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CN-122000125-A - High temperature resistant power cable

CN122000125ACN 122000125 ACN122000125 ACN 122000125ACN-122000125-A

Abstract

The invention relates to the technical field of cable structural design, and discloses a high-temperature-resistant power cable, which comprises conductor pretreatment, inner shielding layer preparation, main insulating layer construction, outer shielding layer forming, irradiation crosslinking and sheath extrusion, wherein through original conductor interface activation treatment and a composite shielding layer structure, an interface air gap between a conductor and an insulating layer in a high-temperature environment is eliminated, the local discharge risk caused by electric field distortion is avoided, a stable inner and outer double-layer electric field shielding mechanism is established, the cable is ensured to maintain uniform electric field distribution under a wide-temperature-range working condition, and the technical defect that the electric field of a traditional cable is unstable due to thermal expansion is overcome; the high-temperature deformation resistance and the molecular structure stability of the insulating material are synchronously improved through the main insulating layer design and irradiation-thermal stability cooperative crosslinking process of the functionalized ceramic microsphere cooperative reinforcement, so that the cable still maintains stable dielectric property and mechanical strength under the extreme temperature condition.

Inventors

  • XU MIAO
  • ZHU JUN

Assignees

  • 无锡纶泽环保材料有限公司

Dates

Publication Date
20260508
Application Date
20260318

Claims (10)

  1. 1. A high temperature resistant power cable is characterized by comprising the following components sequentially coated from inside to outside: A plasma activated copper conductor; an inner shielding layer containing nano boron nitride, wherein the volume resistivity is less than or equal to 103 omega-m; Ceramic microsphere reinforced main insulating layer with dielectric strength not less than 35kV/mm; The surface resistance of the graphene composite outer shielding layer is less than or equal to 10 4 omega; High-temperature resistant sheath, the long-term use temperature is more than or equal to 200 ℃.
  2. 2. The high temperature-resistant power cable according to claim 1, wherein the method for manufacturing the high temperature-resistant power cable comprises the steps of: firstly, conductor pretreatment, namely selecting an annealed copper conductor, and carrying out plasma surface activation treatment under the protection of inert gas, wherein the activation power is 300-500W, and the treatment time is 5-10min; Preparing an inner shielding layer, namely mixing the modified ethylene-vinyl acetate copolymer, the nano boron nitride and the silane coupling agent according to the mass ratio of 100:15-20:0.5-1.5, melting and blending the mixture at 120-140 ℃ by a double screw extruder, extruding and coating the mixture on the surface of a pretreated conductor to form the inner shielding layer with the thickness of 0.3-0.5 mm; Step three, constructing a main insulating layer, namely placing crosslinked polyethylene, functionalized ceramic microspheres and an antioxidant in an internal mixer according to the mass ratio of 100:25-35:1-3, mixing for 20-30min at 150-170 ℃, and coating the external side of an inner shielding layer by three-layer coextrusion equipment to form the main insulating layer with the thickness of 2.0-3.0 mm; step four, forming an outer shielding layer, mixing conductive carbon black, a graphene compound, a vinyl elastomer and a cross-linking agent according to the mass ratio of 100:12-18:0.8-1.2, and coating the main insulating layer in an extrusion coating mode, wherein the thickness is 0.4-0.6mm; step five, irradiation crosslinking, namely carrying out irradiation treatment on the cable by adopting an electron accelerator, wherein the irradiation dose is 120-180kGy, and the energy is 2.5-3.5MeV; Step six, extruding and wrapping the sheath, namely extruding and wrapping the high-temperature-resistant poly-perfluoroethylene propylene resin on the outermost layer of the cable in an argon atmosphere, wherein the thickness is 1.2-1.8mm, and the extrusion temperature is 280-320 ℃.
  3. 3. The high temperature resistant power cable according to claim 2, wherein the plasma surface activation treatment in the first step comprises placing copper conductor in vacuum chamber, and vacuumizing to 5× -1× Pa, argon is introduced to maintain the pressure at 20-50Pa, a radio frequency power supply is adopted to excite the plasma, and the radio frequency is 13.56MHz.
  4. 4. The high temperature resistant power cable according to claim 2, wherein the modified ethylene-vinyl acetate copolymer is prepared by the following method: Mixing ethylene-vinyl acetate copolymer with VA content of 28-33wt% and maleic anhydride graft in the mass ratio of 100:8-12, reacting at 140-160 deg.c for 40-60min, and introducing nitrogen for protecting.
  5. 5. The high temperature resistant power cable according to claim 2, wherein the functionalized ceramic microspheres are prepared by the steps of: I. selecting hollow alumina microspheres with the particle size of 10-20 mu m, introducing hexamethyldisilazane vapor at the concentration of 20-30sccm in a vacuum environment, and treating for 30-45min; II. C, soaking the microspheres treated in the step a in an ethanol solution containing 0.5-1.0wt% of titanate, and performing ultrasonic dispersion for 15-25min; III, carrying out heat treatment for 1-2h at 200-300 ℃ under the protection of nitrogen to obtain the functionalized ceramic microsphere with the surface grafted with the siloxane-titanate composite layer.
  6. 6. The high temperature resistant power cable according to claim 2, wherein the functionalized ceramic microspheres are added to the main insulating layer raw material in an amount of 28-32wt%, and the microspheres comprise: 80-85wt% of alumina matrix Surface grafted Silicone layer 8-12wt% 5-8Wt% of titanate catalytic layer.
  7. 7. The high temperature resistant power cable according to claim 2, wherein the conductive carbon black and graphene composite is prepared by the following method: mixing conductive carbon black with the particle size of 30-50nm with graphene oxide according to the mass ratio of 3:1-5:1, adding the mixture into an aqueous solution containing 0.1mol/L ascorbic acid, controlling the pH value of the solution to be less than or equal to 4, carrying out reduction reaction for 2-4h at 80-95 ℃, and obtaining the three-dimensional interpenetrating network structure compound after freeze drying.
  8. 8. The high temperature resistant power cable according to claim 2, wherein the high temperature resistant poly-perfluoroethylene-propylene resin comprises the following components: 100 parts of tetrafluoroethylene-hexafluoropropylene copolymer matrix; 5-8 parts of nano titanium dioxide; 3-5 parts of perfluorosulfonic acid resin powder; 0.5-1.2 parts of perfluoropolyether lubricant.
  9. 9. The high temperature resistant power cable according to claim 8, wherein the nano titanium dioxide is pretreated by a silane coupling agent KH-550, and the pretreatment method is as follows: the nano titanium dioxide is dispersed in ethanol solution containing 2-3wt% KH-550, and is dried for 2h at 110 ℃ after ultrasonic treatment for 30 min.
  10. 10. The high temperature resistant power cable according to claim 2, wherein the fifth irradiation crosslinking step further comprises a heat stabilization treatment: The cable is placed in a 180-200 ℃ hot air circulation box for 4-6 hours, and the heating rate is less than or equal to 5 ℃ per minute.

