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CN-122025223-A - Environment-friendly low-smoke halogen-free power cable for large megawatt fan and preparation method thereof

CN122025223ACN 122025223 ACN122025223 ACN 122025223ACN-122025223-A

Abstract

The invention discloses an environment-friendly low-smoke halogen-free power cable for a large megawatt fan and a preparation method thereof, wherein the cable comprises a cable core, an elastomer inner sheath coated outside the cable core and an elastomer outer sheath coated outside the elastomer inner sheath; the cable core is formed by stranding three main wire cores, three ground wire cores and a saddle type filling strip, wherein the main wire cores comprise a first conductor, a conductor shielding layer, an ethylene propylene rubber insulating layer and an insulating shielding layer, the ground wire cores comprise a second conductor and a semi-conductive layer, the saddle type filling strip is made of vulcanized semi-conductive elastomer materials and is provided with three arc-shaped gaps matched with the shapes of the main wire cores and the ground wire cores, and the three arc-shaped gaps are used for clamping and positioning the wire cores and filling triangular gaps among the wire cores. According to the invention, through the collaborative design of the conductor structure, the material formula and the double-layer coextrusion process, the technical contradiction that the existing cable is difficult to consider between the current-carrying capacity, the torsion resistance, the wide-temperature-range adaptability, the flame retardance and the flexibility is effectively solved, and the comprehensive performance of the cable is remarkably improved.

Inventors

  • DING HONG
  • YUE CHUNYAN
  • ZHANG LIANQI
  • KANG HUI
  • Yuan Ruobing
  • YUAN GUOLIANG

Assignees

  • 江苏亨通电力电缆有限公司

Dates

Publication Date
20260512
Application Date
20260319

Claims (10)

  1. 1. An environmental-friendly low-smoke halogen-free power cable for a large megawatt fan, comprising: The cable comprises a cable core, wherein the cable core is formed by twisting three main wire cores, three ground wire cores and a saddle-type filling strip, the main wire core sequentially comprises a first conductor, a conductor shielding layer, an ethylene propylene rubber insulating layer and an insulating shielding layer from inside to outside, the ground wire core comprises a second conductor and a semiconductive layer coated outside the second conductor, and the first conductor and the second conductor are both 5 th tinned copper conductors; The saddle-type filling strip is made of vulcanized semi-conductive elastomer material and is provided with three arc-shaped notches matched with the shapes of the main wire core and the ground wire core, and the three arc-shaped notches are used for clamping and positioning each wire core and filling triangular gaps among the wire cores; An elastomer inner sheath coated outside the cable core, and An elastomer outer sheath coated outside the elastomer inner sheath; the elastic body inner sheath and the elastic body outer sheath are formed at one time through a double-layer co-extrusion process, so that a tightly combined gapless interface is formed.
  2. 2. The environmentally-friendly low-smoke halogen-free power cable for a large megawatt fan according to claim 1, wherein before the cable core is formed, talcum powder layers are coated on the surfaces of the main wire core and the ground wire core, and the talcum powder has a granularity of 1400-1600 meshes and a particle size of less than or equal to 45 μm.
  3. 3. The environment-friendly low-smoke halogen-free power cable for a large megawatt fan according to claim 1, wherein the ethylene propylene rubber insulating layer is made of an insulating material comprising, by weight, 100 parts of ethylene propylene diene monomer, 5-15 parts of ethylene-octene copolymer, 90-120 parts of reinforcing filler, 40-70 parts of nano flame retardant, 2-8 parts of phosphorus-nitrogen flame retardant, 5-15 parts of metal oxide activator, 2-6 parts of antioxidant and anti-aging system, 3-8 parts of coupling agent, 15-25 parts of plasticizer, 1.5-3.5 parts of peroxide crosslinking agent, 0.5-2 parts of auxiliary crosslinking agent and 1-3 parts of lubricating dispersion system.
  4. 4. The environment-friendly low-smoke halogen-free power cable for a large megawatt fan according to claim 3, wherein the peroxide crosslinking agent is a compound of BIPB and DTBP, the mass ratio of the peroxide crosslinking agent to the DTBP is (3-6): 1, the auxiliary crosslinking agent is TAIC, the octene content of the ethylene-octene copolymer is 15% -25%, and the melt index is 1-2g/10min.
  5. 5. The environment-friendly low-smoke halogen-free power cable for a large megawatt fan according to claim 3, wherein the reinforcing filler is a mixture of calcined kaolin and talcum powder, the nano flame retardant is a mixture of nano aluminum hydroxide and nano magnesium hydroxide, the phosphorus-nitrogen flame retardant is melamine polyphosphate, and the lubricating dispersion system comprises silicone master batch and glyceryl stearate.
  6. 6. The environment-friendly low-smoke halogen-free power cable for a large megawatt fan according to claim 1, wherein the elastomer outer sheath is made of a low-smoke halogen-free flame retardant polyolefin sheath material, and the low-smoke halogen-free flame retardant polyolefin sheath material comprises, by weight, 100 parts of ternary matrix resin, 100-160 parts of composite nano flame retardant, 15-35 parts of multi-element synergistic flame retardant, 1-4 parts of crosslinking auxiliary agent, 3-10 parts of dispersion lubrication system, 2-8 parts of plasticizing toughening agent, 1-4 parts of antioxidant photostabilizer and 3-10 parts of functional additive.
  7. 7. The environmentally friendly low smoke zero halogen power cable for a large megawatt fan of claim 6 wherein the ternary matrix resin is a ternary blend of metallocene ethylene-vinyl acetate copolymer, metallocene ethylene-octene elastomer and maleic anhydride graft copolymer, wherein the maleic anhydride graft copolymer is used as a compatibilizer with a grafting ratio of 0.8% -2.0%.
  8. 8. The environment-friendly low-smoke halogen-free power cable for a large megawatt fan according to claim 6, wherein the composite nano flame retardant comprises double modified nano aluminum hydroxide and titanate modified nano magnesium hydroxide, wherein the double modified nano aluminum hydroxide is double modified by silane and aluminate, the multi-element synergistic flame retardant system comprises at least four of melamine cyanurate, ammonium polyphosphate, zinc borate, zinc molybdate and an organosilicon flame retardant synergist, and the functional additive comprises an anti-aging agent, carbon black and an anti-copper harm agent.
  9. 9. The environment-friendly low-smoke halogen-free power cable for a large megawatt fan according to claim 1, wherein the resistivity of the conductor shielding layer and the resistivity of the insulating shielding layer respectively meet that the resistivity of the conductor shielding layer is less than or equal to 800 Ω & m, the resistivity of the insulating shielding layer is less than or equal to 500 Ω & m, and the stripping force of the insulating shielding layer is 5N-50N.
  10. 10. A method for preparing an environment-friendly low-smoke halogen-free power cable according to any one of claims 1-9, comprising the following steps: preparing three main wire cores and three ground wire cores; coating talcum powder with granularity more than or equal to 1000 meshes on the surface of the main wire core and the ground wire core; Twisting the coated main wire core, the ground wire core and a saddle-shaped filling strip with a plurality of arc-shaped gaps into a cable to form a cable core; And through a double-layer co-extrusion process, the elastic inner sheath and the elastic outer sheath are molded and coated outside the cable core at one time, so that a tightly combined gapless interface is formed.

