A long-life environmentally friendly new energy storage cable processing method

Abstract

The application belongs to the technical field of cable processing, and discloses a high-life environmentally-friendly new energy storage cable processing method, which comprises the following steps: arranging an inner insulation layer on the surface of a fiber reinforced core, weaving a conductive layer on the surface of the inner insulation layer, and then arranging an outer insulation layer, so that the outer insulation layer is integrated with the inner insulation layer through a woven grid, and a woven insulation wire core is formed; a plurality of insulation wire cores are stranded into a cable core, and a double-helix differential sliding buffer framework composed of an inner layer support rib, a solid lubricating layer and an outer layer support rib is arranged outside the cable core; an armored layer composed of two armored half bodies penetratingly wrapped is arranged outside the buffer framework, and the fins of each armored half body are connected in series through an elastic hinge belt. The application solves the internal structure instability through the conductor level anchoring, the main strain is absorbed through the buffer level differential sliding, the armored layer level elasticity follows and adapts to the external deformation, the three are matched step by step from inside to outside along the radial direction, and the synergistic effect makes the bending life of the cable reach 1x10 7 times or more.

Description

Technical Field

[0001] This invention relates to the field of cable processing technology, and more specifically, to a method for processing long-life, environmentally friendly new energy storage cables. Background Technology

[0002] With the rapid development of the new energy industry, energy storage systems are increasingly widely used in new energy power plants, electric vehicle charging piles, and grid peak shaving. As a key component for power transmission in energy storage systems, the performance of energy storage cables directly affects the safety and reliability of the entire system. Energy storage cables are frequently subjected to mechanical forces such as tension, bending, and torsion during use, placing extremely high demands on their service life.

[0003] Currently, energy storage cables mainly face the following technical problems: Firstly, there is structural instability between the reinforcing core and the conductor. In existing energy storage cables, the reinforcing core (center core) and the conductor are only in mechanical contact, lacking effective axial restraint. Under long-term repeated bending and temperature cycling, relative movement can easily occur between the reinforcing core and the conductor, leading to conductor structural instability and decreased conductivity.

[0004] Secondly, relative slippage is prone to occur between the insulation layer and the conductor. Energy storage systems operate under high voltage and high current conditions, and the cables generate a large amount of Joule heat during long-term operation, leading to periodic temperature changes. Under the combined effects of temperature difference cycles and bending stress, axial relative slippage (i.e., "core detachment") is likely to occur between the insulation layer and the conductor, accelerating insulation aging and reducing electrical reliability.

[0005] Third, the armor layer structure lacks bending adaptability. Existing energy storage cables mostly use continuously wound steel strips or wires for their armor layers, forming a single, rigid, continuous structure. When the cable bends, the armor layer cannot adapt to the bending deformation, leading to the accumulation of plastic deformation within the armor layer itself, ultimately resulting in failure due to low-cycle fatigue.

[0006] To address the aforementioned issues, several technical solutions have been proposed. For example, Chinese invention patent CN119181543A discloses a method for processing high-life, environmentally friendly energy storage cables, which uses an elastic connector to pull misaligned conductors back to their original positions. However, the elastic recovery of this solution mainly acts on the reset after stretching, and its effect on releasing the accumulated strain under repeated bending conditions is limited. Furthermore, its steel strip armor is still a traditional continuous winding structure, failing to fundamentally solve the bending fatigue problem.

[0007] Therefore, developing a method for processing energy storage cables that systematically solves the above problems at the structural level is of great practical significance. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a processing method for high-life and environmentally friendly new energy storage cables.

[0009] To solve the above problems, the present invention adopts the following technical solution: A method for processing long-life, environmentally friendly new energy storage cables includes the following steps: S1. Preparation of braided insulated wire cores with anchoring structures: S11. An inner insulation layer is provided on the surface of the fiber-reinforced core; Specifically, the fiber-reinforced core is an aramid fiber-reinforced core, which has high specific strength, high specific modulus and excellent fatigue resistance. As the central reinforcing element of the wire core, it bears the main tensile load, significantly reduces the tensile stress borne by the conductive single wire, and delays conductor fatigue damage.

[0010] The inner insulation layer can be applied to the surface of the fiber-reinforced core by extrusion coating or solution coating. The material used is polyolefin insulation material with a thickness of 0.3 to 0.8 mm and an extrusion temperature of 160 to 180°C.

[0011] The function of the inner insulation layer is to pre-wrap the fiber reinforcement core in the insulation material, making the reinforcement core the inner core of the insulator, providing a basis for subsequent fusion with the outer insulation layer, and preventing the reinforcement core from axially shifting during subsequent braiding and cable use.

[0012] S12. On the surface of the fiber-reinforced core covered with an inner insulation layer, multiple conductive single wires are bidirectionally cross-braided to form a braided layer.

[0013] Specifically, the conductive single wire is a tin-plated soft copper single wire, with a braiding angle controlled between 40° and 60° and a braiding coverage of 90% to 98%. The bidirectional cross-braiding structure arranges the conductive single wires in a spiral pattern, which not only gives the wire core excellent flexibility but also allows the individual wires to slide relative to each other during bending, avoiding stress concentration. The controlled braiding coverage ensures sufficient current-carrying cross-sectional area and provides ample mesh pores for subsequent penetration and anchoring of the outer insulation layer.

[0014] S13. An outer insulation layer is provided outside the braided layer. The outer insulation layer passes through the mesh of the braided layer and combines with the inner insulation layer to form an integrated insulation layer that wraps the braided layer, thereby obtaining a braided insulated wire core.

