High weather-proof cable for wind power generation

Abstract

The invention discloses a high weather-proof cable for wind power generation, and belongs to the technical field of weather-proof cables. The cable sequentially comprises a conductor, a wrapping layer, an insulating layer, a shielding layer and an outer sheath from inside to outside, wherein the conductor has flexibility, and in the twisting process, the structure can keep certain rebound resilience; the material of the cable outer sheath takes polypropylene resin as a matrix, so that the cable is endowed with good mechanical property and electrical insulation property; the ethylene propylene diene monomer is added into the material of the cable outer sheath, so that the weather resistance of the cable is enhanced; the self-made modifier is added into the material of the cable outer sheath, and the molecules of the modifier contain a plurality of functional groups, so that the weather resistance and certain flame-retardant, low-temperature-resistant and anti-cracking properties of the cable are greatly enhanced; in conclusion, the prepared cable is excellent in mechanical property and good in weather resistance, has certain flame retardance, low temperature resistance and cracking resistance, and has important application value in the technical field of weather-resistant cables.

Description

Technical Field

[0001] The present invention belongs to the technical field of weather-resistant cables, and in particular relates to a highly weather-resistant cable for wind power generation. Background Art

[0002] With the transformation of the global energy mix and the rapid development of renewable energy, wind power has gained widespread adoption worldwide as a clean, efficient, and sustainable form of energy. As a crucial component of wind power systems, cables play a vital role in transmitting electrical energy. However, since wind farms are often located in harsh natural environments (such as high mountains, coastal areas, or deserts), their operating conditions place extremely high demands on cables. Traditional power cables often struggle to meet the requirements for long-term stable operation in these challenging environments. Therefore, developing highly weather-resistant cables specifically for wind power generation has become a pressing technical challenge.

[0003] First, wind turbine cables must withstand extreme climatic conditions. For example, in cold regions, cables may become brittle due to low temperatures; in hotter regions, cable materials may experience performance degradation due to thermal aging. Furthermore, salt spray corrosion and ultraviolet radiation in coastal areas can severely damage the cable's outer sheath, shortening its service life. Traditional cables typically use standard polyvinyl chloride (PVC) or cross-linked polyethylene (XLPE) for insulation and sheathing, but these materials exhibit significant shortcomings in these complex environments, easily leading to cable cracking, leakage, and even failure.

[0004] Secondly, wind power cables must also meet environmental and safety standards. On the one hand, as international awareness of environmental protection grows, countries are imposing stricter environmental requirements for cable materials, such as restricting the use of halogen-containing materials to reduce toxic gases produced during combustion. On the other hand, to ensure the safety of wind power systems, cables must possess excellent flame retardancy, effectively slowing the spread of flames in the event of a fire and reducing the risk of accidents.

[0005] There are already some special cable products designed for wind power generation on the market, but they still have many limitations. Therefore, there is an urgent need to invent a cable with high weather resistance and flame retardant properties to meet the higher requirements in the field of weather-resistant cable technology. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects of the prior art and provide a highly weather-resistant cable for wind power generation.

[0007] The purpose of the present invention can be achieved through the following technical solutions: A high-weather-resistant cable for wind power generation comprises, from the inside to the outside, a conductor, a wrapping layer, an insulating layer, a shielding layer and an outer sheath.

[0008] Furthermore, the conductor is formed by twisting multiple strands of soft fine round copper wires.

[0009] Furthermore, the wrapping layer is a high-temperature polyester tape.

[0010] Furthermore, the material of the insulating layer is polyvinyl chloride.

[0011] Furthermore, the shielding layer is made of copper wire.

[0012] Furthermore, the material of the outer sheath includes the following raw materials in parts by weight: 88-105 parts of polypropylene resin, 23-31 parts of EPDM rubber, 7-19 parts of modifier, and 4-6 parts of lubricant.

[0013] Furthermore, the lubricant is one of paraffin, stearic acid and barium stearate.

