Ultrahigh-voltage cable and processing method thereof

Abstract

The invention specifically discloses an ultrahigh-voltage cable and a processing method thereof, and relates to the technical field of wires and cables, the ultrahigh-voltage cable comprises a wire core, an embossed aluminum sheath, a buffer layer and an outer sheath, and the embossed aluminum sheath and a gap are arranged on the peripheral side of the wire core; the buffer layer is made of a semi-conductive foaming polyethylene material, and the semi-conductive foaming polyethylene material is poured and filled in a gap between the wire core and the embossed aluminum sheath; according to the ultrahigh-voltage cable provided by the embodiment of the invention, the gap between the cable core and the embossed aluminum sheath is filled with the semi-conductive foaming polyethylene material in a pouring manner, so that the gap is completely filled, the corona discharge phenomenon in the use process is avoided, and the service life is long.

Description

Technical Field

[0001] The present invention relates to the technical field of electric wires and cables, and in particular to an ultra-high voltage cable and a processing method thereof. Background Art

[0002] Ultra-high voltage cables have the characteristics of low energy loss, low resistance and inductance, high safety, strong reliability and stability, etc. They are widely used in various fields such as urban power grids, rural power grids and industrial power grids. However, the current ultra-high voltage cables are prone to corona discharge, which affects their service life. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an ultra-high voltage cable that can avoid the generation of corona discharge and has a long service life.

[0004] The present invention also provides a method for processing an ultra-high voltage cable, which is used for processing the ultra-high voltage cable.

[0005] According to an embodiment of the present invention, the ultra-high voltage cable comprises a core, a corrugated aluminum sheath, a buffer layer and an outer sheath. The corrugated aluminum sheath has a gap arranged on the outer peripheral side of the core. The buffer layer is formed of a semi-conductive foamed polyethylene material, and the semi-conductive foamed polyethylene material is poured and filled in the gap between the core and the corrugated aluminum sheath. The outer sheath is extruded on the outer peripheral side of the corrugated aluminum sheath.

[0006] The ultra-high voltage cable according to the embodiment of the present invention has at least the following beneficial effects: by filling the gap between the core and the corrugated aluminum sheath with semi-conductive foamed polyethylene material, the gap is completely filled, thereby avoiding corona discharge during use and prolonging the service life.

[0007] According to an embodiment of the present invention, the outer sheath is formed by extruding a polyvinyl chloride material on the outer peripheral side of the corrugated aluminum sheath.

[0008] According to an embodiment of the present invention, the outer sheath is formed by extruding a polyethylene material on the outer peripheral side of the corrugated aluminum sheath.

[0009] According to one embodiment of the present invention, the wire core includes a conductor, a conductor shielding layer, an insulating layer and an insulating shielding layer, the conductor shielding layer is arranged on the outer peripheral side of the conductor, the insulating layer is arranged on the outer peripheral side of the conductor shielding layer, and the insulating shielding layer is arranged on the outer peripheral side of the insulating layer.

[0010] According to an embodiment of the present invention, the conductor shielding layer is made of cross-linked semi-conductive polyolefin.

[0011] According to an embodiment of the present invention, the insulating layer is made of cross-linked polyethylene.

[0012] According to an embodiment of the present invention, the insulating shielding layer is made of cross-linked semi-conductive polyolefin.

[0013] According to an embodiment of the present invention, the conductor is formed by twisting a plurality of copper monofilaments.

[0014] The processing method of the ultra-high voltage cable according to the embodiment of the present invention is used to process the ultra-high voltage cable according to the embodiment of the present invention. The processing method of the ultra-high voltage cable comprises:

[0015] The corrugated aluminum sheath is intermittently sheathed outside the wire core;

[0016] Pouring the semi-conductive foamed polyethylene material into the gap between the wire core and the corrugated aluminum sheath to form the buffer layer;

[0017] The outer sheath is formed on the outer peripheral side of the corrugated aluminum sheath by an extrusion process.

[0018] The processing method of the ultra-high voltage cable according to the embodiment of the present invention has at least the following beneficial effects: by pouring and filling the gap between the wire core and the corrugated aluminum sheath with semi-conductive foamed polyethylene material, the above-mentioned gap is completely filled, thereby avoiding the occurrence of corona discharge in the processed ultra-high voltage cable during use, and extending the service life.

