A high lifetime, high current aluminum alloy conductor based power cable

Abstract

This invention discloses a high-life, high-current aluminum alloy conductor-based power cable, belonging to the field of cable processing technology. It addresses the technical problem that the mechanical strength, aging resistance, and flame retardant properties of existing high-current aluminum alloy conductor-based power cables need further improvement. Specifically, it comprises a conductor, a wrapping layer, an insulation layer, and an outer sheath layer arranged sequentially from the inside out. This invention prepares a cable material for the outer sheath layer, which is a composite of aging-resistant polyester containing modified fillers and PTMEG-modified polysiloxane. This forms an outer sheath layer on the outside of the aluminum alloy conductor-based power cable, possessing high mechanical strength, excellent aging resistance, and FV-0 flame retardancy. This significantly improves the long-term stability of the aluminum alloy conductor-based power cable in outdoor, high-current scenarios and extends the service life of the cable material.

Description

Technical Field

[0001] This invention relates to the field of cable processing technology, and specifically to a high-life, high-current aluminum alloy conductor-based power cable. Background Technology

[0002] With the rapid development of the power system and the continuous increase in urban electricity load, the demand for high-current transmission and distribution lines is gradually increasing. Traditional power cables mostly use copper conductors. Although copper has excellent conductivity, it consumes a lot of copper resources, is heavy, and has high cost, which is not conducive to the large-scale construction and promotion of power lines. In recent years, aluminum alloy conductors have been gradually applied to the field of power cables due to their light weight, low cost, and better creep resistance than ordinary aluminum conductors, becoming one of the important alternative materials to copper conductors.

[0003] Currently, aluminum alloy conductors exhibit high skin effect and resistance loss under high current operating conditions, resulting in a significant increase in conductor heat generation. This places higher demands on the heat resistance, aging resistance, and flame retardancy of cable insulation and sheath layers. Especially in long-term outdoor operating environments, cable sheath layers must not only withstand thermal aging and oxidation but also resist external factors such as ultraviolet radiation, humid environments, and mechanical damage. Traditional cable sheath materials are mainly composed of polyvinyl chloride, cross-linked polyethylene, or conventional polyolefin elastomers. Although these materials have certain mechanical strength and processability, they are prone to cracking, hardening, and pulverization under high temperature and strong ultraviolet radiation environments, leading to a decline in mechanical properties and insulation protection performance, thereby shortening the service life of the cable.

[0004] In addition, to meet flame retardant safety requirements, commonly used sheath materials need to add a large amount of flame retardant. However, high filler content often leads to a decrease in material flexibility and elongation at break, and even dripping phenomena, making it difficult to balance flame retardant performance and mechanical properties. Although some composite materials improve the flame retardant rating, they still have shortcomings in terms of processing adaptability and long-term stability. Therefore, a solution is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a high-life, high-current aluminum alloy conductor-based power cable to solve the technical problem that the mechanical strength, aging resistance, and flame retardant properties of high-current aluminum alloy conductor-based power cables in the prior art need to be further improved.

[0006] The objective of this invention can be achieved through the following technical solution: a high-life, high-current aluminum alloy conductor-based power cable, comprising a conductor, a wrapping layer, an insulation layer, and an outer sheath layer arranged sequentially from the inside out;

[0007] The conductor comprises two aluminum alloy bars with a thickness of 5-6 mm;

[0008] The wrapping layer has a double-layer wrapping structure and a thickness of 0.8-1mm;

[0009] The insulating layer is obtained by melt extruding polyolefin thermoplastic elastomer over the outside of the wrapping layer, and has a thickness of 2-3 mm.

[0010] The outer sheath layer comprises the following components by weight: 80-90 parts of aging-resistant polyester, 35-40 parts of PTMEG-modified polysiloxane, 0.9-1.1 parts of initiator, and 3-5 parts of additives, and the thickness of the outer sheath layer is 1.6-1.8 mm.

[0011] Furthermore, the outer walls of the two aluminum alloy bars that are far apart from each other are provided with a number of grooves arranged along their length direction, and the outer walls of the two aluminum alloy bars that are close to each other have a continuous corrugated structure, and the outer walls of the two aluminum alloy bars that are close to each other fit together.

[0012] In the double-layer wrapping structure, the inner layer is a mica tape or ceramic fiber tape, and the outer layer is a high-strength aramid fiber tape.

[0013] Furthermore, the preparation method of the aging-resistant polyester is as follows: a mixed alcohol monomer, 1,4-cyclohexanedicarboxylic acid and a catalyst are mixed, an inert gas is introduced into the reaction system, the temperature of the reaction system is raised to 160-170℃, and the reaction is maintained until the amount of water collected as a by-product is 50% of the theoretical mass. Modified filler is added to the reaction system, and the reaction is maintained until the amount of water collected as a by-product is 70% of the theoretical mass. After the reaction system is sealed, a negative pressure of 70 Pa is drawn, the temperature of the reaction system is raised to 215-225℃, and the reaction is maintained for 90-120 min. The material is discharged while hot to obtain the aging-resistant polyester.

[0014] The reaction formulas involved in the synthesis of aging-resistant polyesters are as follows:

[0015]

[0016] In the formula: ; ; a, b, c, d, and n represent the number of repetitions in different chain segments.

[0017] Furthermore, the weight ratio of the mixed alcohol monomer, catalyst, and modified filler is 10:0.1:3.2-3.5, the molar amount of 1,4-cyclohexanedicarboxylic acid is 0.55-0.57 times the total molar amount of hydroxyl groups in the mixed alcohol monomer, the mixed alcohol monomer is composed of 1,4-cyclohexanediethanol, N,N-bis(2-hydroxyethyl)-triacetonediamine, 2-allyl-1,3-propanediol, and polytetrahydrofuran ether diol in a weight ratio of 8:3:1:12-15, and the catalyst is tetrabutyl titanate.

[0018] Furthermore, the preparation of the modified filler includes the following steps:

[0019] A1. Mix expandable graphite and dispersion for 30-50 min, add metal-based solution to reaction system, keep warm and stir for 40-60 min, and then perform post-treatment to obtain loaded graphite;

[0020] A2. Mix supported graphite, nano-calcium carbonate, anhydrous ethanol and hydroxymethyltriethoxysilane, raise the temperature of the reaction system to 55-65℃, add alkaline solution to the reaction system, keep the reaction at this temperature for 2-3 hours, and then perform post-treatment to obtain the modified filler.

