CN210516263U

CN210516263U - Waterproof flexible direct current cable

Info

Publication number: CN210516263U
Application number: CN201921552404.6U
Authority: CN
Inventors: 余德平; 刘焕新; 李金堂; 孟益标; 梁增显
Original assignee: Zhejiang Wanma Co Ltd
Current assignee: Zhejiang Wanma Co Ltd
Priority date: 2019-09-18
Filing date: 2019-09-18
Publication date: 2020-05-12
Anticipated expiration: 2029-09-18

Abstract

The utility model relates to a cable does not receive the invasion of outside moisture, provides the waterproof flexible direct current cable of guarantee for the long-term steady operation of direct current cable line, be circular shape conductor and conductor shield including two piece at least cross-sections, still be equipped with insulating cover outside every conductor shield, insulating shield, semiconduction buffering water blocking layer and metallic shield, the area that blocks water of cladding outside the metallic shield, be equipped with the strap at the outside of the area that blocks water at the limit and indulge wrapping water blocking layer and oversheath, be equipped with the filler that vertically blocks water in the space department of area that blocks water and metallic shield. On one hand, the utility model can effectively inhibit the water tree generation of the insulating layer by selecting the water tree resistant cross-linked polymer insulation; on one hand, the longitudinal and radial omnibearing water-blocking structural design is adopted, so that the new-structure cable is prevented from being invaded by external moisture, and the long-term stable operation of a direct-current cable line is guaranteed.

Description

Waterproof flexible direct current cable

Technical Field

The utility model relates to a cable especially relates to a cable does not receive the invasion of outside moisture, provides the waterproof flexible direct current cable of guarantee for the long-term steady operation of direct current cable circuit.

Background

For a long time, alternating current power transmission is a main power transmission mode because alternating current power generation is relatively simple and does not need rectification, and alternating current power transmission is convenient for voltage transformation and is convenient for adopting high-voltage power transmission to reduce loss. However, with the development of power systems, the increase of transmission capacity and distance, the problems of stability in ac transmission, short-circuit capacity under a cut-off fault, and the like are increasingly complicated, and today, new technologies such as high-power thyristors, automatic control of dc transmission, and the like are developed, the dc transmission technology becomes possible and develops rapidly, and is widely applied worldwide.

Compared with alternating current transmission, the direct current transmission has the following advantages: (1) there is no stability problem. (2) The direct current transmission not only has no stability problem, but also can improve the stability of alternating current systems at two ends of the direct current transmission. (3) The direct current circuit has low manufacturing cost which is about 65 percent of that of the direct current circuit with the same level voltage, and the consumption of nonferrous metals is small. (4) The conveying capacity is large. The power that can be transmitted by direct current transmission is about 1.5 times of the power transmitted by alternating current transmission with the same voltage. (5) The line loss is small. The direct current transmission has no reactive current, and the current and power loss of the line are smaller than those of the alternating current transmission. (6) The direct current transmission has a strong adaptability to the increase of power and transmission voltage. (7) And the power transmission reliability is high. (8) control of power flow in direct current transmission is easier than in alternating current transmission. (9) The interference of direct current transmission to communication is small, the operation of grid connection and disconnection is simpler than that of alternating current, and the system with different frequencies can be connected.

The +/-10 kV flexible direct-current cable is used on a direct-current transmission line.

The dc transmission system employs power electronic rectification technology, so that harmonic components may be contained on the dc side, and the closer to the converter outlet, the more severe the harmonic is. In addition, the mechanical stress at the outlet of the converter is strong, the cable is a weak link, so that the moisture invasion is easily caused by the breakage of a shielding layer formed at the cable, under the long-term action of an electric field, moisture, ions and high-frequency harmonic waves, the water tree is easily caused by the direct current cable, the water tree is a main reason for causing the operation fault of the cable, once the direct current cable causes the cable breakdown accident due to the water tree, the immeasurable loss and influence are brought to national economy and resident life.