[0014] The outer sheath material is based on polypropylene resin. Polypropylene has good tensile strength, rigidity and hardness, as well as certain flexibility and excellent electrical insulation, which gives the outer sheath material good mechanical properties and electrical insulation properties. In addition, EPDM rubber is added to the material of the outer sheath. The saturated carbon chain structure of EPDM rubber makes it extremely resistant to ultraviolet rays, ozone and oxidants, greatly enhancing the weather resistance of the outer sheath material.

[0015] Furthermore, the modifier is prepared by the following steps: Step 1. Pentaerythritol and toluene are added to a three-necked flask equipped with a thermometer, an electromagnetic stirrer, a spherical condenser, and an exhaust gas treatment device. Under stirring conditions, phosphorus trichloride is slowly added dropwise to the device using a constant pressure dropping funnel. The temperature during the addition process does not exceed 30° C. After the addition is completed, the device is heated. When the temperature reaches 76° C., the reaction is refluxed for 3 hours. After the reaction is completed, the solvent benzene and excess phosphorus trichloride are distilled off to obtain intermediate product 1. The ratio of pentaerythritol, toluene, and phosphorus trichloride is 13.6 g:100 mL:28.8 g. Pentaerythritol reacts with phosphorus trichloride to obtain intermediate 1; the specific reaction is as follows: Step 2: The intermediate product 1, 1-nonanol, triethylamine (acid binding agent), and tetrahydrofuran were added to a three-necked flask equipped with a thermometer and an electromagnetic stirrer. After mixing and stirring, the reaction temperature was controlled to 80°C and the reaction was kept warm for 4 hours. After the reaction was completed, the mixture was filtered, and some of the solvent was removed by rotary evaporation. The mixture was then purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate in a volume ratio of 5:1). The eluent was removed by rotary evaporation to obtain the intermediate product 2. The ratio of the amount of the intermediate product 1, 1-nonanol, triethylamine, and tetrahydrofuran was 27.8 g:14.4 g:15 mL:100 mL. Under the catalysis of triethylamine, a chlorine group on intermediate product 1 reacts with the hydroxyl group of 1-nonanol, and intermediate product 1 is slightly in excess to obtain intermediate product 2. The specific reaction process is as follows: Step 3: Add cyanuric chloride, resorcinol, and chlorobenzene to a three-necked flask equipped with a thermometer and an electromagnetic stirrer, mix, and stir continuously until the solid is completely dissolved. Then, add aluminum chloride as a catalyst, control the reaction temperature to 80° C. under stirring, and keep the reaction for 6 hours. After the reaction is completed, filter, steam distill to remove chlorobenzene, filter again, wash with anhydrous ethanol several times, and dry in an oven to obtain intermediate product 3; the ratio of cyanuric chloride, resorcinol, chlorobenzene, and aluminum chloride is 18.2 g:36.4 g:150 mL:3.7 g; Under the catalysis of aluminum chloride, cyanuric chloride and resorcinol undergo an alkylation reaction. By controlling the molar ratio of the two to be close to 1:3 and a slight excess of resorcinol, the three chlorine groups on cyanuric chloride participate in the reaction to obtain intermediate product 3. The specific reaction process is shown below: Step 4, intermediate product 2, intermediate product 3 and N, N-dimethylformamide (DMF) are added to a three-necked flask equipped with a thermometer and an electromagnetic stirrer. After stirring at room temperature for 10 minutes, sodium hydroxide is mixed with distilled water to obtain a sodium hydroxide solution, and the sodium hydroxide solution is added dropwise to the flask using a constant pressure dropping funnel. After stirring and mixing evenly, the reaction temperature of the system is maintained at 60°C. After keeping warm for 6 hours, the reaction is completed, filtered, and the filter residue is washed with distilled water and ethanol several times in sequence, and then separated and purified by column chromatography (the eluent is a mixed solvent of petroleum ether / ethyl acetate, and the volume ratio of the two is 4:1). The eluent is removed by rotary evaporation and placed in an oven for drying to obtain a modifier; the ratio of the amount of intermediate product 2, intermediate product 3, N, N-dimethylformamide, sodium hydroxide, and distilled water is 111.6g:42.2g:200mL:119.8g:200mL; Sodium hydroxide can react with the phenolic hydroxyl group at the para position in the intermediate product 3 molecule to form sodium phenolate with stronger nucleophilicity. Sodium phenolate, as a nucleophilic reagent, attacks the carbon atom connected to the chlorine atom in the intermediate product 2, replacing the chlorine atom, thereby forming an ether bond. By controlling the molar ratio of intermediate product 2 to intermediate product 3 to be close to 3:1 and with a slight excess of intermediate product 3, a modifier is obtained. The structure of the modifier is shown below: The prepared modifier molecule has a triazine ring as its core structure, and three ortho-hydroxy-substituted phenyl groups are connected to it. This molecular design exhibits excellent performance in absorbing ultraviolet rays of a specific wavelength. When ultraviolet rays are absorbed, the hydrogen atoms in the hydrogen bonds within the molecule form a chelate ring structure with the carbonyl oxygen or nitrogen atoms on the triazine ring. As the stabilizer absorbs ultraviolet light energy and undergoes thermal vibration, the hydrogen bonds break and the chelate ring opens, converting the absorbed ultraviolet energy into harmless heat or other forms of energy, thereby significantly improving the ultraviolet resistance of the polypropylene matrix. In a radiation-free environment or under heat release conditions, the molecule can return to its initial state, showing good stability. It is a triazine UV absorber; and the modifier molecule also contains a phosphite structure. As a type of auxiliary antioxidant, phosphite can effectively decompose the hydroperoxides generated by the polymer during the oxidative aging process and convert it into inactive substances, thereby terminating or slowing down the oxidative degradation of the polymer. It can act synergistically with the triazine UV absorber to greatly enhance the weather resistance of the polypropylene matrix. In addition, the modifier molecule contains a long carbon chain, which is a methylene chain segment, which can toughen the matrix and improve the matrix's resistance to low temperatures and cracking. Finally, the modifier molecule contains two heteroatoms, nitrogen and phosphorus, which can improve the flame retardant properties of the matrix to a certain extent.