[0021] The reaction formulas involved in the synthesis of modified fillers are as follows:

[0022]

[0023] In the formula, It is used to load graphite or nano-calcium carbonate particles.

[0024] Further, in step A1, the ratio of expandable graphite, dispersion, and metal-based solution is 10g:100mL:6-8mL. The dispersion is composed of 0.2-0.3mol / L sodium hydroxide solution, sodium citrate, sodium dodecyl sulfate, and polyvinylpyrrolidone in a ratio of 100mL:1.8-2.2g:1.2-1.4g:1.6-1.9g. The metal-based solution is composed of magnesium chloride, zinc chloride, aluminum chloride, and purified water in a ratio of 3-4g:1g:1.8-2.0g:15mL. The post-treatment includes: after the reaction is complete, filtration is performed, the filter cake is washed with purified water until neutral, and then dried. The filter cake is transferred to a drying oven at a temperature of 70-80℃ and dried to constant weight to obtain loaded graphite.

[0025] Further, in step A2, the ratio of the loaded graphite, nano-calcium carbonate, anhydrous ethanol, hydroxymethyltriethoxysilane, and alkaline solution is 5g:2g:50mL:2.1-2.3g:8-10mL. The alkaline solution is composed of sodium hydroxide, sodium carbonate, and purified water in a ratio of 1g:3g:20mL. The post-treatment includes: after the reaction is complete, the temperature of the reaction system is lowered to room temperature, filtered, the filter cake is washed with purified water until neutral, dried, and the filter cake is transferred to a drying oven at a temperature of 70-80℃ and dried to constant weight to obtain the modified filler.

[0026] Furthermore, the preparation of PTMEG-modified polysiloxane includes the following steps:

[0027] B1. Under an inert gas atmosphere, polytetrahydrofuran ether diol and ethyl acetate are mixed and stirred until the system is dissolved. The temperature of the reaction system is raised to 65-75℃. 3-propyl isocyanate methyl diethoxysilane is added to the reaction system and the reaction is kept at this temperature for 60-80 min. After post-treatment, modified PTMEG is obtained.

[0028] The reaction formulas involved in the synthesis of modified PTMEG are as follows:

[0029]

[0030] B2. Mix modified PTMEG, octamethylcyclotetrasiloxane, 5-hexen-1-yldimethoxymethylsilane, and catalyst. Raise the temperature of the reaction system to 95-100℃ and keep the reaction at this temperature for 60-80 min. Add an end-capping agent to the reaction system and keep the reaction at this temperature for 2-3 h. After post-treatment, PTMEG-modified polysiloxane is obtained.

[0031] The reaction formula involved in the synthesis of PTMEG-modified polysiloxanes is as follows:

[0032]

[0033] In the formula: x, y, and z represent the number of repetitions in different chain segments, respectively.

[0034] Further, in step B1, the ratio of polytetrahydrofuran ether diol to ethyl acetate is 1g:5-6mL, the molar ratio of 3-isocyanate methyl diethoxysilane to the total molar amount of hydroxyl groups in polytetrahydrofuran ether diol is 1:1, and the post-treatment includes: after the reaction is complete, the reaction system is evacuated to -0.1MPa, and low-boiling substances are removed by vacuum evaporation to obtain modified PTMEG.

[0035] Further, in step B2, the weight ratio of the modified PTMEG, octamethylcyclotetrasiloxane, 5-hexen-1-yldimethoxymethylsilane, catalyst, and end-capping agent is 10-11:8:2-3:4:2. The catalyst is 60-70 wt% sulfuric acid, and the end-capping agent is tetramethyldivinyldisiloxane. The post-treatment includes: after the reaction is complete, the temperature of the reaction system is lowered to room temperature, 1 wt% sodium bicarbonate aqueous solution is added to the reaction system to adjust the pH of the system to 7.5, the system is allowed to stand and separate, the upper oily substance is washed three times with purified water and then transferred to a rotary evaporator with a water bath temperature of 80-90℃, the pressure is reduced to -0.1 MPa, and the low-boiling substances are removed by vacuum evaporation to obtain PTMEG-modified polysiloxane.

[0036] Furthermore, the outer sheath layer is formed as follows: aging-resistant polyester, PTMEG-modified polysiloxane, initiator and additives are mixed and added to a twin-screw extruder. After melt mixing for 3-5 minutes, the mixture is extruded and coated onto the outside of the insulation layer, forming an outer sheath layer on the outside of the insulation layer.

[0037] Furthermore, the initiator is dicumyl peroxide, and the additives consist of lubricant, dispersant, plasticizer, and antioxidant in a ratio of 1:3:4:1. The lubricant is ethylene bis-stearamide, the dispersant is stearate, the plasticizer is phthalate, and the antioxidant is any one of antioxidant AW, antioxidant DNP, and antioxidant CPPD. The temperatures of the six temperature zones of the twin-screw extruder from the feed end to the discharge end are 165°C, 170°C, 175°C, 175°C, 175°C, and 180°C, respectively.

[0038] The present invention has the following beneficial effects:

[0039] 1. This invention uses two aluminum alloy bars to form a conductor. Compared with traditional circular or single-row conductors, this superimposed structure can reduce the skin effect on high AC current and improve current carrying capacity. The corrugated structure between the two aluminum alloy bars promotes tight bonding, reduces contact resistance, and improves overall conductivity. The corrugated design also increases interfacial friction, preventing conductor displacement under thermal expansion and contraction or mechanical stress. The grooves on the outer wall of the aluminum alloy bars can reduce conductor weight and increase heat dissipation area, improving heat dissipation performance during current carrying, which is beneficial for high current operation. The double-layer wrapping structure improves the cable's fire resistance and mechanical protection, enabling the cable to remain stable in extreme environments. The polyolefin thermoplastic elastomer has good flexibility and resistance to environmental stress cracking, and can adapt to frequent bending and twisting without damaging the insulation. The cable sheath has good wear resistance, UV resistance, oxidation resistance, and heat aging resistance, significantly improving the long-term stability of the cable in outdoor, high-current scenarios and extending the service life of the cable material.

