Medium-voltage coaxial grounding cable

Abstract

The utility model belongs to the technical field of cable manufacturing, and discloses a medium-voltage coaxial grounding cable which comprises an inner conductor layer, a first shielding layer, an insulating layer, an outer conductor layer, a first water-blocking tape and a protective layer which are sequentially arranged from inside to outside, the inner conductor layer is connected with a positive electrode of a power supply and used for transmitting positive current of alternating current, and the outer conductor layer is connected with a negative electrode of the power supply and used for transmitting negative current of the alternating current. The first shielding layer wraps the periphery of the inner conductor layer and shields electromagnetic interference between the inner conductor layer and the outer conductor layer, the insulating layer wraps the periphery of the first shielding layer and insulates the inner conductor layer and the outer conductor layer, power connection of the medium-voltage coaxial cable is avoided, the first water-blocking tape is wound around the periphery of the outer conductor layer, and the first water-blocking tape is wound around the periphery of the inner conductor layer and shields the electromagnetic interference between the inner conductor layer and the outer conductor layer. The protective layer is arranged on the periphery of the first water-blocking tape. According to the medium-voltage coaxial grounding cable of the utility model, separate processing of the positive wire and the negative wire can be avoided, processing materials are saved, processing procedures are relatively few, and rapid processing can be realized.

Description

Technical Field

[0001] The utility model relates to the technical field of cable manufacturing, in particular to a medium-voltage coaxial grounding cable. Background Art

[0002] With the development of modern society, more and more power transmission projects are being carried out to ensure the normal operation of power throughout the country. In the manufacturing process of existing cables, the positive and negative conductors need to be processed separately. The processing steps of the cables are relatively complicated, and the positive and negative conductors need to be wrapped with insulating layers separately, resulting in serious overall consumables of existing cables, more processing steps, and low processing efficiency.

[0003] Therefore, there is an urgent need for a medium voltage coaxial grounding cable to solve the above technical problems. Utility Model Content

[0004] The utility model aims to provide a medium voltage coaxial grounding cable, which can transmit positive current and negative current together, avoids separate processing of positive wire and negative wire, can save processing materials, has relatively few processing steps, and can be processed quickly.

[0005] To achieve this purpose, the utility model adopts the following technical solutions:

[0006] A medium voltage coaxial grounding cable, comprising:

[0007] An inner conductor layer, wherein the inner conductor layer is connected to a positive electrode of a power source;

[0008] A first shielding layer, the first shielding layer covering the outer periphery of the inner conductor layer;

[0009] An insulating layer, the insulating layer covering an outer periphery of the first shielding layer;

[0010] An outer conductor layer is arranged around the outer periphery of the insulating layer, and the outer conductor layer is connected to the negative electrode of the power supply;

[0011] a first water blocking tape, wound around the outer circumference of the outer conductor layer;

[0012] The protective layer is arranged on the outer periphery of the first water blocking tape.

[0013] As a preferred technical solution for a medium voltage coaxial grounding cable, the outer conductor layer includes a first conductor layer, a waterproof conductive tape and a second conductor layer, the first conductor layer is surrounded by the outer periphery of the insulating layer, the waterproof conductive tape is wrapped around the outer periphery of the first conductor layer, and the second conductor layer is surrounded by the outer periphery of the waterproof conductive tape.

[0014] As a preferred technical solution of the medium voltage coaxial grounding cable, the medium voltage coaxial grounding cable further includes a second water blocking tape, and the second water blocking tape is arranged between the inner conductor layer and the first shielding layer.

[0015] As a preferred technical solution of the medium voltage coaxial grounding cable, the medium voltage coaxial grounding cable further includes a second shielding layer, which is arranged between the insulating layer and the outer conductor layer, and the second shielding layer is coated on the outer periphery of the insulating layer.

[0016] As a preferred technical solution for the medium voltage coaxial grounding cable, the first shielding layer, the insulating layer and the second shielding layer are all made of thermoplastic materials.

