WO2023230839A1 - High-voltage resistant cable for big data transmission, preparation method therefor and use thereof - Google Patents

Abstract

A high-voltage resistant cable for big data transmission, a preparation method therefor and the use thereof. The high-voltage resistant cable comprises at least two wire cores, wherein each wire core is composed of a conductor (1) and an insulation layer (2), which wraps around the conductor (1), and every two wire cores are twisted together to form a cable core; and the cable core is sequentially wrapped with a main insulation layer (3), a shielding layer (4) and an outer sheath (5). In the high-voltage resistant cable, the insulation layer (2), which is arranged on the outside of the conductor (1), matches the main insulation layer (3), which is arranged on the outside of the cable core, such that the voltage resistance of the prepared cable is effectively improved, and the cable can meet the requirements for a big data transmission cable.

Description

High-voltage resistant cable for big data transmission and its preparation method and application Technical field

This application relates to the field of cable technology, for example, to a high-voltage resistant cable for big data transmission and its preparation method and application.

Background technique

Cables are widely used in many fields involving people's lives, industrial production, etc., so the amount of cables is extremely large, and the quality requirements for cables are also very high. Different fields have different requirements for the quality and use of cables. For example, in the fields of petroleum, chemical industry, and aviation and trains, cables are required to have good tensile properties and high-voltage resistance to ensure that the cables are durable and meet needs. With the rapid development of Internet companies, the capacity of big data system processing centers is getting larger and larger, resulting in higher and higher safety and stability requirements for power substation systems, which in turn requires the safety and durability of cables used for big data transmission. Pressure performance requirements are also getting higher and higher.

Many types of cables have been reported for data transmission. CN104733085A discloses a high-voltage industrial cable, which includes a cable body including a conductor, an insulating layer, a shielding layer and an outer sheath. Multiple conductors are provided inside the cable body, and the cross-section of the conductor is round. The cable body is provided with a drainage core at the center, the conductor is tightly packed with an insulating layer, and the gap formed between the insulating layer and the conductor is provided with a filling layer; the insulating layer is tightly packed with It is covered with a shielding layer; the shielding layer is extruded with an armor layer and a reinforcing layer in sequence from the inside to the outside; the reinforcing layer is tightly extruded with an outer sheath; the cable has good shielding performance and bending resistance. It has high conductivity, high voltage resistance and anti-magnetic interference properties. CN104810109A discloses a moisture-proof and high-voltage power cable, which includes a cable body including a conductor, an insulating layer, a shielding layer and an outer sheath. A plurality of conductors are arranged inside the cable body; a layer of fiberglass tube is arranged outside the conductor; the fiberglass tube and the conductor together constitute a cable core; an insulation layer is tightly packed outside the cable core; the insulation The gap between the layer and the cable core is provided with filler; the insulation layer is tightly packed with a shielding layer; the shielding layer is packed with a reinforcing braid layer and an anti-corrosion layer from the inside to the outside; the anti-corrosion layer The cable is tightly extruded and wrapped with an outer sheath. Through reasonable overall structure, the cable has the advantages of excellent water and moisture resistance and long service life.

As the capacity of the big data system processing center becomes larger and larger, the requirements for the safety and stability of the substation system are getting higher and higher. The conventional voltage at the output end of the substation system is only a few hundred volts. However, due to the inconsistency of the substation system, Due to stability and external emergencies, the instantaneous voltage of the line can reach up to 13kV and above. Commonly used cables are difficult to meet the above requirements, so they often cause irreversible damage.

Contents of the invention

This application provides a high-voltage resistant cable for big data transmission and its preparation method and application. In the high-voltage resistant cable, a total insulation layer and an insulating layer are provided for matching, so that the resulting cable has excellent high-voltage resistance performance. Able to meet the requirements for big data system processing and use.

In a first aspect, this application provides a high-voltage resistant cable for big data transmission. The high-voltage resistant cable includes at least two wire cores. Each wire core is composed of a conductor and an insulation layer covering the conductor. And every two wire cores are twisted to form a cable core, and the cable core is sequentially covered with a total insulation layer, a shielding layer and an outer sheath.