[0040] 2. In the outer sheath cable material of this invention, the cyclohexane-diethanol unit on the aging-resistant polyester molecular chain provides high strength and thermal stability, while the polytetrahydrofuran ether diol and siloxane soft segments endow the system with excellent flexibility and high elongation at break. The compactness and high thermal stability of the polyester chain brought by the cyclohexane structural unit make the main chain difficult to thermally relax. The high bond energy of the siloxane Si–O main chain makes it difficult to break under thermal and oxygen conditions, maintaining flexibility. The polytetrahydrofuran ether segment on the PTMEG-modified polysiloxane molecular chain enhances its compatibility with the aging-resistant polyester and grafts with the polyester phase under the action of peroxide, so that the system maintains high strength while maintaining flexibility. The modified filler has good interface bonding with the matrix after silane treatment. Nano-calcium carbonate provides toughening effect, and loaded graphite improves the in-plane thermal conductivity and thermal diffusion of the sheath, reducing hot spot accumulation. At the same time, its sheet shielding and nano-filler reduce the free volume and oxygen diffusion coefficient, which slows down the thermal oxidation process from a kinetic perspective, thereby further improving strength and aging resistance.

[0041] 3. This invention also loads expandable graphite. Loaded graphite improves the in-plane thermal conductivity and thermal diffusion of the sheath, reducing hot spot accumulation. Simultaneously, its layered shielding and nanofillers reduce free volume and oxygen diffusion coefficient, kinetically slowing down thermal oxidation. The scavenging of peroxy radicals by 2,2,6,6-tetramethylpiperidine further reduces the probability of ester hydrolysis and chain cleavage, stabilizing the system through chemical reaction pathways. Expandable graphite itself has a unique layered structure; when heated to high temperatures, interlayer compounds decompose to produce gases, causing rapid expansion between graphite layers to form a dense char layer. This layer isolates oxygen and heat transfer, effectively inhibiting combustion and providing flame retardancy. The magnesium, zinc, and aluminum oxides loaded on the expandable graphite catalyze the formation of phosphates or metal oxides during combustion, promoting char layer stabilization, inhibiting the release of combustible gases, and promoting flame retardancy. The charring reaction reduces the generation of combustible gases. When heated, nano-calcium carbonate decomposes and absorbs heat, lowering the ambient temperature. The calcium oxide produced during decomposition also participates in the charring process, complementing the char layer formed by expandable graphite and enhancing its stability and density. This further improves the flame retardant effect. Meanwhile, the cyclohexane ring structure in the aging-resistant polyester increases the glass transition temperature of the polyester, delaying thermal decomposition and destroying the polyester's crystallinity to form an amorphous structure. This makes the modified filler easier to disperse and improves the flame retardant efficiency. PTMEG-modified polysiloxane forms a silicate ceramic layer during combustion, which has excellent heat insulation and high-temperature resistance. It can effectively prevent heat from being transferred to the interior. Blending with the aging-resistant polyester causes the siloxane segments to migrate to the material surface, preferentially forming a protective layer during combustion and improving the flame retardant efficiency. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the structure of the high-current aluminum alloy conductor-based power cable of the present invention.

[0044] In the diagram: 1. Conductor; 2. Wrapping layer; 3. Insulation layer; 4. Outer sheath layer. Detailed Implementation

[0045] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] In this application, the polyolefin thermoplastic elastomer is selected from Dongguan Xinjingchen Plastic Raw Materials Co., Ltd., with an effective component content of POE and a grade of 7367.

[0047] In this application, the aluminum alloy busbar comprises, by mass percentage: Mg 0.20-0.35, Si 0.15-0.30, Zr 0.10-0.18, Ti 0.02-0.05, B 0.002-0.010, Fe 0.06-0.09, Cu 0.01-0.02, Mn 0.02-0.03, Cr 0.01-0.02, Zn 0.01-0.02, Ni 0.008-0.01, other single impurities ≤0.01, and the balance Al;

[0048] In this application, the polyvinylpyrrolidone is selected from commercially available materials from Jinan Pengduo Trading Co., Ltd., model number K-30, CAS number 9003-39-8;

[0049] In this application, the expandable graphite is selected from commercially available materials from Qingdao Yucheng Graphite Co., Ltd., with a specification of 100 mesh, product number 841534716, fixed carbon content of 98-99%, ash content of 2-3%, volatile matter of 5-8%, pH value of 4-6, and moisture content of 0.3-0.5%.

[0050] In this application, the nano-calcium carbonate has a specification of 100 mesh, a content of 96%, and a density of 2.3 g / cm³. 3 The wear rate was 0.1%.

[0051] In this application, the CAS number of hydroxymethyltriethoxysilane is 162781-70-6;

[0052] In this application, the polytetrahydrofuran ether diol is designated as PTMG-1000, has a molecular weight of 1000, an active ingredient content of 99%, and a CAS number of 25190-06-1.

[0053] In this application, the mica tape is selected from commercially available materials from Deyang Dongfang Yili Electromechanical Equipment Co., Ltd., brand name Youyi, with a dielectric strength of 12-15MV / m and a temperature resistance of 155℃.

[0054] In this application, the ceramic fiber tape is selected from commercially available materials from Hejian Tielong Ceramic Fiber Insulation Materials Co., Ltd., and the product name is ceramic fiber tape. The content of ferric oxide in the ceramic fiber tape is 0.7-1.2%, the content of aluminum oxide is 45-48%, the fiber diameter is 1-4μm, the thermal conductivity is 0.130w / m·k, and the breakdown voltage is 5kv / mm.

[0055] In this application, the high-strength aramid fiber tape is selected from commercially available materials from Yixing Chaowei Materials Technology Co., Ltd., with the product name "aramid cloth," a width of 100mm, a thickness of 0.15mm, and a density of 100g / m³. 3 The web is formed by warp and weft weaving.

[0056] Example 1

[0057] This embodiment provides a method for preparing cable material for the outer sheath layer of a cable, specifically including the following steps:

[0058] Step 1: Preparation of modified filler

[0059] Mix 0.2 mol / L sodium hydroxide solution, sodium citrate, sodium dodecyl sulfate, and polyvinylpyrrolidone at a ratio of 100 mL: 1.8 g: 1.2 g: 1.6 g to obtain a dispersion.

[0060] Magnesium chloride, zinc chloride, aluminum chloride, and purified water were mixed evenly at a ratio of 3g:1g:1.8g:15mL to obtain a metal-based solution.