The structure of a common +/-10 kV flexible direct-current cable is as follows: conductor + conductor shield + insulation + metal shield + filling + tape + oversheath.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a cable does not receive the invasion of outside moisture in order to solve the defect that thereby the fracture that present ordinary 10kV flexible direct current cable formed the shielding layer here easily and lead to moisture invasion, provides the waterproof flexible direct current cable of guarantee for the long-term steady operation of direct current cable line.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the waterproof flexible direct current cable comprises at least two conductors with circular cross sections and conductor shielding layers, wherein an insulating sleeve, an insulating shielding layer, a semi-conductive buffer water-blocking layer and a metal shielding layer are further arranged outside each conductor shielding layer, a water-blocking tape is wrapped outside each metal shielding layer, a metal tape longitudinally wrapping the water-blocking layer and an outer sheath is arranged on the outer edge of each water-blocking tape, and a longitudinal water-blocking filler is arranged in a gap between each water-blocking tape and each metal shielding layer. In this technical scheme, waterproof 10kV flexible direct current cable structure does: the water-blocking conductor, the conductor shield, the water tree-resistant crosslinked polyethylene insulation, the insulation shield, the semi-conductive longitudinal water-blocking layer, the metal shield, the longitudinal water-blocking filling, the water-blocking tape, the metal strip longitudinal water-blocking layer and the high-hardness polyethylene sheath. The waterproof +/-10 kV flexible direct current cable adopts a water-blocking structure design on each layer of the cable, each layer of twisted conductors passes through an electrostatic generator during conductor twisting, so that the surfaces of the conductors are charged with static electricity, then the conductors charged with the static electricity pass through a device filled with water-blocking powder, the water-blocking powder is adsorbed on the conductors by the static electricity on the conductors, and meanwhile, a layer of semi-conductive water-blocking tape is longitudinally wrapped, so that gaps of the conductors are filled with the water-blocking powder and the water-blocking tape, and the conductors have a longitudinal water-blocking function; the water tree resistant crosslinked polyethylene insulation is extruded on the water resistant conductor in a three-layer co-extrusion (conductor shielding, water tree resistant crosslinked polyethylene insulation and insulation shielding) mode, so that the insulation layer has the function of inhibiting water tree production; a layer of semi-conductive buffer longitudinal water-blocking tape is wound outside the insulation shield, and a gap twisted by the cable is tightly filled by a longitudinal water-blocking filling rope, so that the outer surface of the insulation layer also has a longitudinal water-blocking function; then longitudinally wrapping a layer of metal belt to be used as a radial waterproof layer of the cable; the outer sheath is made of high-density polyethylene sheath, and the material has compact molecular structure and strong radial water-blocking function.

The cable adopts the structural design and the materials, so that the cable with the new structure has longitudinal and radial omnibearing waterproof functions, and provides guarantee for long-term stable operation of a direct current cable line.

Preferably, the outer sheath is made of high-density polyethylene.

Preferably, the insulating sleeve is made of water tree resistant cross-linked polyethylene.

Preferably, the two metal shielding layers are tangent.

Preferably, the conductor wires have the same diameter and are parallel to each other, and the conductor is a water-blocking conductor.

Preferably, the longitudinal water-blocking filler is water-blocking powder with the surface.

Preferably, the cross section of the water blocking tape is a waist circle.

The utility model has the advantages that: the utility model discloses waterproof 10kV flexible direct current cable all adopts the structural design that blocks water at each layer of cable, and every layer of hank conductor all passes through an electrostatic generator when the conductor hank, lets the conductor surface take the static, then the conductor that takes the static passes through a device that is equipped with the powder that blocks water, blocks water the powder and is given the static on the conductor and adsorb on the conductor, indulges a layer of semi-conductive water-blocking area simultaneously, and the gap of conductor just is filled up by the powder that blocks water and the area that blocks water like this, makes the conductor have the function of vertically blocking water; the water tree resistant crosslinked polyethylene insulation is extruded on the water resistant conductor in a three-layer co-extrusion (conductor shielding, water tree resistant crosslinked polyethylene insulation and insulation shielding) mode, so that the insulation layer has the function of inhibiting water tree production; a layer of semi-conductive buffer longitudinal water-blocking tape is wound outside the insulation shield, and a gap twisted by the cable is tightly filled by a longitudinal water-blocking filling rope, so that the outer surface of the insulation layer also has a longitudinal water-blocking function; then longitudinally wrapping a layer of metal belt to be used as a radial waterproof layer of the cable; the outer sheath is made of high-density polyethylene sheath, the molecular structure of the material is very compact, the material has a strong radial water-blocking function, and on one hand, the water tree of the insulating layer can be effectively inhibited by selecting the water tree-resistant cross-linked polymer insulation; on one hand, the longitudinal and radial omnibearing water-blocking structural design is adopted, so that the new-structure cable is prevented from being invaded by external moisture, and the long-term stable operation of a direct-current cable line is guaranteed.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

In the figure, 1, a conductor; 2. a conductor shield layer; 3. an insulating sleeve; 4. an insulating shield layer; 5. a semiconductive buffer water-resistant layer; 6. a metal shielding layer; 7. longitudinal water-blocking filler; 8. a water blocking tape; 9. longitudinally wrapping a water-resistant layer by the metal strip; 10. an outer sheath.

