CN-122025228-A - High-voltage cable and preparation method thereof

CN122025228ACN 122025228 ACN122025228 ACN 122025228ACN-122025228-A

Abstract

The application relates to a high-voltage cable and a preparation method thereof, wherein the high-voltage cable comprises a conductor, a water-blocking interlayer, an insulating layer and an outer protective layer, the conductor comprises a wire core and a plurality of split strand blocks surrounding the wire core, and the water-blocking interlayer is wrapped on the outer surface of each split strand block; the insulating layer is arranged on the outer side face of the conductor, and the outer protective layer is arranged on the outer side face of the insulating layer. The high-voltage cable improves the current-carrying capacity and the water-blocking performance, and has high safety coefficient.

Inventors

LI YING
ZHANG ZHONGQI
LIU KEXIN
WANG PENG
MA LONG
SONG XINYU

Assignees

特变电工山东鲁能泰山电缆有限公司

Dates

Publication Date: 20260512
Application Date: 20260327

Claims (11)

1. The high-voltage cable is characterized by comprising a conductor, a water-blocking interlayer, an insulating layer and an outer protective layer, wherein the conductor comprises a wire core and a plurality of split strand blocks surrounding the wire core, the water-blocking interlayer is wrapped on the outer surface of each split strand block, the insulating layer is arranged on the outer side surface of the conductor, and the outer protective layer is arranged on the outer side surface of the insulating layer.
2. The high voltage cable of claim 1, further comprising a semiconductive water blocking tie wrapped around an outer side of the conductor, the semiconductive water blocking tie being disposed between the water blocking barrier and the insulating layer; the thickness of the semiconductive water-blocking binding belt is 0.12 mm-0.18 mm; The thickness of the water-blocking interlayer is 0.2 mm-0.4 mm.
3. The high voltage cable of claim 1, further comprising a buffer layer disposed between the insulating layer and the outer jacket; the volume resistivity of the buffer layer is less than or equal to 5000 omega cm; The thickness of the buffer layer is 1.8 mm-2.2 mm.
4. A high voltage cable according to claim 3, wherein the material of the buffer layer comprises semi-conductive carbon black and intumescent powder; The semiconductive carbon black is coated on the outer surface of the expansion type water-blocking powder; The expansion TYPE water-blocking powder comprises at least one of water-blocking powder 10SH-P and water-blocking powder TYPE II.
5. The high voltage cable according to any one of claims 1 to 4, further comprising a metal shielding sheath, wherein the metal shielding sheath is sleeved on the outer side surface of the buffer layer; The metal shielding sheath comprises a smooth aluminum sheath or a wrinkled aluminum sheath; The thickness of the metal shielding protective layer is 1.3 mm-2.0 mm; the metal shielding protective layer is in radial negative clearance fit with the buffer layer.
6. The high voltage cable of claim 5, wherein the method of preparing the metallic shielding layer comprises the steps of: the smooth aluminum sheath is manufactured by welding an aluminum belt into an aluminum pipe or extruding an aluminum rod into the aluminum pipe; And carrying out negative clearance fit on the smooth aluminum sheath and the buffer layer through a dynamic rolling diameter reduction process.
7. The high voltage cable of any of claims 1-4, wherein the plurality of split strands comprises 4-6 split strands in a tile; the radial cross-sectional area of the split strand is 40mm 2 ~875mm 2 .
8. The high-voltage cable according to any one of claims 1 to 4, further comprising a conductor shielding layer and an insulating shielding layer which are sequentially arranged from inside to outside, wherein the insulating layer is positioned between the conductor shielding layer and the insulating shielding layer, and the material of the insulating layer comprises space charge resistant crosslinked polyethylene or high thermal conductivity polypropylene; the power frequency breakdown field strength of the space charge resistant crosslinked polyethylene is more than or equal to 40kV/mm; The volume resistivity of the space charge resistant crosslinked polyethylene at 90 ℃ is more than or equal to 1 multiplied by 10 15 omega-m; The heat conductivity coefficient of the high heat conductivity type polypropylene is 3W/(m.K) -10W/(m.K) at 25 ℃; The highest working temperature of the high thermal conductivity polypropylene is 105-110 ℃; the high-voltage cable is sequentially provided with the conductor, part of the water blocking interlayer, the semiconductive water blocking binding belt, the conductor shielding layer, the insulating shielding layer, the buffer layer, the metal shielding protective layer and the outer protective layer from inside to outside; The thickness of the conductor shielding layer is 0.9 mm-2.0 mm; the thickness of the insulating layer is 11-34 mm; the thickness of the insulating shielding layer is 0.8 mm-2.0 mm.
9. The high voltage cable of any one of claims 1-4, wherein the outer sheath comprises an anti-corrosion layer, a main sheath, a semiconductive outer sheath and a fireproof coating which are sequentially arranged in the inner-to-outer direction; the material of the anti-corrosion layer comprises hot melt adhesive; The material of the main protective layer comprises fiber reinforced polyethylene, and the tearing strength of the main protective layer is more than or equal to 25N/cm; the semiconductive outer protective layer comprises semiconductive flame-retardant polyethylene; The fireproof coating comprises nano graphene; The thickness of the anti-corrosion layer is 0.1 mm-0.3 mm; the thickness of the main protective layer is 4.0 mm-7.0 mm; the thickness of the semiconductive outer protective layer is 0.2 mm-0.5 mm; The thickness of the fireproof coating is 0.5 mm-1.0 mm.
10. The high voltage cable of any of claims 1-4, wherein the conductor has a radial cross-sectional area of 600 mm 2 ~5000mm 2 .
11. A method for manufacturing a high voltage cable according to any one of claims 1 to 10, comprising the steps of: Wrapping the water-blocking interlayer on the outer surfaces of the plurality of split strand blocks; Surrounding the wire core with a plurality of split strand blocks wrapping the water-blocking interlayer to form the conductor; and arranging the insulating layer on the outer side surface of the conductor, and arranging the outer protective layer on the outer side surface of the insulating layer.