Description

High temperature resistant power cable Technical Field The invention relates to the technical field of cable structural design, in particular to a high-temperature-resistant power cable. Background The high-temperature-resistant wire and cable is a special cable capable of stably transmitting signals or electric energy in a specific high-temperature environment for a long time, is mainly applied to the fields of aerospace, automobile manufacturing, industrial robots, 5G base stations and the like, structurally comprises conductors, insulating layers and armor layers, the types of the conductors cover single specifications, multiple specifications and the like, and the insulating materials are made of irradiation crosslinked polyolefin, silicone rubber, fluororesin and other high-temperature-resistant composite materials. In the field of high-temperature working condition power transmission, the traditional cable structure has the defects that the interface binding force of a conductor and an insulating layer is insufficient, high-temperature thermal expansion leads to layering to form an air gap, electric field distortion and partial discharge are induced, a conventional insulating material is thermally degraded in a long-term high-temperature environment, the insulating strength is irreversibly reduced due to molecular chain breakage, the crosslinking degree of an organic insulating material is difficult to be improved to an ideal level, the temperature range tolerance of the conventional crosslinking process is insufficient, the crosslinking structure is easy to disintegrate under the high-temperature condition, the dispersibility of a conductive filler of a shielding layer is poor, a seepage network is unstable in high-temperature operation, the electric field shielding efficiency is fluctuated, the thermal deformation resistance of a sheath material is limited, the mechanical protection function is lost due to the fact that the thermal deformation is easy to soften and deform under the continuous high temperature, the problem of the cooperative improvement of the dielectric property and the heat conduction property of the insulating layer is not solved in the prior art, and the insulation aging is accelerated by the local heat accumulation. Therefore, a high temperature resistant power cable has been proposed to solve the above-mentioned problems. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a high-temperature-resistant power cable, which solves the problems in the background art. In order to achieve the above purpose, the invention provides a high temperature resistant power cable which comprises the following technical scheme that: A plasma activated copper conductor; an inner shielding layer containing nano boron nitride, wherein the volume resistivity is less than or equal to 103 omega-m; Ceramic microsphere reinforced main insulating layer with dielectric strength not less than 35kV/mm; The surface resistance of the graphene composite outer shielding layer is less than or equal to 10 4 omega; High-temperature resistant sheath, the long-term use temperature is more than or equal to 200 ℃. Preferably, the method comprises the following steps: firstly, conductor pretreatment, namely selecting an annealed copper conductor, and carrying out plasma surface activation treatment under the protection of inert gas, wherein the activation power is 300-500W, and the treatment time is 5-10min; Preparing an inner shielding layer, namely mixing the modified ethylene-vinyl acetate copolymer, the nano boron nitride and the silane coupling agent according to the mass ratio of 100:15-20:0.5-1.5, melting and blending the mixture at 120-140 ℃ by a double screw extruder, extruding and coating the mixture on the surface of a pretreated conductor to form the inner shielding layer with the thickness of 0.3-0.5 mm; Step three, constructing a main insulating layer, namely placing crosslinked polyethylene, functionalized ceramic microspheres and an antioxidant in an internal mixer according to the mass ratio of 100:25-35:1-3, mixing for 20-30min at 150-170 ℃, and coating the external side of an inner shielding layer by three-layer coextrusion equipment to form the main insulating layer with the thickness of 2.0-3.0 mm; step four, forming an outer shielding layer, mixing conductive carbon black, a graphene compound, a vinyl elastomer and a cross-linking agent according to the mass ratio of 100:12-18:0.8-1.2, and coating the main insulating layer in an extrusion coating mode, wherein the thickness is 0.4-0.6mm; step five, irradiation crosslinking, namely carrying out irradiation treatment on the cable by adopting an electron accelerator, wherein the irradiation dose is 120-180kGy, and the energy is 2.5-3.5MeV; Step six, extruding and wrapping the sheath, namely extruding and wrapping the high-temperature-resistant poly-perfluoroethylene propylene resin on the outermost layer of the cabl