Aluminum alloy cable is a very mature high-tech environmental protection and energy-saving green power cable, which has been widely used in developed countries in Europe and the United States for 40 years; It accounts for up to 90% of the power cable market in developed countries in Europe and the United States. Aluminum alloy cable not only completely replaces the traditional copper core cable in terms of electrical performance and safety performance, but more importantly, on the premise of meeting the same electrical performance, its cost is less than 50% of the traditional copper core cable, which saves a lot of power facilities for the project investors. We will further pay attention to the safety, progress, quality and investment of the project, and control the investment cost, which is in line with the development theme of building an energy-saving society in China, green energy conservation Economic and environmental protection
the development of aluminum alloy cables in China in recent 10 years has been widely used in all walks of life. Especially in recent years, the comprehensive application of some well-known domestic alloy cable manufacturers' products in many large-scale power projects, such as the universal application of Huaxing aluminum alloy cable in professional power projects of electric and wind power generation projects in recent years, has further consolidated the significant advantages of aluminum alloy cable in comprehensive application performance.
through the analysis of cable Bao Market Research Center according to relevant data such as industry brand influence, market share and enterprise size, The following enterprises were shortlisted as the top ten domestic aluminum alloy cable manufacturers:
top ten aluminum alloy cable manufacturers
Jiangsu Shangshang cable group
Henan Huaxing alloy cable Co., Ltd.
Aluminum (Tianjin) Alloy products Co., Ltd.
Jinbei Electric Co., Ltd.
Shanghai Moen Electric Co., Ltd.
Zhejiang Wanma Co., Ltd.
Aerospace Electric Group Co., Ltd.
Anhui Xinyi Cable Co., Ltd.
Sichuan Wanyang Cable Co., Ltd.
national standards for aluminum alloy cables. See:
[performance and application advantages of aluminum alloy cables]
1 Cable ampacity
◆ when the sectional area of the alloy conductor is 1.5 times that of copper, the electrical properties of the alloy conductor and the copper conductor are the same, realizing the same ampacity, resistance, and voltage loss
◆ the resistivity of aluminum alloy is between aluminum and copper, slightly higher than aluminum, but lower than copper. Under the premise of the same intercepting flow, the weight of aluminum alloy conductor with the same length is only half of copper. If the conductivity of copper is 100%, the purpose of conductivity of alloy conductor is to further listen to the opinion rate of the Council is about 61.2%, the specific gravity of alloy is 2.7, and the specific gravity of copper is 8.9, then (8.9/2.7) (0.612/1) =2, that is, the resistance of copper per unit weight is the same as that of alloy per unit mass. Therefore, when the sectional area of alloy conductor is 1.5 times that of copper, its electrical performance is the same, that is, it realizes the same cut-off flow, resistance, and voltage loss as copper
◆ there are many factors affecting the cut-off flow of power cables, such as; Line characteristics (such as working power, current type, frequency, load factor); The structure of wires and cables (such as the structure of conductor cores, the number of cores, the type of insulating materials, the structure and materials of shielding layers and inner and outer protective layers, and the total outer diameter); Laying conditions (such as laying in air, laying in pipeline, directly buried laying, laying in underground channel, and laying under water); The maximum allowable working temperature of conductive core and surrounding environmental conditions (such as air and soil temperature, soil thermal resistance coefficient, proximity effect of surrounding heat sources), etc
2. Reduce the outer section of the cable
in the production process of aluminum alloy cable, the most advanced compression technology is adopted, so that the filling coefficient of its conductor can reach 93%. And the aluminum alloy cable adopts silane crosslinked polyethylene, which can far exceed the conventional insulation performance with only 2/3 of the thickness of PVC. The filling coefficient of copper can only reach 80% generally, and PVC is commonly used for insulation, so the outer diameter of aluminum alloy cable can only be increased by less than 11% on the basis of copper cable, so it can have the same electrical performance as copper. It can be seen that using aluminum alloy cables does not need to change the original pipeline design using copper cables. (generally, the laying pipe size designed by the designer is 150% of the copper cable. Recently, considering the problem of capacity expansion, the laying pipe size has increased to 200% of the copper cable, so it is not a problem to pass through the pipe.)
