High-voltage cable

Abstract

The present invention provides a high-voltage cable and belongs to the technical field of cable manufacturing. The high-voltage cable includes a cable conductor, a conductor shield layer, an insulating layer, an insulation shield layer, a semiconductive water-stop buffer layer, a copper wire shield layer, a semiconductive water-stop buffer layer, a metal sheath, an anticorrosive layer, and a non-metal sheath layer, which are arranged in sequence from the inside to the outside. By adopting two layers of semiconductive water-stop buffer layers and providing a copper wire shield layer between the two layers of semiconductive water-stop buffer layers, the fault current of the cable system can be shared, and the mechanical properties of the high-voltage cable can also be enhanced. The structural design of the two layers of water-stop buffer layers can withstand the mechanical impact of the copper wire on the insulation shield and at the same time has excellent longitudinal waterproof performance. At the same time, by utilizing the radial waterproof performance and corrosion resistance of the metal sheath, the cable has strong corrosion resistance and waterproof performance, and at the same time, the metal sheath can also conduct a certain amount of system fault current.

Description

Technical Field

[0001] This application claims the priority of a Chinese patent application with the application number 202310518716X and the invention title "High-Voltage Cable", which was filed with the Chinese Patent Office on May 10, 2023, and all of its contents are incorporated herein by reference.

[0002] The present invention relates to the technical field of cable manufacturing, and particularly to high-voltage cables.

Background Art

[0003] High-voltage cables are a type of power cable, referring to power cables for transmitting power of 66 - 220 kV. They are widely used in power transmission and distribution, mainly for long-distance power transmission. Among them, armored high-voltage cables are mainly used for underground burial, can withstand strong pressure from the ground, and can prevent damage caused by other external forces. The structure of medium and high-voltage cables mainly consists of a conductor + three-layer co-extrusion (inner shield, insulator, outer shield) + metal shield + protective layer.

[0004] Generally, problems that are likely to occur in the manufacturing process of high-voltage cables include eccentricity of the insulator, non-uniform thickness of the insulating shield, impurities in the insulator, protrusions of the inner and outer shields, etc. These affect the insulation and shielding properties of the cable. In serious cases, failures may occur during the completion test or immediately after operation. Most of them exist as defects in the cable system, causing significant hidden dangers to the long-term safe operation of the cable.

[0005] Therefore, in this field, how to improve the shielding property of high-voltage cables has become an urgent technical problem.

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to provide a high-voltage cable with excellent insulation, shielding, and corrosion resistance.

Means for Solving the Problem

[0007] To achieve the object of the above invention, the present invention provides the following technical idea.

[0008] The present invention provides a high-voltage cable, which includes, in order from the inside to the outside, a cable conductor, a conductor shield layer, an insulating layer, an insulation shield layer, a semiconductive water-stop buffer layer, a copper wire shield layer, a semiconductive water-stop buffer layer, a metal sheath, an anticorrosion layer, and a non-metal sheath layer.

[0009] Preferably, the applied voltage of the high-voltage cable is 66 to 220 kV.

[0010] Preferably, the cable conductor is composed of copper wire.

[0011] Preferably, the copper wire complies with the regulations of GB / T3953.

[0012] Preferably, the copper wires are twisted together layer by layer and pressed to form the cable conductor.

[0013] Preferably, the raw material of the conductor shield layer is a high-voltage DC cable cross-linked polyethylene insulating material, and the thickness of the conductor shield layer is 0.5 to 1.0 mm.

[0014] Preferably, the material of the insulating layer is an irradiated cross-linked polyethylene material or a soft polyvinyl chloride plastic, and the thickness of the insulating layer is 0.8 to 2.0 mm.

[0015] Preferably, the raw material of the insulation shield layer, in terms of parts by mass, includes 47 to 82 parts by mass of polypropylene, 35 to 48 parts by mass of ethylene-octene copolymer, 3 to 8 parts by mass of nanosilica, 23 to 37 parts by mass of conductive carbon black, 1 to 2 parts by mass of antioxidant, and 0.5 to 1.5 parts by mass of lubricating dispersant.

[0016] Preferably, the polypropylene is a blend of a homopolymer of polypropylene and a copolymer of polypropylene, and the mass ratio of the homopolymer of polypropylene to the copolymer of polypropylene is 1:1 to 1:10.

