Is the aluminum coil transformer good?
Huarui Electric has observed that in recent years, the global output of aluminum coil transformers is huge, and the phenomenon that some of them use aluminum as copper is prominent. Many people define the transformer made of aluminum coil (distribution transformer) as “transformer fraud”, and attribute many transformer accidents to “replacing copper with aluminum”! It really obliterates the legitimacy of this product and its contribution at a specific historical stage.
1、 Aluminum wire transformer is in line with national standards. It is not only a product allowed by the state, but also a product with international standards. It is also a product recognized by developed countries.
According to the statistics of China’s State Grid, China’s transformer market has been close to 500 billion yuan in 2019, and it is predicted to reach 600 billion yuan in 2025.
From 2005 to 2010, the transformer market was in short supply, and the global copper price once reached 80000 yuan / ton. The high cost caused great pressure on the market. The solution to the contradiction is to increase the mining and smelting of global copper mines, but it is also facing great pressure on environmental protection and energy consumption.
Just at this time, the transformer technology of aluminum coil in western countries and Japan was introduced by global manufacturers (at that time, the price of aluminum was only more than 10000 / ton).
As early as the 20th century, the production of transformers in European countries also adopted a large number of aluminum coil schemes and mature technical standards. Up to now, aluminum core transformers are still widely used in Europe and America, and there is a huge stock market in Europe and America. Fuji, including Japan, has also been producing aluminum core transformers in Suzhou.
Since the introduction of aluminum coil transformer technology into the world, thousands of small and medium-sized transformer plants around the world have adopted this technology. After more than a decade of optimization and technological upgrading, it has become a very mature product. Its emergence has solved the shortage of copper materials and energy saving problems, and saved huge costs for the national infrastructure.
From a technical point of view, the aluminum coil for epoxy resin cast dry-type transformer is better. Because the expansion coefficient of aluminum is closer to that of epoxy resin than that of copper, it is better for the safety of transformer.
Therefore, in Europe, most epoxy cast transformers use aluminum coils. As long as the manufacturing quality is qualified, there will be no problem in the use of aluminum coil transformer.
China has also issued the corresponding national technical standards for aluminum coil transformers. For example, for dry-type transformers with aluminum coils, the model is marked as SCLB
2、 The harm of “replacing copper with aluminum” in the field of power transmission should not be blamed on aluminum core transformers
According to the Research Report on the strategic planning of the application of China’s copper and aluminum resources in the power cable Market issued by the Institute of resources and environmental policy of China National Development Research Center, through the comparative analysis of copper aluminum alloy conductors and cables, it is concluded that it is not suitable to “replace copper with aluminum” in the field of power transmission.
According to the statistics of transformer fire accidents, the Research Report on transformer faults from all over the world shows that 23.44% of 100 transformer faults will cause significant social harm, including 7.16% fire, 5.91% explosion, 4.24% leakage and 6.13% other damage.
However, most of the fires and accidents caused by it are caused by overload, which is related to the quality of the transformer and the comprehensive environment of power grid operation, and has little to do with whether it is made of copper or aluminum.
The environment of cables in the power grid is different. Most of them are exposed. “Replacing copper with aluminum” will form a direct ignition point. The coil of the transformer is closed in the pouring coil or oil tank. The harm caused by the two is different. The black pot of wire and cable fire accidents should not be carried by the transformer!
3、 “Replacing copper with aluminum” belongs to business ethics, not product quality
“Replacing copper with aluminum” in transformer refers to the phenomenon that the winding of distribution transformer uses aluminum, aluminum alloy or copper-clad aluminum to replace copper without truthfully identifying it in the nameplate.
“Replacing copper with aluminum” is a problem of business integrity and business ethics, not product quality. At present, the price of copper is about 66000 yuan / ton, and the price of aluminum is 18000 yuan / ton.
Some enterprises cheat customers by substituting aluminum for copper under the market price and low price medium label contract, which is contrary to business ethics.
However, as mentioned above, as long as the aluminum coil transformer meets the national standards, it is still a product with quality assurance.
Huarui electric observed that the State Grid Corporation of China recently pointed out in the guiding ideology of several opinions on improving the quality of purchased equipment (Abstract): selecting the best equipment is the key to strengthening the quality network and realizing quality transformation; Carry out all-round work to improve the quality of purchased equipment from the aspects of planning and design, capital investment, technical standards and equipment selection.
The intensive introduction of a series of policies and measures clarifies the standards and requirements of the State Grid Company for purchasing power equipment, which indicates that transformer manufacturers must take the road of quality control and brand creation, otherwise they will face the risk of being eliminated.