[0017] As a preferred technical solution for the medium voltage coaxial grounding cable, the first shielding layer, the insulating layer and the second shielding layer are co-extruded in the form of three-layer co-extrusion.

[0018] As a preferred technical solution for the medium voltage coaxial grounding cable, the thickness ratio of the first shielding layer, the insulating layer and the second shielding layer is 1:5:1.

[0019] As a preferred technical solution of the medium voltage coaxial grounding cable, the medium voltage coaxial grounding cable further includes a third water blocking tape, and the third water blocking tape is arranged between the second shielding layer and the outer conductor layer.

[0020] As a preferred technical solution for a medium voltage coaxial grounding cable, the second water-blocking tape is spirally wound around the outer periphery of the inner conductor layer in a forward direction, the third water-blocking tape is spirally wound around the outer periphery of the second shielding layer in a reverse direction, the waterproof conductive tape is spirally wound around the outer periphery of the first conductor layer in a forward direction, and the first water-blocking tape is spirally wound around the outer periphery of the second conductor layer in a reverse direction.

[0021] As a preferred technical solution for the medium voltage coaxial grounding cable, the protective layer includes a sheath layer and a semiconductive layer, the sheath layer is arranged on the periphery of the first water blocking tape, and the semiconductive layer is coated on the periphery of the sheath layer.

[0022] The beneficial effects of the utility model are:

[0023] The medium-voltage coaxial grounding cable provided by the utility model comprises, from the inside to the outside, an inner conductor layer, a first shielding layer, an insulating layer, an outer conductor layer, a first water-blocking tape and a protective layer. The inner conductor layer is connected to the positive pole of the power supply and is used to transmit the positive current of the alternating current. The outer conductor layer is connected to the negative pole of the power supply and is used to transmit the negative current of the alternating current. The first shielding layer is coated on the outer periphery of the inner conductor layer to shield the electromagnetic interference between the inner conductor layer and the outer conductor layer. The medium-voltage coaxial grounding cable can stably transmit voltage. The insulating layer is coated on the outer periphery of the first shielding layer to insulate the inner conductor layer and the outer conductor layer to avoid electrical connection in the medium-voltage coaxial grounding cable. By coaxially arranging the inner conductor layer and the outer conductor layer, the positive current and the negative current can be transmitted simultaneously in one cable. Compared with the prior art in which the positive cable and the negative cable are processed separately, the medium-voltage coaxial grounding cable uses less material to transmit the positive current and the negative current, and the processing steps are reduced, and the processing efficiency is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The utility model is a structural schematic diagram of a medium-voltage coaxial grounding cable provided by the utility model.

[0025] In the figure:

[0026] 1. Inner conductor layer; 2. First shielding layer; 3. Insulation layer;

[0027] 4. outer conductor layer; 41. first conductor layer; 42. waterproof conductive tape; 43. second conductor layer;

[0028] 5. first water blocking tape; 6. protective layer; 61. sheath layer; 62. semi-conductive layer;

[0029] 7. The second water blocking tape; 8. The second shielding layer; 9. The third water blocking tape. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0031] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0034] like Figure 1 As shown in , this embodiment provides a medium-voltage coaxial grounding cable, which includes an inner conductor layer 1, a first shielding layer 2, an insulating layer 3, an outer conductor layer 4, a first water-blocking tape 5 and a protective layer 6 from the inside to the outside. The inner conductor layer 1 is connected to the positive pole of the power supply and is used to transmit the positive current of the alternating current. The outer conductor layer 4 is connected to the negative pole of the power supply and is used to transmit the negative current of the alternating current. The first shielding layer 2 is coated on the outer periphery of the inner conductor layer 1 to shield the electromagnetic interference between the inner conductor layer 1 and the outer conductor layer 4. The medium-voltage coaxial grounding cable can stably transmit voltage. The insulating layer 3 is coated on the outer periphery of the first shielding layer 2 to insulate the inner conductor layer 1 and the outer conductor layer 4 to avoid the medium-voltage coaxial grounding cable from being electrically connected. By arranging the inner conductor layer 1 and the outer conductor layer 4 coaxially, the positive current and the negative current can be transmitted simultaneously in one cable. Compared with the prior art in which the positive conductor and the negative conductor are processed separately, the medium-voltage coaxial grounding cable can transmit the positive current and the negative current using less material, and the processing steps are reduced, and the processing efficiency is higher.