[0019] According to an embodiment of the present invention, it also includes:

[0020] Plasticizing the aluminum strip into a tube;

[0021] The tubular aluminum strip is welded into an aluminum tube by argon arc welding;

[0022] The surface of the aluminum tube is rolled into a wave shape by a corrugating machine to form the corrugated aluminum sheath.

[0023] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0025] Figure 1 A schematic cross-sectional view of an ultra-high voltage cable according to an embodiment of the present invention;

[0026] Figure 2 A schematic flow chart of a method for processing an ultra-high voltage cable according to an embodiment of the present invention;

[0027] Figure 3The present invention is a schematic flow chart of a method for processing an ultra-high voltage cable according to an embodiment of the present invention.

[0028] Reference numerals:

[0029] Ultra-high voltage cable 1000;

[0030] Core 100; conductor 110; conductor shielding layer 120; insulating layer 130; insulating shielding layer 140;

[0031] Corrugated aluminum sheath 200;

[0032] Buffer layer 300;

[0033] Outer sheath 400. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0035] In the description of the present invention, it is necessary to understand that descriptions involving orientations, such as up, down, inside, outside, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0036] In the description of the present invention, if there is a description of first and second, it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0037] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0038] Ultra-high voltage cables have the characteristics of low energy loss, low resistance and inductance, high safety, strong reliability and stability. They are widely used in various fields such as urban power grids, rural power grids and industrial power grids.

[0039] Ultra-high voltage cables are generally single-core cables, and the buffer layer is generally a wrapped semi-conductive buffer tape, and a corrugated aluminum sheath is produced on the outside. However, the gap between the insulating shielding layer and the aluminum sheath in this structure cannot be completely filled, resulting in large gaps and easy corona discharge, which affects the service life of the cable and the laying environment.

[0040] In order to solve the gap discharge problem of the wire core + wrapped semi-conductive buffer tape + corrugated aluminum sheath structure, some companies now change the corrugated aluminum sheath to a smooth aluminum sheath. However, this greatly reduces the aluminum sheath's ability to resist lateral pressure, affects the bending performance of the ultra-high voltage cable, and is not conducive to installation. At the same time, the risk of cable damage caused by construction is also relatively high.

[0041] To this end, the present invention provides an ultra-high voltage cable 1000, specifically referring to the accompanying drawings of the specification Figure 1 shown.

[0042] Reference Figure 1 As shown, an ultra-high voltage cable 1000 of an embodiment of the present invention includes a core 100, a corrugated aluminum sheath 200, a buffer layer 300 and an outer sheath 400. Among them, the corrugated aluminum sheath 200 is arranged at the outer peripheral side of the core 100. It can be understood that the corrugated aluminum sheath 200 has good pressure resistance and bending ability, can play a role in protecting the cable, and at the same time, can also play a good shielding role. In addition, the buffer layer 300 is formed by a semi-conductive foamed polyethylene material. It should be noted that the semi-conductive foamed polyethylene material is poured and filled in the gap between the core 100 and the corrugated aluminum sheath 200. That is to say, the semi-conductive foamed polyethylene material is poured and filled in the gap between the core 100 and the corrugated aluminum sheath 200 to form a buffer layer 300.

[0043] It should be noted that the semi-conductive foamed polyethylene material has good mechanical strength, wear resistance and anti-aging properties, and can effectively homogenize the electric field. At the same time, the semi-conductive foamed polyethylene material can effectively fill the gap between the core 100 and the corrugated aluminum sheath 200 by pouring. It can be understood that by pouring the semi-conductive foamed polyethylene material into the gap between the core 100 and the corrugated aluminum sheath 200, the above gap is completely filled, thereby avoiding the occurrence of corona discharge in the ultra-high voltage cable 1000 during use, and the service life is long.