[0015] Specifically, the outer insulation layer and the inner insulation layer are made of the same polyolefin material; the extrusion temperature of the outer insulation layer is higher than that of the inner insulation layer. Further, the extrusion temperature of the outer insulation layer is 190–220°C, which is 20–30°C higher than that of the inner insulation layer, and the extrusion pressure is increased to 25–30 MPa. This allows the molten outer insulation material to pass through the mesh pores of the braided layer under pressure and come into contact with the outer surface of the inner insulation layer. Because both are made of the same material and the temperature of the outer insulation layer is higher than that of the inner insulation layer, local melting occurs on the surface of the inner insulation layer. Molecular chains diffuse between the two layers at the interface, and after cooling, a homogeneous, integrated structure without an interface is formed.

[0016] The conductive single wires of the braided layer are firmly anchored inside the integrated insulation layer, forming a "rivet"-like reinforced structure with extremely high interfacial bonding strength, and will not delaminate under repeated bending conditions.

[0017] To further improve the heat resistance and mechanical strength of the insulation layer, the integrated insulation layer is cross-linked by irradiation with an irradiation dose of 80-120 kGy. After cross-linking, the insulation layer forms a three-dimensional network structure, which significantly improves the heat resistance and tear resistance.

[0018] S2. Preparation of the double-helix differential sliding buffer skeleton: S21. Twist the multiple braided insulated wire cores together to form a cable core; S22. A buffer skeleton is provided outside the cable core. The buffer skeleton includes an inner support rib, a solid lubricating layer and an outer support rib. The inner support rib and the outer support rib have different helical directions and / or pitches. The solid lubricating layer is disposed between the inner support rib and the outer support rib.

[0019] Furthermore, the inner support ribs and the outer support ribs have opposite spiral directions, and the pitch of the outer support ribs is greater than the pitch of the inner support ribs.

[0020] The inner support rib has a winding angle of 20° to 35°, while the outer support rib has a winding angle of 45° to 65°. This difference in winding angle and pitch allows for differential slippage between the inner and outer support ribs when the cable is bent, dispersing localized bending deformation over a longer section and preventing stress concentration.

[0021] Furthermore, the solid lubricating layer is a PTFE fiber braided layer or a graphite-coated fiber braided layer. The solid lubricating layer is used to reduce the frictional force when the two support ribs slide relative to each other, ensuring the smoothness of differential sliding.

[0022] S3: An armor layer is provided on the outside of the buffer frame: The armor layer is composed of two armor halves that are symmetrically interlocked and wrapped around each other. Each armor halves includes several fins arranged sequentially along the cable axis. Adjacent fins are connected in series by an elastic hinge band. The two armor halves are inserted from opposite sides of the buffer frame. The fins of the two armor halves interlock and are wedge-locked to form a complete circumferential wrap.

[0023] As a further aspect of the invention: the fins 311 are arranged equidistantly along the axial direction of the sheath, with a spacing of 1.5–2.5 mm between adjacent fins 311. The fins are trapezoidal in shape, with the larger end located in the middle of the sheath and the smaller ends located on both sides of the sheath. The larger end in the middle provides maximum mechanical strength, ensuring the stability of the armor layer structure in a straight state and effectively bearing axial tensile loads. The smaller ends on both sides allow relative rotation between the fins during bending, reducing interference and stress concentration; at the same time, they form a wedge-shaped slope, facilitating the insertion and locking of two sheaths, achieving self-positioning installation.

[0024] The width of the elastic hinge band is less than the maximum width of the fin, so that a gap is formed between adjacent fins that can expand and contract when bent; the elastic hinge band is made of spring steel sheet, which undergoes elastic deformation when the cable is bent and returns to its original shape after bending.

[0025] In addition, flexible foamed buffer strips are filled in the gaps between the inner support ribs, the outer support ribs and the armor to absorb external impact energy and provide elastic support for the internal structure.

[0026] S4. A shielding layer and an outer sheath are provided outside the armor layer.

[0027] As a further aspect of the present invention: the shielding layer is a copper tape wrapped shielding layer or a copper wire braided shielding layer, used for electromagnetic shielding and fault current path. The outer sheath is a low-smoke halogen-free flame-retardant outer sheath layer, which is extruded onto the outside of the shielding layer to ensure the low-smoke and non-toxic characteristics of the cable under fire conditions, meeting environmental protection requirements.

[0028] Compared with the prior art, the advantages of this invention are: I. This invention permanently fixes the reinforcing core inside the insulator by pre-extruding an inner insulating layer, braiding a conductive layer, and then extruding an outer insulating layer on the surface of the fiber-reinforced core, fusing the inner and outer layers through the braided mesh. Simultaneously, the insulator passes through the pores of the braided mesh, creating a "rivet" effect that prevents relative slippage between the braided layer and the insulator, thus solving the problems of relative movement between the reinforcing core and conductor, braided layer loosening, and insulation layer "detachment" in existing technologies.

[0029] Second, this invention uses a double-layered, reverse-wound, and differently pitched support spiral rib in conjunction with a solid lubricating layer. When the cable is bent, the two layers of support ribs rotate relative to each other in the circumferential direction through the differential spiral principle, which converts the macroscopic axial strain generated by bending into rotational motion rather than internal material stress, thereby eliminating the concentration and accumulation of strain in the structural layer.

[0030] Third, the present invention adopts a structure in which two armor halves are symmetrically interwoven and wrapped, and each fin is connected in series by an elastic hinge band; when the cable is bent, the elastic hinge band on the outer side of the bend is stretched and the inner side is compressed. The bending strain is released through elastic deformation and relative sliding between the inclined surfaces of the fins. After bending, the elastic hinge band returns to its original shape; the armor material itself does not bear plastic strain, thus eliminating the risk of fatigue failure of traditional continuous armor layers.

