Seven-segment cable core structure and production process method

Abstract

The invention belongs to the field of cables, and provides a seven-segment cable core structure and a production process method.The seven-segment cable core structure comprises seven fan-shaped segment strand block conductors which are twisted around the center of a cable to form a cable core with a circular cross section, every two adjacent fan-shaped segment strand block conductors are isolated through insulation crepe paper, and a wrapping copper strip covers the cable core; the cable comprises a cable core, a semi-conductive buffer strip, a flat aluminum sheath and an extruded semi-conductive layer, and the semi-conductive buffer strip is wrapped outside the cable core so as to provide a buffer space when insulation expands with heat and contracts with cold; the inner diameter of the flat aluminum sheath is tightly attached to the semi-conductive buffer strip, and the flat aluminum sheath and the extruded semi-conductive layer on the outermost layer of the cable can form two electrodes for detecting whether the cable sheath is damaged or not. Compared with the prior art, the power cable has the advantages that the wire cores of the 1000KV voltage class are adopted, and the seven-segment fan-shaped segment strand block conductor structure is utilized, so that the loss of electric energy in the line transmission process is effectively reduced, and the reliability and the stability of the cable in operation are improved.

Description

Technical Field

[0001] The invention belongs to the field of cables, and in particular relates to a seven-section cable core structure and a production process method. Background Art

[0002] With the rapid economic development, the demand for electricity in various places has become more urgent. Electricity transmission needs to span hundreds or even thousands of kilometers. The voltage level of existing long-distance transmission cables is generally 220kV or 500kV, and a few are 750kV. Under the premise of transmitting the same amount of electric energy, as the cable level increases, the current flowing through the cable conductor gradually decreases, and the loss of electric energy in the cable will be reduced.

[0003] The current transmission capacity of a conductor does not increase linearly with the conductor cross-section. For cables with larger cross-sectional areas, the distribution of current inside the conductor will become more complicated and the skin effect will become more obvious due to the increase in the conductor cross-section. This means that in high-frequency circuits or high current loads, a larger cable cross-sectional area may cause the current distribution inside the conductor to be more uneven, thereby increasing the resistance and power loss of the cable and reducing the transmission efficiency of the cable. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to propose a seven-section cable core structure and a production process method which has a simple overall structure, reduces line transmission loss, and improves cable reliability and stability.

[0005] The technical solution adopted by the present invention to solve the technical problem is to propose a seven-segment cable core knot, comprising: seven sector-shaped segmented block conductors, twisted around the center of the cable to form a cable core with a circular cross-section, two adjacent sector-shaped segmented block conductors are isolated by insulating crepe paper, and a wrapped copper tape is covered on the outside of the cable core to prevent the interface between the conductor shield and the insulation from being not smooth and causing the insulation electric field concentration;

[0006] A semi-conductive buffer tape, a flat aluminum sheath and an extruded semi-conductive layer, wherein the semi-conductive buffer tape is wrapped around the cable core to provide a buffer space for insulation expansion and contraction; the inner diameter of the flat aluminum sheath is tightly attached to the semi-conductive buffer tape, and can form two electrodes with the extruded semi-conductive layer of the outermost layer of the cable to detect whether the cable sheath is damaged.

[0007] In the above-mentioned seven-section cable core structure, a layer of semi-conductive butyl tape with an overlap rate of 50% is applied on the outside of the cable core.

[0008] In the above-mentioned seven-section cable core structure, the thickness of the wrapped copper tape is 0.10 mm.

[0009] In the above seven-segment cable core structure, the cable core is successively provided with a wrapped semi-conductive tape, an extruded conductor shielding layer, cross-linked polyethylene insulation, and an insulation shielding layer from the inside to the outside, and the semi-conductive butyl tape is wrapped around the outside of the insulation shielding layer.

[0010] In the above seven-segment cable core structure, at least two layers of the semi-conductive buffer tape with a lapping rate of 50% are wrapped around the outside of the semi-conductive butyl tape.

[0011] In the above seven-segment cable core structure, the flat aluminum sheath is coated on the semi-conductive buffer tape, and an extruded hot melt adhesive and a cable insulation sheath are successively arranged between the flat aluminum sheath and the extruded semi-conductive layer from the inside to the outside.