Description

High-voltage cable and preparation method thereof Technical Field The application relates to the technical field of cables, in particular to a high-voltage cable and a preparation method thereof. Background With the deep advancement of new construction, new energy industries represented by wind power and photovoltaic, and energy and information infrastructures represented by pumped storage power stations, ultra-high voltage power grids and large data centers are undergoing rapid development, and higher requirements are put forward on the safety performance of power transmission cables. However, when the traditional high-voltage cable is used, the safety coefficient is low, the current-carrying capacity (transmission capacity) and the water resistance of the traditional high-voltage cable are difficult to meet the requirements, and the cable is easy to overheat or damage. Disclosure of Invention Based on this, there is a need to provide a high-voltage cable capable of improving current-carrying capacity and water resistance, and a method of manufacturing the same. The application provides a high-voltage cable, which comprises a conductor, a water-blocking interlayer, an insulating layer and an outer protective layer, wherein the conductor comprises a wire core and a plurality of split strand blocks surrounding the wire core, the water-blocking interlayer is wrapped on the outer surface of each split strand block, the insulating layer is arranged on the outer side surface of the conductor, and the outer protective layer is arranged on the outer side surface of the insulating layer. The conductor of the high-voltage cable comprises a wire core and a plurality of split strand blocks surrounding the wire core, the structure can increase the surface area of the conductor, inhibit the skin effect and the proximity effect of current, further effectively reduce the alternating current resistance of the large-section conductor and improve the current-carrying capacity and the transmission efficiency of the high-voltage cable; the conductor is divided into a plurality of divided strand blocks to surround the wire core, the low-loss divided conductor is adopted, the current-carrying capacity is obviously improved under the same section, the radial sectional area of the conductor can be reduced under the same current-carrying capacity, the outer diameter of the high-voltage cable is smaller, the dual improvement of transmission capacity and space efficiency is realized, the water-blocking interlayer is wrapped on the outer surface of each divided strand block, the water seepage paths between the divided strand blocks and the wire core can be blocked, a longitudinal water-blocking structure for inhibiting water tree and ablation is formed, the current-carrying capacity of the high-voltage cable is further improved, the water-blocking performance of the high-voltage cable is improved, the high-voltage cable meets the complex environment laying requirements of extremely humid water tree easy to produce such as river, lake, sea, wet tunnel and the like, and the high-voltage cable can be suitable for ultra-high voltage and large-capacity power transmission scenes. In some embodiments, the high voltage cable further comprises a semiconductive water blocking tie wrapped around an outer side of the conductor, the semiconductive water blocking tie being disposed between the water blocking barrier and the insulating layer; optionally, the thickness of the semiconductive water-blocking binding belt is 0.12 mm-0.18 mm; optionally, the thickness of the water-blocking interlayer is 0.2 mm-0.4 mm. By wrapping the semiconductive water-blocking binding belt outside the conductor, a second water-blocking defense line is formed, double guarantee of longitudinal water blocking of the conductor is realized, the semiconductive characteristic of the semiconductive water-blocking binding belt can be utilized to form smooth electrical transition with a subsequent conductor shielding layer, the phenomenon of electric field concentration possibly caused by uneven conductor surface is eliminated, and the electrical safety of the cable is improved. In some of these embodiments, the high voltage cable further comprises a buffer layer disposed between the insulating layer and the outer jacket; Optionally, the volume resistivity of the buffer layer is less than or equal to 5000 Ω·cm; optionally, the thickness of the buffer layer is 1.8 mm-2.2 mm. In some of these embodiments, the material of the buffer layer includes semi-conductive carbon black and intumescent powder; optionally, the semiconductive carbon black is coated on the outer surface of the expansion type water-resistant powder; optionally, the expansion TYPE water-blocking powder comprises at least one of water-blocking powder 10SH-P and water-blocking powder TYPE II. The material of the buffer layer comprises semi-conductive carbon black and expansion type water-blocking powder, which is be