[0031] Fourth, through a temperature gradient extrusion process, molecular chains of the inner and outer insulation layers diffuse into each other at the mesh pores of the braided layer, forming a homogeneous insulator without interfaces upon cooling. Combined with radiation cross-linking technology, the heat resistance and crack resistance of the insulation system are significantly improved, eliminating the problem of weak points in aging caused by the presence of interfaces in traditional multi-layer insulation structures, thus extending the overall service life of the cable.

[0032] In summary, this invention addresses internal structural instability through conductor-level anchoring, absorbs major strain through differential slippage in the buffer layer, and adapts to external deformation through elastic following in the armor layer. These three elements work in tandem from the inside out, achieving a synergistic effect that enables the cable's bending life to reach 1×10⁻⁶. 7 More than once. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a cross-sectional view of the braided insulated wire core of the present invention; Figure 3 This is a schematic diagram of the structure of the braided layer of the present invention; Figure 4 This is a schematic diagram of the structure of multiple braided insulated wire cores twisted together according to the present invention; Figure 5 This is a schematic diagram of the armor layer structure of the present invention.

[0034] Explanation of the labels in the diagram: 1. Braided insulated core; 11. Fiber-reinforced core; 12. Inner insulation layer; 13. Braided layer; 131. Conductive single wire; 14. Outer insulation layer; 2. Buffer skeleton; 21. Inner support ribs; 22. Solid lubricating layer; 23. Outer support ribs; 24. Flexible foamed buffer strips; 3. Armor layer; 31. Armor half-body; 311. Fin; 312. Elastic hinge strip; 4. Shielding layer; 5. Outer protective sleeve. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0036] In the description of this invention, it should be noted that the terms "inner", "outer", "axial", "radial", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention. Example

[0037] This embodiment provides a method for processing long-life, environmentally friendly new energy storage cables, including the following steps: Step S1: Prepare braided insulated core 1 with anchoring structure S11. An inner insulation layer 12 is provided on the surface of the fiber-reinforced core 11, such as... Figure 2 As shown: In this embodiment, an aramid fiber reinforcing core with a diameter of 1.5 mm is selected as the fiber reinforcing core 11. The aramid fiber reinforcing core is passed through a first extruder, and an inner insulation layer 12 is extruded onto its surface. The material of the inner insulation layer 12 is polyolefin insulation material with a thickness of 0.5 mm. The temperatures of each section of the extruder are set as follows: feeding section 160°C, compression section 165°C, homogenization section 170°C, and die head 170°C. The melt temperature is controlled between 165°C and 175°C.

[0038] The function of the inner insulation layer 12 is to pre-wrap the aramid fiber reinforcing core in the insulation material, so that the fiber reinforcing core 11 becomes the inner core of the insulator, providing a basis for subsequent fusion with the outer insulation layer, and at the same time preventing the fiber reinforcing core 11 from axially shifting during subsequent braiding and cable use.

[0039] S12. On the surface of the fiber-reinforced core 11 covered with the inner insulation layer 12, multiple conductive single wires 131 are bidirectionally cross-braided to form a braided layer 13, such as... Figure 3 As shown.

[0040] In this embodiment, tin-plated soft copper single wires with a diameter of 0.20 mm are selected as the conductive single wires 131. On the surface of the aramid fiber reinforced core covered with the inner insulation layer 12, 48 tin-plated soft copper single wires (3 wires per spindle) are bidirectionally cross-braided using a 16-spindle vertical high-speed braiding machine. The braiding angle (i.e., the angle between the braided single wire and the cable axis) is 50°, and the braiding coverage is 95%. During braiding, a braiding pattern such as one up and one down or two up and two down is used, and the tension is controlled at 2-4 N / wire, ensuring that the braided layer uniformly and tightly covers the surface of the inner insulation layer, forming the braided layer 13. The diamond-shaped mesh of the braided layer 13 is evenly distributed, serving as a channel for the subsequent fusion of the inner and outer insulation layers.

[0041] S13. An outer insulating layer 14 is provided outside the braided layer 13, such as... Figure 2 As shown.

[0042] The woven semi-finished product is then extruded through a second extruder to form an outer insulation layer 14 around the braided layer 13. The material of the outer insulation layer 14 is the same polyolefin material as the inner insulation layer 12. The extruder temperatures for the outer insulation layer 14 are set as follows: feeding section 180°C, compression section 190°C, homogenization section 200°C, and die head 200°C. The melt temperature is controlled between 195°C and 205°C, approximately 30°C higher than the extrusion temperature of the inner insulation layer. The extrusion pressure is increased to 25–30 MPa, causing the high-temperature molten outer insulation material to pass through the mesh pores of the braided layer 13 under pressure and come into contact with the outer surface of the inner insulation layer 12.

[0043] At high temperatures, molecular chains diffuse and entangle at the contact interface between the inner and outer layers. After cooling, the inner and outer insulating layers form an integrated insulating layer without an interface. The braided layer 13 is wrapped inside the integrated insulating layer, that is, the insulator passes through each braided mesh to form a "rivet" effect, and the braided layer 13 is permanently anchored, resulting in a braided insulated core 1.

[0044] The aforementioned integrated insulation layer was subjected to cross-linking irradiation using an electron accelerator at a dose of 100 kGy. This irradiation cross-linking process resulted in a three-dimensional network structure in the insulation material, further integrating the inner and outer layers through chemical cross-linking, completely eliminating the interface and thus improving the insulation layer's heat resistance, aging resistance, and interlayer bonding strength.

