CN213339756U - Multi-core high-tensile medium-voltage overhead insulated cable - Google Patents

Abstract

A multi-core high-tensile medium-voltage aerial insulated cable is structurally characterized in that: phase lines: the cable comprises a hard aluminum conductor, three layers of conductor shields, insulation and insulation shields are co-extruded outside the conductor, a copper belt shield is wrapped outside the insulation shields, and a weather-resistant polyvinyl chloride sheath is wrapped outside the copper belt shield; carrying a wire: the aluminum alloy core carrier cable is externally extruded with a layer of weather-resistant polyvinyl chloride sheath; 3 phase lines are twisted with 1 bearing line, and the two ends of the cable are fastened by a binding belt. Compared with the international medium-voltage overhead insulated cable, the structure increases copper strip shielding, can prevent the axial surface of the cable from discharging, and has excellent lightning protection property; meanwhile, the cable is provided with an aluminum alloy core bearing line, so that long-distance laying can be met.

Description

Multi-core high-tensile medium-voltage overhead insulated cable

Technical Field

This technical scheme belongs to cable technical field, specifically is a built on stilts insulated cable of high tensile middling pressure of multicore type.

Background

Three phases of the single-core medium-voltage overhead insulated cable need to be erected independently, the occupied space is large, and the operation is troublesome.

The multi-core aerial cable can solve the problem, three phases can be erected at one time, the operation intensity is greatly reduced, and meanwhile the erection space is reduced. Besides the requirement of power transmission function and performance, the tensile property of the multi-core cable is also an important requirement. Because the erection environment is outdoor, the general weather resistance can not meet the lightning strike condition.

Disclosure of Invention

In order to solve the above problems in the prior art, the invention provides a multi-core high-tensile medium-voltage overhead insulated cable, which comprises the following specific steps:

a multi-core high-tensile medium-voltage aerial insulated cable is structurally characterized in that: the cable is formed by twisting 3 phase lines and 1 carrier line, and the twisting pitch diameter ratio ranges from 15 to 25 times; the cable is only tied tightly by the binding tapes at the head and the tail ends;

the structure of the 3 phase lines is the same, and any phase line is formed by sequentially wrapping a conductor shielding layer, an insulating shielding layer, a metal shielding layer and a phase line outer sheath outside an aluminum conductor; the bearing line is formed by a bearing cable externally wrapping a bearing line outer sheath;

in the phase line:

the aluminum conductor is formed by twisting LY9 type hard aluminum round wires, the twisting directions of the hard aluminum round wires of adjacent layers are opposite, the twisting direction of the outermost layer is the left direction, and the pitch diameter ratio of the outermost layer ranges from 12 to 14;

the diameter range of the monofilament of the hard aluminum round wire is 1.35-3.12 mm;

the nominal thickness of the conductor shielding layer is 0.4-0.7 mm;

the nominal thickness of the insulating layer is 3.0-4.0 mm, and the thinnest point is not less than 90-0.1 mm of the nominal value;

the nominal thickness of the insulation shielding layer is 0.5-1.0 mm;

the metal shielding layer is formed by wrapping a copper strip, the average covering rate of the wrapping is less than or equal to 15 percent, the minimum covering rate is greater than or equal to 5 percent, the nominal thickness of the copper strip is 0.12mm, and the thinnest point is not less than 0.108 mm;

the thickness of the phase line outer sheath is 1.8 mm; the phase line outer sheath is a weather-resistant polyvinyl chloride outer sheath;

in the bearing line:

the carrier cable is formed by regularly twisting aluminum alloy wires; the twisting directions of the aluminum alloy wires of the adjacent layers are opposite, the twisting direction of the outermost layer is the left direction, the maximum pitch-diameter ratio of the outermost layer is 20 times,

the diameter range of the aluminum alloy monofilament is 1.46-3.36 mm;

the outer sheath of the carrier wire is a weather-resistant polyvinyl chloride outer sheath; the nominal thickness of the outer sheath of the load-bearing wire is 1.8mm, and the thinnest point is not less than (85% -0.1) mm of the nominal value.

In the implementation:

the conductor shielding layer and the insulation shielding layer are both made of peroxide cross-linked semi-conductive shielding materials, and the model can be YPJ-10; the insulating layer is made of peroxide crosslinked polyethylene insulating material, and the type can adopt YJ-10.

The conductor shielding layer, the insulating layer and the insulating shielding layer are of a three-layer co-extrusion structure.

The thickness of the conductor shielding layer is 0.6 mm; the thickness of the insulating layer is 3.4 mm; the thickness of the insulating shielding layer is 0.8 mm.