The schematic cross-sectional structure diagram of the high-voltage resistant cable provided by this application is shown in Figure 1, where 1 represents the conductor, 2 represents the insulation layer, the insulation layer 2 is wrapped on the surface of the conductor 1 to form a core, and every two cores are twisted to form a cable. Core, 3 represents the total insulation layer. The total insulation layer 3 is covered outside the cable core. The total insulation layer 3 is also covered with a shielding layer 4 and an outer sheath 5. Total insulation is set between the cable core and the shielding layer 4. Layer 3 allows it to coordinate with the insulation layer 2 to ensure that the resulting cable has excellent high voltage resistance.

The "big data" in the high-voltage cable for big data transmission in this application refers to "a data collection so large that its acquisition, storage, management, and analysis greatly exceed the capabilities of traditional database software tools. "Data with four major characteristics: massive data scale, fast data flow, diverse data types and low value density", and "high voltage resistance" refers to the ability to withstand AC voltages up to 13kV.

In one embodiment, the conductor is a tinned copper conductor.

As a technical solution of this application, selecting a tinned copper conductor as the conductor of the high-voltage cable provided by this application can prevent pure copper from oxidizing after being in contact with air for a long time, thereby affecting its own conductivity and signal transmission efficiency.

In one embodiment, the tinned copper conductor is formed by stranding tinned copper wires.

In one embodiment, the diameter of the tinned copper wire is 0.19-0.205mm, such as 0.192mm, 0.194mm, 0.196mm, 0.198mm, 0.2mm, 0.202mm or 0.204mm, etc.

In one embodiment, the tinned copper wire is obtained by plating tin on the copper wire.

As a technical solution of this application, the copper wire selected in this application is a high-purity copper wire with a purity of 99.99%, which can ensure that the obtained tin-plated copper wire has high conductivity.

In one embodiment, the resistivity of the tinned copper wire is approximately 0.0167Ωmm ² /m.

In one embodiment, the insulating layer is a polyethylene insulating layer, and the material of the polyethylene insulating layer is polyethylene with a resistivity of not less than 6×1014Ω·m (20°C).

In one embodiment, the thickness of the polyethylene insulation layer is not less than 0.6mm, such as 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm or 1.5mm, etc.

In one embodiment, the overall insulation layer is a polyethylene overall insulation layer.

In one embodiment, the thickness of the total insulation layer is not less than 1.3mm, such as 1.35mm, 1.4mm, 1.45mm, 1.5mm, 1.55mm, 1.6mm or 1.65mm, etc.

In one embodiment, the shielding layer is a tinned copper wire braided shielding layer.

In one embodiment, the diameter of the tinned copper wire in the tinned copper wire braided shielding layer is 0.1 to 0.12mm, such as 0.102mm, 0.104mm, 0.106mm, 0.108mm, 0.11mm, 0.112mm, 0.114mm, 0.116 mm or 0.118mm, etc.

In one embodiment, the outer sheath is a polyvinyl chloride outer sheath.

In one embodiment, the thickness of the outer sheath is not less than 1.5mm, such as 1.55mm, 1.6mm, 1.65mm, 1.7mm, 1.75mm, 1.8mm, 1.85mm or 1.9mm, etc.

In one embodiment, the outside of the outer sheath is also covered with a polyamide layer.

As a technical solution of this application, arranging a polyamide layer on the outside of the outer sheath can help improve the safety of high-voltage cables. The polyamide layer can effectively prevent rodents from damaging the cable structure by gnawing.

In one embodiment, the thickness of the polyamide layer is no less than 0.5mm, such as 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm or 0.9mm, etc.

In a second aspect, the present application provides a method for preparing a high-voltage cable for big data transmission as described in the first aspect. The preparation method includes the following steps:

(1) Extrude the insulation layer material on the outside of the conductor to obtain the wire core;

(2) Twist every two wire cores obtained in step (1) to obtain a cable core;

(3) Extruding the total insulation layer material outside the core obtained in step (2), braiding the shielding layer material, and then extruding the outer sheath material to obtain the high-voltage resistant cable.