[0045] Step S2: Prepare the double-helix differential slip buffer skeleton 2: S21. Twist multiple braided insulated wire cores 1 together to form a cable core, such as... Figure 1 , 4 As shown.

[0046] Take 5 braided insulated wire cores 1 obtained in step S1, and twist them into a cable core in an equal angle. During twisting, control the tension of the wires to be consistent to ensure that the cable core is round and the structure is stable.

[0047] S22. A buffer frame 2 is installed outside the cable core, such as... Figure 1 As shown.

[0048] On the outside of the cable core, inner support ribs 21 (made of 3.0mm diameter galvanized steel wire) are wound in a left-handed direction at a winding angle of 28° and a winding spacing 1.5 times the diameter of the support ribs. The inner support ribs 21 are wound around the surface of the outer insulation layer 14 of the cable core, and the two have a non-fixed contact fit—the inner support ribs 21 maintain contact with the cable core by the radial clamping force generated by the winding, but are not bonded or fixed to the outer insulation layer 14. The purpose of this non-fixed contact design is to ensure that the differential sliding function between the inner support ribs 21 and the outer support ribs 23 is unrestricted, while avoiding stress concentration between the metal support ribs and the insulation layer, which could lead to damage to the insulation layer.

[0049] It should be noted that, to prevent uncontrollable movement or displacement of the inner support rib 21 along the cable core axial direction during long-term use and repeated bending of the cable, the following axial restraint measures are also taken: a shallow spiral groove is pre-set on the surface of the outer insulation layer 14 of the cable core. The spiral angle of the shallow groove is consistent with the winding angle of the inner support rib 21, so that the inner support rib 21 is embedded in the shallow groove to form axial positioning. The shallow groove only restricts the axial movement of the inner support rib 21, but does not restrict its radial elastic deformation with the cable core when the cable is bent, nor does it interfere with the circumferential differential sliding function between the inner support rib 21 and the outer support rib 23.

[0050] Outside the inner support rib 21, a 0.2mm thick PTFE fiber braided layer is woven as a solid lubricating layer 22. The PTFE fiber braided layer has an extremely low coefficient of friction, which can effectively reduce the friction between the inner support rib 21 and the outer support rib 23, allowing the two support ribs to smoothly slip relative to each other when the cable is bent, while reducing frictional heat generation.

[0051] Outside the solid lubricating layer 22, an outer layer support rib 23 (using spring steel wire with a diameter of 2.5 mm) is wound in a right-handed direction (opposite to the inner layer's rotation), at a winding angle of 55° (greater than the inner layer's winding angle), with a winding spacing 2.0 times the diameter of the support rib. The pitch of the outer layer support rib 23 is greater than the pitch of the inner layer support rib 21.

[0052] When a cable is subjected to bending, the outer side of the cable experiences tensile strain, while the inner side experiences compressive strain. The outer support rib 23 needs to accommodate the elongation deformation on the outer side, while the inner support rib 21 needs to accommodate the compressive deformation on the inner side. Due to the opposite rotation directions and different pitches of the two support ribs (differential helical principle), under the mediation of the solid lubrication layer 22, the inner and outer support ribs will undergo relative differential slippage—that is, the outer support rib 23 rotates circumferentially relative to the inner support rib 21. This differential slippage transforms the macroscopic axial strain generated by bending into circumferential relative rotation between the two support ribs, thereby eliminating the concentration of bending stress on the cable structural layers.

[0053] Step S3: Set an armor layer 3 outside the buffer frame 2, such as... Figure 1 , 5 As shown.

[0054] The armor layer 3 is composed of two armor halves 31 that are symmetrically interwoven and wrapped around each other.

[0055] Each armored half 31 includes multiple fins 311 arranged sequentially along the cable axis, with a spacing of 2.0 mm between adjacent fins 311. Adjacent fins 311 are connected in series by an elastic hinge band 312. The elastic hinge band 312 is located between adjacent fins 311, integrally stamped with the fins 311, and its width is 40% of the maximum width of the fins 311, creating a gap between adjacent fins 311 that allows for expansion and contraction during bending. The elastic hinge band 312 is made of spring steel sheet (65Mn spring steel) with a thickness of 0.3 mm, and undergoes elastic deformation when the cable is bent, returning to its original shape after bending.

[0056] Each fin 311 is trapezoidal in shape, with its large end located in the middle of the sheath (width 12mm) and its small end located on both sides of the sheath (width 8mm). Each fin 311 is arranged equidistantly along the axial direction of the sheath, and the distance between adjacent fins 311 is 2mm.

[0057] For cables of different lengths in actual production, the total number of fins 311 is determined according to the cable design length. The specific number can be calculated and determined by those skilled in the art based on the principle of arranging them at equal intervals according to the actual length of the cable.

[0058] During assembly, the two armored halves 31 are inserted from opposite sides of the buffer frame 2. The fins 311 of the two armored halves 31 interlock and wedge-lock together to form a complete circumferential wrap.

[0059] In the gaps between the inner support rib 21, the outer support rib 23, and the armor layer 3, foamed polyethylene strips are filled as flexible foamed buffer strips 24. The compression set of the foamed polyethylene strips is ≤12%, and the filling compression ratio is 30%. The function of the flexible foamed buffer strip 24 is twofold: firstly, it acts as an elastic buffer medium to absorb vibration and impact; secondly, when the cable bends, the foamed material further absorbs residual strain through its own compression deformation, combined with the differential slippage of the double helical ribs and the elastic deformation of the armor layer 3.

[0060] Step S4: Install a shielding layer 4 and an outer sheath 5 outside the armor layer 3, such as... Figure 1 As shown.