[0044] Continue to refer to Figure 1 As shown, it should be noted that the outer sheath 400 is extruded on the outer peripheral side of the corrugated aluminum sheath 200. It can be understood that the outer sheath 400 mainly plays the role of insulation and protection of the internal structure. In one embodiment, the outer sheath 400 is formed by extruding a polyvinyl chloride material on the outer peripheral side of the corrugated aluminum tube. In other words, the polyvinyl chloride material is extruded on the outer peripheral side of the corrugated aluminum tube to form the outer sheath 400. It should be noted that the polyvinyl chloride material is an important synthetic polymer material with good flame retardancy, electrical insulation and mechanical strength, and is an ideal material for the outer sheath 400.

[0045] In another embodiment, the outer sheath 400 is formed by extruding a polyethylene material on the outer peripheral side of the corrugated sheath. That is, the polyethylene material is extruded on the outer peripheral side of the corrugated aluminum tube to form the outer sheath 400. It should be noted that the polyethylene material is a thermoplastic resin polymerized from ethylene monomers, has good waterproofness and electrical insulation, and is an ideal material for the outer sheath 400.

[0046] Reference Figure 1 As shown, in an ultra-high voltage cable 1000 according to an embodiment of the present invention, the core 100 includes a conductor 110, a conductor shielding layer 120, an insulating layer 130 and an insulating shielding layer 140. The conductor shielding layer 120 is arranged on the outer peripheral side of the conductor 110, the insulating layer 130 is arranged on the outer peripheral side of the conductor shielding layer 120, and the insulating shielding layer 140 is arranged on the outer peripheral side of the insulating layer 130. It can be understood that, through the above arrangement, the insulating layer 130 plays an insulating role, and the conductor shielding layer 120 and the insulating shielding layer 140 play a shielding role, thereby improving the anti-interference ability of the ultra-high voltage cable 1000.

[0047] In one embodiment, the conductor shielding layer 120 is made of cross-linked semi-conductive polyolefin. It should be noted that the cross-linked semi-conductive polyolefin is a polyolefin material modified by a cross-linking reaction, has good conductivity and mechanical properties, and is an ideal material for the conductor shielding layer 120.

[0048] In one embodiment, the insulating layer 130 is made of cross-linked polyethylene. It should be noted that cross-linked polyethylene is a material that transforms polyethylene molecular chains from a linear structure to a three-dimensional network structure by chemical or physical methods. This modification significantly improves the comprehensive properties of polyethylene, including mechanical strength, heat resistance, chemical corrosion resistance, and electrical properties, and is an ideal material for the insulating layer 130.

[0049] In one embodiment, the insulating shielding layer 140 is made of cross-linked semi-conductive polyolefin. It should be noted that the cross-linked semi-conductive polyolefin is a polyolefin material modified by a cross-linking reaction, has good conductivity and mechanical properties, and is an ideal material for the insulating shielding layer 140.

[0050] In one embodiment, the conductor shielding layer 120, the insulating layer 130 and the insulating shielding layer 140 are extruded by a three-layer co-extrusion process. It should be noted that the three-layer co-extrusion technology is a method of simultaneously extruding particles of three different materials through a die head and forming a film. It is understandable that by adopting the three-layer co-extrusion process, the manufacturing time can be significantly shortened and the comprehensive performance of the product can be improved.

[0051] In one embodiment, the conductor 110 is formed by twisting multiple copper wires. It should be noted that twisting is a process of twisting multiple single wires together in a certain direction and rule to form a whole. Through twisting, the mechanical strength and anti-interference ability of the conductor 110 are improved.

[0052] The present invention provides a processing method for an ultra-high voltage cable 1000, specifically referring to the accompanying drawings of the specification Figures 1 to 3 shown.

[0053] Reference Figure 1 and Figure 2 As shown, a processing method of an ultra-high voltage cable 1000 according to an embodiment of the present invention includes:

[0054] The corrugated aluminum sheath 200 is intermittently sheathed outside the wire core 100;

[0055] The semi-conductive foamed polyethylene material is poured into the gap between the wire core 100 and the corrugated aluminum sheath 200 to form a buffer layer 300;

[0056] The outer sheath 400 is formed on the outer peripheral side of the corrugated aluminum sheath 200 by an extrusion process.