[0012] The technical solution adopted by the present invention to solve its technical problems is to also propose a production process method, including: equally dividing into seven sector-segmented strand conductors according to the cross-sectional area of the cable core, isolating adjacent two sector-segmented strand conductors with insulating crepe paper, and lap-wrapping a layer of copper tape on the outside thereof;

[0013] Performing a three-layer co-extrusion process through a VCV cross-linking machine, and adopting a die head with a nano-coating to make the cross-section between the insulation and the shielding smooth;

[0014] Degassing process: After the core reaches the predetermined time of 70 degrees, turn off the heating, the circulating fan continues to work for 6 hours, and at the same time open the degassing chamber to form a gap with a width of 30 - 50 cm, so that the core cools slowly after degassing and reduces the generation of insulation stress;

[0015] Wrapping process: Wrapping a semi-conductive butyl tape around the cable core through a wrapping machine, and adding at least two layers of semi-conductive buffer tape to provide a buffer space for the thermal expansion and contraction of the insulation;

[0016] Adopting a smooth aluminum process to make the inner diameter of the flat aluminum sheath contact the semi-conductive buffer tape, and adopting an extruded anti-corrosion hot melt adhesive process on the outside of the flat aluminum sheath, and wrapping it with the outermost extruded semi-conductive layer.

[0017] In the above production process method, the VCV cross-linking machine uses a cross-linking process to co-extrude an extruded conductor shielding, cross-linked polyethylene insulation, and an insulation shielding layer.

[0018] In the above production process method, the sector-segmented strand conductors are stranded by a bunching machine, and the insulating crepe paper is isolated by an assembling machine.

[0019] In the above production process method, the flat aluminum sheath and the extruded semi-conductive layer are completed by processes such as argon arc welding, diameter reduction, and sheath extrusion and compounding.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The seven-segment cable core structure and production process method of the present invention uses a core with a voltage level of 1000 KV and utilizes a seven-segment sector-divided strand conductor structure, effectively reducing the loss of electric energy during line transmission and enhancing the reliability and stability of the cable during operation.

[0022] (2) At least two layers of semiconductive buffer tapes and butyl tapes with a lapping rate of 50% each provide a reliable buffer space for the thermal expansion and contraction of the insulation, thereby protecting the cable core from damage and extending its service life.

[0023] (3) The process of extruding anti-corrosion hot melt adhesive is adopted outside the flat aluminum sheath. Compared with the traditional spraying-type hot melt adhesive process, it has uniform and firm extrusion, better temperature resistance performance, and better corrosion resistance to the aluminum sheath. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the overall structure of this application;

[0025] Figure 2 is a flowchart of the entire production process method.

[0026] In the figure, 1, sector-divided strand conductor; 2, insulating crepe paper; 3, wrapped copper tape; 4, semiconductive buffer tape; 5, flat aluminum sheath; 6, extruded semiconductive layer; 7, semiconductive butyl tape; 8, wrapped semiconductive tape; 9, extruded conductor shielding layer; 10, cross-linked polyethylene insulation; 11, insulation shielding layer; 12, extruded hot melt adhesive; 13, cable insulation sheath. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following are specific embodiments of the present invention in combination with the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0028] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If this specific posture changes, then the directional indications will also change accordingly.

[0029] Embodiment 1:

[0030] As Figures 1 to 2As shown in the figure, a seven-segment cable core structure includes: seven sector-segmented strand conductors 1, which are stranded around the cable center to form a cable core with a circular cross-section. Insulating crimped paper 2 is used to isolate adjacent two sector-segmented strand conductors 1, and a wrapped copper tape 3 is covered outside the cable core to prevent the insulation electric field concentration caused by the non-smooth interface between the conductor shield and the insulation; a semi-conductive buffer tape 4, a flat aluminum sheath 5, and an extruded semi-conductive layer 6. The semi-conductive buffer tape 4 is wrapped outside the cable core to provide a buffer space for the thermal expansion and contraction of the insulation; the inner diameter of the flat aluminum sheath 5 is closely attached to the semi-conductive buffer tape 4, and it can form two electrodes with the extruded semi-conductive layer 6 on the outermost layer of the cable to detect whether the cable sheath is damaged.