[0061] Weigh out 50g of expandable graphite and 500mL of dispersion and add them to the reaction flask. Stir for 30min. At room temperature, add 30mL of metal-based solution to the reaction flask, keep warm and stir for 40min, filter, wash the filter cake with purified water until neutral, and then dry it. Transfer the filter cake to a drying oven at 70℃ and dry it to constant weight to obtain loaded graphite.

[0062] During the reaction, after the expandable graphite is dispersed in the dispersion, the dispersion is alkaline. When the metal-based solution is added, the pH changes abruptly, and the metal ions begin to hydrolyze to generate hydroxides. Under room temperature conditions, these metal hydroxide nuclei gradually grow and anchor on the surface or in the pores of the expandable graphite sheets, thus preparing loaded graphite.

[0063] Sodium hydroxide, sodium carbonate, and purified water were mixed evenly at a ratio of 1g:3g:20mL to obtain an alkaline solution.

[0064] Weigh out 50g of supported graphite, 20g of nano-calcium carbonate, 500mL of anhydrous ethanol and 21g of hydroxymethyltriethoxysilane and add them to a reaction flask. Stir the mixture and raise the temperature of the reaction flask to 55℃. Add 80mL of alkaline solution to the reaction flask and keep it at this temperature for 2 hours. Then lower the temperature of the reaction flask to room temperature and filter the mixture. Wash the filter cake with purified water until it is neutral and then dry it. Transfer the filter cake to a drying oven at 70℃ and dry it to constant weight to obtain the modified filler.

[0065] During the reaction, the siloxane bonds on the hydroxymethyltriethoxysilane molecule hydrolyze to form silanols, which then condense with the active reaction sites on the surface of supported graphite or nano-calcium carbonate particles to form hydroxyl modifications with polysiloxane coating, thus preparing the modified filler.

[0066] Step 2: Preparation of aging-resistant polyester

[0067] 1,4-cyclohexanediethanol, N,N-bis(2-hydroxyethyl)-triacetonediamine, 2-allyl-1,3-propanediol and polytetrahydrofuran ether diol were mixed in a weight ratio of 8:3:1:12 to obtain a mixed alcohol monomer.

[0068] Weigh out 500g of mixed alcohol monomers and 5g of tetrabutyl titanate catalyst and add them to an argon-protected reaction flask and stir. Calculate the amount of 1,4-cyclohexanedicarboxylic acid to be added based on 0.55 times the total molar amount of hydroxyl groups in the mixed alcohol monomers and add it to the reaction flask. Continuously introduce argon gas into the reaction flask at a rate of 600mL / min and raise the temperature of the reaction flask to 160℃. Collect the by-product water using a water separator and maintain the temperature until the amount of by-product water collected is 50% of the theoretical mass.

[0069] Add 160g of modified filler to the reaction flask, keep the reaction at the temperature until the amount of water collected as a byproduct is 70% of the theoretical mass, seal the reaction flask and draw a negative pressure to 50Pa, raise the temperature of the reaction flask to 215℃, keep the reaction at the temperature for 90min, and discharge the material while it is hot to obtain aging resistant polyester.

[0070] During the reaction, the mixed alcohol monomers undergo pre-esterification with 1,4-cyclohexanedicarboxylic acid under the catalysis of tetrabutyl titanium. When the reaction reaches 50% of the theoretical water release, the modified filler is added. The hydroxyl groups on the modified filler serve as reactive sites. When the esterification reaction reaches 70% of the theoretical water release, the equilibrium is pushed towards ester bond formation through deep dehydration. At the same time, limited transesterification occurs to make the chain segment distribution more uniform, resulting in a thermoplastic polyester backbone composed of alicyclic ester hard segments and ether soft segments. It contains a uniformly dispersed inorganic filler phase anchored by covalent / coordination, thus preparing an aging-resistant polyester.

[0071] Step 3: Preparation of PTMEG-modified polysiloxane

[0072] Weigh 200g of polytetrahydrofuran ether diol and 1000mL of ethyl acetate and add them to an argon-protected reaction flask. Stir until the system is dissolved. Raise the temperature of the reaction flask to 65℃. Calculate the amount of 3-isocyanate methyl diethoxysilane to be added based on the total molar amount of hydroxyl groups in the polytetrahydrofuran ether diol. Add it to the reaction flask and keep it at this temperature for 60min. Then, evacuate the reaction flask to -0.1MPa and remove low-boiling substances by vacuum distillation to obtain modified PTMEG.

[0073] During the reaction, the isocyanate group on the propyl isocyanate methyl diethoxysilane molecule undergoes condensation with the hydroxyl group on the polytetrahydrofuran ether diol molecular chain, and triethoxysilane is modified at both ends of the polytetrahydrofuran ether to prepare modified PTMEG.

[0074] Weigh out 200g of modified PTMEG, 160g of octamethylcyclotetrasiloxane, 40g of 5-hexen-1-yldimethoxymethylsilane, and 80g of 60wt% sulfuric acid. Mix them together. Raise the temperature of the reaction flask to 95℃ and keep it at that temperature for 60min. Add 40g of end-capping agent tetramethyldivinyldisiloxane to the reaction flask and keep it at that temperature for 2h. Lower the temperature of the reaction flask to room temperature and add 1wt% sodium bicarbonate aqueous solution to adjust the pH of the system to 7.5. Let it stand and separate the layers. Wash the upper oily substance three times with purified water and transfer it to a rotary evaporator with a water bath temperature of 80℃. Apply a negative pressure to -0.1MPa and remove low-boiling substances by vacuum evaporation to obtain PTMEG-modified polysiloxane.

[0075] During the reaction, sulfuric acid acts as a catalyst, and octamethylcyclotetrasiloxane undergoes cationic ring-opening polymerization to generate linear polydimethylsiloxane chains. Simultaneously, modified PTMEG and allyl dimethoxysilane undergo hydrolysis to produce silanol, which then condenses with the growing siloxane chains, thereby covalently introducing polyether segments and allyl units into the siloxane backbone. In the later stage of the reaction, tetramethyldivinyldisiloxane end-capping agent condenses with the active chain ends, terminating chain growth and introducing vinyl groups into the polymer end groups, thus preparing PTMEG-modified polysiloxane.

[0076] Step 4: Prepare cable material for the outer sheath layer of the cable.

[0077] Ethylene bis-stearamide, zinc stearate, diisobutyl phthalate and antioxidant AW were mixed evenly in a weight ratio of 1:3:4:1 to obtain the additive.