[0017] Preferably, the melt index of the homopolymer of polypropylene is 1.0 to 5.0 g / 10 min, and the melt index of the copolymer of polypropylene is 1.0 to 4.0 g / 10 min.

[0018] Preferably, the antioxidant is 4,4'-thiobis(6-tert-butyl-3-methylphenol), and the lubricating dispersant is polyethylene wax.

[0019] Preferably, the method for manufacturing the insulating shield layer is to mix polypropylene, ethylene-octene copolymer, nanosilica, conductive carbon black, antioxidant, and lubricating dispersant, knead them, then extrude and granulate to obtain particles, melt the particles and coat them on the surface of the insulating layer to obtain the insulating shield layer.

[0020] Preferably, the semiconductive water-stop buffer layer is a semiconductive water-stop tape or a semiconductive buffer water-stop tape. The performance of the semiconductive water-stop buffer layer complies with the JB / T10259 standard, and the thickness of the semiconductive water-stop buffer layer is 0.6 to 0.8 mm.

[0021] Preferably, the copper wire shield layer is formed by twisting copper wires, and the thickness of the copper wire shield layer is 1 to 1.5 mm.

[0022] Preferably, the metal sheath is an aluminum sheath or a lead sheath.

[0023] Preferably, the raw materials of the anticorrosion layer, in terms of parts by mass, include 52 to 65 parts by mass of asphalt, 1 to 5 parts by mass of emulsifier, 1 to 2 parts by mass of stabilizer, and 35 to 40 parts by mass of water.

[0024] Preferably, the method for manufacturing the anticorrosion layer is Step (1) of mixing an emulsifier, a stabilizer, and water and stirring to obtain an emulsified aqueous solution; Step (2) of heat-treating asphalt to obtain molten asphalt; Step (3) of mixing the emulsified aqueous solution obtained in step (1) with the molten asphalt obtained in step (2), followed by high-speed stirring and coating the surface of the metal sheath to obtain an anticorrosive layer.

[0025] The order of executing step (1) and step (2) is not limited.

Advantages of the Invention

[0026] The present invention provides a high-voltage cable. The high-voltage cable includes, in order from the inside to the outside, a cable conductor, a conductor shield layer, an insulating layer, an insulating shield layer, a semiconductive water-stop buffer layer, a copper wire shield layer, a semiconductive water-stop buffer layer, a metal sheath, an anticorrosion layer, and a non-metal sheath layer. The present invention adopts two layers of semiconductive water-stop buffer layers, and by providing a copper wire shield layer between the two layers of semiconductive water-stop buffer layers, the copper wire shield layer can share the fault current of the cable system and can also enhance the mechanical properties of the high-voltage cable. The structural design of the two layers of semiconductive water-stop buffer layers can withstand the mechanical impact of the copper wire on the insulating shield and at the same time has excellent longitudinal waterproof performance. By providing a metal sheath after the semiconductive water-stop buffer layer and utilizing the radial waterproof performance and corrosion resistance of the metal sheath, the cable has strong corrosion resistance and waterproof performance. At the same time, a certain amount of system fault current may also flow through the metal sheath. The results of the examples show that when the test frequency is 100 MHz, the shielding characteristics of the high-voltage cables manufactured in Examples 1 to 3 of the present invention are ≧ 95 dB, while the shielding characteristics of the high-voltage cables manufactured in Comparative Examples 1 and 2 are < 85 dB. When the test frequency is 1 GHz, the shielding characteristics of the high-voltage cables manufactured in Examples 1 to 3 of the present invention are ≧ 60 dB, while the shielding characteristics of the high-voltage cables manufactured in Comparative Examples 1 and 2 are ≦ 56 dB. This shows that the shielding characteristics of the high-voltage cable manufactured by the present invention are significantly improved compared with other high-voltage cables, and at the same time, the high-voltage cable has excellent corrosion resistance and a longer service life.

Embodiments for Carrying out the Invention

[0027] The present invention provides a high-voltage cable. The high-voltage cable includes, in order from the inside to the outside, a cable conductor, a conductor shield layer, an insulating layer, an insulating shield layer, a semiconductive water-stop buffer layer, a copper wire shield layer, a semiconductive water-stop buffer layer, a metal sheath, an anticorrosion layer, and a non-metal sheath layer.

[0028] Unless otherwise specified, all raw materials used in the high-voltage cable provided by the present invention are commercially available products well known to those skilled in the art.