[0035] The first water-blocking tape 5 is wound around the outer periphery of the outer conductor layer 4. On the one hand, it can bind the outer conductor layer 4 to improve the compactness, roundness and pressure resistance of the internal structure of the medium-voltage coaxial grounding cable. On the other hand, it can improve the waterproof performance of the medium-voltage coaxial grounding cable and avoid the short circuit problem of the medium-voltage coaxial grounding cable due to water ingress. The protective layer 6 is arranged on the outer periphery of the first water-blocking tape 5 to ensure the compression resistance and wear resistance of the medium-voltage coaxial grounding cable and ensure its service life.

[0036] In this embodiment, the outer conductor layer 4 includes a first conductor layer 41, a waterproof conductive tape 42 and a second conductor layer 43. The first conductor layer 41 surrounds the outer periphery of the insulating layer 3, the waterproof conductive tape 42 is wound around the outer periphery of the first conductor layer 41, and the second conductor layer 43 surrounds the outer periphery of the waterproof conductive tape 42. The first conductor layer 41 is formed by a plurality of copper conductors surrounding the outer periphery of the insulating layer 3. The provision of the waterproof conductive tape 42 can bind the plurality of copper conductors, making the outer conductor layer 4 more compact, thereby making the medium voltage coaxial grounding cable more rounded. At the same time, the waterproof conductive tape 42 can electrically conduct the first conductor layer 41 and the second conductor layer 43, so that the first conductor layer 41 and the second conductor layer 43 transmit the negative current together, ensuring the stable transmission of the negative current. The second conductor layer 43 is also formed by a plurality of copper conductor cores wrapped around the outer periphery of the waterproof conductive tape 42. Since the first water-blocking tape 5 is wrapped around the outer periphery of the outer conductor layer 4, the first water-blocking tape 5 can bind the second conductor layer 43 to prevent the second conductor layer 43 from loosening, further ensuring the roundness of the medium-voltage coaxial grounding cable. The first conductor layer 41 is bound and fixed by the waterproof conductive tape 42, and the second conductor layer 43 is bound and fixed by the first water-blocking tape 5. Compared with the processing method of directly twisting the second conductor layer 43 on the first conductor layer 41, the processing difficulty is relatively lower, and the processing efficiency is higher while ensuring the performance of the medium-voltage coaxial grounding cable.

[0037] In this embodiment, the medium voltage coaxial grounding cable also includes a second water blocking tape 7, wherein the second water blocking tape 7 is arranged between the first shielding layer 2 and the inner conductor layer 1, and is specifically spirally wound on the inner conductor layer 1. The arrangement of the second water blocking tape 7 can not only prevent water vapor from entering the inner conductor layer 1, improve the stability of the positive current transmission of the inner conductor layer 1, and further improve the overall safety of the medium voltage coaxial grounding cable, but also avoid the inner conductor layer 1 from jumping thorns, and prevent the inner conductor layer 1 from having a local excessive voltage, causing the medium voltage coaxial grounding cable to spontaneously combust. The medium voltage coaxial grounding cable also includes a second shielding layer 8, which is arranged between the insulating layer 3 and the outer conductor layer 4, and is coated on the outer periphery of the insulating layer 3. The arrangement of the second shielding layer 8 can further reduce the electromagnetic interference generated by the inner conductor layer 1 and the outer conductor layer 4 when current flows through, and ensure the stable transmission of the positive current and the negative current.