In one embodiment, the extrusion in step (1) is performed by a 70-type extruder.

In the preparation method provided in this application, the insulation layer material is coated on the outside of the conductor through a 70-type extruder. During the coating process, it is necessary to cooperate with the infrared polarization meter and the host controller to ensure that the concentricity of the wire core reaches 95 % or more, and a vacuum machine is installed on the machine head to ensure that the insulation layer material can be tightly coated on the tinned copper conductor. After the coating is completed, the wire core obtained is cooled by three-stage water, which can ensure that the wire core is quickly cooled to At room temperature, after the coating is completed, the thickness of the thinnest point of the insulation layer, concentricity and apparent quality need to be checked to ensure that the obtained wire core has no defects before proceeding to the next process.

In one embodiment, the screw length-to-diameter ratio of the 70-type extruder is 12 to 20, such as 13, 14, 15, 16, 17, 18 or 19, etc.

In one embodiment, the working temperatures of multiple zones of the 70-type extruder are respectively: zone 1 155-165°C (for example, 156°C, 157°C, 158°C, 159°C, 160°C, 161°C, 162°C , 163℃ or 164℃, etc.), zone 2 165~175℃ (such as 166℃, 167℃, 168℃, 169℃, 170℃, 171℃, 172℃, 173℃ or 174℃, etc.), zone 3 175~ 185℃ (such as 176℃, 177℃, 178℃, 179℃, 180℃, 181℃, 182℃, 183℃ or 184℃, etc.), zone 4 185~195℃ (such as 186℃, 187℃, 188℃, 189℃, 190℃, 191℃, 192℃, 193℃ or 194℃, etc.), 5 zones 185~195℃ (such as 186℃, 187℃, 188℃, 189℃, 190℃, 191℃, 192℃, 193 ℃ or 194 ℃, etc.), the machine head temperature is 190~200 ℃ (such as 191 ℃, 192 ℃, 193 ℃, 194 ℃, 195 ℃, 196 ℃, 197 ℃, 198 ℃ or 199 ℃, etc.).

In one embodiment, the twisting method in step (2) is reverse twisting.

In one embodiment, the twisting described in step (2) is performed on a single twisting machine, and the take-up speed and twisting speed of the single twisting machine need to be controlled to ensure that the twisting pitch meets the requirements.

In one embodiment, the twisting pitch of the pair of twists in step (2) is not greater than 50mm, such as 45mm, 40mm, 35mm, 30mm, 25mm, 20mm, 15mm or 10mm, etc.

In one embodiment, the extrusion of the total insulation layer material in step (3) is carried out through a 70-type extruder. After the completion of the extrusion of the total insulation layer material, the thickness and apparent quality of the thinnest point of the total insulation layer also need to be checked. , the next process can be carried out only after there are no defects.

In one embodiment, the screw length-to-diameter ratio of the 70-type extruder is 12 to 20, such as 13, 14, 15, 16, 17, 18 or 19, etc.

In one embodiment, the working temperatures of multiple zones of the 70-type extruder are respectively: Zone 1 155-165°C (for example, 156°C, 157°C, 158°C, 159°C, 160°C, 161°C, 162°C , 163℃ or 164℃, etc.), zone 2 165~175℃ (such as 166℃, 167℃, 168℃, 169℃, 170℃, 171℃, 172℃, 173℃ or 174℃, etc.), zone 3 175~ 185℃ (such as 176℃, 177℃, 178℃, 179℃, 180℃, 181℃, 182℃, 183℃ or 184℃, etc.), zone 4 185~195℃ (such as 186℃, 187℃, 188℃, 189℃, 190℃, 191℃, 192℃, 193℃ or 194℃, etc.), 5 zones 185~195℃ (such as 186℃, 187℃, 188℃, 189℃, 190℃, 191℃, 192℃, 193 ℃ or 194 ℃, etc.), the machine head temperature is 190~200 ℃ (such as 191 ℃, 192 ℃, 193 ℃, 194 ℃, 195 ℃, 196 ℃, 197 ℃, 198 ℃ or 199 ℃, etc.).