[0078] Weigh out the following components by weight: 80 parts of aging-resistant polyester, 35 parts of PTMEG-modified polysiloxane, 0.9 parts of diisopropylbenzene peroxide, and 3 parts of additives. Mix them evenly to obtain the outer sheath cable material.

[0079] Example 2

[0080] This embodiment provides a method for preparing cable material for the outer sheath layer of a cable, specifically including the following steps:

[0081] Step 1: Preparation of modified filler

[0082] Mix 0.25 mol / L sodium hydroxide solution, sodium citrate, sodium dodecyl sulfate, and polyvinylpyrrolidone at a ratio of 100 mL: 2.0 g: 1.3 g: 1.7 g to obtain a dispersion.

[0083] Magnesium chloride, zinc chloride, aluminum chloride, and purified water were mixed evenly at a ratio of 3.5g:1g:1.9g:15mL to obtain a metal-based solution.

[0084] Weigh out 50g of expandable graphite and 500mL of dispersion and add them to the reaction flask. Stir for 40min. At room temperature, add 35mL of metal-based solution to the reaction flask, keep warm and stir for 50min, filter, wash the filter cake with purified water until neutral, and then dry it. Transfer the filter cake to a drying oven at 75℃ and dry it to constant weight to obtain loaded graphite.

[0085] Sodium hydroxide, sodium carbonate, and purified water were mixed evenly at a ratio of 1g:3g:20mL to obtain an alkaline solution.

[0086] Weigh out 50g of supported graphite, 20g of nano-calcium carbonate, 500mL of anhydrous ethanol and 22g of hydroxymethyltriethoxysilane and add them to a reaction flask. Stir the mixture and raise the temperature of the reaction flask to 60℃. Add 90mL of alkaline solution to the reaction flask and keep it at this temperature for 2.5h. Then lower the temperature of the reaction flask to room temperature, filter the mixture, wash the filter cake with purified water until neutral, and then dry it. Transfer the filter cake to a drying oven at 75℃ and dry it to constant weight to obtain the modified filler.

[0087] Step 2: Preparation of aging-resistant polyester

[0088] 1,4-cyclohexanediethanol, N,N-bis(2-hydroxyethyl)-triacetone diamine, 2-allyl-1,3-propanediol, and polytetrahydrofuran ether diol were mixed in a weight ratio of 8:3:1:13.5 to obtain a mixed alcohol monomer.

[0089] Weigh out 500g of mixed alcohol monomers and 5g of tetrabutyl titanate catalyst and add them to an argon-protected reaction flask and stir. Calculate the amount of 1,4-cyclohexanedicarboxylic acid to be added based on 0.56 times the total molar amount of hydroxyl groups in the mixed alcohol monomers and add it to the reaction flask. Continuously introduce argon gas into the reaction flask at a rate of 600mL / min and raise the temperature of the reaction flask to 165℃. Collect the byproduct water using a water separator and maintain the temperature until the amount of byproduct water collected is 50% of the theoretical mass.

[0090] Add 168g of modified filler to the reaction flask, keep the reaction at the temperature until the amount of water collected as a byproduct is 70% of the theoretical mass, seal the reaction flask and draw a negative pressure to 50Pa, raise the temperature of the reaction flask to 220℃, keep the reaction at the temperature for 105min, and discharge the material while it is hot to obtain aging resistant polyester.

[0091] Step 3: Preparation of PTMEG-modified polysiloxane

[0092] Weigh 200g of polytetrahydrofuran ether diol and 1100mL of ethyl acetate and add them to an argon-protected reaction flask. Stir until the system is dissolved. Raise the temperature of the reaction flask to 70℃. Calculate the amount of 3-isocyanate methyl diethoxysilane to be added based on the total molar amount of hydroxyl groups in the polytetrahydrofuran ether diol. Add it to the reaction flask and keep it at this temperature for 70min. Then, evacuate the reaction flask to -0.1MPa and remove low-boiling substances by vacuum distillation to obtain modified PTMEG.

[0093] Weigh out 210g of modified PTMEG, 160g of octamethylcyclotetrasiloxane, 50g of 5-hexen-1-yldimethoxymethylsilane, and 80g of 65wt% sulfuric acid. Mix them together. Raise the temperature of the reaction flask to 98℃ and keep it at that temperature for 70min. Add 40g of end-capping agent tetramethyldivinyldisiloxane to the reaction flask and keep it at that temperature for 2.5h. Lower the temperature of the reaction flask to room temperature and add 1wt% sodium bicarbonate aqueous solution to the reaction flask to adjust the pH of the system to 7.5. Let it stand and separate the layers. Wash the upper oily substance three times with purified water and transfer it to a rotary evaporator with a water bath temperature of 85℃. Apply a negative pressure to -0.1MPa and remove low-boiling substances by vacuum evaporation to obtain PTMEG-modified polysiloxane.

[0094] Step 4: Prepare cable material for the outer sheath layer of the cable.

[0095] Ethylene bis-stearamide, calcium stearate, diisooctyl phthalate and antioxidant DNP were mixed evenly in a weight ratio of 1:3:4:1 to obtain the additive.

[0096] Weigh out the following components by weight: 85 parts of aging-resistant polyester, 37 parts of PTMEG-modified polysiloxane, 1.0 part of dicumyl peroxide, and 4 parts of additives. Mix them evenly to obtain the outer sheath cable material.

[0097] Example 3

[0098] This embodiment provides a method for preparing cable material for the outer sheath layer of a cable, specifically including the following steps:

[0099] Step 1: Preparation of modified filler

[0100] A dispersion was obtained by mixing 0.3 mol / L sodium hydroxide solution, sodium citrate, sodium dodecyl sulfate, and polyvinylpyrrolidone at a ratio of 100 mL: 2.2 g: 1.4 g: 1.9 g.

[0101] Magnesium chloride, zinc chloride, aluminum chloride, and purified water were mixed evenly at a ratio of 4g:1g:2.0g:15mL to obtain a metal-based solution.

[0102] Weigh out 50g of expandable graphite and 500mL of dispersion and add them to the reaction flask. Stir for 50min. At room temperature, add 40mL of metal-based solution to the reaction flask, keep warm and stir for 60min, filter, wash the filter cake with purified water until neutral, and then dry it. Transfer the filter cake to a drying oven at 80℃ and dry it to constant weight to obtain loaded graphite.

[0103] Sodium hydroxide, sodium carbonate, and purified water were mixed evenly at a ratio of 1g:3g:20mL to obtain an alkaline solution.