[0038] In this embodiment, the first shielding layer 2, the insulating layer 3 and the second shielding layer 8 are all made of thermoplastic materials, so that the first shielding layer 2 can be coated on the outer periphery of the inner conductor layer 1 by extrusion, the insulating layer 3 can be coated on the outer periphery of the first shielding layer 2 by extrusion, and the second shielding layer 8 can be coated on the outer periphery of the insulating layer 3 by extrusion. Exemplarily, the first shielding layer 2 and the second shielding layer 8 can be made of graphene material, and the insulating layer 3 can be made of polypropylene material. Preferably, the first shielding layer 2, the insulating layer 3 and the second shielding layer 8 are co-extruded by three-layer co-extrusion, which can further simplify the processing procedures of the medium voltage coaxial grounding cable and improve its processing efficiency. Specifically, the thickness ratio of the first shielding layer 2, the insulating layer 3 and the second shielding layer 8 is 1:5:1. The average thickness of the first shielding layer 2 is 1.0mm-1.2mm, and the thickness of the thinnest point is not less than 0.90mm. The average thickness of the insulating layer 3 is 4.5mm-5.5mm, and the thickness of the thinnest point is not less than 3.2mm. The average thickness of the second shielding layer 8 is 1.0 mm-1.2 mm, and the thickness at the thinnest point is not less than 0.90 mm.

[0039] In this embodiment, the medium voltage coaxial grounding cable also includes a third water blocking tape 9, which is arranged between the second shielding layer 8 and the outer conductor layer 4 to further improve the waterproof performance of the medium voltage coaxial grounding cable. Preferably, during the actual processing of the medium voltage coaxial grounding cable, the second water blocking tape 7 is spirally wound around the outer periphery of the inner conductor layer 1, the third water blocking tape 9 is spirally wound around the outer periphery of the second shielding layer 8, the waterproof conductive tape 42 is spirally wound around the outer periphery of the first conductor layer 41, and the first water blocking tape 5 is spirally wound around the outer periphery of the second conductor layer 43. In this way, the medium voltage coaxial grounding cable can be made more compact as a whole, and the medium voltage coaxial grounding cable can be prevented from being loosened during subsequent use, so that the medium voltage coaxial grounding cable has higher roundness and stronger pressure resistance.

[0040] In this embodiment, the protective layer 6 includes a sheath layer 61 and a semiconductive layer 62, wherein the sheath layer 61 is arranged on the periphery of the first water-blocking tape 5, and the semiconductive layer 62 is coated on the periphery of the sheath layer 61. The sheath layer 61 is made of thermoplastic low-smoke fire-retardant polypropylene, and has good fire resistance and resistance to temperature changes to meet the flame retardancy requirements of the medium-voltage coaxial grounding cable. The average thickness of the sheath layer 61 is 4.5mm-5.0mm, and the thickness at the thinnest point is not less than 4.00mm. The semiconductive layer 62 can make the medium-voltage coaxial grounding cable have good grounding properties, making the medium-voltage coaxial grounding cable safer during operation. The average thickness of the semiconductive layer 62 is 0.3mm-0.5mm, and the thickness at the thinnest point is not less than 0.15mm.

[0041] The medium voltage coaxial grounding cable in Example 1 has been tested, and the test performance parameters are as follows:

[0042] Insulation mechanical properties: before aging, the tensile strength is 26 MPa and the elongation at break is 730%; after aging at 135°C for 1008h, the tensile strength is 29 MPa and the elongation at break is 560%.

[0043] The medium voltage coaxial grounding cable is subjected to a full structural longitudinal water resistance test in accordance with IEC 60502-2-2014, with holes opened inside the conductor. After the test, the water seepage length of each layer is measured, and all meet the standard requirements. The medium voltage coaxial grounding cable has good waterproof performance. IEC 60502-2-2014 is a well-known testing standard in the field of cables and does not belong to the protection content of this utility model.

[0044] The medium voltage coaxial grounding cable was subjected to a bundled flame retardant test according to IEC 60332-3-24, and the carbonization height was 0.5 meters, which was lower than the standard requirement of ≤2.5 meters, and the flame retardant performance was good. IEC 60332-3-24 is a well-known testing standard in the field of cables and does not belong to the protection content of this utility model.