[0029] In the present invention, the applied voltage of the high-voltage cable is preferably 66 - 220 kV, more preferably 110 - 220 kV.

[0030] The high-voltage cable provided by the present invention includes a cable conductor. In the present invention, the composition of the cable conductor is preferably a copper wire, the copper wire preferably complies with the GB / T3953 standard, and the copper wire is preferably twisted and pressed layer by layer to form a cable conductor. In the present invention, the size of the cable conductor is not particularly limited and may be determined according to the specifications of the required high-voltage cable. The present invention can improve the strength of the cable conductor by the above method.

[0031] The high-voltage cable provided by the present invention includes a conductor shield layer disposed outside the cable conductor. In the present invention, the conductor shield layer is preferably a cross-linked polyethylene insulating material for high-voltage DC cables, and the thickness of the conductor shield layer is preferably 0.5 - 1.0 mm. The present invention does not impose special restrictions on a specific source of the cross-linked polyethylene insulating material for the high-voltage DC cable, and commercially available products well known to those skilled in the art may be used. By providing the conductor shield layer, the present invention can homogenize the conductive wire core and the insulating electric field, eliminate the increase in the electric field strength on the conductor surface due to the roughness of the conductor surface, and improve the transmission efficiency.

[0032] The high-voltage cable provided by the present invention includes an insulating layer disposed outside the conductor shield layer. In the present invention, the material of the insulating layer is preferably an irradiated cross-linked polyethylene material or a soft polyvinyl chloride plastic, more preferably an irradiated cross-linked polyethylene material, and the thickness of the insulating layer is preferably 0.8 - 2.0 mm, more preferably 1.0 - 1.5 mm. In the present invention, the main role of the insulating layer is to enhance the insulation effect of the cable and prevent problems such as leakage.

[0033] The high-voltage cable provided by the present invention includes an insulating shield layer disposed outside the insulating layer. In the present invention, the raw materials of the insulating shield layer preferably include, in terms of parts by mass, 47 to 82 parts by mass of polypropylene, 35 to 48 parts by mass of ethylene-octene copolymer, 3 to 8 parts by mass of nanosilica, 23 to 37 parts by mass of conductive carbon black, 1 to 2 parts by mass of antioxidant, and 0.5 to 1.5 parts by mass of lubricating dispersant. More preferably, it includes 55 to 68 parts by mass of polypropylene, 38 to 43 parts by mass of ethylene-octene copolymer, 4 to 6 parts by mass of nanosilica, 25 to 30 parts by mass of conductive carbon black, 1 to 2 parts by mass of antioxidant, and 0.5 to 1.5 parts by mass of lubricating dispersant. The present invention optimizes the composition of the insulating shield layer and uses polypropylene and ethylene-octene copolymer as matrix materials, thereby solving the disadvantages of low toughness and brittleness at low temperatures of polypropylene, adding a certain amount of nanosilica to enhance the insulation resistance, combining with conductive carbon black to improve the shielding effect, adding antioxidant to improve the corrosion resistance, and enabling the insulating shield effect of the insulating shield layer to last for a long time.

[0034] In the present invention, the polypropylene is preferably a blend of a homopolymer of polypropylene and a copolymer of polypropylene. The melt index of the homopolymer of polypropylene is preferably 1.0 to 5.0 g / 10 min, the melt index of the copolymer of polypropylene is preferably 1.0 to 4.0 g / 10 min, and the mass ratio of the homopolymer of polypropylene to the copolymer of polypropylene is preferably 1:1 to 1:10, more preferably 1:2 to 1:8. In the present invention, by using two different types of polypropylene as raw materials, the insulation effect can be further improved.

[0035] In the present invention, the specific particle sizes of the nanosilica and the conductive carbon black are not particularly limited, and commercially available products well-known to those skilled in the art may be used.

[0036] In the present invention, the antioxidant is preferably 4,4'-thiobis(6-tert-butyl-3-methylphenol). By adding an antioxidant, the present invention can improve the antioxidant effect of the insulating shield layer, and by selecting a specific type of antioxidant, it is possible to prevent the antioxidant from precipitating from the insulating shield layer at high temperatures.

[0037] In the present invention, the lubricating dispersant is preferably polyethylene wax. By adding a lubricating dispersant, the present invention promotes better uniform mixing of the components during preparation and facilitates coating.