[0104] Weigh out 50g of supported graphite, 20g of nano-calcium carbonate, 500mL of anhydrous ethanol and 23g of hydroxymethyltriethoxysilane and add them to a reaction flask. Stir the mixture and raise the temperature of the reaction flask to 65℃. Add 100mL of alkaline solution to the reaction flask and keep it at this temperature for 3 hours. Then lower the temperature of the reaction flask to room temperature, filter the mixture, wash the filter cake with purified water until neutral, and then dry it. Transfer the filter cake to a drying oven at 80℃ and dry it to constant weight to obtain the modified filler.

[0105] Step 2: Preparation of aging-resistant polyester

[0106] 1,4-cyclohexanediethanol, N,N-bis(2-hydroxyethyl)-triacetonediamine, 2-allyl-1,3-propanediol and polytetrahydrofuran ether diol were mixed in a weight ratio of 8:3:1:15 to obtain a mixed alcohol monomer.

[0107] Weigh out 500g of mixed alcohol monomers and 5g of tetrabutyl titanate catalyst and add them to an argon-protected reaction flask and stir. Calculate the amount of 1,4-cyclohexanedicarboxylic acid to be added based on 0.57 times the total molar amount of hydroxyl groups in the mixed alcohol monomers and add it to the reaction flask. Continuously introduce argon gas into the reaction flask at a rate of 600mL / min and raise the temperature of the reaction flask to 170℃. Collect the byproduct water through a water separator and maintain the temperature until the amount of byproduct water collected is 50% of the theoretical mass.

[0108] Add 175g of modified filler to the reaction flask, keep the reaction at the temperature until the amount of water collected as a byproduct is 70% of the theoretical mass, seal the reaction flask and draw a negative pressure to 50Pa, raise the temperature of the reaction flask to 225℃, keep the reaction at the temperature for 120min, and discharge the material while it is hot to obtain aging resistant polyester.

[0109] Step 3: Preparation of PTMEG-modified polysiloxane

[0110] Weigh 200g of polytetrahydrofuran ether diol and 1200mL of ethyl acetate and add them to an argon-protected reaction flask. Stir until the system is dissolved. Raise the temperature of the reaction flask to 75℃. Calculate the amount of 3-isocyanate methyl diethoxysilane to be added based on the total molar amount of hydroxyl groups in the polytetrahydrofuran ether diol. Add it to the reaction flask and keep it at this temperature for 80min. Then, evacuate the reaction flask to -0.1MPa and remove low-boiling substances by vacuum distillation to obtain modified PTMEG.

[0111] Weigh out 220g of modified PTMEG, 160g of octamethylcyclotetrasiloxane, 60g of 5-hexen-1-yldimethoxymethylsilane, and 80g of 70wt% sulfuric acid. Mix them together. Raise the temperature of the reaction flask to 100℃ and keep it at that temperature for 80min. Add 40g of end-capping agent tetramethyldivinyldisiloxane to the reaction flask and keep it at that temperature for 3h. Lower the temperature of the reaction flask to room temperature and add 1wt% sodium bicarbonate aqueous solution to adjust the pH of the system to 7.5. Let it stand and separate the layers. Wash the upper oily substance three times with purified water and transfer it to a rotary evaporator with a water bath temperature of 90℃. Apply a negative pressure to -0.1MPa and remove low-boiling substances by vacuum evaporation to obtain PTMEG-modified polysiloxane.

[0112] Step 4: Prepare cable material for the outer sheath layer of the cable.

[0113] Ethylene bis-stearamide, barium stearate, dibutyl phthalate and antioxidant CPPD were mixed evenly in a weight ratio of 1:3:4:1 to obtain the additive.

[0114] Weigh out the following components by weight: 90 parts of aging-resistant polyester, 40 parts of PTMEG-modified polysiloxane, 1.1 parts of diisopropylbenzene peroxide, and 5 parts of additives. Mix them evenly to obtain the outer sheath cable material.

[0115] Example 4

[0116] This embodiment provides a high-life, high-current aluminum alloy conductor-based power cable, comprising:

[0117] Two aluminum alloy bars with a thickness of 5mm are selected and bonded together to form an overlap. Several grooves are opened on the outer wall of the two aluminum alloy bars on the side away from each other, and the outer wall of the two aluminum alloy bars on the side close to each other has a continuous corrugated structure. The corrugated structures on the two aluminum alloy bars match each other. The corrugated structures of the two aluminum alloy bars are bonded together to obtain conductor 1.

[0118] After wrapping the mica tape around the outside of the conductor 1, a high-strength aramid fiber tape is used for further wrapping to form a wrapping layer 2 with a thickness of 0.8 mm and a double-layer wrapping structure.

[0119] After the polyolefin thermoplastic elastomer is melt-extruded and coated onto the outside of the wrapping layer 2, an insulating layer 3 with a thickness of 2 mm is formed on the outside of the wrapping layer 2.

[0120] The outer sheath cable material prepared in Example 1 was added to a twin-screw extruder. The temperatures of the six temperature zones of the twin-screw extruder from the feed end to the discharge end were set to 165°C, 170°C, 175°C, 175°C, 175°C, and 180°C, respectively. After melting and mixing for 3 minutes, the material was extruded and coated on the outside of the insulation layer 3, forming an outer sheath layer 4 with a thickness of 1.6 mm on the outside of the insulation layer 3, thus obtaining an aluminum alloy conductor-based power cable.

[0121] Example 5

[0122] This embodiment provides a high-life, high-current aluminum alloy conductor-based power cable, comprising:

[0123] Two aluminum alloy bars with a thickness of 5.5 mm are selected and bonded together to form an overlapping structure. Several grooves are opened on the outer wall of the two aluminum alloy bars on the side away from each other, and the outer wall of the two aluminum alloy bars on the side close to each other has a continuous corrugated structure. The corrugated structures on the two aluminum alloy bars match each other. The corrugated structures of the two aluminum alloy bars are bonded together to obtain conductor 1.

[0124] After wrapping the ceramic fiber tape around the outside of the conductor 1, a high-strength aramid fiber tape is used for further wrapping to form a wrapping layer 2 with a thickness of 0.9 mm and a double-layer wrapping structure.

[0125] After the polyolefin thermoplastic elastomer is melt-extruded and coated onto the outside of the wrapping layer 2, an insulating layer 3 with a thickness of 2.5 mm is formed on the outside of the wrapping layer 2.