[0016] Beneficial effects of the present invention: The cable prepared by the present invention comprises, from the inside to the outside, a conductor, a wrapping layer, an insulating layer, a shielding layer and an outer sheath; 1. The conductor adopts a conductor structure of multiple strands of soft fine round copper wires, which can make the conductor core more flexible. In the torsion process, this structure can maintain a certain resilience and prevent the conductor from being damaged. 2. The material of the cable outer sheath is based on polypropylene resin, which gives the cable good mechanical properties and electrical insulation properties; 3. EPDM rubber is added to the material of the cable outer sheath to enhance the weather resistance of the cable; 4. A self-made modifier is added to the material of the cable outer sheath. The modifier molecules contain multiple functional groups, which greatly enhances the cable's weather resistance and certain flame retardancy, low temperature resistance, and crack resistance. In summary, the cable produced by the present invention has excellent mechanical properties and good weather resistance, and also has certain flame retardancy, low temperature resistance, and anti-cracking properties, and has important application value in the field of weather-resistant cable technology. DETAILED DESCRIPTION

[0017] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] Example 1 Preparation of modifier: Step 1, 13.6g of pentaerythritol and 100mL of toluene were added to a three-necked flask equipped with a thermometer, an electromagnetic stirrer, a spherical condenser and an exhaust gas treatment device. Under stirring conditions, 28.8g of phosphorus trichloride was slowly added dropwise to the device using a constant pressure dropping funnel. The temperature during the addition process did not exceed 30°C. After the addition was completed, the device was heated. When the temperature reached 76°C, the reaction was refluxed for 3h. After the reaction was completed, the solvent benzene and excess phosphorus trichloride were distilled off to obtain an intermediate product 1; Step 2, 27.8 g of intermediate product 1, 14.4 g of 1-nonanol, 15 mL of triethylamine and 100 mL of tetrahydrofuran were added to a three-necked flask equipped with a thermometer and an electromagnetic stirrer. After mixing and stirring, the reaction temperature was controlled to 80 ° C. and the reaction was kept warm for 4 hours. After the reaction was completed, it was filtered, and part of the solvent was removed by rotary evaporation. It was then purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate, and the volume ratio of the two was 5:1). The eluent was removed by rotary evaporation to obtain intermediate product 2; Step 3, 18.2 g of cyanuric chloride, 36.4 g of resorcinol and 150 mL of chlorobenzene were added to a three-necked flask equipped with a thermometer and an electromagnetic stirrer, mixed, and stirred continuously until the solid was completely dissolved, and then 3.7 g of aluminum chloride was added as a catalyst. Under stirring conditions, the reaction temperature was controlled to 80° C. and the reaction was kept warm for 6 hours. After the reaction was completed, the mixture was filtered, and the chlorobenzene was removed by steam distillation. The mixture was then filtered, washed with anhydrous ethanol several times, and dried in an oven to obtain intermediate product 3; Step 4, 111.6g of intermediate product 2, 42.2g of intermediate product 3 and 200mL of N,N-dimethylformamide were added to a three-necked flask equipped with a thermometer and an electromagnetic stirrer. After stirring