[0038] In the present invention, the method for manufacturing the insulating shield layer preferably comprises mixing polypropylene, ethylene-octene copolymer, nanosilica, conductive carbon black, antioxidant, and lubricating dispersant, kneading them, then performing extrusion granulation to obtain particles, melting the particles, and coating the surface of the insulating layer to obtain the insulating shield layer.

[0039] In the present invention, the kneading is preferably carried out in a continuous kneading unit, and the continuous kneading unit is preferably one of a reciprocating kneader, a co-rotating twin-screw extruder, and four or more continuous closed kneading units.

[0040] In the present invention, the kneading and melting temperature are not particularly limited and may be determined based on the common general knowledge of those skilled in the art. The present invention has no special restrictions regarding the specific coating operation, and a coating method well-known to those skilled in the art may be used.

[0041] The high-voltage cable provided by the present invention includes a semiconductive water-stop buffer layer disposed outside the insulating shield layer. In the present invention, the semiconductive water-stop buffer layer is preferably a semiconductive water-stop tape or a semiconductive buffer water-stop tape, and the performance of the semiconductive water-stop buffer layer preferably complies with the JB / T10259 standard. In the present invention, the thickness of the semiconductive water-stop buffer layer is preferably 0.6 to 0.8 mm.

[0042] The high-voltage cable provided by the present invention includes a copper wire shield layer disposed outside the semiconductive water-stop buffer layer. In the present invention, the copper wire shield layer is preferably formed by twisting copper wires. In the present invention, the thickness of the copper wire shield layer is preferably 1 to 1.5 mm. The present invention can further improve the mechanical properties of the high-voltage cable by controlling the thickness of the copper wire shield layer.

[0043] The high-voltage cable provided by the present invention includes a semiconductive water-stop buffer layer disposed outside the copper wire shield layer. In the present invention, the semiconductive water-stop buffer layer is preferably a semiconductive water-stop tape or a semiconductive buffer water-stop tape, and the performance of the semiconductive water-stop buffer layer preferably complies with the JB / T10259 standard. In the present invention, the thickness of the semiconductive water-stop buffer layer is preferably 0.6 to 0.8 mm.

[0044] The present invention adopts two layers of semiconductive water-stop buffer layers and provides a copper wire shield layer between the two layers of semiconductive water-stop buffer layers. The copper wire shield layer can share the fault current of the cable system and also enhance the mechanical properties of the high-voltage cable.

[0045] The high-voltage cable provided by the present invention includes a metal sheath disposed outside the semiconductive water-stop buffer layer. In the present invention, the metal sheath is preferably an aluminum sheath or a lead sheath. More preferably, it is an alloy lead sheath layer. The present invention has no particular limitation on the specific components of the alloy lead sheath layer, and commercially available products well-known to those skilled in the art may be used. The present invention provides a metal sheath after the semiconductive water-stop buffer layer and utilizes the radial waterproof performance and corrosion resistance of the metal sheath, so that the cable has strong corrosion resistance and waterproof performance. At the same time, a certain amount of system fault current may flow through the metal sheath.

[0046] The high-voltage cable provided by the present invention includes an anticorrosion layer disposed outside the metal sheath. In the present invention, the raw materials of the anticorrosion layer preferably include, in terms of parts by mass, 52 to 65 parts by mass of asphalt, 1 to 5 parts by mass of emulsifier, 1 to 2 parts by mass of stabilizer, and 35 to 40 parts by mass of water, and more preferably 55 to 60 parts by mass of asphalt, 2 to 3 parts by mass of emulsifier, 1 to 2 parts by mass of stabilizer, and 35 to 40 parts by mass of water. In the present invention, the asphalt is preferably 10# petroleum asphalt, the emulsifier is preferably either asphalt emulsifier BH-Z1 or BH-Z2, and the stabilizer is preferably any one of bentonite, attapulgite, and aluminum silicate. The present invention can improve the thermal stability of the anticorrosion layer by optimizing the composition of the anticorrosion layer. As a result, a good anticorrosion effect can be maintained even at high temperatures. On the other hand, the pollution caused thereby can be reduced. When a stabilizer is added, the stability of the anticorrosion layer is improved, and problems such as cracks can be avoided.

[0047] In the present invention, the manufacturing method of the anticorrosion layer preferably includes step (1) of mixing and stirring an emulsifier, a stabilizer, and water to obtain an emulsified aqueous solution, step (2) of heat-treating asphalt to obtain molten asphalt, step (3) of mixing the emulsified aqueous solution obtained in step (1) and the molten asphalt obtained in step (2), and then performing high-speed stirring to coat the surface of the metal sheath to obtain an anticorrosion layer, The order of executing step (1) and step (2) is not limited.