[0031] In the first embodiment, on the premise of the same conductor cross-section, a cable core is formed by stranding seven sector-segmented strand conductors 1 into a circle, as Figure 1 shown. This structure enables the sector-segmented strand conductor 1 to have a larger conductor surface area, so it can better resist the influence of the skin effect, reduce the AC resistance and line loss of the conductor. It should be noted that in the first embodiment, in order to improve the allowable transmission voltage level of the cable and reduce the line transmission loss, the cable core of the 1000KV voltage level is used. With each segmented strand conductor isolated by the insulating crimped paper 2, it is ensured that the current will not leak and the electric field is evenly distributed. Then, a copper tape with a thickness of 0.10mm can be wrapped outside the formed cable core by using special equipment. The wrapping of the copper tape can effectively avoid the influence of the gap between the segmented conductor strands on the inner screen and the insulation interface, improve the interface smoothness, and reduce the insulation electric field concentration phenomenon; on the basis of wrapping the copper tape 3, two layers of semi-conductive buffer tapes 4 (with a 50% overlapping rate) are further wrapped in this embodiment to provide a reliable buffer space for the insulation material during the thermal expansion and contraction process, ensuring the stability of the cable in different temperature environments; moreover, the flat aluminum sheath 5 is installed outside the cable core by using an argon arc welder (not shown in the figure) to ensure that its inner diameter is in full contact with the semi-conductive buffer tape 4, providing good mechanical protection and electrical shielding. With the extruded semi-conductive layer 6 on the outermost layer of the cable and the flat aluminum sheath 5 respectively connected to the external positive and negative electrodes (not shown in the figure), the integrity of the sheath can be detected to ensure that the overall protection ability of the cable meets the required usage requirements and effectively prevent the occurrence of cable faults.

[0032] It should be noted that the skin effect in this embodiment refers to the interaction between the electric field and the magnetic field under the action of a high-frequency electromagnetic field, which causes the electric field to gather on the surface of the conductor, thus generating a strong surface current and electric field. This phenomenon is called the skin effect. Due to the existence of the skin effect, the current tends to flow through the surface of the conductor rather than the entire cross-section of the conductor, which means that only the resistance on the surface of the conductor will generate the actual current.

[0033] Preferably, the stranded cable core is fixed on the wrapping machine to ensure its stable position. Then, starting from one end of the cable core, a copper tape with a thickness of 0.10 mm is tightly attached to the surface of the cable, and the wrapping machine is started. According to the preset tension and speed, the copper tape is evenly and tightly wrapped around the outer layer of the entire cable core. The wrapped copper tape 3 can effectively fill the gaps between the sector-divided strand conductors 1, making the cross-section of the cable core smoother. Moreover, this design helps to reduce the electric field concentration phenomenon, thereby improving the electrical performance of the cable. Since the copper tape has good electrical conductivity and mechanical strength, it helps to reduce the local overheating phenomenon caused by uneven electric fields, and can also effectively disperse the electric field. The smooth interface is used to avoid local discharge phenomena caused by uneven electric fields and extend the service life of the cable.

[0034] The cable core is sequentially provided with a wrapped semi-conductive tape 8, an extruded conductor shielding layer 9, a cross-linked polyethylene insulation 10, and an insulation shielding layer 11 from the inside to the outside, and is wrapped with a semi-conductive butyl tape 7 outside the insulation shielding layer 11.

[0035] Further preferably, as Figure 1 shown, a suitable semi-conductive material is selected to ensure its good electrical conductivity and mechanical strength. A special device (such as a wrapping machine) is used to evenly wrap the semi-conductive tape around the cable core to form a tightly attached semi-conductive layer. This structure is conducive to evenly distributing the electric field, reducing local discharge phenomena, and improving the safety and stability of the cable. Similarly, prepare ultra-smooth semi-conductive shielding material to ensure its good electrical conductivity and processing performance. Use an extruder to evenly extrude and wrap the ultra-smooth semi-conductive shielding material outside the core to form a smooth conductor shielding layer. The main function of this layer is to evenly distribute the electric field and reduce local discharge phenomena. It should be noted that the extruded conductor shielding layer 9, cross-linked polyethylene insulation 10 (XLPE), and insulation shielding layer 11 in the first embodiment are formed by the VCV three-layer co-extrusion process, that is, a die head with a nano-coating is used, and the surface of the die is ensured to be bright to ensure the smoothness of the interfaces between the insulation, conductor shielding, and insulation shielding, improving the reliability of the cable.

