomposite insulating material layer 3, the surface of the nanocomposite insulating material layer undergoes corona treatment at a voltage of 10 kV to 15 kV, an electrode spacing of 1 mm to 3 mm, and a treatment time of 30 seconds to 90 seconds.

[0035] The working principle of the embodiment of the present invention is: the superconducting core wire strands serve as the main body for power transmission, and their preparation is completed through a twisting process. The superconducting material filaments form a stable and highly conductive wire strand structure under the control of predetermined twisting pitch, tension and speed parameters. It can carry high-density current and transmit it stably. At the same time, it has good mechanical strength and flexibility, and can adapt to complex laying environments and mechanical stresses.

[0036] Subsequently, a graphene reinforcement layer is applied to the outer surface of the superconducting core strands using chemical vapor deposition or solution coating, followed by a curing process. The formation of the graphene reinforcement layer is achieved through precise control of deposition or coating parameters and a staged temperature-increasing curing process, ensuring a close bond with the superconducting core strands, forming a continuous and uniform reinforcement layer.

[0037] The preparation of the nanocomposite insulation layer involves surface modification of nanosilica and boron nitride particles, followed by melt blending with a cross-linked polyethylene matrix in a twin-screw extruder. By controlling the extrusion temperature and screw speed, the nanoparticles are uniformly dispersed within the matrix, forming a nanocomposite insulation layer with a three-dimensional network structure. This nanocomposite insulation layer undergoes corona treatment after extrusion to optimize its surface properties. The nanosilica particles enhance the mechanical strength and thermal stability of the nanocomposite insulation layer, while the boron nitride particles improve thermal conductivity, ensuring that the nanocomposite insulation layer reliably isolates electrical energy and prevents leakage in high-voltage environments.

[0038] The inner semi-conductive layer is prepared by uniformly mixing highly conductive carbon black with a polyethylene composite material and then coating it onto the outer surface of the nanocomposite insulation layer via an extrusion process. Precisely controlling the carbon black content ensures optimal conductivity and electric field homogenization, effectively eliminating surface charge accumulation, reducing the concentrated distribution of electric field intensity, and minimizing corona discharge, thereby increasing the service life and reliability of the nanocomposite insulation layer.

[0039] The conductive copper tape shield is produced by spirally wrapping copper tape around the outer surface of the inner semi-conductive layer and ultrasonically welding the edges of the tape to ensure excellent conductivity and electromagnetic shielding effectiveness. Precisely controlled copper tape parameters create a continuous conductive path, effectively shielding against external electromagnetic interference while limiting the cable's internal electromagnetic field and preventing electromagnetic energy leakage. The spirally wound copper tape also provides mechanical strength and elasticity, providing additional protection for the inner layer.

[0040] The silver-plated copper wire braided shielding layer is prepared using a braiding machine, weaving the silver-plated copper wire into a mesh with controlled braiding angles and density within a predetermined range. The high conductivity and corrosion resistance of the silver-plated copper wire form a dense and stable conductive shielding layer on the cable surface, further enhancing the cable's electromagnetic shielding effectiveness.

[0041] The preparation of the intelligent monitoring and protection sheath involves uniformly mixing a polyvinyl chloride (PVC) base material with anti-aging, wear-resistant, and flame-retardant additives, as well as lubricants. The mixture is then extruded through an extruder and coated onto the outer surface of the shielding layer. The sheath's material formulation and extrusion process parameters are precisely controlled, imparting excellent resistance to environmental aging, mechanical wear, and flame retardancy, ensuring the long-term safety and reliability of the cable. Fiber optic sensors and micro-nano sensors uniformly dispersed throughout the sheath enable real-time monitoring of physical parameters such as temperature, strain, and vibration, as well as electrical parameters such as partial discharge. The data collected by these sensors is transmitted to a monitoring system for analysis and processing, enabling timely identification of potential faults and anomalies during cable operation. This provides a basis for cable maintenance and management, enabling intelligent monitoring and proactive protection.

[0042] In actual operation, each structural layer works closely together. The superconducting core strands efficiently transmit power, the graphene reinforcement layer provides mechanical support and thermal management, the nanocomposite insulation layer ensures safe insulation during power transmission, the inner semi-conductive layer optimizes electric field distribution, the conductive copper tape shield and the silver-plated copper wire braid shield create an electromagnetic shield, and the intelligent monitoring and protection sheath monitors the cable status in real time and provides physical protection.