The technical scheme meets the requirements of the multi-core cable on power transmission function, performance and tensile property. Compared with the international medium-voltage overhead insulated cable, the structure is additionally provided with the copper strip shield, can prevent the axial surface of the cable from discharging, and has excellent lightning protection property; meanwhile, the cable is provided with an aluminum alloy core bearing line, so that long-distance laying can be met.

Drawings

FIG. 1 is a schematic radial cross-section of the present cable;

in the figure: the cable comprises an aluminum conductor 1, a conductor shielding layer 2, an insulating layer 3, an insulating shielding layer 4, a metal shielding layer 5, a phase line outer sheath 6, an aluminum alloy carrier cable 7 and a carrier line outer sheath 8.

Detailed Description

The technical scheme is further explained by combining the drawings and the detailed implementation mode as follows:

as shown in fig. 1, a multi-core high tensile medium voltage overhead insulated cable has the following structure: the cable is formed by twisting 3 phase lines and 1 carrier line, and the twisting pitch diameter ratio ranges from 15 to 25 times; the cable is only tied tightly by the binding tapes at the head and the tail ends;

the structure of the 3 phase lines is the same, and any phase line is formed by sequentially wrapping a conductor shielding layer, an insulating shielding layer, a metal shielding layer and a phase line outer sheath outside an aluminum conductor; the bearing line is formed by a bearing cable externally wrapping a bearing line outer sheath;

in the phase line:

the aluminum conductor is formed by twisting LY9 type hard aluminum round wires, the twisting directions of the hard aluminum round wires of adjacent layers are opposite, the twisting direction of the outermost layer is the left direction, and the pitch diameter ratio of the outermost layer ranges from 12 to 14;

the diameter range of the monofilament of the hard aluminum round wire is 1.35-3.12 mm;

the nominal thickness of the conductor shielding layer is 0.4-0.7 mm;

the nominal thickness of the insulating layer is 3.0-4.0 mm, and the thinnest point is not less than 90-0.1 mm of the nominal value;

the nominal thickness of the insulation shielding layer is 0.5-1.0 mm;

the metal shielding layer is formed by wrapping a copper strip, the average covering rate of the wrapping is less than or equal to 15 percent, the minimum covering rate is greater than or equal to 5 percent, the nominal thickness of the copper strip is 0.12mm, and the thinnest point is not less than 0.108 mm;

the thickness of the phase line outer sheath is 1.8 mm; the phase line outer sheath is a weather-resistant polyvinyl chloride outer sheath;

in the bearing line:

the carrier cable is formed by regularly twisting aluminum alloy wires; the twisting directions of the aluminum alloy wires of the adjacent layers are opposite, the twisting direction of the outermost layer is the left direction, the maximum pitch-diameter ratio of the outermost layer is 20 times,

the diameter range of the aluminum alloy monofilament is 1.46-3.36 mm;

the outer sheath of the carrier wire is a weather-resistant polyvinyl chloride outer sheath; the nominal thickness of the outer sheath of the load-bearing wire is 1.8mm, and the thinnest point is not less than (85% -0.1) mm of the nominal value.

In this example:

the conductor shielding layer and the insulation shielding layer are both made of peroxide cross-linked semi-conductive shielding materials, and the model can be YPJ-10; the insulating layer is made of peroxide crosslinked polyethylene insulating material, and the type can adopt YJ-10.

The conductor shielding layer, the insulating layer and the insulating shielding layer are of a three-layer co-extrusion structure.

The conductor shielding layer, the insulating layer and the insulation shielding layer adopt a totally-enclosed full-dry chemical crosslinking production process, and N is adopted₂Crosslinking by heating, N₂And (6) cooling. The conductor shielding layer, the insulating layer and the insulating shielding layer are completed in a three-layer co-extrusion machine head, so that the insulating and purifying degree of the cable and the quality of an extruded product are ensured.

The nominal thickness of the conductor shielding layer is 0.6mm, the nominal thickness of the insulating layer is 3.4mm, the thinnest point is not less than (90% -0.1) mm of the nominal value, and the nominal thickness of the insulating shielding layer is 0.8 mm.

The weather-resistant polyvinyl chloride sheath material has good weather resistance, and can ensure that the cable can be exposed to the sun for a long time; the outer sheath of the phase line has a nominal thickness of 1.8mm, and the thinnest point is not less than (85% -0.1) mm of the nominal value.

The cable is formed by twisting 3 phase lines and 1 bearing line, is free of filling and wrapping, and is only fastened at two ends by using binding tapes.