at room temperature for 10min, 119.8g of sodium hydroxide was mixed with 200mL of distilled water to obtain a sodium hydroxide solution. The sodium hydroxide solution was then added dropwise to the flask using a constant pressure dropping funnel. After stirring and mixing, the reaction temperature of the system was maintained at 60°C. After insulation for 6h, the reaction was completed and filtered. The filter residue was washed with distilled water and ethanol several times, and then separated and purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate, and the volume ratio of the two was 4:1). The eluent was removed by rotary evaporation and placed in an oven for drying to obtain a modifier.

[0019] Example 2 Preparation of modifier: Step 1, 27.2g of pentaerythritol and 200mL of toluene were added to a three-necked flask equipped with a thermometer, an electromagnetic stirrer, a spherical condenser and an exhaust gas treatment device. Under stirring conditions, 57.6g of phosphorus trichloride was slowly added dropwise to the device using a constant pressure dropping funnel. The temperature during the addition process did not exceed 30°C. After the addition was completed, the device was heated. When the temperature reached 76°C, the reaction was refluxed for 3h. After the reaction was completed, the solvent benzene and excess phosphorus trichloride were distilled off to obtain an intermediate product 1; Step 2, 55.6 g of intermediate product 1, 28.8 g of 1-nonanol, 30 mL of triethylamine and 200 mL of tetrahydrofuran were added to a three-necked flask equipped with a thermometer and an electromagnetic stirrer. After mixing and stirring, the reaction temperature was controlled to 80 ° C. and the reaction was kept warm for 4 hours. After the reaction was completed, it was filtered, and part of the solvent was removed by rotary evaporation. It was then purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate, and the volume ratio of the two was 5:1). The eluent was removed by rotary evaporation to obtain intermediate product 2; Step 3, 36.4g of cyanuric chloride, 72.8g of resorcinol and 300mL of chlorobenzene were added to a three-necked flask equipped with a thermometer and an electromagnetic stirrer, and the mixture was stirred continuously until the solid was completely dissolved. Then, 7.4g of aluminum chloride was added as a catalyst. Under stirring conditions, the reaction temperature was controlled to 80°C, and the reaction was kept warm for 6 hours. After the reaction was completed, the mixture was filtered, chlorobenzene was removed by steam distillation, and the mixture was filtered again, washed with anhydrous ethanol several times, and dried in an oven to obtain intermediate product 3; Step 4, 223.2g of intermediate product 2, 84.4g of intermediate product 3 and 400mL of N,N-dimethylformamide were added to a three-necked flask equipped with a thermometer and an electromagnetic stirrer. After stirring at room temperature for 10min, 239.6g of sodium hydroxide was mixed with 400mL of distilled water to obtain a sodium hydroxide solution. The sodium hydroxide solution was then added dropwise to the flask using a constant pressure dropping funnel. After stirring and mixing evenly, the reaction temperature of the system was maintained at 60°C. After insulation for 6h, the reaction was completed and filtered. The filter residue was washed with distilled water and ethanol several times, and then separated and purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate, and the volume ratio of the two was 4:1). The eluent was removed by rotary evaporation and placed in an oven for drying to obtain a modifier.

