CN202650698U - 20kV steel core wear-resistant overhead insulated cable - Google Patents

Abstract

The utility model discloses a 20kV steel core abrasion-resistant overhead insulated cable, which comprises an inner core, an aluminum single-line multilayer stranded conductor, a semi-conductive conductor shielding layer, an insulated layer, a semi-conductive insulated shield layer, and a nylon wear-resistant protecting layer which are arranged in turn from the inside to the outside, wherein the inner core is an aluminum-coated steel stranded wire. The 20kV steel core abrasion-resistant overhead insulated cable has advantages of reduced cable weight, reduced cable arc sag and increased pole clearance when erecting the cable, and reduced number of towers.

Description

20kV steel core wear-resistant overhead insulated cable

technical field

The utility model relates to a 20kV steel core wear-resistant overhead insulated cable.

Background technique

In 1956, my country's Ministry of Electric Power Industry began to promote 10kV power distribution across the country. The power distribution network adopts 10kV power supply, which has played an important role in promoting the development of my country's economy and power grid. my country has always used 10kV as the medium-voltage distribution voltage, and 65% of the power supply is output through the 10kV level. However, with the continuous and rapid economic development and the continuous improvement of the urbanization level, the 10kV power distribution system is increasingly showing defects such as small capacity, large loss, and large land occupation.

In view of the defects in the distribution network, it is necessary to introduce a distribution voltage level of 20kV from the perspective of urban power grid development and load growth. The emergence of 20kV voltage level is to increase the medium-voltage distribution voltage and meet the needs of load density growth and power grid development. From the analysis of increasing the capacity of the distribution network, reducing the voltage loss on the line, increasing the power supply radius of the distribution network, and reducing line loss, it has greater advantages than the 10kV level. The application of 20kV power supply system can not only improve power supply capacity, reduce land occupation, reduce construction investment, reduce loss and improve voltage household quality, but also simplify voltage level and cancel 10kV and 35kV voltage level. Reduce operating costs and improve power quality. The 20kV power supply system needs to be equipped with 20kV overhead insulated cables. The existing 20kV overhead insulated cables mostly use copper core overhead insulated cables. Due to the large unit mass of copper, the overhanging arc of the line will increase, the span will decrease, and the number of towers will increase. At the same time, due to the high price of copper, it will increase Engineering costs for large lines.

Utility model content

The utility model provides a 20kV steel-core wear-resistant aerial insulated cable to avoid the disadvantages of the above-mentioned prior art, so as to solve the problems of increasing the hanging radian of the existing cable and increasing the number of poles and towers.

The utility model provides a 20kV steel core wear-resistant overhead insulated cable.

20kV steel core wear-resistant overhead insulated cable, its structural characteristics are, from inside to outside: inner core, aluminum single-wire multi-layer stranded conductor, semi-conductive conductor shield, insulation layer, semi-conductive insulation shield and nylon wear-resistant The sheath layer; the inner core is an aluminum-clad steel strand.

Compared with the prior art, the beneficial effects of the utility model are reflected in:

The 20kV steel core wear-resistant overhead insulated cable of the utility model is composed of an aluminum-clad steel wire, a stranded aluminum conductor, a semi-conductive conductor shielding layer, an insulating layer, a semi-conductive insulating shielding layer and a nylon wear-resistant sheath layer.

In order to increase the tensile strength of the cable and carry the weight of the cable, the conductor core of the overhead insulated cable uses aluminum-clad steel wire as the load-bearing core, mainly because the aluminum-clad aluminum wire has excellent conductivity. The resistivity of the aluminum-clad steel-reinforced aluminum stranded wire is reduced by about 3% to 4%, which greatly reduces the line loss. In terms of strength, use aluminum-clad steel wire instead of galvanized steel wire. Since the tensile strength of aluminum-clad steel wire is higher than that of galvanized steel wire, the strength of the wire can be increased by 2% to 4%. In terms of weight per unit length of stranded wire , Aluminum-clad steel-reinforced aluminum stranded wire is 3% to 4% lower than steel-reinforced aluminum stranded wire. Therefore, the sag of the cable can be reduced when the line is erected, the pole distance can be increased, and the total cost of the project can be reduced.

The semi-conductive conductor shielding layer acts on the same potential as the shielded conductor and is in good contact with the insulating layer, so as to avoid partial discharge between the conductor and the insulating layer. The semi-conductive insulating shielding layer is in good contact with the insulating layer, and its main function is to eliminate the phenomenon of discharge between the insulating layer and the sheath layer.

