CN201590286U - An insulated aerial cable - Google Patents

Abstract

An insulated overhead cable, comprising a conductive core (1) and an insulating layer (4) located outside the conductive core (1), between the conductive core (1) and the insulating layer (4) Stranded carbon fiber layers (2). The carbon fiber layer includes a plurality of composite carbon fiber filaments, and the carbon fiber layer (2) is composed of the composite carbon fiber filaments loosely wound and twisted on the conductive wire core (1). The insulated aerial cable has high tensile strength and light weight, can reduce the number of poles and towers in the transmission line and the strength requirements for the poles and towers, thereby reducing the cost of laying lines, and at the same time reducing transportation costs and labor intensity of workers.

Description

An insulated overhead cable

technical field

The utility model belongs to the technical field of power cables, in particular to an insulating aerial cable.

Background technique

Insulated overhead cable is a common high-altitude transmission line. Its structure is to extrude a layer of weather-resistant insulating material on the outside of aluminum conductors or copper conductors (in most cases, aluminum conductors are used, and copper conductors are rarely used). The weather-resistant insulating materials can be used Cross-linked polyethylene, polyethylene or polyvinyl chloride.

The overhead cable with the above-mentioned structure has weak tensile strength during use, and is prone to breakage after long-term use. In order to enhance the tensile strength of overhead cables and avoid breakage, they must be laid on two overhead poles with steel wires or steel strands when in use. There are usually two ways of laying: one way is to combine the insulated overhead cables with steel wires or strands, and then lay them between two poles; the other way is to put the steel wires or strands After laying, the insulated overhead cables are bundled with steel wires or steel strands. The laying process of the above two methods is complicated, and the labor intensity of workers is high during construction. Therefore, on this basis, an insulated overhead cable with a steel core was produced, that is, a steel core was added to the center of the aluminum wire layer, and an insulating layer was extruded outside the aluminum wire layer. The material used for the insulating layer was also cross-linked. Polyethylene, polyethylene or polyvinyl chloride. The cable with this structure can directly improve the tensile strength of the insulated overhead cable, and it is convenient for construction and low in labor intensity.

However, adding a steel core at the center of the cable increases the weight of the cable and shortens the span of the cable. Therefore, the number of towers needs to be increased when the line is erected, thereby increasing the cost of the line. In addition, due to the increase in the weight of the cable, the design strength of the tower is required to be higher, which also causes an increase in the cost of the line.

Utility model content

In order to solve the above-mentioned disadvantages in the prior art, the utility model provides an insulating overhead cable with high tensile strength and light weight. The insulating overhead cable not only has low laying cost, but also has low labor intensity during laying and convenient construction.

The technical solution adopted to solve the technical problem of the utility model is that the insulated overhead cable includes a conductive core and an insulating layer located outside the conductive core, and a carbon fiber layer is twisted between the conductive core and the insulating layer .

The carbon fiber layer includes composite carbon fiber filaments, and the carbon fiber layer is composed of multiple composite carbon fiber filaments loosely wound and stranded on a conductive core. The carbon fiber layer mainly plays the role of improving the longitudinal tensile strength of the cable. Since the carbon fiber is semi-conductive, it can also function as a shielding layer on the conductive core to homogenize the surface electric field of the conductive core.

The composite carbon fiber filaments can be formed by gluing and curing bundled carbon fiber filaments with a thermosetting modified epoxy resin, and then coating the surface of the composite carbon fiber filaments with glass fibers and curing them with a thermosetting epoxy resin. According to different requirements, there are also different requirements for the temperature resistance grade of epoxy resin. The temperature resistance grade of epoxy resin is 90°0, 120°, 150°, and 200°.

The carbon fiber layer has the following advantages: ① light weight, the density is about 1.6g/cm ³ , while the density of steel is about 7.8g/cm ³ , the weight is reduced by about 80%, which can reduce the weight of the cable per unit volume; ② tensile strength High, about 7 to 8 times that of steel, so the span of the cable can be increased, thereby reducing the number of poles and towers, and reducing the construction cost of transmission lines; ③High temperature resistance, can withstand high temperatures of about 160°; Conductivity, therefore, can reduce the loss of the cable; ⑤ also has the characteristics of corrosion resistance, wear resistance, and small expansion coefficient, so the life of the cable can be improved.

For medium and high voltage overhead cables, preferably, a shielding layer may also be provided between the carbon fiber layer and the insulating layer. The function of the shielding layer is to homogenize the electric field on the surface of the conductive core under high voltage, eliminate the discharge of the spikes on the surface of the conductive core, protect the insulation, and avoid the breakdown of the cable. Preferably, the shielding layer is a semi-conductive shielding layer. The material of the semi-conductive shielding layer can be semi-conductive shielding material, which is mostly made of polyolefin as the base material and conductive carbon black, and is divided into two types: thermoplastic type and cross-linked type.

Preferably, the conductive wire core is formed by tightly twisting multiple wires in multiple layers, and the twisting direction of the outermost layer is left or right. The wire can be aluminum single wire or copper single wire.

Further preferably, the insulating layer is made of weather-resistant insulating material. Preferably, the weather-resistant insulating material can be cross-linked polyethylene, polyethylene or polyvinyl chloride.

The conductive wire core can adopt a non-compressed circular structure or a compressed circular structure.