[0036] Further preferably, as Figure 1As shown in the figure, in the first embodiment, a buffer layer structure with special design is adopted to improve the reliability of the cable. Specifically, before the semi-conductive butyl tape 7 is wound, the cable core with cross-linked polyethylene insulation 10 (XLPE) and insulation shielding layer 11 is inspected for quality to ensure that the surface is smooth and flawless, so as to prepare for the subsequent winding process; the parameters of the winding machine are adjusted to ensure that the semi-conductive butyl tape 7 can be wound evenly and tightly outside the insulation shielding layer 11. The winding machine needs to have a tension control function to ensure that the tape will not wrinkle or become loose during the winding process. Each turn of the tape covers half the width of the previous turn to ensure that there is no gap between the tapes, forming a tight and uniform protective layer. Finally, under the action of the semi-conductive butyl tape 7 with a lapping rate of 50%, the overall mechanical strength of the cable is enhanced.

[0037] Further preferably, in the first embodiment, at least two layers (two layers are adopted in this embodiment) of semi-conductive buffer tapes 4 with a lapping rate of 50% are wound outside the semi-conductive butyl tape 7. The two layers of semi-conductive buffer tapes 4 provide a stronger buffering effect, can provide a more reliable buffering space when the insulating material expands and contracts due to temperature changes, and avoid mechanical damage to the insulating layer; at the same time, under the action of the double-layer buffer tape, the stress concentration phenomenon inside the insulating layer is reduced, and the service life is prolonged.

[0038] The flat aluminum sheath 5 is coated on the semi-conductive buffer tape 4, and an extruded hot melt adhesive 12 and a cable insulation type sheath 13 are sequentially arranged from the inside to the outside between the flat aluminum sheath 5 and the extruded semi-conductive layer 6.

[0039] Further preferably, as Figure 1 shown, the first embodiment adopts a smooth aluminum process, so that the inner diameter of the aluminum sheath is in full and comprehensive contact with the semi-conductive buffer tape 4, effectively avoiding the occurrence of buffer tape ablation problems and further improving the reliability of the cable. The flat aluminum sheath 5 provides strong mechanical protection to prevent external pressure from damaging the internal structure of the cable. Its strong metal material can effectively resist external impact and tensile force and is suitable for complex and changeable laying environments; the hot melt adhesive layer not only enhances the adhesion between the flat aluminum sheath 5 and the cable insulation type sheath 13, but also provides additional mechanical support to prevent the sheath layer from falling off or being damaged. Preferably, in this embodiment, an extruded anti-corrosion hot melt adhesive process is also adopted outside the flat aluminum sheath 5. Compared with the traditional spray-type hot melt adhesive process, it has uniform and firm extrusion, better temperature resistance performance and better corrosion resistance performance to the aluminum sheath.

[0040] Embodiment Two:

[0041] Based on the seven-segment cable core structure in the above-mentioned Embodiment 1, this Embodiment 2 proposes a production process method, including: equally dividing into seven sector-divided strand conductors 1 according to the cross-sectional area of the cable core, using insulating crepe paper 2 to isolate two adjacent sector-divided strand conductors 1, and covering and winding a layer of copper tape on the outside thereof; performing a three-layer co-extrusion process through a VCV cross-linking machine, and using a die head with a nano-coating to make the interface between the insulation and the shield smooth; degassing process: after the core reaches the predetermined time of 70 degrees, turn off the heating, the circulating fan continues to work for 6 hours, and at the same time open the degassing chamber to form a gap with a width of 30-50 cm, so that the cable core cools slowly after degassing and reduces the generation of insulation stress; winding process: winding a semi-conductive butyl tape 7 around the cable core through a winding machine, and adding at least two layers of semi-conductive buffer tapes 4 to provide a buffer space for the thermal expansion and contraction of the insulation; adopting a smooth aluminum process, making the inner diameter of the flat aluminum sheath 5 contact the semi-conductive buffer tape 4, and adopting an extrusion anti-corrosion hot melt adhesive process outside the flat aluminum sheath 5, and wrapping it with an outermost extruded semi-conductive layer 6.

