Performance of aluminum alloy power cable
I. Safety performance
1. In China, the connector passed the IECl000 time thermal cycle test standard.
2. In North America, it has passed the IECl000 thermal cycle test standard for cold water quenched joints made by authoritative testing laboratories based on long-term operation (more than 30 years).
Second, electrical conductivity.
6 1% copper (IACS) is the most commonly used reference material. Its thermal conductivity is second only to silver, copper and gold. Therefore, it has become a conductive material with wide application and the largest output at home and abroad.
The performance of the produced high strength aluminum alloy power cable meets the requirements of the International Electrotechnical Commission (IEC). With the increasing output and consumption, it has been applied in various fields, and achieved good economic benefits, saved a lot of costs and improved the line quality.
Third, corrosion resistance.
When the surface comes into contact with air, a thin and firm oxide layer will be formed immediately. Aluminum alloy has the characteristics of withstanding the worst environment, so aluminum alloy is widely used as the conductor of cables in trays. In sulfur-containing environment, such as railway tunnels and other similar places, the corrosion resistance of aluminum cables is much better than that of copper cables.
Fourth, mechanical properties.
1, the resilience is 40% less than that of copper cable;
2. The flexibility is 25% higher than that of copper cable;
3. The bending performance is good, and the laying radius is far less than the requirement of copper cable, so it is easier to lay and connect terminals;
4. The special formula and heat treatment process greatly reduce the "creep" tendency of metals under high temperature and high pressure. The electrical connection made of aluminum alloy conductor is as stable as that made of copper conductor;
5. The thermal expansion coefficient is slightly higher than that of copper cable, and the expansion or contraction is a little more than that of copper. Therefore, aluminum alloy wires cannot be connected with copper joints, but with transition joints to ensure safe operation.
Verb (abbreviation for verb) connectivity
This is the fundamental reason of alloy conductor material (ACW). Especially when the conductor meets fire, the added iron produces high-strength creep resistance, which can ensure the stability of the connection even if it is overloaded and overheated for a long time. When using CSA-approved 900C mechanical connectors (marked as AL9CU or AL90CU), the test results of connectors in the test facilities provided by GeorgiaPower show that their performance is the same as that of copper wires connected in the same way.
Economic achievements of intransitive verbs
The direct purchasing cost of aluminum alloy power cables (including special terminals) is lower than that of copper cables15%-20%; General building saving 15%-20% or more, long-span building saving more than 30%. Taking two power plants with 600,000 kW units as an example, the cost of using copper core cable is about 300 million yuan, and the use of aluminum alloy power cable saves 30%. This can not only save a lot of government and enterprise investment, but also have an inestimable impact on the creation of a conservation-oriented society and country.
Advantages of aluminum alloy power cable
1. Creep strength
The alloy material and annealing process reduce the "creep" tendency of the conductor under heat and pressure, and the creep resistance is improved by 300% compared with pure aluminum, thus avoiding the relaxation problem caused by cold flow or creep.
2. Tensile strength and elongation
Compared with pure aluminum conductor, aluminum alloy conductor is added with special components and processing technology, and its tensile strength and elongation are improved to 30%, making it safer and more reliable to use.
3. Thermal expansion coefficient
The coefficient of thermal expansion of aluminum alloy is equivalent to that of copper. For many years, aluminum connectors have been reliably used for copper and aluminum conductors, and most electrical connectors used today are made of aluminum, which is especially suitable for aluminum alloys. Therefore, the expansion and contraction of aluminum alloy conductor and connector are completely consistent.
4. Connection performance
The composition of aluminum alloy greatly improves its connection performance. When the conductor is annealed, the added iron produces high strength creep resistance, which can ensure the connection stability even if it is overloaded and overheated for a long time.
5. Strong self-weight bearing capacity
Aluminum alloy improves the tensile strength of pure aluminum. Aluminum cable can support 4000m self-weight, and copper cable can only support 2750m m. This advantage is particularly prominent in the wiring of long-span buildings, such as stadiums.
6. Corrosion resistance
Corrosion is related to the environment, and protective measures can be taken to prevent corrosion. Such as the use of lubricating oils, antioxidants and protective coatings. Alkaline soil and acidic soil environment are corrosive to aluminum, and aluminum conductors should be protected by insulating layer or molded sheath. In sulfur-containing environment, the corrosion resistance of aluminum alloy is much better than that of copper.
7, good bending performance
Its unique alloy formula and processing technology greatly improve its flexibility. The flexibility of aluminum alloy is 30% higher than that of copper, and the elasticity is 40% lower than that of copper. Generally, the bending radius of copper cable is 10~20 times of the outer diameter, while the bending radius of aluminum cable is only 7 times of the outer diameter, making it easier to connect terminals.
8. Advantages of aluminum alloy armor
According to the American standard, the metal interlocking armored cable adopts aluminum alloy belt interlocking armor, which ensures that it can withstand strong destructive power from the outside and is not easy to be broken down when it is subjected to great pressure and impact, which improves the safety performance, flame retardancy and fire resistance, and reduces the fire risk coefficient. Compared with steel belt armored structure, aluminum alloy belt armored structure has the advantages of light weight, convenient laying, no bridge installation and 20%~40% reduction in installation cost.
9. Compaction characteristics between conductors
We adopt unconventional compaction technology, which makes the compaction coefficient reach 0.93, while the compaction coefficient of special-shaped line can reach 0.95, which is the first in China. Through maximum compression, the deficiency of aluminum alloy in volume conductivity can be made up, so that the stranded conductor core is like a solid conductor, the outer diameter of the core is obviously reduced and the conductivity is improved. Under the same current carrying capacity, the outer diameter of conductor is only 10% larger than that of copper cable.