Wear-resistant nylon material has good electrical performance, wear resistance, heat resistance, oil resistance and chemical resistance. Wear-resistant nylon material also has excellent electrical insulation performance and will not affect the insulation performance due to moisture. Therefore, the outer sheath is covered with a sheath layer of silver-gray nylon material. It not only increases the insulation performance of the cable but also increases the wear resistance of the cable, and also changes the visual effect of the overhead insulated cable.

The 20kV steel core wear-resistant overhead insulated cable of the utility model has the advantages of reducing the weight of the cable, reducing the sag of the cable when erecting the line, increasing the distance between the poles, and reducing the number of poles and towers.

Description of drawings

Fig. 1 is a structural diagram of a 20kV steel core wear-resistant overhead insulated cable of the present invention.

Numbers in Figure 1: 1 inner core, 2 aluminum single-wire multi-layer stranded conductor, 3 semi-conductive conductor shielding layer, 4 insulating layer, 5 semi-conductive insulating shielding layer, 6 nylon wear-resistant sheath layer.

The utility model will be further described below through specific embodiments in conjunction with the accompanying drawings.

Detailed ways

See Figure 1, 20kV steel core wear-resistant overhead insulated cable, from inside to outside are: inner core 1, aluminum single-wire multi-layer stranded conductor 2, semi-conductive conductor shielding layer 3, insulating layer 4, semi-conductive insulating shielding layer 5 And a nylon wear-resistant sheath layer 6; the inner core 1 is an aluminum-clad steel strand.

The cable conductor structure uses a 1 or 1+6 aluminum-clad steel wire 1 as the inner core, and the outer layer is an aluminum-clad steel-cored aluminum stranded conductor formed by twisting multiple layers of aluminum single wires 2 at a time.

The surface of the conductor is evenly covered with semi-conductive conductor shielding layer 3, insulating layer 4 and semi-conductive insulating shielding layer 5, and the wire core is produced by three-layer co-extrusion of the dry cross-linking production line at the same time, which ensures the inner and outer shielding layers and insulation of the wire core. Layer eccentricity.

The outermost layer of the cable is covered with a silver-gray nylon wear-resistant sheath layer 6, which is extruded at one time by a specially designed mold to ensure the eccentricity of the sheath.

The 20kV steel core wear-resistant overhead insulated cable of the utility model has the excellent conductivity, insulation and weather resistance of the black overhead cable; the designed long-term operation allows a maximum temperature of 90 ° C; the allowable maximum temperature of 250 ° C when the conductor is short-circuited; the elongation at break 200%; the cable has a good overload temperature coefficient, excellent thermal stability and wear resistance. It also has the advantages of high tensile strength of steel-cored aluminum stranded wire, while ensuring the safe operation of the transmission line. It also meets the requirements of urban distribution network to adapt to urban beautification and lighting.

The 20kV steel core wear-resistant overhead insulated cable of the utility model is suitable for fixed laying on the AC 50Hz, rated voltage 20kV power transmission and distribution lines for power transmission and distribution. In addition to the excellent conductivity, insulation and weather resistance of the black overhead cable In addition, it also has the advantages of high tensile strength and high conductivity of aluminum-clad steel-cored aluminum stranded wire, which improves the self-supporting and anti-vibration performance of the cable. Increase the span of cable erection, reduce the number of towers, save the construction cost of line engineering,

The insulating layer is made of cross-linked polyethylene insulating material. Because the cross-linked polyethylene insulating material has excellent electrical insulation properties, the outer diameter of this product is smaller than that of traditional cables with the same specification and section, and the weight of the cable product is 10% lighter. Left and right, easier to install and transport, reduce labor intensity and reduce transportation costs.

The outer sheath layer uses a new silver-gray nylon wear-resistant material. The appearance of the cable has changed the black appearance of the traditional overhead insulated cable, which not only increases the insulation performance of the cable, but also reduces the visual pollution of urban space. The cable also has excellent electrical insulation properties and will not be affected by environmental humidity. At the same time, the abrasion resistance of the cable is increased. While ensuring the safe operation of power transmission and transformation lines. It also meets the requirements of urban distribution network to adapt to urban beautification and lighting.

Claims (1)

1. 20kV steel core wear-resistant overhead insulated cable is characterized in that, from inside to outside, it is: inner core (1), aluminum single-wire multi-layer stranded conductor (2), semi-conductive conductor shielding layer (3), insulating layer ( 4), a semi-conductive insulating shielding layer (5) and a nylon wear-resistant sheath layer (6); the inner core (1) is an aluminum-clad steel strand.