[0048] The present invention preferably mixes and stirs an emulsifier, a stabilizer, and water to obtain an emulsified aqueous solution. In the present invention, as long as each component can be uniformly mixed, there is no particular limitation on the stirring speed and stirring time.

[0049] In the present invention, the temperature of the water is preferably 60 to 70 °C. When the temperature of the water does not satisfy the above conditions, in the present invention, preferably, the water is heat-treated. By controlling the temperature of the water, the present invention can prevent the asphalt from rapidly cooling and solidifying when it is subsequently mixed with the molten asphalt.

[0050] The present invention preferably heat-treats asphalt to obtain molten asphalt. In the present invention, the temperature of the heat treatment is not particularly limited as long as the asphalt melts into a liquid state. By heat-treating asphalt, the present invention can remove the moisture in the asphalt and promote the mixing and emulsification with other solutions.

[0051] In the present invention, preferably, after obtaining the emulsified aqueous solution and the molten asphalt, the emulsified aqueous solution and the molten asphalt are mixed and stirred at a high speed, and then coated on the surface of the metal sheath to obtain an anticorrosive layer.

[0052] In the present invention, the high-speed stirring is preferably carried out in an emulsifier. Regarding the speed of the high-speed stirring in the present invention, there is no particular limitation, and it is determined based on the common general knowledge in the art that the asphalt can be emulsified. By high-speed stirring, the present invention can form an oil-in-water asphalt emulsion from the emulsifier aqueous solution and the asphalt, and improve its anticorrosion performance.

[0053] The high-voltage cable provided by the present invention includes a non-metallic sheath layer disposed outside the anticorrosive layer. In the present invention, the non-metallic sheath layer is preferably composed of an outer sheath layer and a semiconductive layer. The outer sheath layer is preferably extruded from a polyvinyl chloride sheath material or a polyethylene sheath material, and the semiconductive layer is preferably a graphite semiconductive layer.

[0054] The present invention adopts a two-layer semiconductive water-stop buffer layer, and a copper wire shield layer is provided between the two-layer semiconductive water-stop buffer layer. The copper wire shield layer can share the fault current of the cable system and can also enhance the mechanical properties of the high-voltage cable. The structural design of the two-layer semiconductive water-stop buffer layer can withstand the mechanical impact of the copper wire on the insulation shield and at the same time has excellent longitudinal waterproof performance. A metal sheath is provided behind the semiconductive water-stop buffer layer, and by utilizing the radial waterproof performance and corrosion resistance of the metal sheath, the cable has strong corrosion resistance and waterproof performance. At the same time, a certain amount of system fault current may also flow through the metal sheath.

[0055] With reference to the embodiments of the present invention below, the technical solutions of the present invention will be clearly and completely described. The described embodiments are only a part of the embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the protection scope of the present invention.

Embodiment

[0056] [Embodiment 1] The high-voltage cable provided in this embodiment is arranged in the order of a cable conductor, a conductor shield layer, an insulating layer, an insulation shield layer, a semiconductive water-stopping buffer layer, a copper wire shield layer, a semiconductive water-stopping buffer layer, a metal sheath layer, a corrosion-resistant layer, and a non-metal sheath layer from the inside to the outside. The cable conductor is composed of copper conductors. The copper conductors are twisted layer by layer and pressed to form a cable conductor. The conductor shield layer is a cross-linked polyethylene insulating material for high-voltage DC cables. The thickness of the conductor shield layer is 0.7 mm. The insulating layer is a radiation-cross-linked polyethylene material, and the thickness of the insulating layer is 0.8 mm. The semiconductive water-stopping buffer layer is a semiconductive water-stopping tape, and the performance of the semiconductive water-stopping buffer layer complies with the JB / T10259 standard. The thickness of each layer of the semiconductive water-stopping buffer layer is 0.6 mm. The thickness of the copper wire shield layer is 1.5 mm. The metal sheath is an alloy lead sheath layer. The non-metal sheath layer is composed of an outer sheath layer and a semiconductive layer. The outer sheath layer is extruded from a polyvinyl chloride sheath material sheath, and the semiconductive layer is a graphite semiconductive layer.