[0042] As Figure 1 and Figure 2 shown, first, in the wire drawing process, select a suitable copper rod and perform multiple stretches through a wire drawing machine to form a conductor with the required diameter. Use a 91-frame stranding machine to strand the seven sector-divided strand conductors 1 around the cable center to form a circular cable core, and use insulating crepe paper 2 to isolate between two adjacent sector-divided strand conductors 1 to prevent current leakage and evenly distribute the electric field; as the formed cable core after stranding is fixed on the winding machine, combined with an outer layer of wound semi-conductive tape 8, it effectively improves the smoothness and conductivity of the cable core; it should be noted that in this embodiment, a 3150 aggregator is used through the conductor aggregation process, so that during the division of the sector-divided strand conductors 1, the isolation operation of the insulating crepe paper 2 is synchronously performed, thereby saving the beat time of the entire production process.

[0043] Further preferably, in the three-layer co-extrusion process, the VCV cross-linking extruder evenly extrudes and wraps the cross-linked polyethylene material, the conductor shield layer and the insulation shield layer 11 in sequence outside the core through a die head with a nano-coating to form a three-layer co-extrusion structure; the die head with a nano-coating ensures that the interface between the insulation and the shield layer is smooth, reduces the friction between the interfaces, and improves the overall electrical performance of the cable; the cross-linked polyethylene material improves the heat resistance and mechanical strength of the material through the cross-linking reaction under high temperature and high pressure, and enhances the service life of the cable.

[0044] Further preferably, this embodiment also formulates a special degassing method: heating the core to 70 degrees and maintaining it for a predetermined time, turning off the heating device, the circulation fan continues to work for 6 hours, and at the same time opening the large door of the degassing chamber to form a gap with a width of 30-50 mm, so that the cable cools down slowly, reducing the generation of insulation stress. This is beneficial to reducing the stress concentration phenomenon in the insulating material and improving the reliability of the cable operation. The degassing process helps to remove the microbubbles in the insulating material, avoiding the partial discharge phenomenon caused by the bubbles and prolonging the service life of the cable. In the subsequent wrapping process, a wrapping machine can be used to evenly wrap the buffer layer structure and at least two layers of semi-conductive buffer tapes 4 outside the semi-conductive butyl tape 7, and the overlapping rate of each layer is 50%. In this process, the double-layer semi-conductive buffer tape 4 can provide a reliable buffer space when the insulating material expands and contracts due to temperature changes, avoiding mechanical damage to the insulating layer; the semi-conductive butyl tape 7 and the buffer tape have certain conductivity, which can effectively and evenly distribute the electric field, reduce the partial discharge phenomenon, and improve the safety and stability of the cable.

[0045] In the second embodiment, an argon arc welder is used to install the flat aluminum sheath 5 outside the cable core to ensure that its inner diameter is in full contact with the semi-conductive buffer tape 4. As the cable core covered with the flat aluminum sheath 5 is fed into the extruder, the extruder can evenly extrude and wrap the extrusion-type hot melt adhesive 12 outside the flat aluminum sheath 5 to form a thick and uniform hot melt adhesive layer. Subsequently, the extruder evenly extrudes and wraps the outermost extrusion semi-conductive layer 6 outside the hot melt adhesive layer. It should be added that the argon arc welder, the diameter-reducing machine, and the sheath extrusion group are connected in series to complete the final production process at one time, that is, the semi-finished product after the wrapping process can be processed into the required finished product through the aluminum sheath and extrusion sheath composite process. In this process, the semi-finished product of the flat aluminum sheath 5 after diameter reduction is very difficult to bend without the outer sheath. After bending, the aluminum sheath is prone to wrinkling and causing cable scrapping. Therefore, after the cable is released from the wire reel in the argon arc welding process and goes through a series of processes of the argon arc welder and the extruder, the flat aluminum sheath 5 can provide strong mechanical protection, preventing external pressure from damaging the internal structure of the cable and effectively resisting external impact and tensile force; preferably, the extrusion anti-corrosion hot melt adhesive process is adopted outside the flat aluminum sheath 5, which not only enhances the adhesion between the flat aluminum sheath 5 and the cable insulation sheath 13, but also provides additional sealing and corrosion resistance, preventing moisture and impurities from invading the cable interior; finally, after the outermost extrusion semi-conductive layer 6 and the flat aluminum sheath 5 are respectively connected to the external positive and negative electrodes, the cable sheath can be detected whether it meets the required use requirements (voltage withstand test), ensuring the overall protection ability of the cable and enabling the cable to operate stably for a long time in various harsh environments, prolonging the service life and meeting the needs of long-distance and large-capacity power transmission.