Detailed Description

The invention will be further explained with reference to the following embodiments and drawings:

examples

Referring to fig. 1, the waterproof flexible direct current cable comprises two water-blocking conductors 1 with circular cross sections, the wire diameters of the conductors are the same and parallel to each other, a conductor shielding layer 2, an insulating sleeve 3, an insulating shielding layer 4, a semi-conductive buffer water-blocking layer 5 and a metal shielding layer 6 are arranged outside each conductor, the two metal shielding layers are externally tangent to each other, a water-blocking tape 8 is further arranged outside the metal shielding layers, a longitudinal water-blocking filler 7 is filled in a gap between the water-blocking tape and the metal shielding layers, and a metal tape longitudinally wrapping the water-blocking layer 9 and an outer sheath 10 is further arranged outside the water-blocking tape 8.

The waterproof +/-10 kV flexible direct current cable adopts a water-blocking structure design on each layer of the cable, each layer of twisted conductors passes through an electrostatic generator during conductor twisting, so that the surfaces of the conductors are charged with static electricity, then the conductors charged with the static electricity pass through a device filled with water-blocking powder, the water-blocking powder is adsorbed on the conductors by the static electricity on the conductors, and meanwhile, a layer of semi-conductive water-blocking tape is longitudinally wrapped, so that gaps of the conductors are filled with the water-blocking powder and the water-blocking tape, and the conductors have a longitudinal water-blocking function; the water tree resistant crosslinked polyethylene insulation is extruded on the water resistant conductor in a three-layer co-extrusion (conductor shielding, water tree resistant crosslinked polyethylene insulation and insulation shielding) mode, so that the insulation layer has the function of inhibiting water tree production; a layer of semi-conductive buffer longitudinal water-blocking tape is wound outside the insulation shield, and a gap twisted by the cable is tightly filled by a longitudinal water-blocking filling rope, so that the outer surface of the insulation layer also has a longitudinal water-blocking function; then longitudinally wrapping a layer of metal belt to be used as a radial waterproof layer of the cable; the outer sheath is made of high-density polyethylene sheath, the molecular structure of the material is very compact, the material has a strong radial water-blocking function, and on one hand, the water tree of the insulating layer can be effectively inhibited by selecting the water tree-resistant cross-linked polymer insulation; on one hand, the longitudinal and radial omnibearing water-blocking structural design is adopted, so that the new-structure cable is prevented from being invaded by external moisture, and the long-term stable operation of a direct-current cable line is guaranteed.

The above-described embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention in any way, and other variations and modifications may be made without departing from the scope of the claims.

Claims

1. Waterproof flexible direct current cable, including two piece at least cross-sections for circular shape conductor (1) and conductor shield (2), its characterized in that, still be equipped with insulating cover (3), insulating shield (4), semiconduction buffering water-blocking layer (5) and metallic shield (6) outside every conductor shield (2), some water blocking tape (8) of cladding outside metallic shield (6), it indulges package water-blocking layer (9) and oversheath (10) to be equipped with the metal tape at water blocking tape (8) outer fringe, be equipped with vertically to block water filler (7) in the space department of water blocking tape (8) and metallic shield (6).

2. The waterproof flexible direct current cable according to claim 1, wherein the outer sheath (10) is a high density polyethylene sheath.

3. The waterproof flexible direct current cable according to claim 1, wherein the insulating sheath (3) is a water tree resistant cross-linked polyethylene insulating sheath.

4. The waterproof flexible direct current cable according to claim 1, characterized in that the two metallic shielding layers (6) are tangent.

5. The waterproof flexible direct current cable according to claim 1, wherein the conductors (1) have the same wire diameter and are parallel to each other, and the conductors (1) are water-blocking conductors.

6. The waterproof flexible direct current cable according to claim 1, wherein the longitudinal water-blocking filler (7) is a powder having a water-blocking surface.

7. The waterproof flexible direct current cable according to claim 1, characterized in that the cross-section of the water-blocking tape (8) is kidney-round.