[0061] Outside the armor layer 3, a copper strip with a thickness of 0.10 mm is used for wrapping and shielding, with a wrapping overlap rate of 20% of the copper strip width, forming a copper strip wrapped shielding layer as shielding layer 4. The copper strip wrapped shielding layer 4 can effectively suppress electromagnetic interference and ensure the stability of signal transmission in the energy storage system.

[0062] Outside the shielding layer 4, a low-smoke, halogen-free, flame-retardant polyolefin sheath material is extruded onto the outer sheath 5. The extruder temperatures are set as follows: feeding section 160℃, compression section 175℃, homogenization section 185℃, and die head 185℃. The melt temperature does not exceed 185℃, and the outer sheath 5 has a layer thickness of 2.5mm. This outer sheath 5 material does not produce toxic fumes or corrosive gases when burned, meeting stringent environmental protection requirements. It also possesses excellent wear resistance, weather resistance, and oil resistance, providing effective protection for the cable's internal structure.

[0063] Step S5: Post-processing: The manufactured cable is subjected to power frequency spark test (test voltage is 6kV), partial discharge test (discharge amount ≤5pC) and withstand voltage test (power frequency withstand voltage 15kV / 5min without breakdown). After passing the test, it is wound and packaged.

[0064] Example 2 The difference between this embodiment and Embodiment 1 lies in another combination of parameters within the scope of the claims, as detailed below: In step S11, the thickness of the inner insulation layer 12 is controlled to be approximately 0.3 mm, the extrusion temperature is approximately 165°C, and the diameter of the aramid fiber reinforcing core is 1.2 mm. The inner insulation layer uses the same polyolefin insulation material formulation as in Example 1. Due to the smaller diameter of the reinforcing core 11 and the thinner inner insulation layer 12, the temperatures of each section of the extruder are correspondingly reduced to ensure moderate melt flow and avoid unstable extrusion pressure caused by an excessively thin inner insulation layer 12.

[0065] In step S12, tin-plated soft copper single wire with a diameter of 0.15 mm (fineer than 0.20 mm in Example 1) is selected, the braiding angle is 45°, and the braiding coverage is 92%. The number of spindles on the braiding machine is adjusted to 24 spindles, with 2 single wires per spindle, and the wire tension is controlled at 2-3 N / spindle. The finer conductive single wire and the higher number of spindles make the braided layer denser, with smaller but more numerous mesh pores, which is beneficial for the subsequent penetration and anchoring of the outer insulation layer.

[0066] In step S13, the extrusion temperature of the outer insulation layer 14 is 195°C (30°C higher than the extrusion temperature of the inner insulation layer), the extrusion pressure is 28 MPa, and the irradiation dose is 90 kGy; the thickness of the outer insulation layer 14 is the same as in Example 1.

[0067] In step S22, the winding angle of the inner support rib 21 is 25°, and the winding angle of the outer support rib 23 is 60° (the angle difference between the two is 35°, which is greater than 27° in Example 1, resulting in a more significant differential slippage effect). The solid lubrication layer 22 is a graphite-coated aramid braided layer (0.15mm thick, replacing the PTFE fiber braided layer in Example 1). The inner support rib 21 uses galvanized steel wire with a diameter of 2.5mm, and the outer support rib 23 uses spring steel wire with a diameter of 2.0mm. The thinner wire diameter makes the overall buffer skeleton more flexible, suitable for applications requiring a smaller bending radius.

[0068] In step S3, each armored half includes several fins 311 arranged sequentially along the cable axis, with the spacing between adjacent fins controlled to be approximately 1.5 mm. The width of the large end of the fin is approximately 10 mm, and the width of the small end is approximately 6 mm. The elastic hinge strip 312 is approximately 0.25 mm thick and made of 50CrVA spring steel.

[0069] In step S4, the shielding layer 4 is a copper wire braided shielding layer, which is braided with tin-plated copper wire with a nominal diameter of about 0.15mm, with a braiding angle of about 45° and a braiding coverage of more than 90%.

[0070] Compared to Example 1, this embodiment uses a thinner conductive single wire and a thinner supporting rib wire diameter, combined with a graphite-coated aramid braided lubricating layer and a copper wire braided shielding layer, making the overall cable more flexible and suitable for mobile energy storage scenarios such as electric vehicle charging piles that require frequent deployment and small-radius bending.

[0071] The remaining steps and parameters are the same as in Example 1.

[0072] Example 3 The difference between this embodiment and Embodiment 1 lies in another combination of parameters within the scope of the claims, as detailed below: In step S11, the thickness of the inner insulation layer 12 is 0.8 mm, the extrusion temperature is 175 °C, and the diameter of the aramid fiber reinforced core is 2.0 mm.

[0073] In step S12, tin-plated soft copper single wire with a diameter of 0.25mm is selected, the braiding angle is controlled at approximately 55°, and the braiding coverage is approximately 98%. The braiding machine has 16 spindles, with 4 single wires per spindle, and the wire tension is controlled at approximately 3-5N / wire.

[0074] In step S13, the extrusion temperature of the outer insulation layer 14 is about 210°C, the extrusion pressure is about 32 MPa, and the irradiation dose is about 110 kGy.

[0075] In step S22, the inner support rib 21 is wound at an angle of approximately 32°, and the outer support rib 23 is wound at an angle of approximately 50°. The inner support rib 21 is made of galvanized steel wire with a diameter of approximately 3.5 mm, and the outer support rib 23 is made of spring steel wire with a diameter of approximately 3.0 mm.