[0046] It should be noted that in the present invention, descriptions such as "first", "second", "one", etc. are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined as "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. Terms such as "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the internal connection of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0048] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or use similar means for substitution, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A seven-segment cable core structure, characterized in that, Comprising: Seven sector-segmented strand conductors are stranded around the cable center to form a cable core with a circular cross-section. Insulating crepe paper is used to isolate adjacent sector-segmented strand conductors, and a wrapped copper tape is covered outside the cable core to prevent the concentration of the insulation electric field caused by the non-smooth interface between the conductor shield and the insulation. A semi-conductive buffer tape, a flat aluminum sheath, and an extruded semi-conductive layer. The semi-conductive buffer tape is wrapped around the cable core to provide a buffer space for the thermal expansion and contraction of the insulation. The inner diameter of the flat aluminum sheath is closely attached to the semi-conductive buffer tape, and together with the extruded semi-conductive layer on the outermost layer of the cable, they can form two electrodes to detect whether the cable sheath is damaged.

2. The seven-segment cable core structure according to claim 1, characterized in that A semi-conductive butyl tape with a lapping rate of 50% is used outside the cable core.

3. A seven-segment cable core structure according to claim 1, characterized in that, The thickness of the wrapped copper tape is 0.10 mm.

4. A seven-segment cable core structure according to claim 2, characterized in that The cable core is sequentially provided with a wrapped semi-conductive tape, an extruded conductor shield layer, cross-linked polyethylene insulation, and an insulation shield layer from the inside to the outside, and the semi-conductive butyl tape is wrapped outside the insulation shield layer.

5. A seven-segment cable core structure according to claim 4, characterized in that, At least two layers of semi-conductive buffer tapes with a lapping rate of 50% are wrapped outside the semi-conductive butyl tape.

6. The seven-segment cable core structure according to claim 4, characterized in that, The flat aluminum sheath is coated on the semi-conductive buffer tape, and an extruded hot-melt adhesive and a cable insulation-type sheath are sequentially arranged from the inside to the outside between the flat aluminum sheath and the extruded semi-conductive layer.

7. A production process method of applying the seven-segment cable core structure according to any one of claims 1-6, characterized in that, Comprising: According to the cross-sectional area of the cable core, it is equally divided into seven sector-segmented strand conductors. Insulating crepe paper is used to isolate adjacent sector-segmented strand conductors, and a layer of copper tape is wrapped and covered outside. Through a VCV cross-linking machine for a three-layer co-extrusion process, and a die head with a nano-coating is used to make the cross-section between the insulation and the shield smooth. Degassing process: After the core reaches the predetermined time of 70 degrees, the heating is turned off, the circulating fan continues to work for 6 hours, and at the same time, the degassing chamber is opened to form a gap with a width of 30 - 50 cm, so that the cable core cools down slowly after degassing and reduces the generation of insulation stress. Wrapping process: A semi-conductive butyl tape is wrapped around the cable core through a wrapping machine, and at least two layers of semi-conductive buffer tapes are added to provide a buffer space for the thermal expansion and contraction of the insulation. The smooth aluminum process is adopted, so that the inner diameter of the flat aluminum sheath contacts the semi-conductive buffer tape. An extruded anti-corrosion hot-melt adhesive process is adopted outside the flat aluminum sheath, and it is wrapped by the outermost extruded semi-conductive layer.

8. The production process method of the seven-segment cable core structure according to claim 7, characterized in that, The VCV cross-linking machine uses a cross-linking process to co-extrude three layers of an extruded conductor shield, cross-linked polyethylene insulation, and an insulation shield layer.

9. The production process method of the seven-segment cable core structure according to claim 7, characterized in that, The sector-segmented strand conductors are stranded by a bunching machine, and the insulating crepe paper is isolated by an assembling machine.

10. The production process method of the seven-segment cable core structure according to claim 7, characterized in that, The flat aluminum sheath and the extruded semi-conductive layer are completed by argon arc welding, necking-down, and sheath extrusion composite processes.

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