In one embodiment, the weaving in step (3) is performed using a 16-spindle braiding machine or a 24-spindle braiding machine; try not to have joints during the weaving process. If a connection is required, the joints must be ensured to be flat and no damage to the total insulation layer is allowed. damage.

In one embodiment, the braiding angle in step (3) is 30 to 60°, such as 35°, 40°, 45°, 50° or 55°.

In one embodiment, the density of the weaving in step (3) is not less than 90%, such as 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%, etc.

In one embodiment, the extrusion of the outer sheath material in step (3) is performed using a 90-type extruder.

In one embodiment, the working temperatures of multiple zones of the 90-type extruder are respectively: Zone 1 135-145°C (for example, 136°C, 137°C, 138°C, 139°C, 140°C, 141°C, 142°C , 143℃ or 144℃, etc.), Zone 2 155~165℃ (such as 156℃, 157℃, 158℃, 159℃, 160℃, 161℃, 162℃, 163℃ or 164℃, etc.), Zone 3 165~ 175℃ (such as 166℃, 167℃, 168℃, 169℃, 170℃, 171℃, 172℃, 173℃ or 174℃, etc.), zone 4 165~175℃ (such as 166℃, 167℃, 168℃, 169℃, 170℃, 171℃, 172℃, 173℃ or 174℃, etc.), the machine head and die opening are independently 165~175℃ (such as 166℃, 167℃, 168℃, 169℃, 170℃, 171℃, 172℃, 173℃ or 174℃, etc.).

In one embodiment, the step of extruding the outer sheath material in step (3) further includes the step of extruding polyamide.

In one embodiment, the extrusion of polyamide is carried out through a 90-type extruder.

In one embodiment, the working temperatures of the multiple zones of the 90-type extruder are respectively: zone 1 160-180°C (for example, 162°C, 164°C, 166°C, 168°C, 170°C, 172°C, 174°C). ℃, 176℃ or 178℃, etc.), Zone 2 190~210℃ (such as 192℃, 194℃, 196℃, 198℃, 121℃, 123℃, 125℃, 127℃ or 129℃, etc.), Zone 3 210 ~230℃ (such as 212℃, 214℃, 216℃, 218℃, 220℃, 222℃, 224℃, 226℃ or 228℃, etc.), zone 4 210~230℃ (such as 212℃, 214℃, 216℃ , 218℃, 220℃, 222℃, 224℃, 226℃ or 228℃, etc.), the machine head and die opening are independently 230~250℃ (such as 232℃, 234℃, 236℃, 238℃, 240℃ , 242℃, 244℃, 246℃ or 248℃, etc.).

As a technical solution, the preparation method includes the following steps:

(1) The insulating layer material is extruded outside the conductor through a 70-type extruder. The screw length-to-diameter ratio of the 70-type extruder is 12 to 20. The working temperatures of the multiple zones are: 155 to 165°C in zone 1, 2 Zone 165~175℃, Zone 3 175~185℃, Zone 4 185~195℃, Zone 5 185~195℃, the machine head temperature is 190~200℃, and the wire core is obtained;

(2) On a single twisting machine, twist every two wire cores obtained in step (1) using the untwisting method, and the twisting pitch is less than 50mm to obtain the cable core;

(3) Extrude the total insulation layer material outside the cable core obtained in step (2) through a 70-type extruder. The operating temperatures of the multiple zones of the 90-type extruder are: 155~165℃ in zone 1, 165°C in zone 2 165~175℃, zone 3 is 175~185℃, zone 4 is 185~195℃, zone 5 is 185~195℃, the machine head temperature is 190~200℃; then use a 16-spindle braiding machine or a 24-spindle braiding machine to weave the shielding layer material , the braiding angle is 30 to 60°, and the braiding density is greater than 90%; finally, the outer sheath material and optional polyamide are extruded sequentially through a 90-type extruder, and the 90% polyamide used for the outer sheath material is extruded. The working temperatures of the multiple zones of the extruder are: Zone 1 135~145°C, Zone 2 155~165°C, Zone 3 165~175°C, Zone 4 165~175°C. The machine head and die opening are independent. The ground temperature is 165-175°C. The working temperatures of the multiple zones of the 90-type extruder used to extrude the optional polyamide are: zone 1 160-180°C, zone 2 190-210°C, zone 3 210-230°C, zone 4 210-230°C, and the machine head and die opening are independently 230-250°C to obtain the high-voltage resistant cable.