Through detection, the performance parameters of the cable are as follows:

(1) carrier cable: linear expansion coefficient not more than 23.1X 10^-6 ℃^-1The elastic modulus is 62000 +/-3000 Mpa, the breaking force of the bearing cable is 1.15 times of that of the aluminum alloy bearing cable in GB/T14049, the tensile strength of the aluminum alloy bearing cable is not less than 290Mpa, and the tensile strength of the aluminum alloy bearing cable in GB/T14049 is 251 Mpa;

(2) the direct current resistance of the conductor meets the requirement of GB/T14049 standard;

(3) insulating thermal extension: at 250 ℃, 15min, the maximum elongation under load is 175 percent under the condition of 0.2N/mm2, and the maximum permanent elongation after cooling is 15 percent;

(4) mechanical properties before and after insulation aging: the tensile strength before aging is not less than 12.5Mpa, and the elongation at break is not less than 200%; after aging at 135 ℃ for 168 hours, the change rate of the tensile strength is +/-25% at most, and the change rate of the elongation at break is +/-25% at most;

(5) mechanical properties before and after jacket aging: the tensile strength before aging is not less than 9.0Mpa, and the elongation at break is not less than 125%; after aging for 168 hours at 100 ℃, the change rate of the tensile strength is +/-40 percent at most, and the change rate of the elongation at break is +/-40 percent at most;

(6) insulation resistance constant at 20 ℃: the environment temperature is 20 ℃, and the insulation resistance constant is not less than 1500M omega km.

The cable adopts the aluminum alloy carrier cable material meeting the NFC 33 standard, simultaneously reduces the number of single filaments in the aluminum alloy carrier cable, and thickens the diameter of the single filaments, thereby achieving a larger breaking force index.

Claims (6)

1. The utility model provides a high tensile middling pressure aerial insulated cable of multicore type, its characterized by structure is: the cable is formed by twisting 3 phase lines and 1 carrier line, and the twisting pitch diameter ratio ranges from 15 to 25 times; the cable is only tied tightly by the binding tapes at the head and the tail ends;

the structure of the 3 phase lines is the same, and any phase line is formed by sequentially wrapping a conductor shielding layer, an insulating shielding layer, a metal shielding layer and a phase line outer sheath outside an aluminum conductor; the bearing line is formed by a bearing cable externally wrapping a bearing line outer sheath;

in the phase line:

the aluminum conductor is formed by twisting LY9 type hard aluminum round wires, the twisting directions of the hard aluminum round wires of adjacent layers are opposite, the twisting direction of the outermost layer is the left direction, and the pitch diameter ratio of the outermost layer ranges from 12 to 14;

the diameter range of the monofilament of the hard aluminum round wire is 1.35-3.12 mm;

the nominal thickness of the conductor shielding layer is 0.4-0.7 mm;

the nominal thickness of the insulating layer is 3.0-4.0 mm, and the thinnest point is not less than 90-0.1 mm of the nominal value;

the nominal thickness of the insulation shielding layer is 0.5-1.0 mm;

the metal shielding layer is formed by lapping a copper strip;

in the bearing line:

the carrier cable is formed by regularly twisting aluminum alloy wires; the twisting directions of the aluminum alloy wires of the adjacent layers are opposite, the twisting direction of the outermost layer is the left direction, the maximum pitch-diameter ratio of the outermost layer is 20 times,

the diameter range of the aluminum alloy monofilament is 1.46-3.36 mm.

2. The multi-core high tensile medium voltage overhead insulated cable according to claim 1, wherein the conductor shield layer and the insulation shield layer are both made of peroxide cross-linked semiconductive shield material; the insulating layer is made of peroxide crosslinked polyethylene insulating material.

3. The multi-core high tensile medium voltage overhead insulated cable according to claim 1, wherein the conductor shield layer, the insulation layer and the insulation shield layer are of a three-layer co-extrusion structure.

4. The multi-core high tensile medium voltage aerial insulated cable according to claim 1, wherein the thickness of the conductor shielding layer is 0.6 mm; the thickness of the insulating layer is 3.4 mm; the thickness of the insulating shielding layer is 0.8 mm.

5. The multi-core high-tensile medium-voltage overhead insulated cable according to claim 1, wherein the average lapping rate of the copper strip lapping of the metal shielding layer is less than or equal to 15%, the minimum lapping rate is greater than or equal to 5%, the nominal thickness of the copper strip is 0.12mm, and the thinnest point is not less than 0.108 mm.

6. The multi-core high tensile medium voltage aerial insulated cable according to claim 1, wherein the phase wire outer sheath has a thickness of 1.8 mm; the phase line outer sheath is a weather-resistant polyvinyl chloride outer sheath;

the outer sheath of the carrier wire is a weather-resistant polyvinyl chloride outer sheath; the nominal thickness of the outer sheath of the load-bearing wire is 1.8mm, and the thinnest point is not less than (85% -0.1) mm of the nominal value.

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