[0057] The raw materials of the insulation shield layer, in terms of parts by mass, are 55 parts by mass of polypropylene, 42 parts by mass of ethylene-octene copolymer, 5 parts by mass of nano-silica, 28 parts by mass of conductive carbon black, 1 part by mass of antioxidant, and 1 part by mass of lubricating dispersant. The polypropylene is a blend of a homopolymer of polypropylene and a copolymer of polypropylene. The melt index of the homopolymer of polypropylene is 3.0 - 4.0 g / 10 min, the melt index of the copolymer of polypropylene is 2.0 - 3.0 g / 10 min, and the mass ratio of the homopolymer of polypropylene to the copolymer of polypropylene is 1:10. The antioxidant is 4,4'-thiobis(6-tert-butyl-3-methylphenol), and the lubricating dispersant is polyethylene wax. The manufacturing method of the insulation shield layer is to add polypropylene, ethylene-octene copolymer, nano-silica, conductive carbon black, antioxidant, and lubricating dispersant to a co-rotating twin-screw extruder, mix and knead them, then extrude and granulate to obtain particles, and melt the particles to coat the surface of the insulating layer to obtain the insulation shield layer.

[0058] The raw materials of the anticorrosion layer, in terms of parts by mass, are 55 parts by mass of asphalt, 3 parts by mass of emulsifier, 2 parts by mass of stabilizer, and 40 parts by mass of water. The asphalt is 10# petroleum asphalt, the emulsifier is asphalt emulsifier BH-Z2, and the stabilizer is bentonite.

[0059] The manufacturing method of the anticorrosion layer is Step (1) of mixing an emulsifier, a stabilizer, and water at 70°C and stirring to obtain an emulsified aqueous solution, Step (2) of heat-treating asphalt to obtain molten asphalt, Step (3) of mixing the emulsified aqueous solution obtained in step (1) and the molten asphalt obtained in step (2) in an emulsifier, followed by high-speed stirring and coating on the surface of the metal sheath to obtain an anticorrosion layer.

[0060] [Example 2] The raw materials of the insulation shield layer, in terms of parts by mass, are 65 parts by mass of polypropylene, 40 parts by mass of ethylene-octene copolymer, 8 parts by mass of nanosilica, 25 parts by mass of conductive carbon black, 1 part by mass of antioxidant, and 1 part by mass of lubricating dispersant. The raw materials of the anticorrosion layer, in terms of parts by mass, are 53 parts by mass of asphalt, 2 parts by mass of emulsifier, 2 parts by mass of stabilizer, and 40 parts by mass of water. Other conditions were the same as in Example 1.

[0061] [Example 3] The raw materials of the insulation shield layer, in terms of parts by mass, are 68 parts by mass of polypropylene, 40 parts by mass of ethylene-octene copolymer, 6 parts by mass of nanosilica, 32 parts by mass of conductive carbon black, 1 part by mass of antioxidant, and 1 part by mass of lubricating dispersant. The raw materials of the anticorrosion layer, in terms of parts by mass, are 65 parts by mass of asphalt, 4 parts by mass of emulsifier, 2 parts by mass of stabilizer, and 40 parts by mass of water. Other conditions were the same as in Example 1.

[0062] [Comparative Example 1] The insulating shield layer is crosslinked polyethylene that has been crosslinked and cured, and other conditions were the same as in Example 1.

[0063] [Comparative Example 2] The anticorrosion layer was obtained by melting and coating 10# asphalt. and other conditions were the same as in Example 1.

[0064] (Performance Test) The shielding properties of the high-voltage cables manufactured in Examples 1 to 3 and Comparative Examples 1 to 2 were tested using the 3-coaxial method and the line injection method, respectively. The test frequency of the 3-coaxial method was 100 MHz, and the reference standard was GB9023-88. The test frequency of the line injection method was 1 GHz, and the reference standard was GB / T17737.1-2000. The results are shown in Table 1.

[0065]

Table 1

[0066] As can be seen from Table 1, the shielding properties of the high-voltage cables manufactured according to the present invention are significantly improved compared to other high-voltage cables, and it can be understood that the present invention enables the obtaining of high-voltage cables having more excellent shielding properties.

[0067] The above description of the embodiments only contributes to understanding the method and its core idea of the present invention. It should be pointed out that those skilled in the art can make several improvements and modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications are also included within the protection scope of the claims. Those skilled in the art will find that multiple types of modifications to these embodiments are obvious, and the general principles defined in this specification can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but should be in agreement with the broadest scope that conforms to the principles and novel features disclosed herein.

