CN215730974U

CN215730974U - Medium-voltage direct-current cable for distribution network

Info

Publication number: CN215730974U
Application number: CN202121652865.8U
Authority: CN
Inventors: 于阳; 王新国; 杨宏旭; 杨东; 岳春艳; 张宇; 连钧宇; 张峰; 张会明
Original assignee: Jiangsu Hengtong Power Cable Co Ltd
Current assignee: Jiangsu Hengtong Power Cable Co Ltd
Priority date: 2021-07-20
Filing date: 2021-07-20
Publication date: 2022-02-01
Anticipated expiration: 2031-07-20

Abstract

The utility model relates to a cable for a medium-voltage direct-current distribution network, which comprises a cable core, a filling layer arranged in the cable core and an outer coating layer coated outside the cable core; two groups of stranded and extended copper conductors are arranged in the cable core, each copper conductor comprises a copper core, three co-extrusion layers are coated outside the copper cores, the three co-extrusion layers sequentially comprise a conductive shield, an XLPE (cross linked polyethylene) insulator and an insulating shield from inside to outside, and a metal shield is coated outside the insulating shield; the filling layer comprises a spiral supporting piece which is arranged in a spiral gap formed by twisting the copper conductor, and the supporting piece is tightly attached to the copper conductor and is coated by a wrapping tape; the outer covering includes the armor, and the armor cladding is in around the band, and the armor still cladding has the oversheath. Overall structure is simple, and electrical performance is good, and support piece has strengthened the crushing resistance and the pull resistance of cable when guaranteeing the cable circularity, still is provided with the extension passageway on the support piece simultaneously, can set up the optical unit and increase communication function, perhaps sets up the intensity that the core further strengthened the cable of strengthening.

Description

Medium-voltage direct-current cable for distribution network

Technical Field

The utility model relates to the technical field of cables, in particular to a cable for a medium-voltage direct-current distribution network.

Background

At present, the power transmission mostly adopts an alternating current power transmission mode, an electric terminal needs to perform primary rectification exchange to convert alternating current into direct current for use, a plurality of rectifier transformers are arranged in the whole alternating current power transmission system to convert the alternating current, and a lot of electric energy can be dissipated in a heat energy mode in the conversion process; if direct current is adopted for power supply, the use of a rectifier transformer in the middle process can be reduced, the loss of electric energy can be correspondingly reduced, and the investment of a ventilation and heat dissipation system can be reduced; dc cables are increasingly used in power distribution systems as an intermediate medium for dc power transmission.

However, the existing direct current cable has poor electrical performance, low safety level and poor overall strength, and when the cable is extruded or stretched externally, the cable is easily deformed or broken, thereby affecting the transmission of signals and power.

Therefore, it is necessary to design a high-strength dc cable which has good electrical performance, is safe and reliable, and can bear external force extrusion or stretching.

SUMMERY OF THE UTILITY MODEL

Therefore, the utility model aims to solve the technical problems that the direct current cable in the prior art is poor in electrical performance, and the cable is easy to deform or break when being extruded or stretched externally, so that signal and power transmission are affected.

In order to solve the technical problem, the utility model provides a medium-voltage direct-current distribution network cable which comprises a cable core, a filling layer arranged in the cable core and an outer coating layer coated outside the cable core;

two groups of stranded and extended copper conductors are arranged in the cable core, each copper conductor comprises a copper core, three co-extrusion layers are coated outside the copper cores, the three co-extrusion layers sequentially comprise a conductive shield, an XLPE (cross linked polyethylene) insulator and an insulating shield from inside to outside, and a metal shield is coated outside the insulating shield;

the filling layer comprises a spiral supporting piece, the spiral supporting piece is arranged in a spiral gap formed by twisting the two copper conductors, and the spiral supporting piece is tightly attached to the copper conductors and is wrapped into a cable core through a wrapping tape;

the outer coating includes the armor, the armor cladding in around the covering tape on, just the armor still cladding has the oversheath.

In one embodiment of the utility model, the supporting pieces are provided in two groups, and the spiral direction of the two groups of supporting pieces is the same as the twisting direction of the copper conductor.

In an embodiment of the utility model, the supporting member includes a spiral main body and two accommodating grooves arranged inside the spiral main body, and the two accommodating grooves are used for enabling the supporting member to be tightly attached to the copper conductor.

In an embodiment of the present invention, an expansion channel is further disposed on the support, and an optical unit is disposed in the expansion channel and includes an optical fiber bundle, a hollow micro-tube and an outer protective layer, which are sequentially disposed from inside to outside.

In an embodiment of the utility model, the support member is further provided with an expanding channel, a reinforcing core is arranged in the expanding channel, and the reinforcing core comprises a steel wire and an insulating layer coated outside the steel wire.

In one embodiment of the utility model, the filling layer further comprises a filling strip, the filling strip is filled in a gap between the copper conductor, the supporting piece and the wrapping tape, and the cross section of the filling strip is semicircular.

In an embodiment of the present invention, an isolation layer is further disposed between the armor layer and the wrapping tape, and the isolation layer is used for isolating the metal shield from the armor layer.