[0020] Example 3 Preparation of outer sheath material: 88 g of polypropylene resin and 23 g of EPDM rubber were placed in an oven and dried for 12 hours. Subsequently, the dried polypropylene resin, EPDM rubber, 7 g of the modifier prepared in Example 1, and 4 g of paraffin were added to a high-speed mixer and stirred for 45 minutes to mix them evenly. After that, the mixture was added to a twin-screw extruder for melt blending and processed by extrusion to finally obtain an outer sheath material.

[0021] Example 4 Preparation of outer sheath material: 96 g of polypropylene resin and 27 g of EPDM rubber were placed in an oven and dried for 12 hours. Subsequently, the dried polypropylene resin, EPDM rubber, 13 g of the modifier prepared in Example 2, and 5 g of barium stearate were added to a high-speed mixer and stirred for 45 minutes to mix them evenly. After that, the mixture was added to a twin-screw extruder for melt blending and processed by extrusion process to finally obtain an outer sheath material.

[0022] Example 5 Preparation of outer sheath material: 105 g of polypropylene resin and 31 g of EPDM rubber were placed in an oven and dried for 12 hours. Subsequently, the dried polypropylene resin, EPDM rubber, 19 g of the modifier prepared in Example 2, and 6 g of barium stearate were added to a high-speed mixer and stirred for 45 minutes to mix them evenly. After that, the mixture was added to a twin-screw extruder for melt blending and processed by extrusion process to finally obtain an outer sheath material.

[0023] Example 6 A plurality of soft fine round copper wires are twisted to form a conductor, and then a high-temperature polyester tape is wrapped around the conductor to form a wrapping layer, and then polyvinyl chloride is extruded to form an insulating layer. The insulating layer is then wrapped with copper wire to form a shielding layer. Finally, 105g of polypropylene resin and 31g of EPDM rubber are placed in an oven and dried for 12 hours. Subsequently, the dried polypropylene resin, EPDM rubber, 19g of the modifier prepared in Example 2, and 6g of barium stearate are added to a high-speed mixer and stirred for 45 minutes to mix them evenly. Thereafter, the mixture is added to a twin-screw extruder for melt blending, and extruded and coated on the shielding layer through an extrusion process to obtain a high-weather-resistant cable for wind power generation.

[0024] Comparative Example 1 A commercially available anti-ultraviolet additive of equal quality was used to replace the modifier in Example 5, and the remaining steps were the same as in Example 5.

[0025] Comparative Example 2 Use commercially available weather-resistant polypropylene cable compound.

[0026] The following performance tests were conducted on Examples 3, 4, and 5 and Comparative Examples 1 and 2 according to different test standards: The notched impact strength of the samples at 25°C and -20°C was measured using the national standard GB / T 1043.1-2008 "Determination of impact properties of plastics - Part 1: Non-instrumented impact test"; The sample was placed in a xenon lamp aging test chamber for accelerated aging for 30 days. The aging conditions were air atmosphere, xenon lamp wavelength 280-800nm, and irradiation intensity 500W / m 2 , test the notched impact strength of the sample before and after aging (GB / T 1043.1-2008) and calculate the notched impact strength retention rate; notched impact strength retention rate = notched impact strength after test / notched impact strength before test × 100%; The limiting oxygen index of the sample is determined using the national standard GB / T 2406-2008 "Test method for combustion performance of plastics"; The measured results are shown in the following table: Test items Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 <![CDATA[Izod impact strength, 25 °C / (kJ / m 2 )]]> 15.5 16.3 17.1 7.6 8.1 <![CDATA[Izod impact strength, -20 °C / (kJ / m 2 )]]> 7.4 8.1 8.8 4.2 4.7 Notched impact strength retention rate / % 93.2 93.9 94.5 81.6 89.3 Limiting oxygen index / % 28.7 29.2 29.5 21.2 20.9 It can be seen from the above table that the outer sheath material prepared in the embodiment of the present invention has improved mechanical properties, weather resistance, flame retardancy and low-temperature resistance compared with the comparative example. Therefore, when it is used as one of the components of the cable, the corresponding performance of the cable will also be enhanced. In summary, the present invention has important application value in the field of weather-resistant cable technology.