Claims

1. A high-voltage cable comprising, in order from the inside to the outside, a cable conductor, a conductor shield layer, an insulating layer, an insulation shield layer, a semiconductive water-stop buffer layer, a copper wire shield layer, a semiconductive water-stop buffer layer, a metal sheath, an anticorrosion layer, and a non-metal sheath layer.

2. The high-voltage cable according to claim 1, characterized in that the applied voltage of the high-voltage cable is 66 to 220 kV.

3. The high-voltage cable according to claim 1, characterized in that the cable conductor is composed of copper wires.

4. The high-voltage cable according to claim 3, characterized in that the copper wires comply with the GB / T 3953 standard.

5. The high-voltage cable according to claim 3, characterized in that the copper wires are twisted together layer by layer and pressed to form the cable conductor.

6. The high-voltage cable according to claim 1, characterized in that the raw material of the conductor shield layer is a high-voltage DC cable cross-linked polyethylene insulating material, and the thickness of the conductor shield layer is 0.5 to 1.0 mm.

7. The high-voltage cable according to claim 1, characterized in that the material of the insulating layer is an irradiated cross-linked polyethylene material or a soft polyvinyl chloride plastic, and the thickness of the insulating layer is 0.8 to 2.0 mm.

8. The high-voltage cable according to claim 1, characterized in that the raw material of the insulation shield layer, in terms of parts by mass, comprises 47 to 82 parts of polypropylene, 35 to 48 parts by mass of an ethylene-octene copolymer, 3 to 8 parts by mass of nanosilica, 23 to 37 parts by mass of conductive carbon black, 1 to 2 parts by mass of an antioxidant, and 0.5 to 1.5 parts by mass of a lubricating dispersant.

9. The high-voltage cable according to claim 8, characterized in that the polypropylene is a blend of a homopolymer of polypropylene and a copolymer of polypropylene, and the mass ratio of the homopolymer of polypropylene to the copolymer of polypropylene is 1:1 to 1:

10.

10. The high-voltage cable according to claim 9, characterized in that the melt index of the homopolymer of polypropylene is 1.0 to 5.0 g / 10 min, and the melt index of the copolymer of polypropylene is 1.0 to 4.0 g / 10 min.

11. The high-voltage cable according to claim 8, characterized in that the antioxidant is 4,4'-thiobis(6-tert-butyl-3-methylphenol), and the lubricating dispersant is polyethylene wax.

12. The manufacturing method of the insulating shield layer is to mix polypropylene, ethylene-octene copolymer, nanosilica, conductive carbon black, antioxidant, and lubricating dispersant, knead them, then extrude and granulate to obtain particles, and melt the particles to coat the surface of the insulating layer to obtain the insulating shield layer. The high-voltage cable according to claim 8 is characterized in that.

13. The semiconductive water-stop buffer layer is a semiconductive water-stop tape or a semiconductive buffer water-stop tape. The performance of the semiconductive water-stop buffer layer complies with the JB / T 10259 standard, and the thickness of the semiconductive water-stop buffer layer is 0.6 to 0.8 mm. The high-voltage cable according to claim 1 is characterized in that.

14. The copper wire shield layer is formed by twisting copper wires, and the thickness of the copper wire shield layer is 1 to 1.5 mm. The high-voltage cable according to claim 1 is characterized in that.

15. The metal sheath is an aluminum sheath or a lead sheath. The high-voltage cable according to claim 1 is characterized in that.

16. The raw materials of the anticorrosion layer, in terms of parts by mass, include 52 to 65 parts by mass of asphalt, 1 to 5 parts by mass of emulsifier, 1 to 2 parts by mass of stabilizer, and 35 to 40 parts by mass of water. The high-voltage cable according to claim 1 is characterized in that.

17. The manufacturing method of the anticorrosion layer is Step (1) of mixing an emulsifier, a stabilizer, and water and stirring to obtain an emulsified aqueous solution, Step (2) of heat-treating asphalt to obtain molten asphalt, Step (3) of mixing the emulsified aqueous solution obtained in step (1) and the molten asphalt obtained in step (2), then stirring at high speed and coating the surface of the metal sheath to obtain the anticorrosion layer, and The high-voltage cable according to claim 1 is characterized in that the order of executing step (1) and step (2) is not limited.

Images