Description

Environment-friendly low-smoke halogen-free power cable for large megawatt fan and preparation method thereof Technical Field The invention relates to the technical field of cables, in particular to an environment-friendly low-smoke halogen-free power cable for a large megawatt fan and a preparation method thereof. Background With the increasing global demand for clean energy, wind power generation technology is developing at an unprecedented speed, the single-unit capacity of a unit is continuously upgraded to a megawatt level (10 MW and above), and the application scene is also extended from land to areas with more severe environmental conditions such as deep open sea, high altitude and the like. The development trend puts forward unprecedented stringent requirements on the matched power cable for wind power generation, namely the power cable not only can bear high-capacity power transmission, but also needs to resist frequent torsional stress generated by yaw and pitch movement of a fan for a long time, and meanwhile, the power cable can cope with the test of various complex environments such as low temperature, salt spray corrosion, strong ultraviolet rays, ozone and the like, and ensures the safe and stable operation of the wind turbine generator set for more than 25 years. In the prior art, the power cable for the fan mainly adopts a low-smoke halogen-free material to meet the environmental protection and safety requirements, but the following technical defects still exist when the composite working conditions are handled: First, it is difficult to achieve both the current-carrying capacity and the torsion resistance. The traditional conductor structure has higher loss during large current transmission and can not fully match the power requirement of a large megawatt fan. Meanwhile, when the conductor is subjected to torsional stress for a long time, the conventional conductor structure is easy to have the problems of monofilament fracture, insulating layer fracture and the like. Although attempts have been made to improve the torsional resistance by conductor structure optimization (e.g., like stranding, control of pitch ratio), the current-carrying capacity improvement is limited in magnitude and it is difficult to meet the transmission requirements of higher voltage levels and higher power. Second, flame retardant properties are inherently contradictory to mechanical flexibility. To achieve low smoke, halogen-free flame retardant properties, it is often necessary to add large amounts of inorganic flame retardants (e.g., aluminum hydroxide, magnesium hydroxide) to the material. However, the high filling amount can lead to the remarkable reduction of the mechanical properties of the matrix resin, the embrittlement and the flexibility of the material are reduced, and the material is easy to generate brittle fracture particularly in a low-temperature environment of-40 ℃ and cannot meet the use requirements in severe cold areas. How to balance high flame retardant grades (such as IEC 60332-3A class) with excellent low temperature properties (-40 ℃ without cracking) remains an industry technical challenge. Third, the insulation and jacket materials have insufficient comprehensive weatherability. The salt fog resistance, the ultraviolet resistance and the ozone resistance of the cable are extremely high in the offshore wind power and high-altitude environment. The conventional low-smoke halogen-free material is easy to age and crack under long-term salt spray erosion and strong ultraviolet irradiation, and the service life is greatly shortened. Meanwhile, under the working condition of high voltage (66 kV and above), the purity of the insulating material, the uniformity of electric field distribution and the adhesive force control of the insulating shielding layer are directly related to the long-term operation reliability of the cable, and the prior art is difficult to fully meet. Fourth, environmental indicators are to be further improved. Although the low smoke halogen-free cable has significantly reduced toxic gas emissions compared to conventional halogen-containing cables, the smoke density of some products is still high (minimum light transmittance is less than 60%) or trace amounts of residual halides remain during combustion, with the risk of secondary pollution. Along with the increasingly strict environmental protection regulations of RoHS, REACH and the like of European Union, the development of the environment-friendly cable with lower smoke toxicity index, zero heavy metal content and higher material recycling rate during combustion has become the necessary trend of industry development. In view of the foregoing, there is a need to develop a novel power cable that has high current-carrying capacity, excellent torsion resistance, wide temperature range adaptability (-40 ℃ to +110 ℃) and strong weather resistance (salt spray resistance, ultraviolet resistance, ozone resistance), and high envir