[0076] In step S3, each armored half includes several fins 311 arranged sequentially along the cable axis, with the spacing between adjacent fins controlled to be approximately 2.5 mm. The width of the large end of the fin is approximately 14 mm, and the width of the small end is approximately 10 mm. The elastic hinge strip 312 is approximately 0.4 mm thick. The flexible foamed buffer strip 24 is made of polyurethane foam with a compression set ≤10% and a filler compression ratio of approximately 25%.

[0077] Compared to Example 1, this embodiment uses thicker conductive wires, thicker insulation layers, and thicker support ribs, resulting in a higher overall cable structure strength and greater current carrying capacity. It is suitable for fixed installations in scenarios such as energy storage power stations where high reliability is required.

[0078] The remaining steps and parameters are the same as in Example 1.

[0079] Example 4 The difference between this embodiment and Embodiment 1 lies in the way the inner insulating layer is configured: In step S11, the inner insulation layer 12 is not extruded but solution coated. The aramid fiber reinforcing core is impregnated in a polyolefin resin solution with a solid content of 8%, and then dried with hot air (drying temperature 80°C, drying time 30 seconds), forming a thin and uniform resin coating with a thickness of 0.08 mm on the surface of the reinforcing core. This resin coating serves as the inner insulation layer 12, and its material is the same polyolefin material as the subsequent outer insulation layer 14.

[0080] In step S13, the extrusion temperature of the outer insulation layer 14 is about 205°C and the extrusion pressure is about 35 MPa, ensuring that the polyolefin melt can fully penetrate the mesh pores of the braided layer and completely fuse with the thin inner insulation coating under high temperature and high pressure.

[0081] The remaining steps and parameters are the same as in Example 1.

[0082] The advantages of this embodiment are: solution coating does not require dedicated extrusion equipment, resulting in low equipment investment and a simple process, making it particularly suitable for small-batch production or situations with limited equipment conditions. However, due to the thinner coating, the control requirements for the extrusion temperature and pressure of the outer layer are higher, ensuring that the coating fully melts and completely fuses with the outer insulating material.

[0083] It should be noted that the specific values ​​given in the above embodiments are preferred implementations within the specified range. Those skilled in the art can adjust any parameter according to actual working conditions without exceeding the scope of the claims to obtain a technical solution that meets specific needs. The parameter combinations shown in each embodiment can be replaced and recombinated according to actual production needs, and are not limited to the above correspondence.

[0084] Comparative Example To verify the technical effects of the present invention, the following comparative examples are provided: Comparative Example 1: A conventional stranded conductor (non-braided structure, the conductor is composed of round copper single wires stranded in the same layer and direction) is used, without an inner insulation layer pre-covering the reinforcing core (the reinforcing core is placed directly in the center of the conductor, and there is only mechanical contact between it and the conductor), and a conventional single-layer continuous steel strip armor (non-segmented structure, the steel strip is continuously wound) is used, without a double helix differential sliding buffer skeleton (it is replaced by solid elastomer filling), and the rest is the same as in Example 1.

[0085] Comparative Example 2: The braided insulated core structure of the present invention (including an inner insulation layer pre-covered reinforcing core and an inner and outer insulation layer fusion anchoring) is adopted, but the double helix differential sliding buffer skeleton is not set (it is replaced by solid elastomer filling), and the traditional continuous steel strip armor is adopted. The rest is the same as Example 1.

[0086] Comparative Example 3: The present invention uses a double-helix differential sliding buffer skeleton and an interlocking elastic armor layer, but the conductor is a conventional stranded conductor (non-braided structure, without an inner insulation layer pre-coated reinforcing core), and the rest is the same as Example 1.

[0087] Performance testing The cables prepared in Examples 1-4 and Comparative Examples 1-3 were subjected to performance tests according to relevant standards. The specific methods, conditions, and results for each test item are as follows: I. Test Items and Methods (1) Bending life test: The bending performance test was conducted according to GB / T 2951.11-2008 "General Test Methods for Insulation and Sheath Materials of Cables and Optical Fibers" and T / CNESA1003-2020 "Battery Connection Cables for Power Energy Storage Systems". The specimen length was 1500 mm, the bending radius was set to 5 times the cable's outer diameter, the bending angle was ±90°, the bending frequency was 60 cycles / minute ±5%, and the test temperature was 23±2℃. The number of cycles before conductor breakage or visible cracks appeared in the insulation layer was recorded as the bending life.

[0088] (2) Test of axial slippage between the reinforcing core and the conductor: Referring to the thermal cycling test method in GB / T 2951.26-1994, the specimen was subjected to 500 thermal cycles. Each cycle included: heating the conductor to 90±5℃ by passing a rated current through the conductor and holding it for 5 hours, followed by natural cooling to no higher than 30℃ (for no less than 2 hours). After 500 thermal cycles, the axial displacement of the reinforcing core end relative to the conductor end was measured by X-ray fluoroscopy or micro-CT scanning.

[0089] (3) Test of axial slippage between insulation layer and conductor: The same 500-cycle thermal cycle test conditions as described above were used. After the thermal cycle was completed, the insulation layer was circumferentially cut at both ends of the sample, and the axial displacement of the insulation layer end face relative to the conductor end face was measured.

[0090] (4) Permanent deformation rate test of armor layer: Referring to the method for evaluating the bending performance of the armor layer, cable samples with a length ≥300mm were cut and subjected to reciprocating bending with a bending radius of 10 times the cable's outer diameter. The number of bending cycles was 1×10. 6 The bending angle was ±90°. After the test, the surface of the armor layer was observed for cracks, fractures, or permanent deformation. The permanent deformation rate was calculated by measuring the change rate of the outer diameter of the armor layer before and after bending.