In a third aspect, this application provides an application of the high-voltage resistant cable for big data transmission in a power substation system as described in the first aspect.

The high-voltage resistant cable for big data transmission provided by this application includes at least two wire cores. Each wire core is composed of a conductor and an insulation layer covering the conductor, and each two wire cores are twisted to form a cable core. , the cable core is covered with a total insulation layer, a shielding layer and an outer sheath in sequence; in the high-voltage resistant cable, by matching the total insulation layer and the insulation layer on the outside of the cable core, it is possible to ensure that the core and shielding layer The withstand voltage reaches 13kV, so that the resulting high-voltage resistant cable can withstand high voltages of 13.7 to 16.8kV. The anti-corrosion test is greater than 55 hours, and the transmission efficiency is 87.2 to 99.8%, which meets the requirements of cables for big data transmission.

Description of the drawings

Figure 1 is a schematic cross-sectional structural diagram of a high-voltage resistant cable provided by an embodiment of the present application;

Figure 2 is a schematic cross-sectional structural diagram of another high-voltage resistant cable provided by an embodiment of the present application.

Among them: 1. Conductor; 2. Insulating layer; 3. Total insulation layer; 4. Shielding layer; 5. Outer sheath; 6. Polyamide layer.

Detailed ways

The technical solutions of the present application will be described below through specific implementations. Those skilled in the art should understand that the embodiments are only to help understand the present application and should not be regarded as specific limitations of the present application.

Example 1

A high-voltage resistant cable for big data transmission. Its cross-sectional structural diagram is shown in Figure 2. It includes two wire cores. Each wire core is composed of a tinned copper conductor 1 and is wrapped around the tinned copper conductor 1. It consists of an insulation layer 2, two wire cores are twisted to form a cable core, and the cable core is covered with a total insulation layer 3, a shielding layer 4, an outer sheath 5 and a polyamide layer 6 in sequence;

The tinned copper conductor 1 is twisted by 7 tinned copper wires with a diameter of 0.195mm; the insulation layer 2 is a polyethylene insulation layer with a thickness of 0.6mm (the material is polyethylene); the total insulation layer 3 has a thickness of 1.4mm polyethylene total insulation layer (material is polyethylene); shielding layer 4 is a tinned copper wire braided shielding layer, the material is 0.12mm tinned copper wire; outer sheath 5 is polyvinyl chloride with a thickness of 1.6mm Outer sheath (material is polyvinyl chloride); the thickness of polyamide layer 6 is 0.6mm, and the material is polyamide (low/medium viscosity).

The preparation method of high-voltage resistant cable provided in this embodiment includes the following steps:

(1) The polyethylene is extruded outside the tinned copper conductor through a 70-type extruder to form an insulating layer. The screw length-to-diameter ratio of the 70-type extruder is 15. The operating temperatures of the multiple zones are: 160°C in zone 1, Zone 2 is 170°C, zone 3 is 180°C, zone 4 is 190°C, zone 5 is 190°C, and the machine head temperature is 195°C to obtain the wire core.

(2) Twist the two wire cores obtained in step (1) on a single twisting machine using a back-twisting method. The twisting pitch is 40mm to obtain a cable core.