The utility model has the following advantages:

The insulated overhead cable of the utility model is provided with a carbon fiber layer between the conductive wire core and the insulating layer. The carbon fiber layer can not only improve the tensile strength of the insulated overhead cable, but also reduce the weight of the cable. Therefore, the span of the cable can be increased. Reduce the number of towers and reduce the strength requirements of the towers, thereby reducing the cost of laying transmission lines. In addition, because the insulated overhead cable of the utility model has the characteristics of light weight and small outer diameter (compared with the insulated overhead cable with steel core in the prior art), it can also reduce transportation costs and labor intensity of workers.

Description of drawings

Fig. 1 is the structural representation of the utility model low-voltage insulated overhead cable

Fig. 2 is a structural schematic diagram of a medium-voltage insulated overhead cable of the utility model

In the figure: 1-conductive core 2-carbon fiber layer 3-shield layer 4-insulation layer

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the utility model, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments.

The following examples are non-limiting examples of the present invention.

As shown in Figure 1, the insulated overhead cable in this embodiment includes a conductive core 1, a carbon fiber layer 2 and an insulating layer 4, and the carbon fiber layer 2 is arranged between the conductive core 1 and the insulating layer 4. The insulated overhead cable of this structure Suitable for use under low pressure conditions.

The conductive wire core 1 adopts 36 aluminum wires with a diameter of 3.0mm (of course, copper wires or other wires can also be used) and is tightly twisted together in three layers, wherein the twisting direction of the innermost conductive wire core is left. The stranding direction of the second outer layer is right, and the stranding direction of the outermost layer is left. In this embodiment, the conductive wire core 1 adopts a compact circular structure.

The carbon fiber layer 2 is formed by winding 40 composite carbon fiber filaments with a diameter of 1.0 mm on the conductive core 1 in a right direction. A single composite carbon fiber filament is formed by bonding carbon fiber filaments together with a thermosetting modified epoxy resin for curing and gluing together, and then coating glass fiber on its outside and curing with a thermosetting epoxy resin. Among them, the temperature resistance grade of thermosetting epoxy resin is 160°. Since the density of carbon fiber is about 1.6g/cm ² , the weight of the insulated overhead cable can be reduced by about 80%, but the tensile strength is increased instead (the tensile strength is 350N/mm ² , increased by 25%). In practical applications, the number of composite carbon fiber filaments can also be increased according to the situation to improve the tensile strength of the cable.

The insulating layer 4 is formed by extruding weather-resistant cross-linked polyethylene, polyethylene or polyvinyl chloride on the carbon fiber layer 2 . In this embodiment, the thickness of the insulating layer 4 is 2.2 mm.

When the insulated overhead cable is used under medium voltage, the structure of the insulated overhead cable is shown in Figure 2 (the figure is a medium voltage 240mm ² aluminum conductor insulated overhead cable). The difference between Figure 2 and the low-voltage insulated overhead cable in Figure 1 is that a shielding layer 3 is added between the carbon fiber layer 2 and the insulating layer 4, and the other structures are exactly the same as those of the low-voltage insulated overhead cable in Figure 1, and the thickness of the insulating layer 4 is 3.4mm.

The shielding layer 3 can homogenize the electric field on the surface of the conductive wire core, eliminate the discharge of spikes on the surface of the conductive wire core, and protect the insulating layer 4. In this embodiment, the shielding layer 3 is made of a cross-linkable semi-conductive shielding material. The shielding layer 3 is extruded on the carbon fiber layer 2 , and then the insulating layer 4 is extruded on the shielding layer 3 . The material and extrusion method of the insulating layer 4 are the same as those in FIG. 1 .

It can be understood that, the above embodiments are only exemplary embodiments adopted to illustrate the principles of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the utility model, and these variations and improvements are also within the protection scope of the utility model.

Claims (10)

1. An insulated overhead cable, comprising a conductive core (1) and an insulating layer (4) positioned at the outside of the conductive core (1), characterized in that the conductive core (1) and the insulating layer A carbon fiber layer (2) is twisted between (4). 2. The insulated aerial cable according to claim 1, characterized in that a shielding layer (3) is provided between the carbon fiber layer (2) and the insulating layer (4). 3. The insulated overhead cable according to claim 2, characterized in that the shielding layer (3) is a semi-conductive shielding layer. 4. The insulated overhead cable according to any one of claims 1-3, characterized in that the carbon fiber layer (2) includes a plurality of composite carbon fiber filaments, and the carbon fiber layer (2) is loosely wound by the composite carbon fiber filaments The stranding is formed on the conductive core (1). 5. The insulated overhead cable according to claim 4, characterized in that the composite carbon fiber filaments are bonded and solidified by the bundled carbon fiber filaments and thermosetting modified epoxy resin, and then coated with glass fiber on its surface and sealed with a thermosetting ring. Oxygen resin is cured to form. 6. The insulated overhead cable according to any one of claims 1-3, characterized in that the conductive core (1) is formed by tightly twisting multiple conductors in multiple layers. 7. The insulated overhead cable according to claim 6, characterized in that said conductors are aluminum single wires or copper single wires. 8. The insulated overhead cable according to any one of claims 1-3, characterized in that the insulating layer (4) is made of weather-resistant insulating material. 9. The insulated overhead cable according to claim 8, characterized in that the weather-resistant insulating material is cross-linked polyethylene, polyethylene or polyvinyl chloride. 10. The insulated overhead cable according to any one of claims 1-3, characterized in that the conductive core (1) is of a non-compacted circular structure or a compacted circular structure.

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