3. Reduce cable line loss
non magnetic materials will not produce eddy current and can reduce line loss. Aluminum alloy belt armor lock material is non-magnetic material, even if there is three-phase unbalanced current, it will not produce eddy current, which can reduce the loss of the line
mechanical properties of aluminum alloy cables
1. Extension properties of aluminum alloy cables
elongation is an important indicator of the mechanical properties of conductors and an important symbol of the quality of products and the size of external forces that they can withstand. It is also an important index for testing the mechanical properties of cable conductors. The elongation of aluminum alloy cable after annealing can reach 30%, while the elongation of copper cable is 25%, and the elongation of ordinary aluminum rod is 15%, which is an important index to replace aluminum core cable and copper cable
2. Flexibility of aluminum alloy cable
torsion test: it mainly tests the toughness of metal wires. The better the toughness, the more torsion times it can withstand. An important disadvantage of ordinary aluminum wire is its high brittleness. As long as it is twisted at a certain angle for several times during installation, the conductor will produce cracks, and the cracks will be heated and corroded, which is an important cause of fire. Using aluminum alloy cable, because of its good toughness, it will not produce cracks, and the potential safety hazards in installation will be reduced
3. Bending performance of aluminum alloy cable
bending test: mainly tests the bending resistance of metal. Uneven or brittle materials have poor bending resistance
according to gb/t12706 on the bending radius of copper cable installation, the bending radius of copper cable is times the cable diameter, and the minimum bending radius of aluminum alloy cable is 7 times the cable diameter. Using aluminum alloy cable can reduce the layout space, make it easier to lay and reduce the installation cost
4. Rebound performance of aluminum alloy cable
practice has proved that when the copper cable and aluminum alloy cable are bent 90 degrees at room temperature, the rebound angle of aluminum alloy cable is 60% of that of copper cable after stress release. Because the aluminum alloy cable has no memory, its rebound performance is better than that of copper core cable. During the installation process, the terminal connection joint is easy to compress, which increases its tightness and improves the stability of the connection
service life of aluminum alloy cable
1 there are two main types of conductor corrosion: chemical corrosion and electrochemical corrosion
◆ chemical corrosion: refers to the corrosion of metals in the atmosphere with oxygen, chlorine, sulfur dioxide, hydrogen sulfide and other gases
different metal oxides are formed after the metal surface reacts with oxygen
aluminum oxide can form a dense surface protective film with a certain hardness
the oxide structure of iron is loose and easy to fall off, and continues to penetrate and diffuse into the metal, damaging the material
copper oxide, commonly known as copper green, is between the above two and is a toxic substance
◆ electrochemical corrosion: refers to the corrosion process of metal after the primary cell is composed of metal and medium. When two metals with different electrode potentials are connected, and there is water or other electrolyte between them, an electric current will be generated between the two metals to form a primary cell, in which one metal is at a positive potential and the other is at a negative potential, and the metal at a negative potential will continuously accumulate to the metal at a positive potential through the electrolyte in an ionic state. Make the metal at negative potential gradually lose and destroy, forming electrochemical corrosion. The greater the difference between the electrode potentials of the two metals, the stronger the electrochemical corrosion. The higher the temperature, the more serious the corrosion of metal
different metals have different electrode potentials. The order of electrode potentials of several commonly used metals is; Metal Ag (silver) Cu (copper) Pb (lead) Sn (TIN) Fe (iron) Zn (zinc) A1 (aluminum). Potential +0.8+0 33 the greater the negative value of electrode potential, the stronger the trend of metal transferring into electrolyte to become ions, that is, the more vulnerable it is to corrosion. The negative value of the electrode potential of aluminum is large, but its surface often has an oxide film protective layer, which can improve its corrosion resistance
rare earth aluminum alloy material is to add rare earth elements to aluminum, which can purify, improve purity, fill surface defects and refine grains. Reduce segregation, eliminate the effect of local corrosion caused by micro unevenness, and also bring negative shift of electrode potential of aluminum, which has the anode effect and excellent conductivity, thus greatly improving the corrosion resistance of aluminum. For the corrosion problems of c1- in marine environment and s, h2s+c02 in petroleum and chemical environment, this material has a unique anti-corrosion mechanism. The strong reducibility of rare earth metals can effectively combine and interact with the strong oxidation of S, H2S, c1- to form stable compounds (c1- and rare earth aluminum alloys form stable coordination compounds), organically unify and interact the oxidation and reduction processes in chemical reactions, and fundamentally stop the corrosion damage caused by the oxidation activities of corrosive media such as s, H2S, c1-, Thus, the problems that cannot be solved well in developed countries including the United States around the world have been completely solved. The detection and engineering case data analysis of national testing departments such as Beijing Nonferrous Metals Research Institute show that the annual corrosion rate of rare earth aluminum alloy is zero or almost zero under the conditions of chloride ion, sea water, marine atmosphere, salt spray environment (alternating wet and dry), saturated HZS, sulfur, high temperature and high pressure environment
2. Insulation part
◆ the current carrying capacity of power cable refers to the maximum current that the cable conductor is allowed to pass under the maximum allowable temperature. When designing and selecting cables, the heat generated by the loss of each part of the cable should not exceed the maximum allowable temperature of the cable. In most cases, the transmission capacity of the cable is determined by the maximum temperature of the cable. The maximum allowable temperature of the cable mainly depends on the thermal aging performance of the insulation material used, because the cable working temperature is too high, the aging of the insulation material will accelerate, and the cable life will be greatly shortened. If the cable operates above the maximum allowable temperature, the cable will work safely for 30 years
◆ XLPE is the abbreviation of the English name of cross-linked polyethylene. Polyethylene is a linear molecular structure, which is easily deformed at high temperature. The process of crosslinking polyethylene makes it become a kind of like structure. This structure has strong deformation resistance even at high temperature
◆ the excellent aging resistance and super heat-resistant deformation of XLPE determine that large current can be allowed to pass under the conditions of normal operating temperature (90C), short-term fault (130c) and short circuit (250C). Because its operating temperature is 20c higher than that of PVC, it has excellent heat resistance and increases the aging resistance of insulation. 12 The service life of electromechanical drive system is greatly increased
economic performance of aluminum alloy cable
◆ direct procurement cost
price comparison between aluminum alloy cable and copper core cable: on the premise that aluminum alloy cable has superior safety performance, electrical performance, mechanical performance and longer service life, the price of aluminum alloy cable is only about 40% of that of copper cable
◆ reduce installation cost
save installation cost: because aluminum is not an easy thing, gold cable has good bending performance and light weight, which is easy to install
the installation and laying of aluminum alloy cables do not need bridges and pipes, which can save a lot of installation materials and reduce the installation cost by 20% - 50%