[0043] Example 3; please refer to Figures 1-4 In the embodiment of the present invention, a specific embodiment of a method for preparing an ultra-high conductive wire and cable is provided as follows: Step S01: Preparation of superconducting core strands: YBCO superconducting filaments with a diameter of 0.1 mm are twisted with a twisting pitch of 20 mm, a twisting tension of 20 Newtons, and a twisting speed of 20 meters per minute to form superconducting core strands. A graphene reinforcement layer with a graphene content of 10% and a thickness of 0.2 mm is deposited at 900°C. The superconducting core strands are then cured at 250°C for 20 minutes.

[0044] Step S02: Preparation of a nanocomposite insulating material layer: Surface-modify nanosilica particles (30 nanometers in diameter) and boron nitride particles (15 nanometers in diameter) at 10% and 6% addition levels, respectively. The modified nanoparticles are melt-blended with a cross-linked polyethylene matrix in a twin-screw extruder at an extrusion temperature of 180°C and a screw speed of 45 rpm to produce a nanocomposite insulating material. This insulating material is then coated onto the outer surface of the superconducting core strands via an extrusion process at a temperature of 185°C, using water cooling at a temperature of 15°C and a cooling rate of 7 meters per minute. The nanocomposite insulating material layer is controlled to a thickness of 3 mm, and its breakdown strength can exceed 20 kilovolts per millimeter.

[0045] Step S03, preparing the shielding layer: First, prepare the inner semi-conductive layer. Highly conductive carbon black (25%) is mixed evenly with a polyethylene composite material. The mixture is extruded through an extruder and coated onto the outer surface of the nanocomposite insulating material layer at a temperature of 145°C and a thickness of 0.1 mm. Next, prepare the conductive copper tape shielding layer. A 0.2 mm thick, 20 mm wide copper tape is spirally wrapped around the outer surface of the inner semi-conductive layer at a 45-degree angle, with the copper tape overlapping each other by 3 mm. Finally, prepare the silver-plated copper wire braided shielding layer. The silver-plated copper wire has a diameter of 0.1 mm, a braid density greater than 80%, a thickness of 0.5 mm, a braid angle of 50 degrees, and a braiding speed of 20 meters per minute.

[0046] Step S04: Prepare the intelligent monitoring and protection sheath: Polyvinyl chloride (PVC) substrate is uniformly mixed with an anti-aging additive (content 1%), a wear-resistant additive (content 0.8%), a flame retardant additive (content 2%), and a lubricant (mass fraction 0.3%). The mixed sheath material is extruded through an extruder and coated onto the outer surface of the shielding layer. The extrusion temperature is 180°C, and the cooling method is water-cooled at a temperature of 20°C and a cooling rate of 12 meters per minute. The sheath thickness is 2 mm. During the sheath extrusion process, fiber optic sensors and micro-nano sensors are evenly dispersed within the sheath by implantation. The fiber optic sensors are spaced 30 cm apart, and the micro-nano sensors are spaced 40 cm apart. The sensor implantation depth is between one-third and one-half of the sheath thickness.

[0047] Working Principle: The superconducting core strands serve as the primary power transmission mechanism. Multiple YBCO superconducting filaments are twisted together to form a stable structure capable of carrying high current densities while exhibiting excellent mechanical properties. A graphene reinforcement layer tightly wraps around the core strands, leveraging graphene's exceptional properties to reduce interfacial resistance, facilitate electron transfer, and aid heat dissipation. The nanocomposite insulation layer, produced through a specialized process and incorporating nano-silicon dioxide and boron nitride particles, enhances mechanical strength and thermal stability, ensuring insulation and effective heat dissipation. The inner semiconductive layer, made from a highly conductive carbon black and polyethylene composite, eliminates surface charge accumulation on the nanocomposite insulation layer and optimizes electric field distribution. The conductive copper tape shield is helically wrapped to create a continuous conductive path, shielding against electromagnetic interference. A silver-plated copper braided mesh shield further enhances electromagnetic shielding. The intelligent monitoring and protection sheath incorporates various additives to enhance environmental resistance and features built-in fiber optic sensors and micro-nano sensors for real-time cable status monitoring. These structural layers work seamlessly together to achieve efficient power transmission while ensuring the cable's mechanical strength, thermal stability, and electromagnetic compatibility, ensuring long-term, stable operation.