(3) Extrude polyethylene on the outside of the cable core obtained in step (2) through a 70-type extruder to form a total insulation layer. The screw length-to-diameter ratio of the 70-type extruder is 15. The operating temperatures of the multiple zones are: Zone 1 is 160℃, Zone 2 is 170℃, Zone 3 is 180℃, Zone 4 is 190℃, Zone 5 is 190℃, the machine head temperature is 195℃; then a 16-spindle braiding machine is used to weave tinned copper wire to form a shielding layer, and the braiding angle is 50°, the braiding density is 95%, and then the polyvinyl chloride is extruded on the outside of the shielding layer through a 90-type extruder to form an outer sheath. The screw length-to-diameter ratio of the 90-type extruder is 22, and the multi-zone The working temperatures are: 140°C in zone 1, 160°C in zone 2, 170°C in zone 3, and 170°C in zone 4. The machine head and die mouth temperatures are both 170°C; finally, the extruder is extruded on the outside of the outer sheath by the 90-type extruder. Amide forms the polyamide layer. The screw length-to-diameter ratio of the 90-type extruder is 22. The working temperatures of the multiple zones are: 170°C in zone 1, 200°C in zone 2, 220°C in zone 3, and 220°C in zone 4. The machine head and the die opening temperature are both 240°C, and the high-voltage resistant cable is obtained.

Example 2

A high-voltage resistant cable for big data transmission. Its cross-sectional structural diagram is shown in Figure 1. It includes two wire cores. Each wire core is composed of a tinned copper conductor 1 and is wrapped around the tinned copper conductor 1. It consists of an insulation layer 2, and two wire cores are twisted to form a cable core. The cable core is covered with a total insulation layer 3, a shielding layer 4 and an outer sheath 5 in sequence; the raw materials of each layer in the high-voltage resistant cable provided by this embodiment The same as Embodiment 1; the preparation method of the high-voltage resistant cable provided in this embodiment includes the following steps:

(1) The polyethylene is extruded outside the tinned copper conductor through a 70-type extruder to form an insulating layer. The screw length-to-diameter ratio of the 70-type extruder is 15. The operating temperatures of the multiple zones are: 160°C in zone 1, Zone 2 is 170°C, zone 3 is 180°C, zone 4 is 190°C, zone 5 is 190°C, and the machine head temperature is 195°C to obtain the wire core.

(2) Twist the two wire cores obtained in step (1) on a single twisting machine using a back-twisting method. The twisting pitch is 40mm to obtain a cable core.

(3) Extrude polyethylene on the outside of the cable core obtained in step (2) through a 70-type extruder to form a total insulation layer. The screw length-to-diameter ratio of the 70-type extruder is 15. The operating temperatures of the multiple zones are: Zone 1 is 160℃, Zone 2 is 170℃, Zone 3 is 180℃, Zone 4 is 190℃, Zone 5 is 190℃, the machine head temperature is 195℃; then a 16-spindle braiding machine is used to weave tinned copper wire to form a shielding layer, and the braiding angle is 50°, the braiding density is 95%, and then the polyvinyl chloride is extruded on the outside of the shielding layer through a 90-type extruder to form an outer sheath. The screw length-to-diameter ratio of the 90-type extruder is 22, and the work of multiple zones The temperatures are respectively: 140°C in zone 1, 160°C in zone 2, 170°C in zone 3, and 170°C in zone 4. The machine head and die opening temperatures are both 170°C, and the high-voltage resistant cable is obtained.

Example 3

A high-voltage resistant cable for big data transmission, which differs from Embodiment 1 only in that the thickness of the total insulation layer is 1.2 mm, and other structures, parameters and preparation methods are the same as Embodiment 1.

Example 4

A high-voltage resistant cable for big data transmission, which differs from Embodiment 1 only in that the thickness of the insulation layer is 0.5 mm, and other structures, parameters and preparation methods are the same as Embodiment 1.

Example 5

A high-voltage resistant cable for big data transmission, which differs from Example 1 only in that the thickness of the polyamide layer is 0.2 mm, and other structures, parameters and preparation methods are the same as Example 1.

Example 6

A high-voltage resistant cable for big data transmission, which differs from Embodiment 1 only in that copper conductors are used instead of tinned copper conductors. Other structures, parameters and preparation methods are the same as Embodiment 1.

Comparative example 1

A high-voltage resistant cable for big data transmission. The difference from Embodiment 1 is that there is no total insulation layer, the shielding layer is directly covered outside the cable core, and the thickness of the insulation layer is 2mm. Other structures, parameters and The preparation methods are the same as Example 1.