[0091] (5) Smoke density test: Refer to IEC 61034-2 "Determination of smoke density from burning cables or optical fibers under specified conditions" test method. Place the cable sample horizontally at a depth of 3m. 3 Inside the combustion chamber, under flame combustion conditions, the transmittance is measured and the minimum transmittance value is recorded.

[0092] (6) Halogen acid gas release test The test method was adopted according to IEC 60754-1 "Determination of the total amount of halogen acid gas released during combustion of cable materials". After sampling the cable insulation and sheath materials, they were heated and burned in a tube furnace. The released halogen acid gas was absorbed by 0.1M sodium hydroxide solution, and the amount of halogen acid gas released (mg / g) was calculated by titration.

[0093] II. The test results are shown in the table below:

[0094] Test Result Analysis: (1) Bending life: The bending life of Examples 1 to 4 all reached 1.0 × 10 7 This is more than twice as good, far superior to Comparative Examples 1 to 3. Comparative Example 1 (fully conventional structure) has a bending life of only 1.2 × 10⁻⁶. 6 The second example (conductor innovation only) is 3.5 × 10⁻⁶. 6 The second example; Comparative Example 3 (buffering and armor innovation only) is 4.5 × 110. 6 This indicates that the three-stage strain relief structure of the present invention—conductor-level anchoring, buffer-level differential absorption, and armor-level elastic following—has a significant synergistic effect, and the combined effect of the three is far greater than the sum of the effects of using them individually.

[0095] (2) Regarding the anti-slip properties between the reinforcing core and the conductor: After 500 thermal cycles, there was almost no axial slippage (<0.1 mm) between the reinforcing core and the conductor in Examples 1-4 and Comparative Example 2, while the slippage in Comparative Example 1 and Comparative Example 3 was more than 1.5 mm. This verifies the effectiveness of the pre-coated reinforcing core with inner insulation layer and the fusion anchoring structure of inner and outer insulation layers—the reinforcing core is permanently fixed inside the insulator and will not move relative to the conductor.

[0096] (3) Regarding the anti-slip properties of the insulation layer: After 500 thermal cycles, there was almost no axial slip between the insulation layer and the conductor in Examples 1-4 and Comparative Example 2 (<0.1 mm), while the slip in Comparative Example 1 and Comparative Example 3 was more than 1.2 mm. This verifies the effectiveness of the braided layer being anchored by the insulator through the mesh holes in a "riveting" manner—the insulator passes through each mesh hole to form a "riveting" effect, and relative slippage between the braided layer and the insulator is impossible.

[0097] (4) Regarding the reliability of the armor layer: The interlocking elastic armor layers of Examples 1-4 and Comparative Example 3 showed a reliability of 1×10 6 After the first bending, no permanent deformation was observed, while the permanent deformation rates of the conventional continuous steel strip armor in Comparative Examples 1 and 2 reached 6.8% and 5.2%, respectively. This demonstrates that the interlocking elastic armor layer absorbs bending strain through the elastic deformation of the elastic hinge strip and the relative sliding between the fin inclined surfaces. The armor material itself does not bear bending plastic strain, thus fundamentally eliminating the fatigue failure problem of the armor layer.

[0098] (5) Environmental performance: According to IEC 61034-2, a minimum light transmittance of ≥50% is the low-smoke qualification standard. The minimum light transmittance of Examples 1 to 4 is 50%~55%, all of which meet the requirements; Comparative Example 1 has a minimum light transmittance of only 18%, which is far below the standard. According to IEC 60754-1, a halogen-free gas emission of <5mg / g is the halogen-free qualification standard; the test results show that the present invention maintains excellent environmental performance while achieving structural innovation.

[0099] The above test results fully demonstrate the effectiveness and superiority of the technical solution of this invention.

[0100] In summary, the synergistic mechanism of each step in this invention is as follows: ① Mechanism of improved fatigue life due to anchoring structure: The conductive single wires 131 of the braided layer 13 are wrapped and anchored by an integrated insulation layer (inner insulation layer 12 + outer insulation layer 14), and the circumferential surface of each conductive single wire 131 is tightly bonded to the insulation material. When the cable is bent, the fiber-reinforced core 11 bears the tensile stress, and the conductive single wires 131 cannot slide relative to each other because they are anchored, thus avoiding friction and wear. At the same time, the geometric flexibility of the braided structure itself allows bending deformation to be coordinated through the elastic bending and torsion of the single wires, rather than through relative sliding between the single wires. This three-in-one structure of "fiber-reinforced core bearing + braided conductor conducting + insulation layer anchoring" significantly improves the bending fatigue life of the cable.

[0101] ② The buffering mechanism of the double-helix differential slip buffer skeleton: When the cable is subjected to external radial impact, the outer support rib 23 first bears the impact force, transferring it to the solid lubrication layer 22 and the inner support rib 21. The flexible foam buffer strip 24 absorbs the impact energy through compression deformation, achieving primary buffering. When the cable is subjected to bending load, the inner support rib 21 and the outer support rib 23 generate differential slip due to their different helical directions and pitches, dispersing the bending deformation over a larger length range and avoiding local stress concentration, achieving secondary buffering. The two buffering mechanisms work together to comprehensively protect the internal insulated core.

[0102] ③ Mechanism of interface fusion achieved by temperature gradient extrusion: The extrusion temperature of the outer insulation layer 14 is higher than that of the inner insulation layer 12 (temperature difference 30-40℃). The high-temperature outer insulation layer material passes through the braided mesh under extrusion pressure, causing the surface of the inner insulation layer to melt. Polyolefin materials of the same system undergo molecular chain diffusion and entanglement at the interface, forming a homogeneous structure without interfaces after cooling. This mechanism achieves interface fusion through a purely physical means without the addition of any additives, ensuring the purity and long-term stability of the insulation system.