[0048] While the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An ultra-high conductivity wire and cable, characterized in that: include: Superconducting core strand (1): Made of multiple strands of YBCO superconducting material filaments twisted together; Graphene reinforcement layer (2): wrapped around the outside of the superconducting core strand (1), the graphene content in the graphene reinforcement layer (2) is 5% to 20%, and the thickness of the reinforcement layer is 0.1 mm to 0.5 mm; Nanocomposite insulating material layer (3): with cross-linked polyethylene as the matrix, and nano-silicon dioxide particles and boron nitride particles added; Inner semi-conductive layer (4): made of a composite material of highly conductive carbon black and polyethylene, with a carbon black content of 20% to 30% and a thickness of 0.05 mm to 0.2 mm, and coated on the outside of the nanocomposite insulating material layer (3) by an extrusion process, with an extrusion temperature of 130 degrees Celsius to 160 degrees Celsius; Conductive copper tape shielding layer (5): the copper tape has a thickness of 0.1 mm to 0.3 mm and a width of 10 mm to 30 mm; Silver-plated copper wire braided mesh shielding layer (6): the diameter of the silver-plated copper wire is 0.05 mm to 0.15 mm, the braiding density is greater than 80%, the thickness is 0.3 mm to 0.8 mm, and the braiding angle is 45 degrees to 55 degrees; Intelligent monitoring and protection sheath (7): Based on polyvinyl chloride, with anti-aging additives, wear-resistant additives and flame retardant additives added.

2. The ultra-high conductivity wire and cable according to claim 1, characterized in that: The superconducting core strand (1) further comprises superconducting material filaments having a diameter ranging from 0.05 mm to 0.2 mm, a stranding pitch ranging from 10 mm to 100 mm, a stranding tension controlled at 10 Newtons to 50 Newtons, and a stranding speed ranging from 10 m / min to 30 m / min; The graphene enhancement layer (2) is formed by chemical vapor deposition or solution coating, with a deposition temperature of 800 to 1000 degrees Celsius or a coating temperature of 60 to 100 degrees Celsius, and is subjected to a curing treatment, with a curing temperature of 200 to 300 degrees Celsius and a curing time of 10 to 30 minutes; The nanocomposite insulating material layer (3) further comprises nano-silicon dioxide with a particle size of 10 nanometers to 50 nanometers and an addition amount of 5% to 15%, and boron nitride with a particle size of 5 nanometers to 30 nanometers and an addition amount of 3% to 10%. The nanocomposite insulating material layer (3) has a thickness of 1 mm to 5 mm and a breakdown strength greater than 20 kilovolts per millimeter. The conductive copper tape shielding layer (5) is wrapped around the outer side of the inner semi-conductive layer (4) in a spiral winding manner, with a winding angle of 30 degrees to 60 degrees, and the copper tapes are overlapped with each other, with an overlap width of 2 mm to 5 mm; The intelligent monitoring and protection sheath (7) further comprises an anti-aging additive content of 0.5% to 2%, a wear-resistant additive content of 0.3% to 1.5%, a flame retardant additive content of 1% to 3%, and a sheath layer thickness of 1 mm to 3 mm; optical fiber sensors and micro-nano sensors are uniformly dispersed in the sheath layer, the optical fiber sensors are arranged at a spacing of 10 cm to 50 cm, and the micro-nano sensors are arranged at a spacing of 20 cm to 60 cm.

3. The ultra-high conductivity wire and cable according to claim 1, characterized in that: The nanocomposite insulating material layer (3) is prepared by melt blending in a twin-screw extruder, the extrusion temperature is 150 degrees Celsius to 200 degrees Celsius, and the screw speed is 30 revolutions per minute to 60 revolutions per minute. The inner semi-conductive layer (4) and the nanocomposite insulating material layer (3) are treated with plasma or a chemical coupling agent.

4. The ultra-high conductivity wire and cable according to claim 1, characterized in that: The preparation material of the intelligent monitoring and protection sheath (7) also includes a lubricant with a mass fraction of 0.1% to 0.5%.