[0045] The medium voltage coaxial grounding cable was tested for smoke density according to IEC 61034, and the light transmittance was 87%, far exceeding the standard requirement of not less than 60%, and it would not release a lot of smoke when burning. IEC 61034 is a well-known testing standard in the field of cables and does not belong to the protection content of this utility model.

[0046] The medium voltage coaxial grounding cable was subjected to halogen-free test according to IEC 60754, and the acidity, alkalinity and conductivity content all met the standard requirements, showing excellent halogen-free performance. Among them, IEC 60754 is a well-known testing standard in the field of cables and does not belong to the protection content of this utility model.

[0047] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. A medium voltage coaxial grounding cable, characterized in that: include: An inner conductor layer (1), the inner conductor layer (1) being connected to the positive electrode of a power source; A first shielding layer (2), the first shielding layer (2) covering the outer periphery of the inner conductor layer (1); An insulating layer (3), the insulating layer (3) covering the outer periphery of the first shielding layer (2); An outer conductor layer (4) is arranged around the outer periphery of the insulating layer (3), and the outer conductor layer (4) is connected to the negative electrode of the power supply; A first water blocking tape (5) is wound around the outer circumference of the outer conductor layer (4); A protective layer (6) is arranged on the outer periphery of the first water blocking tape (5).

2. The medium voltage coaxial grounding cable according to claim 1, characterized in that: The outer conductor layer (4) comprises a first conductor layer (41), a waterproof conductive tape (42) and a second conductor layer (43); the first conductor layer (41) surrounds the outer periphery of the insulating layer (3); the waterproof conductive tape (42) is wound around the outer periphery of the first conductor layer (41); and the second conductor layer (43) surrounds the outer periphery of the waterproof conductive tape (42).

3. The medium voltage coaxial grounding cable according to claim 2, characterized in that: The medium voltage coaxial grounding cable further comprises a second water blocking tape (7), wherein the second water blocking tape (7) is arranged between the inner conductor layer (1) and the first shielding layer (2).

4. The medium voltage coaxial grounding cable according to claim 3, characterized in that: The medium voltage coaxial grounding cable further comprises a second shielding layer (8), wherein the second shielding layer (8) is arranged between the insulating layer (3) and the outer conductor layer (4), and the second shielding layer (8) is coated on the outer periphery of the insulating layer (3).

5. The medium voltage coaxial grounding cable according to claim 4, characterized in that: The first shielding layer (2), the insulating layer (3) and the second shielding layer (8) are all made of thermoplastic materials.

6. The medium voltage coaxial grounding cable according to claim 5, characterized in that: The first shielding layer (2), the insulating layer (3) and the second shielding layer (8) are co-extruded in the form of three-layer co-extrusion.

7. The medium voltage coaxial grounding cable according to claim 6, characterized in that: The thickness ratio of the first shielding layer (2), the insulating layer (3) and the second shielding layer (8) is 1:5:

1.

8. The medium voltage coaxial grounding cable according to claim 4, characterized in that: The medium voltage coaxial grounding cable further comprises a third water blocking tape (9), wherein the third water blocking tape (9) is arranged between the second shielding layer (8) and the outer conductor layer (4).

9. The medium voltage coaxial grounding cable according to claim 8, characterized in that: The second water-blocking tape (7) is spirally wound in the forward direction on the outer periphery of the inner conductor layer (1), the third water-blocking tape (9) is spirally wound in the reverse direction on the outer periphery of the second shielding layer (8), the waterproof conductive tape (42) is spirally wound in the forward direction on the outer periphery of the first conductor layer (41), and the first water-blocking tape (5) is spirally wound in the reverse direction on the outer periphery of the second conductor layer (43).

10. The medium voltage coaxial grounding cable according to claim 1, characterized in that: The protective layer (6) comprises a sheath layer (61) and a semi-conductive layer (62); the sheath layer (61) is arranged on the periphery of the first water-blocking tape (5); and the semi-conductive layer (62) is coated on the periphery of the sheath layer (61).

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