[0103] ④ Structure and Functional Mechanism of the Double-Half Interlocking Wedge-Shaped Locking Armor Layer: Two armor halves 31 are inserted from opposite sides of the buffer frame 2, with fins 311 interlocking and locked together by the wedge-shaped inclined surface. The trapezoidal structure of the fins 311 causes the mating surfaces of the two halves to form a wedge angle, generating a self-locking effect under radial pressure. The elastic hinge band 33 connects the fins 311 in series, ensuring the structural integrity of the armor layer and allowing the fins 311 to deflect relative to each other when bending through the hinge.

[0104] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concepts, should be covered within the scope of protection of the present invention.

Claims

1. A method for processing a long-life, environmentally friendly new energy storage cable, characterized in that, Includes the following steps: S1. Preparation of braided insulated wire core with anchoring structure (1): S11. An inner insulation layer (12) is provided on the surface of the fiber-reinforced core (11). S12. On the surface of the fiber-reinforced core (11) covered with the inner insulation layer (12), multiple conductive single wires (131) are bidirectionally cross-braided to form a braided layer (13). S13. An outer insulation layer (14) is provided outside the braided layer (13). The outer insulation layer (14) passes through the mesh of the braided layer (13) and combines with the inner insulation layer (12) to form an integrated insulation layer that wraps the braided layer (13), thus obtaining a braided insulated wire core (1). S2. Preparation of the double-helix differential sliding buffer skeleton (2): S21. Twist the multiple braided insulated wire cores (1) together to form a cable core; S22. A buffer skeleton (2) is provided outside the cable core. The buffer skeleton (2) includes an inner support rib (21), a solid lubricating layer (22) and an outer support rib (23). The inner support rib (21) and the outer support rib (23) have different helical directions and / or pitches. The solid lubricating layer (22) is provided between the inner support rib (21) and the outer support rib (23). S3: An armor layer (3) is provided on the outside of the buffer frame (2): The armor layer (3) is composed of two armor halves (31) that are symmetrically interlocked and wrapped around each other. Each armor half (31) includes several fins (311) arranged sequentially along the cable axis. Adjacent fins (311) are connected in series by an elastic hinge band (312). The two armor halves (31) are inserted from opposite sides of the buffer frame (2), and the fins (311) of the two armor halves (31) interlock and wedge-lock to form a complete circumferential wrapping. S4. A shielding layer (4) and an outer sheath (5) are provided outside the armor layer (3).

2. The processing method for a long-life, environmentally friendly new energy storage cable according to claim 1, characterized in that, The fiber-reinforced core (11) is an aramid fiber-reinforced core, and the conductive single wire (131) is a tin-plated soft copper single wire.

3. The processing method for a long-life, environmentally friendly new energy storage cable according to claim 1, characterized in that, The inner insulation layer (12) and the outer insulation layer (14) are polyolefin materials of the same system; the extrusion temperature of the outer insulation layer (14) is higher than that of the inner insulation layer (12), so that the material of the outer insulation layer (14) diffuses with the material of the inner insulation layer (12) through the mesh pores of the braided layer (13), and forms an interface-free integrated insulation layer after cooling.

4. The processing method for a long-life, environmentally friendly new energy storage cable according to claim 3, characterized in that, The thickness of the inner insulation layer (12) is 0.3 to 0.8 mm, and the extrusion temperature is 160 to 180°C; the extrusion temperature of the outer insulation layer (14) is 190 to 220°C.

5. The processing method for a long-life, environmentally friendly new energy storage cable according to claim 3, characterized in that, The integrated insulating layer is cross-linked by irradiation, with an irradiation dose of 80–120 kGy.

6. The processing method for a long-life, environmentally friendly new energy storage cable according to claim 1, characterized in that, The braided layer (13) has a braiding angle of 40° to 60° and a braiding coverage of 90% to 98%.

7. The processing method for a long-life, environmentally friendly new energy storage cable according to claim 1, characterized in that, The inner support rib (21) has the opposite spiral direction to the outer support rib (23), and the pitch of the outer support rib (23) is greater than the pitch of the inner support rib (21).

8. The processing method for a long-life, environmentally friendly new energy storage cable according to claim 1, characterized in that, The inner layer support rib (21) has a winding angle of 20° to 35°, and the outer layer support rib (23) has a winding angle of 45° to 65°. The solid lubricating layer (22) is a PTFE fiber braided layer or a graphite-coated fiber braided layer; The gap between the inner support rib (21), the outer support rib (23) and the armor layer (3) is filled with flexible foamed buffer strips (24).

9. The processing method for a long-life, environmentally friendly new energy storage cable according to claim 1, characterized in that, Each of the fins (311) is arranged at equal intervals along the axial direction of the sheath, and the spacing between adjacent fins (311) is 1.5 to 2.5 mm; The fin (311) is trapezoidal in shape, with its large end located in the middle of the sheath and its small end located on both sides of the sheath; The width of the elastic hinge band (312) is less than the maximum width of the fin (311), so that a gap is formed between adjacent fins (311) that can be extended and retracted when bent; the elastic hinge band (312) is made of spring steel sheet.

10. The processing method for a long-life, environmentally friendly new energy storage cable according to claim 1, characterized in that, The shielding layer (4) is a copper strip wrapped shielding layer or a copper wire braided shielding layer, and the outer sheath (5) is a low-smoke halogen-free flame-retardant outer sheath layer.

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