[0057] It should be noted that after the semi-conductive foamed polyethylene material is poured into the above gap, it can be foamed within 30 seconds, and the foaming degree is constant and controllable, and the volume resistivity after foaming meets the standard requirement value. It can be understood that after the semi-conductive foamed polyethylene material is poured and foamed, the structure between the insulating shielding layer 140 and the corrugated aluminum sheath 200 is stable and fully filled, and there will be no problems such as corona discharge that affect the safe operation of the cable, and the service life is long.

[0058] In one embodiment, polyvinyl chloride material is extruded onto the outer peripheral side of the corrugated aluminum sheath 200 through an extrusion process to form the outer sheath 400; in another embodiment, polyethylene material is extruded onto the outer peripheral side of the corrugated aluminum sheath 200 through an extrusion process to form the outer sheath 400.

[0059] Reference Figure 1 and Figure 3 As shown, a processing method of an ultra-high voltage cable 1000 according to an embodiment of the present invention further includes:

[0060] Plasticizing the aluminum strip into a tube;

[0061] The tubular aluminum strip is welded into an aluminum tube by argon arc welding;

[0062] The surface of the aluminum tube is rolled into a wave shape by a corrugating machine to form a corrugated aluminum sheath 200 .

[0063] It should be noted that argon arc welding, also known as tungsten inert gas shielded welding, is a welding technology that uses inert gases such as argon as shielding gas. Its main feature is the use of non-melting tungsten electrodes, which melt the welding material into a liquid on the welded substrate through high current to form a molten pool, thereby achieving metallurgical bonding between the metals.

[0064] It can be understood that, through the above method, the corrugated aluminum sheath 200 can be produced efficiently.

[0065] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. Extra high voltage cable, characterized in that: include: Wire core; A corrugated aluminum sheath, with a gap provided on the outer peripheral side of the wire core; A buffer layer is formed of a semi-conductive foamed polyethylene material, wherein the semi-conductive foamed polyethylene material is poured and filled in the gap between the wire core and the corrugated aluminum sheath; The outer sheath is extruded and molded on the outer peripheral side of the corrugated aluminum sheath.

2. The ultra-high voltage cable according to claim 1, characterized in that: The outer sheath is formed by extruding a polyvinyl chloride material on the outer peripheral side of the corrugated aluminum sheath.

3. The ultra-high voltage cable according to claim 1, characterized in that: The outer sheath is formed by extruding a polyethylene material on the outer peripheral side of the corrugated aluminum sheath.

4. The ultra-high voltage cable according to claim 1, characterized in that: The wire core includes a conductor, a conductor shielding layer, an insulating layer and an insulating shielding layer. The conductor shielding layer is arranged on the outer peripheral side of the conductor, the insulating layer is arranged on the outer peripheral side of the conductor shielding layer, and the insulating shielding layer is arranged on the outer peripheral side of the insulating layer.

5. The ultra-high voltage cable according to claim 4, characterized in that: The conductor shielding layer is made of cross-linked semi-conductive polyolefin.

6. The ultra-high voltage cable according to claim 4, characterized in that: The insulating layer is made of cross-linked polyethylene.

7. The ultra-high voltage cable according to claim 4, characterized in that: The insulating shielding layer is made of cross-linked semi-conductive polyolefin.

8. The ultra-high voltage cable according to claim 4, characterized in that: The conductor is formed by twisting a plurality of copper monofilaments.

9. A method for processing an ultra-high voltage cable, used for processing the ultra-high voltage cable according to any one of claims 1 to 8, characterized in that: include: The corrugated aluminum sheath is intermittently sheathed outside the wire core; Pouring the semi-conductive foamed polyethylene material into the gap between the wire core and the corrugated aluminum sheath to form the buffer layer; The outer sheath is formed on the outer peripheral side of the corrugated aluminum sheath by an extrusion process.

10. The method for processing an ultra-high voltage cable according to claim 9, characterized in that: Also includes: Plasticizing the aluminum strip into a tube; The tubular aluminum strip is welded into an aluminum tube by argon arc welding; The surface of the aluminum tube is rolled into a wave shape by a corrugating machine to form the corrugated aluminum sheath.

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