5. A method for preparing an ultra-high conductive wire and cable, which is implemented by using the ultra-high conductive wire and cable according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: Step S01, preparing a superconducting core strand (1), forming a superconducting core strand (1) by twisting superconducting material filaments through a twisting process, controlling the twisting pitch, tension and speed within a predetermined range; wrapping a graphene reinforcement layer (2) on the outer side of the superconducting core strand (1) by a chemical vapor deposition method or a solution coating method, and performing a curing treatment after deposition or coating; Step S02, preparation of a nanocomposite insulating material layer (3), surface modification of nano-silicon dioxide particles and boron nitride particles; melt blending the modified nano-particles with a cross-linked polyethylene matrix in a twin-screw extruder to prepare a nanocomposite insulating material; coating the insulating material on the outside of the conductor layer through an extrusion process, the extrusion temperature is 160 degrees Celsius to 210 degrees Celsius, the cooling method is water cooling, the cooling water temperature is 10 degrees Celsius to 20 degrees Celsius, and the cooling rate is 5 meters per minute to 10 meters per minute; Step S03, preparing a shielding layer; Step S04, preparation of the intelligent monitoring and protection sheath (7).

6. The method for preparing an ultra-high conductive wire and cable according to claim 5, characterized in that: Said step S03, preparing the shielding layer, further comprises the following steps: Step S031, preparing the inner semi-conductive layer (4), uniformly mixing the highly conductive carbon black and the polyethylene composite material, extruding the mixture through an extruder and coating the mixture on the outside of the nanocomposite insulating material layer (3), at an extrusion temperature of 130 degrees Celsius to 160 degrees Celsius; Step S032, preparing a conductive copper tape shielding layer (5), wrapping the copper tape around the outer side of the inner semi-conductive layer (4) in a spiral winding manner, and controlling the thickness, width, winding angle and overlap width of the copper tape within a predetermined range; Step S033, preparing a silver-plated copper wire braided mesh shielding layer (6), using a braiding machine to weave the silver-plated copper wire into a mesh, controlling the braiding angle and density within a predetermined range, and the braiding speed is 10 meters per minute to 30 meters per minute; The step S04 also includes the following steps: uniformly mixing the polyvinyl chloride substrate with an anti-aging additive, a wear-resistant additive, a flame retardant additive, and a lubricant; extruding the mixed sheath material through an extruder and coating the outer side of the shielding layer, the extrusion temperature is 160 degrees Celsius to 200 degrees Celsius, the cooling method is water cooling, the cooling water temperature is 15 degrees Celsius to 25 degrees Celsius, and the cooling rate is 8 meters per minute to 15 meters per minute; during the extrusion process of the sheath layer, the optical fiber sensor and the micro-nano sensor are uniformly dispersed in the sheath layer by implantation, and the sensor implantation depth is one-third to one-half of the thickness of the sheath layer.

7. The method for preparing an ultra-high conductive wire and cable according to claim 5, wherein: The curing treatment of the graphene reinforcement layer (2) adopts a staged heating process. In the first stage, the temperature is raised to 150 degrees Celsius at a rate of 5 degrees Celsius per minute and kept at this temperature for 5 minutes; in the second stage, the temperature is raised to the target curing temperature at a rate of 3 degrees Celsius per minute.

8. The method for preparing an ultra-high conductive wire and cable according to claim 5, wherein: During the spiral winding process of the conductive copper tape shielding layer (5), the edges of the copper tape are subjected to ultrasonic welding treatment, with a welding frequency of 20 kHz to 40 kHz and a welding pressure of 0.2 MPa to 0.5 MPa.

9. The method for preparing an ultra-high conductive wire and cable according to claim 5, wherein: During the preparation of the nanocomposite insulating material layer (3), the surface modification degree of the nano-silicon dioxide particles and the boron nitride particles is adjusted by controlling the amount of the modifier and the modification time.

10. The method for preparing an ultra-high conductive wire and cable according to claim 5, wherein: After the nanocomposite insulating material layer (3) is extruded, the surface of the nanocomposite insulating material layer (3) is subjected to corona treatment, with a treatment voltage of 10 kilovolts to 15 kilovolts, an electrode spacing of 1 millimeter to 3 millimeters, and a treatment time of 30 seconds to 90 seconds.

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