In one embodiment of the utility model, the conductive shield adopts 10kV inner screen material, the XLPE insulation adopts 10kV chemical crosslinking insulation material, and the insulation shield adopts 10kV strippable semi-conductive outer screen material.

In one embodiment of the present invention, the metal shield is a copper tape shield, the average overlapping rate between the copper tapes is greater than 15%, the minimum overlapping rate is greater than 5%, and the copper tape is a soft copper tape with a minimum thickness greater than 90% of the nominal value.

In one embodiment of the utility model, the wrapping tape is made of a flame-retardant non-hygroscopic tape, the armor layer is made of a non-magnetic steel tape, and the outer sheath is made of a flame-retardant polyvinyl chloride material.

Compared with the prior art, the technical scheme of the utility model has the following advantages:

the cable for the medium-voltage direct-current distribution network is simple in overall structure and good in electrical performance, the supporting piece is arranged on the filling layer and is attached to the spiral gap formed by twisting the two wire cores, the whole cable is closer to a cylinder, the roundness of the cable is guaranteed, the pressure resistance and the tensile resistance of the cable are enhanced, meanwhile, the supporting piece is further provided with the extension channel, the optical unit can be extended, the communication function is increased, or the strength of the whole cable is further enhanced by adding the reinforcing core.

Drawings

In order that the present disclosure may be more readily and clearly understood, reference is now made to the following detailed description of the embodiments of the present disclosure taken in conjunction with the accompanying drawings, in which

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic illustration of a copper conductor of the present invention;

FIG. 3 is a schematic view of a support of the present invention;

FIG. 4 is a schematic illustration of the stranding of the copper conductors of the present invention;

fig. 5 is a schematic view of the support (single) of the present invention mated with a stranded copper conductor.

The specification reference numbers indicate: 1. a cable core; 11. a copper conductor; 111. a copper core; 112. three co-extrusion layers; 113. a conductive shield; 114. XLPE insulation; 115. insulating shielding; 116. metal shielding; 2. a filling layer; 21. a support member; 211. a helical body; 212. a containing groove; 213. expanding the channel; 22. filling the strip; 23. wrapping a tape; 3. an outer cover; 31. an armor layer; 32. an isolation layer; 33. an outer sheath.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

Referring to fig. 1 to 5, the cable for a medium-voltage direct-current distribution network of the present invention includes a cable core 1, a filling layer 2 disposed inside the cable core 1, and an outer coating layer 3 coated outside the cable core 1;

two groups of stranded and extended copper conductors 11 are arranged in the cable core 1, each copper conductor 11 comprises a copper core 111, three co-extrusion layers 112 are coated outside the copper cores 111, the three co-extrusion layers 112 sequentially comprise a conductive shield 113, an XLPE (cross linked polyethylene) insulator 114 and an insulating shield 115 from inside to outside, and a metal shield 116 is coated outside the insulating shield 115;

the filling layer 2 comprises a support member 21, the support member 21 is spiral, the support member 21 is arranged in a spiral gap formed by twisting the two copper conductors 11, and the support member 21 is tightly attached to the copper conductors 11 and is wrapped by a wrapping tape 23 to form the cable core 1;

outer cover 3 includes armor 31, and the armor 31 cladding is on lapping band 23, and armor 31 still cladding has oversheath 33.

Furthermore, the supporting pieces 21 are provided with two groups, the spiral direction of the two groups of supporting pieces 21 is the same as the twisting direction of the copper conductor 11, the two groups of supporting pieces 21 are twisted with the copper conductor 11 together to fill up the spiral gap formed after the two copper conductors 11 are twisted, so that the whole body is closer to a cylinder shape, the roundness of the cable is ensured, and the final anti-extrusion and anti-stretching capacity of the cable can be improved.

Further, the supporting member 21 includes a spiral main body 211 and two receiving grooves 212 disposed inside the spiral main body 211, and the two receiving grooves 212 are used for making the supporting member 21 tightly contact with the copper conductor 11.

Furthermore, the support member 21 is further provided with an expansion channel 213, the expansion channel 213 is internally provided with an optical unit, the optical unit comprises an optical fiber bundle, a hollow micro-tube and an outer protective layer, the optical fiber bundle, the hollow micro-tube and the outer protective layer are sequentially arranged from inside to outside, the expansion channel 213 is arranged inside the support member 21, the internal structure of the cable can be expanded while the supporting effect of the support member 21 is not affected, the optical unit is combined with the cable, and the communication transmission function is increased.

Furthermore, the support member 21 is further provided with an expansion passage 213, the expansion passage 213 is internally provided with a reinforcing core, and the reinforcing core comprises a steel wire and an insulating layer coated outside the steel wire, so as to further enhance the tensile strength of the cable.

Further, the filling layer 2 further comprises a filling strip 22, the filling strip 22 is filled in gaps among the copper conductor 11, the supporting piece 21 and the wrapping tape 23, the cross section of the filling strip 22 is semicircular, the filling strip 22 is used for filling fine gaps, the integral roundness after cabling is further guaranteed, and the final strength of the cable is guaranteed.