[0126] The outer sheath cable material prepared in Example 2 was added to a twin-screw extruder. The temperatures of the six temperature zones of the twin-screw extruder from the feed end to the discharge end were set to 165°C, 170°C, 175°C, 175°C, 175°C, and 180°C, respectively. After melting and mixing for 4 minutes, the material was extruded and coated on the outside of the insulation layer 3, forming an outer sheath layer 4 with a thickness of 1.7 mm on the outside of the insulation layer 3, thus obtaining an aluminum alloy conductor-based power cable.

[0127] Example 6

[0128] This embodiment provides a high-life, high-current aluminum alloy conductor-based power cable, comprising:

[0129] Two aluminum alloy bars with a thickness of 6mm are selected and bonded together to form an overlapping structure. Several grooves are opened on the outer wall of the two aluminum alloy bars on the side away from each other, and the outer wall of the two aluminum alloy bars on the side close to each other has a continuous corrugated structure. The corrugated structures on the two aluminum alloy bars match each other. The corrugated structures of the two aluminum alloy bars are bonded together to obtain conductor 1.

[0130] After wrapping the mica tape around the outside of the conductor 1, a high-strength aramid fiber tape is used for further wrapping to form a wrapping layer 2 with a thickness of 1 mm and a double-layer wrapping structure.

[0131] After the polyolefin thermoplastic elastomer is melt-extruded and coated onto the outside of the wrapping layer 2, an insulating layer 3 with a thickness of 3 mm is formed on the outside of the wrapping layer 2.

[0132] The outer sheath cable material prepared in Example 3 was added to a twin-screw extruder. The temperatures of the six temperature zones of the twin-screw extruder from the feed end to the discharge end were set to 165°C, 170°C, 175°C, 175°C, 175°C, and 180°C, respectively. After melting and mixing for 5 minutes, the material was extruded and coated onto the outside of the insulation layer 3, forming an outer sheath layer 4 with a thickness of 1.8 mm on the outside of the insulation layer 3, thus obtaining an aluminum alloy conductor-based power cable.

[0133] Comparative Example 1

[0134] The difference between this comparative example and Example 6 is that, in the preparation of the outer sheath cable material, expandable graphite is used instead of load graphite in the preparation of the modified filler in step 1.

[0135] Comparative Example 2

[0136] The difference between this comparative example and Example 6 is that, in the preparation of the outer sheath cable material, the modified filler in step 1 is replaced by a mixture of loaded graphite and nano-calcium carbonate in a weight ratio of 5:2.

[0137] Comparative Example 3

[0138] The difference between this comparative example and Example 6 is that, in the preparation of the outer sheath cable material, 1,4-cyclohexanedicarboxylic acid was replaced by oxalic acid in equal molar amounts.

[0139] Comparative Example 4

[0140] The difference between this comparative example and Example 6 is that, in the preparation of the outer sheath cable material, no modified PTMEG was added during the preparation of the PTMEG-modified polysiloxane in step 3.

[0141] Performance testing:

[0142] The aluminum alloy conductor-based power cables prepared in Examples 4-6 and Comparative Examples 1-4 were subjected to thermal aging and artificial accelerated climate aging. The tensile strength, elongation at break and flame retardant properties of the insulation layer of the aluminum alloy conductor-based power cables before and after aging were measured.

[0143] The tensile strength and elongation at break of the sheath layer of aluminum alloy conductor-based power cables can be tested in accordance with the standard GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber".

[0144] The flame retardant properties of the sheath layer of aluminum alloy conductor-based power cables can be determined in accordance with the standard GB / T 10707-2008 "Determination of the flammability of rubber";

[0145] The thermal aging method is as follows: place the aluminum alloy conductor-based power cable sample in an oven at 120℃ and keep it at that temperature for 240 hours.

[0146] Artificial accelerated weathering was conducted according to Method B of GB / T 16422.3-2022 "Laboratory Light Source Exposure Test Methods for Plastics - Part 3: Fluorescent Ultraviolet Lamps", using a UVA-351 lamp with an irradiance of 75 W / m². 2 Artificial accelerated weathering was carried out on aluminum alloy conductor-based power cables at a blackboard temperature of 60±2°C and an irradiation time of 720h. The tensile strength and elongation at break of the samples were measured. The specific test data are shown in Table 1 below.

[0147] Table 1 - Performance test data of samples before and after aging

[0148]

[0149] Data Analysis:

[0150] Comparative analysis of the data in Table 1 shows that the tensile strength of the aluminum alloy conductor-based power cable sheath layer prepared by this invention reaches 19.2 MPa and the elongation at break reaches 260%. After thermal aging, the tensile strength of the aluminum alloy conductor-based power cable sheath layer reaches 16.5 MPa and the elongation at break reaches 225%. After ultraviolet irradiation aging, the tensile strength of the aluminum alloy conductor-based power cable sheath layer reaches 17.3 MPa and the elongation at break reaches 235%. Furthermore, the vertical flammability rating of the aluminum alloy conductor-based power cable sheath layer reaches FV-0. All performance test data are superior to the comparative example. This indicates that by preparing a cable outer sheath layer composite of aging-resistant polyester containing modified fillers and PTMEG-modified polysiloxane, this invention forms an outer sheath layer on the outside of the aluminum alloy conductor-based power cable that combines high mechanical strength, excellent aging resistance, and FV-0 flame retardancy, significantly improving the long-term stability of the aluminum alloy conductor-based power cable in outdoor, high-current scenarios and extending the service life of the cable material.

[0151] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high lifetime, high current aluminum alloy conductor-based power cable characterized by, It includes a conductor (1), a wrapping layer (2), an insulation layer (3), and an outer sheath layer (4) arranged sequentially from the inside out. The conductor (1) comprises two aluminum alloy bars with a thickness of 5-6 mm; The wrapping layer (2) has a double-layer wrapping structure with a thickness of 0.8-1mm; The insulating layer (3) is obtained by melt extrusion of polyolefin thermoplastic elastomer over the outside of the wrapping layer (2), and has a thickness of 2-3 mm; The outer sheath layer (4) comprises the following components by weight: 80-90 parts of aging-resistant polyester, 35-40 parts of PTMEG-modified polysiloxane, 0.9-1.1 parts of initiator and 3-5 parts of additives, and the thickness of the outer sheath layer (4) is 1.6-1.8 mm. The structural formula of aging-resistant polyester is: ； The structural formula of PTMEG-modified polysiloxane is: ； In the formula: ; ; ; 。 2. The high-life, high-current aluminum alloy conductor-based power cable according to claim 1, characterized in that, The outer walls of the two aluminum alloy bars that are far apart from each other are provided with a number of grooves along their length direction. The outer walls of the two aluminum alloy bars that are close to each other have a continuous corrugated structure and the outer walls of the two aluminum alloy bars that are close to each other fit together. In the double-layer wrapping structure of the wrapping layer (2), the inner layer is a mica tape or ceramic fiber tape and the outer layer is a high-strength aramid fiber tape.

