Future development trend of aluminum alloy wire

At present, many countries in the world use aluminum alloy wires on the line, mainly aluminum alloys of high strength, medium strength and heat resistance. High-strength aluminum alloy conductors are mainly used in medium-to-heavy ice areas and across line areas to increase the span between line towers, reduce the number of towers and floor space, and ultimately increase the conductivity of the conductors; and heat-resistant aluminum alloy wires It is mainly used in areas where capacity expansion is required, tension in the line corridors, economically developed cities, and peaks and valleys in electricity consumption are large, and construction periods are required to be short.

High-strength aluminum alloy products (using Al-Mg-Si heat-treated high-strength aluminum alloy wire as an example), the application surface and development trend of the world's advanced industrial countries, aluminum alloy wire and steel-cored aluminum stranded wire, due to its high strength , light weight, and good electrical conductivity (53%IACS) and other advantages. As early as 1921, it was used for overhead lines. With the improvement of transmission and transformation technologies and the development of power transmission lines, aluminum alloy wires have increasingly demonstrated their superiority. They have been used since 1950s in the world, and have been widely adopted in Western Europe, Northern Europe, the United States, Canada, and Japan. In France, almost 90% of the transmission lines in France use aluminum alloy wires, and Japan has also reached more than 50%. The use of Southeast Asian countries has been increasing year by year (China's current application is less than 2%). This is due to the fact that aluminum alloy wires are superior to steel-cored aluminum stranded wires because of their incomparable advantages. They have an exclusive advantage in long distances, large spans, and ultra-high voltage transmissions. In rural power grid reconstruction, they are both advanced and economical. A good product, it is a replacement product of common ACSR, and it is also a product of energy saving, material saving and land saving (saving the transmission corridor).

The earliest high-strength aluminum alloy wire was produced in Switzerland in 1921 under the trade name Aldrey. Later, various countries developed and produced many different brands, such as Simalec (United Kingdom), Almelec (France), 6201 (United Kingdom), and Nickname (Japan). , Aж (former Soviet Union), SI-33 (Japan), etc. In general, these high-strength aluminum alloys belong to the heat-treatable Al-Mg-Si alloys, and after many years of experience, the formulas and elemental composition of the alloys have remained basically unchanged and have been used up to now, but with the development of technology, manufacturing New developments have been made in such areas as process and equipment control.

Medium strength aluminum alloy stranded wire is now widely used in foreign countries. Especially in Europe, if more than 50% of the transmission lines in France use AAAC, their applications in Germany and the Nordic countries (Sweden, Norway, Iceland, etc.) are also very common, and the United States has applications; but it is seen in the literature about its operation. Very little information. According to the overseas bidding information provided by Shanghai Zhongtian Aluminum Wire Co., Ltd. in recent years, the application of medium-strength all-aluminum stranded wires in South America, Africa, India and other countries and regions has increased rapidly in recent years. Thousands of kilometers are more than a few kilometers, and the voltage level is from 66kV to 500kV. China also uses AAAC wires on a small number of 220kV and ±500kV lines. Among them, the ±500kV Tianguang four-times total length of 230 kilometers and the 10 kilometers high-altitude Daling block used JLHA2(2)-400(37/3.9).

Heat-resistant aluminum alloy wires are mainly used in high-voltage and extra-high voltage overhead lines for large-capacity wires, high-current ground wires, large-span wires, and high-current busbars for substations. In addition, heat-resistant aluminum alloy wires are also used in retrofitting of old wires. It is possible to increase the line capacity by more than 50% without changing the height of the tower or changing the line corridor, so as to obtain a good technical and economical effect. At present, the heat-resistant aluminum alloy wire is mainly composed of four types: high conductivity, high strength, super heat resistance, and special heat resistance. The most widely used in practical use are high-conductivity (60% IACS) heat-resistant aluminum alloy wires and high-strength heat-resistance (tensile strength 240 MPa, conductivity 55% IACS), and the conductivity is 58% IACS. Aluminum alloy wire has basically been eliminated.

Because the heat-resistant aluminum alloy wire can deliver more electric energy than a common steel-cored aluminum stranded wire of the same specification, it has attracted people's attention shortly after it was introduced, and with the continuous improvement of performance and the increasing variety, it has been decades. Its application has been greatly developed. Japan began to use heat-resistant aluminum alloy wires in transmission lines since 1960. Except for the use of heat-resistant aluminum alloy wires in the busbars of substations, the wires of Japan's 500kV transmission lines had all been made of heat-resistant aluminum in 1990. Alloy wire. With the increase of power demand, Japan has used a large number of steel core 60% conductive heat-resisting aluminum alloy strands (60TACSR) instead of ordinary ACSR, and the usage amount has reached the national level before and after 2000. 70% of the total length of transmission lines. In the United States, Canada, and France, the use of heat-resistant aluminum alloy wires on transmission lines is also considerable. In the past 20 years, the use of heat-resistant aluminum alloy wires in Southeast Asia has also grown.

According to the continuous promotion of the use of medium-strength aluminum alloys, high-strength aluminum alloys and heat-resistant aluminum alloy wires by State Grid Corporation, many domestic manufacturers have aroused great interest in aluminum alloy wires. Experts on the development trend of aluminum alloy products. It is believed that with the maturity of the industrial production technology of aluminum alloy wires represented by medium-strength aluminum alloy wires, the expansion of market size will effectively reduce the price of new products. Under the drive of market demand-oriented, aluminum alloy series wires will surely Become an alternative to ACSR.