Comparative example 2

A high-voltage resistant cable for big data transmission. The difference from Embodiment 2 is that there is no total insulation layer, the shielding layer is directly covered outside the cable core, and the thickness of the insulation layer is 2mm. Other structures, parameters and The preparation methods are the same as Example 2.

Performance Testing:

(1) Withstand voltage performance: Connect all the conductors at one end of the obtained high-voltage cable in parallel, and separate the other end to ensure that there is no conduction between the multiple cores. Connect the high-voltage level of the test equipment to the shielding layer of the cable, and connect the low-voltage level in parallel. At the conductor end together, first slowly increase the test voltage to 200V and check if there are any abnormalities. If there are no abnormalities, continue to slowly increase the voltage step by step to 5kV for 1 minute, then to 10kV for 1 minute, and finally to 15kV. Press for 1 minute to test the upper limit voltage when breakdown occurs.

(2) Anticorrosion performance: The test uses sodium chloride solution in the neutral salt spray test, and the preparation method is 50±10g/L (the International Organization for Standardization (ISO) standard is (50±5)g/L) Distilled or deionized water solution of chemically pure sodium chloride. The test conditions are 25°C and the pH value is 6.5 to 7.2. Mark the grid on the conductor and place it in a test chamber with a constant temperature of 35°C for continuous salt spray spraying. Leach, and record the time it takes for the corrosion area of the sample to reach 5%.

(3) Transmission efficiency, etc.: Connect a signal transmitting device to one end of the cable, and connect a passive automatic receiver and an AND gate to the other end to test the attenuation degree of the signal;

(4) Anti-rodent performance: SD rats (about 12 weeks old, weight between 250 and 300g) were selected for the test. Two sections of samples of about 300mm were prepared and hung in the middle of the test cage. Five rats were placed in the cage. The test cycle was 14 Days, feed normally during the test. After the test, check whether there are any signs of gnawing on the cable. If there is gnawing, the gnawing depth is less than 1 mm, which means it is qualified. If the gnawing depth is greater than or equal to 1mm, it is unqualified.

The high-voltage resistant cables provided in Examples 1 to 6 and Comparative Examples 1 to 2 were tested according to the above test methods. The test results are shown in Table 1:

Table 1

​	Withstand voltage performance (kV)	Anti-corrosion performance(h)	Transmission efficiency (%)	Anti-rodent performance
Example 1	16.6kV	＞5000	99.7	pass
Example 2	16.4kV	＞5000	99.8	Did not pass
Example 3	13.7kV	＞5000	98.3	pass
Example 4	14.2kV	＞5000	96.7	pass
Example 5	16.4kV	＞5000	99.7	Did not pass
Example 6	16.8	55	87.2	pass
Comparative example 1	7.3	＞5000	92.6	pass
Comparative example 2	7.7	＞5000	93.5	Did not pass

According to the data in Table 1, it can be seen that the high-voltage resistant cable provided by this application has excellent high-voltage resistance performance, anti-corrosion performance and high transmission efficiency, and by arranging a polyamide layer on the outermost side of the cable, the resulting cable can also have anti- Mouse performance; the voltage resistance performance of the cables obtained in Examples 1 to 6 is 13.7-16.8kV, the anti-corrosion tests are all greater than 55 hours, and the transmission efficiency is 87.2-99.8%.

Comparing Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, it can be found that the high-voltage withstand performance of the cables obtained without providing a total insulation layer (Comparative Example 1, Comparative Example 2) is significantly reduced.

Comparing Example 1 with Examples 2 and 5, it can be found that the cable obtained without a polyamide layer (Example 2) or with a low thickness of the polyamide layer (Example 5) has poor anti-rodent performance and cannot be avoided during use. Cables are eaten by rodents and cannot ensure the safety and stability of data transmission.

Comparing Example 1 and Examples 3 to 4, it can be found that the voltage resistance performance of the cable obtained by the lower thickness of the total insulating layer (Example 3) or the lower thickness of the insulating layer (Example 4) is also reduced.

Finally, comparing Example 1 and Example 6, it can be found that the corrosion resistance of the cable obtained by replacing the tin-plated copper conductor with a copper conductor has decreased.

