Wire and cable is composed of a root or more insulated conductors and outsourcing insulation layer is made, will power or information transfer from one place to another wire. Conductor is the core of it, lose the conduction function of conductor, wire and cable has lost its value. Represented by copper aluminum and other metal conductor of the "traditional", how to resist "aluminum alloy, the fiber, carbon fiber", "new power", is the new material such as representative of expectations appear more attractive.
First, the metal conductor
Now common metal conductor arranged according to the electrical conductivity, followed by gold, silver, copper, aluminum, iron (steel) and so on, but comprehensive considering the application on the wire and cable conductor cost factors such as raw materials, copper and aluminum is a high cost performance, especially the copper, the price was lower than those of gold, silver, electrical conductivity and better than aluminum, is the most commonly used cable conductor.
1, copper conductor
Cable to the national standard is the oxygen-free copper, copper conductor used wire and cable industry is a heavy material light industrial industry, according to relevant statistics show that wire and cable with copper content accounts for about 60-70% of the copper consumption. Copper conductor is copper wire and cable core parts, no matter how external technical change and progress, the cost of copper conductors are accounted for the lion's share of the total cost of wire and cable, is said to be as high as 75% above. With the depletion of copper resources in China and the rise in copper prices, while copper is still a cable conductor of the "big brother", but people have begun to actively seek alternatives.
2, aluminum conductor
Aluminum extremely rich mineral resources in China, is one of the world's ten bauxite resources and reserves of 2.503 billion tons. As early as in 1957, our country has put "by aluminum and copper" identified as a national technology policy. S and seventy s, because the copper as a strategic material is restraint of trade, domestic aluminum has been widely used as the main transmission cable conductor materials. However, in comparison with copper conductors, pure aluminium conductor low melting point, high resistivity, oxidation resistance is poor, poor mechanical strength, often leads to overheating, the problem such as corrosion, short circuit, in the early ninety s, gradually withdraw from the low-voltage distribution market, but there are still used in the field of high voltage power transmission.
3, combination of metal conductor
Is a kind of composite wires: using the high frequency signal, the current "skin effect", in the high frequency signal transmission (greater than 5 MHZ) and electric current, the transmission performance is the same as the surface of the metal conductor wire. Such as copper clad aluminum wire (compared with those shoddy), through the use of advanced cladding welding manufacturing technology, make such conductor has a unique composite performance, without reducing transmission performance at the same time to reduce costs, increase strength, etc. One is reinforced wire: by composed of two different conductors twisted. Such as aluminium stranded wire and steel core function increase the strength of the main, aluminium conductor mainly ACTS as transmit power, suitable for overhead transmission lines, especially in the field of high voltage power transmission.
Second, the alloy metal conductor
We usually mean by metal is elemental metal. Alloy is composed of two or more than two kinds of metal and nonmetal by certain method of synthesis of material with metal properties. Although broadly as part of the metal alloy metal, but is not metal mixture on chemical classification.
Using the alloy of metal on cable conductor mainly refers to aluminum alloy conductor, due to the pure aluminium conductor various deficiencies, aluminum alloy conductor arises at the historic moment. Among them, the AA8030 series aluminum alloy materials for aluminium alloy power cable conductor, the conductor is the use of special compression technology and the advanced technology such as annealing treatment invention of new materials. The conductivity of the aluminum alloy is the most commonly used benchmark material copper 61.8% IACS, carrying capacity is 79% of the copper, on the premise of meet the same electrical performance, using half the weight of the aluminum alloy cable is copper cable, the cross section of 1.1 ~ 1.25 times that of the traditional copper cable, price is 15-30% lower than the traditional copper cable.
Three, non-metallic materials, or is given priority to with the conductor
Nonmetallic material made of nonmetal elements or compounds, with the development of inorganic chemistry and organic chemistry industry, human to natural mineral, plant, such as oil as raw materials, manufacturing and synthesized many new nonmetal material, widely used in many fields. In wire and cable conductor choice, optical fiber and carbon fiber is representative of this materials.
1, optical fiber
Fiber optics is the shorthand of optical fiber, is a kind of fiber made of glass or plastic, can be used as light transmission tool. Transmission principle is "total reflection of light", so usually is used for signal transmission. Beginning, fiber made from glass fiber (main ingredient is silicon dioxide), as the technology progress, people began to incorporating different elements, to control the distribution of refractive index of fiber core and cladding, in order to meet different needs.
It is important to note that although in general is not conductive fiber, but the use of optical fiber transmission has proven to be feasible, although the study is in the experimental stage at present, but as a result of optical fiber transmission power loss is low, conductive fiber is still has the research value.
2, carbon fiber
Carbon fiber is a kind of carbon content in more than 95% of the high strength and high modulus fibers of new fiber materials. Carbon fiber conductor is divided into: pure carbon fiber and carbon fiber as base with composite conductive composed of aluminium or copper stranded core body, made of wire, it is mainly used for overhead line, has the advantages of low sag, qualitative light, low transmission loss, corrosion resistance and other characteristics, represents the future technology development trend of overhead conductors. The ACCC carbon fiber composite wire is the current electric power transmission systems around the world ideal to replace the traditional steel reinforced aluminum hinge wires, aluminum clad steel wire, aluminum alloy wire and imported invar lead new product.
3, conductive plastic
Conductive plastic resin and conductive material (carbon) is often mixed with plastic processing way to carry on the processing of functional polymer materials. Mainly used in electronics, integrated circuit packaging, electromagnetic shielding, etc. Among them, the carbon black filled conductive plastics are used in high voltage cable, communication cable, is used as a medium and high voltage cable semi conductive layer shielding material, use semi-conducting layer of conductive plastic, to ease the conductor surface voltage gradient, prevent partial discharge between the conductor and semiconductor. At present, this kind of products each year about thousands of tons of domestic market demand, which is used in high voltage cable basically rely on imports. With the deepening of the research on electrically conductive plastic people, perhaps, the future we can expect it to play a bigger role in transmission.
Conclusion: in the conductor, copper, aluminum and other metal conductor can be described as a "traditional" cable conductor industry, aluminum alloy, such as optical fiber, carbon fiber is the emerging "new forces", as the old and new forces, power and signal transmission will be more economical, more environmental protection and more efficient.