[0027] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0028] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A high weather-resistant cable for wind power generation, comprising, from inside to outside: The conductor, the wrapping layer, the insulating layer, the shielding layer and the outer sheath are characterized in that the material of the outer sheath comprises the following raw materials in parts by weight: 88-105 parts of polypropylene resin, 23-31 parts of EPDM rubber, 7-19 parts of modifier and 4-6 parts of lubricant.

2. A high weather-resistant cable for wind power generation according to claim 1, characterized in that: The conductor is formed by twisting a plurality of soft thin round copper wires.

3. A highly weather-resistant cable for wind power generation according to claim 1, characterized in that: The wrapping layer is a high-temperature polyester tape.

4. A highly weather-resistant cable for wind power generation according to claim 1, characterized in that: The material of the insulating layer is polyvinyl chloride.

5. The high weather-resistant cable for wind power generation according to claim 1, characterized in that: The shielding layer is made of copper wire.

6. A highly weather-resistant cable for wind power generation according to claim 1, characterized in that: The modifier is prepared by the following steps: Step 1: Pentaerythritol and toluene are added to a three-necked flask. Phosphorus trichloride is added dropwise to the device under stirring. The temperature during the addition process does not exceed 30°C. After the addition is completed, the device is heated. When the temperature reaches 76°C, reflux reaction is carried out for 3 hours. After the reaction is completed, distillation is performed to obtain intermediate product 1. Step 2: Add the intermediate product 1, 1-nonanol, triethylamine and tetrahydrofuran into a three-necked flask, mix and stir evenly, and then heat at 80°C for 4 hours. After the reaction is complete, filter, rotary evaporate, purify by column chromatography, and rotary evaporate to obtain the intermediate product 2; Step 3: Add cyanuric chloride, resorcinol, and chlorobenzene into a three-necked flask and mix with stirring until the solid is completely dissolved. Then, add aluminum chloride and control the reaction temperature to 80° C. under stirring. Keep the temperature for 6 hours. After the reaction is complete, filter, steam distill, filter again, wash, and dry in an oven to obtain intermediate 3. Step 4: Add intermediate product 2, intermediate product 3 and N,N-dimethylformamide to a three-necked flask, stir at room temperature, mix sodium hydroxide with distilled water to obtain a sodium hydroxide solution, and then add the sodium hydroxide solution dropwise to the flask, stir and mix evenly, keep warm at 60°C for 6 hours, and after the reaction is completed, filter with suction, wash the filter residue, separate and purify it by column chromatography, rotary evaporate, and dry to obtain a modifier.

7. A high weather-resistant cable for wind power generation according to claim 6, characterized in that: In step 1, the ratio of pentaerythritol, toluene and phosphorus trichloride is 13.6 g:100 mL:28.8 g.

8. A highly weather-resistant cable for wind power generation according to claim 6, characterized in that: In step 2, the ratio of the amount of intermediate product 1, 1-nonanol, triethylamine, and tetrahydrofuran is 27.8 g:14.4 g:15 mL:100 mL.

9. The high weather-resistant cable for wind power generation according to claim 6, characterized in that: In step 3, the ratio of cyanuric chloride, resorcinol, chlorobenzene and aluminum chloride is 18.2g:36.4g:150mL:3.7g.

10. A highly weather-resistant cable for wind power generation according to claim 6, characterized in that: In step 4, the ratio of the amount of intermediate product 2, intermediate product 3, N,N-dimethylformamide, sodium hydroxide, and distilled water is 111.6 g:42.2 g:200 mL:119.8 g:200 mL.

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