Further, still be provided with isolation layer 32 between armor 31 and the taped wound 23, isolation layer 32 is used for isolated metallic shield 116 and armor 31, sets up the isolation layer 32 of making with the polyvinyl chloride material to prevent that metallic shield 116 and armor 31 from contacting and taking place the electrochemical corrosion.

Furthermore, the conductive shield 113 adopts a 10kV inner screen material, so that an electric field on the outer surface of the wire core can be uniform, and partial discharge of a conductor and insulation caused by unsmooth surface of the wire core and air gaps generated by twisting of the wire core is avoided; the XLPE insulation 114 adopts 10kV chemical crosslinking insulation material, adopts direct-current special crosslinking polyethylene insulation material, adopts more thorough degassing treatment, and keeps the temperature for more than 36 hours; the insulation shield 115 is made of 10kV strippable semi-conductive outer shield material, and the semi-conductive outer shield layer needs to be in good contact with the outer surface of the insulation layer and has the same potential as the metal shield layer, so that partial discharge between the insulation surface defect of the cable and the metal shield layer is avoided.

Further, the metal shield 116 is shielded by a copper strip, the average covering rate among copper strips is greater than 15%, the minimum covering rate is greater than 5%, the copper strip is a soft copper strip, the minimum thickness of the copper strip is greater than 90% of a nominal value, the copper strip is composed of a layer of soft copper strips which are lapped in an overlapped mode, and the lapping is uniform, continuous, flat and smooth and is not broken.

Furthermore, the wrapping tape 23 is made of a flame-retardant non-hygroscopic tape, the armor layer 31 is made of a non-magnetic steel tape, the outer sheath 33 is made of a flame-retardant polyvinyl chloride material, and the flame-retardant non-hygroscopic tape can prevent the cable from loosening and ensure the flame retardant property of the whole cable; the armor layer 31 can be magnetized under the action of a small magnetic field, so that a non-magnetic steel belt is selected as the armor layer 31; the outer sheath 33 is made of flame-retardant polyvinyl chloride material which is adaptive to the operating temperature of the cable, so that the cable is protected mechanically and prevented from being corroded by different environmental factors.

It is conceivable that when the cable is powered on and off, a corresponding alternating magnetic field is generated around the cable, induced current is generated in the metal material and moves in the metal material to form eddy current, the heat effect of the eddy current is to heat the metal material in a short time, if the heat cannot be dissipated timely, the insulation layer of the cable is melted or aged, the insulation performance is weakened, and the cable is finally broken down, so that the armor layer 31 is made of a non-magnetic steel strip.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the utility model.

Claims

1. The utility model provides a medium voltage direct current is cable for distribution network which characterized in that: the cable comprises a cable core, a filling layer arranged in the cable core and an outer coating layer coated outside the cable core;

2. The cable for a medium voltage direct current distribution network of claim 1, wherein: the supporting pieces are provided with two groups, and the spiral directions of the two groups of supporting pieces are the same as the twisting direction of the copper conductor.

3. The cable for a medium voltage direct current distribution network of claim 1, wherein: the supporting piece comprises a spiral main body and two accommodating grooves arranged on the inner side of the spiral main body, and the two accommodating grooves are used for enabling the supporting piece to be tightly attached to the copper conductor.

4. The cable for a medium voltage direct current distribution network of claim 1, wherein: the support piece is further provided with an expansion channel, an optical unit is arranged in the expansion channel, and the optical unit comprises an optical fiber bundle, a hollow micro-tube and an outer protective layer which are sequentially arranged from inside to outside.

5. The cable for a medium voltage direct current distribution network of claim 1, wherein: the support piece is further provided with an expansion channel, a reinforcing core is arranged in the expansion channel, and the reinforcing core comprises a steel wire and an insulating layer coated outside the steel wire.

6. The cable for a medium voltage direct current distribution network of claim 1, wherein: the filling layer further comprises a filling strip, the filling strip is filled in a gap among the copper conductor, the supporting piece and the wrapping tape, and the cross section of the filling strip is semicircular.

7. The cable for a medium voltage direct current distribution network of claim 1, wherein: an isolation layer is further arranged between the armor layer and the wrapping tape and used for isolating the metal shield from the armor layer.

8. The cable for a medium voltage direct current distribution network of claim 1, wherein: the conductive shielding adopts a 10kV inner shielding material, the XLPE insulation adopts a 10kV chemical crosslinking insulation material, and the insulation shielding adopts a 10kV strippable semi-conductive outer shielding material.

9. The cable for a medium voltage direct current distribution network of claim 1, wherein: the metal shield is a copper strip shield, the average overlapping rate among copper strips is more than 15%, the minimum overlapping rate is more than 5%, the copper strip is a soft copper strip, and the minimum thickness of the copper strip is more than 90% of a nominal value.

10. The cable for a medium voltage direct current distribution network of claim 1, wherein: the wrapping tape is made of a flame-retardant non-hygroscopic tape, the armor layer is made of a non-magnetic steel tape, and the outer sheath is made of a flame-retardant polyvinyl chloride material.