Claims (10)

1. A high-voltage resistant cable for big data transmission, including at least two wire cores, each wire core is composed of a conductor and an insulation layer covering the conductor, and each two wire cores are twisted to form a cable core, The outside of the cable core is covered with a total insulation layer, a shielding layer and an outer sheath in sequence.
2. The high voltage resistant cable according to claim 1, wherein the conductor is a tinned copper conductor;

   Preferably, the tinned copper conductor is made of twisted tinned copper wires;

   Preferably, the diameter of the tinned copper wire is 0.19~0.205mm;

   Preferably, the tinned copper wire is obtained by tin plating copper wire.
3. The high-voltage cable according to claim 1 or 2, wherein the insulation layer outside the conductor is a polyethylene insulation layer;

   Preferably, the thickness of the polyethylene insulation layer is not less than 0.6mm;

   Preferably, the overall insulation layer is a polyethylene overall insulation layer;

   Preferably, the thickness of the total insulation layer is not less than 1.3mm.
4. The high-voltage resistant cable according to any one of claims 1 to 3, wherein the shielding layer is a tinned copper wire braided shielding layer;

   Preferably, the diameter of the tinned copper wires in the tinned copper wire braided shielding layer is 0.1 to 0.12 mm;

   Preferably, the outer sheath is a polyvinyl chloride outer sheath;

   Preferably, the thickness of the outer sheath is not less than 1.5mm.
5. The high-voltage resistant cable according to any one of claims 1 to 4, wherein the outer sheath is covered with a polyamide layer;

   Preferably, the thickness of the polyamide layer is not less than 0.5 mm.
6. A method for preparing a high-voltage cable for big data transmission according to any one of claims 1 to 5, including:

   Extrude the insulation layer material outside the conductor to obtain the wire core;

   Twist every two wire cores to obtain the cable core;

   The total insulation layer material is extruded outside the obtained cable core, the shielding layer material is braided, and the outer sheath material is extruded to obtain the high-voltage resistant cable.
7. The preparation method according to claim 6, wherein the extrusion packaging is performed by a 70-type extruder;

   Preferably, the screw aspect ratio of the 70-type extruder is 12 to 20;

   Preferably, the working temperatures of the multiple zones of the 70-type extruder are: zone 1 155-165°C, zone 2 165-175°C, zone 3 175-185°C, zone 4 185-195°C, zone 5 185～195℃, the machine head temperature is 190～200℃.
8. The preparation method according to claim 6 or 7, wherein the twisted pair is an untwisted twisted pair;

   Preferably, the pair twisting is performed on a single twisting machine;

   Preferably, the twisting pitch of the pair of twists is no more than 50 mm.
9. The preparation method according to any one of claims 6 to 8, wherein the extrusion of the total insulation layer material is carried out by a 70-type extruder;

   Preferably, the screw aspect ratio of the 70-type extruder is 12 to 20;

   Preferably, the working temperatures of the multiple zones of the 70-type extruder are: zone 1 155-165°C, zone 2 165-175°C, zone 3 175-185°C, zone 4 185-195°C, zone 5 185～195℃, machine head temperature is 190～200℃;

   Preferably, the weaving is performed using a 16-spindle knitting machine or a 24-spindle knitting machine;

   Preferably, the braiding angle is 30 to 60°;

   Preferably, the density of the weaving is not less than 90%;

   Preferably, the extrusion of the outer sheath material is carried out through a 90-type extruder;

   Preferably, the working temperatures of the multiple zones of the 90-type extruder are: zone 1 135-145°C, zone 2 155-165°C, zone 3 165-175°C, zone 4 165-175°C, the machine head and the die opening are independently 165~175℃;

   Preferably, after extruding the outer sheath material, it also includes: extruding polyamide;

   Preferably, the extruded polyamide is carried out through a 90-type extruder;

   Preferably, the working temperatures of the multiple zones of the 90-type extruder are: zone 1 160-180°C, zone 2 190-210°C, zone 3 210-230°C, zone 4 210-230°C, the machine head and the die opening are independently 230 to 250°C.
10. An application of the high-voltage resistant cable for big data transmission according to any one of claims 1 to 5 in a power substation system.

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