3. The high-life, high-current aluminum alloy conductor-based power cable according to claim 1, characterized in that, The method for preparing the aging-resistant polyester is as follows: a mixed alcohol monomer, 1,4-cyclohexanedicarboxylic acid and a catalyst are mixed, an inert gas is introduced into the reaction system, the temperature of the reaction system is raised to 160-170℃, and the reaction is maintained until the amount of water collected as a by-product is 50% of the theoretical mass. Modified filler is added to the reaction system, and the reaction is maintained until the amount of water collected as a by-product is 50% of the theoretical mass. After the reaction system is sealed, a negative pressure of 70 Pa is drawn, the temperature of the reaction system is raised to 215-225℃, and the reaction is maintained for 90-120 min. The material is discharged while hot to obtain the aging-resistant polyester.

4. A high-life, high-current aluminum alloy conductor-based power cable according to claim 3, characterized in that, The weight ratio of the mixed alcohol monomer, catalyst, and modified filler is 10: The molar amount of 1,4-cyclohexanedicarboxylic acid is 0.55-0.57 times the total molar amount of hydroxyl groups in the mixed alcohol monomers. The mixed alcohol monomers are composed of 1,4-cyclohexanediethanol, N,N-bis(2-hydroxyethyl)-triacetone diamine, 2-allyl-1,3-propanediol, and polytetrahydrofuran ether diol in a weight ratio of 8:3:1:12-15. The catalyst is tetrabutyl titanate.

5. A high-life, high-current aluminum alloy conductor-based power cable according to claim 3, characterized in that, The preparation of modified fillers includes the following steps: A1. Mix expandable graphite and dispersion for 30-50 min, add metal-based solution to reaction system, keep warm and stir for 40-60 min, and then perform post-treatment to obtain loaded graphite; A2. Mix supported graphite, nano-calcium carbonate, anhydrous ethanol and hydroxymethyltriethoxysilane, raise the temperature of the reaction system to 55-65℃, add alkaline solution to the reaction system, keep the reaction at this temperature for 2-3 hours, and then perform post-treatment to obtain the modified filler.

6. A high-life, high-current aluminum alloy conductor-based power cable according to claim 5, characterized in that, In step A1, the ratio of expandable graphite, dispersion, and metal-based solution is 10g:100mL:6-8mL. The dispersion is composed of 0.2-0.3mol / L sodium hydroxide solution, sodium citrate, sodium dodecyl sulfate, and polyvinylpyrrolidone in a ratio of 100mL:1.8-2.2g:1.2-1.4g:1.6-1.9g. The metal-based solution is composed of magnesium chloride, zinc chloride, aluminum chloride, and purified water in a ratio of 3-4g:1g:1.8-2.0g:15mL. In step A2, the ratio of loaded graphite, nano-calcium carbonate, anhydrous ethanol, hydroxymethyltriethoxysilane, and alkaline solution is 5g:2g:50mL:2.1-2.3g:8-10mL. The alkaline solution is composed of sodium hydroxide, sodium carbonate, and purified water in a ratio of 1g:3g:20mL.

7. A high-life, high-current aluminum alloy conductor-based power cable according to claim 1, characterized in that, The preparation of PTMEG-modified polysiloxanes includes the following steps: B1. Under an inert gas atmosphere, polytetrahydrofuran ether diol and ethyl acetate are mixed and stirred until the system is dissolved. The temperature of the reaction system is raised to 65-75℃. 3-propyl isocyanate methyl diethoxysilane is added to the reaction system and the reaction is kept at this temperature for 60-80 min. After post-treatment, modified PTMEG is obtained. B2. Mix modified PTMEG, octamethylcyclotetrasiloxane, 5-hexen-1-yldimethoxymethylsilane, and catalyst. Raise the temperature of the reaction system to 95-100℃ and keep the reaction at this temperature for 60-80 min. Add an end-capping agent to the reaction system and keep the reaction at this temperature for 2-3 h. After post-treatment, PTMEG-modified polysiloxane is obtained.

8. A high-life, high-current aluminum alloy conductor-based power cable according to claim 7, characterized in that, In step B1, the ratio of polytetrahydrofuran ether diol to ethyl acetate is 1g:5-6mL, and the molar ratio of propyl isocyanate methyl diethoxysilane to the total molar amount of hydroxyl groups in polytetrahydrofuran ether diol is 1:1; in step B2, the weight ratio of modified PTMEG, octamethylcyclotetrasiloxane, 5-hexen-1-yldimethoxymethylsilane, catalyst, and end-capping agent is 10-11:8:2-3:4:2, the catalyst is 60-70wt% sulfuric acid, and the end-capping agent is tetramethyldivinyldisiloxane.

9. A high-life, high-current aluminum alloy conductor-based power cable according to claim 1, characterized in that, The outer sheath layer (4) is formed by mixing aging-resistant polyester, PTMEG modified polysiloxane, initiator and additives and adding them into a twin-screw extruder. After melting and mixing for 3-5 minutes, it is extruded and coated on the outside of the insulation layer (3), forming the outer sheath layer (4) on the outside of the insulation layer (3).

10. A high-life, high-current aluminum alloy conductor-based power cable according to claim 9, characterized in that, The initiator is dicumyl peroxide, and the additives consist of lubricant, dispersant, plasticizer, and antioxidant in a ratio of 1:3:4:

1. The lubricant is ethylene bis-stearamide, the dispersant is stearate, the plasticizer is phthalate, and the antioxidant is any one of antioxidant AW, antioxidant DNP, and antioxidant CPPD. The temperatures of the six temperature zones of the twin-screw extruder from the feed end to the discharge end are 165℃, 170℃, 175℃, 175℃, 175℃, and 180℃, respectively.

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