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Features of transformer winding aluminum foil

Source:Original Editing:frank Time:2017-10-19 10:09
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Features of Transformer Winding Aluminum foil
 
Transformer coil is the core of transformer equipment, the performance of transformer depends largely on the coil material. At the same time, the development and use of coil materials also represent the advanced technology of transformer manufacturers. The material of the conductor coil made of traditional method mostly uses copper or copper and aluminum composite materials. With the development of science and technology, many domestic and foreign manufacturers of epoxy dry-type transformer, coil conductor material has been made of aluminum foil material. The characteristics and quality of transformer winding aluminum foil  have been highly evaluated.



1. Comparison of properties between copper and aluminum

Aluminum ingots, rods, plates are sold in the market, the price of copper to teach low yield is relatively large.
 
Conductive material is a kind of conductor material to reduce power loss. When choosing conductor material, it mainly depends on its resistance when passing through current. The main use of copper or aluminum, or copper aluminum composite materials.

The electrical conductivity of aluminum is 1.64 times as much as that of 100% copper in order to obtain the same resistance. However, the density of aluminum copper is only 1/3, so, in the same resistance value, the quality of aluminium copper only 1/2, that is to say, made of aluminum and copper equivalent transformer production comparison, quality aluminum winding transformer coil of copper is only general. In this way, the use of aluminum conductor is a very effective means of lightening the electrical machinery. In general, the cost of materials can also be reduced, and cheaper transformers can be produced. Therefore, aluminum is a kind of conductive material which is widely used as copper and has high reliability.

2. Specialty of transformer winding aluminum foil

The transformer winding aluminum foil produced by epoxy dry type transformer manufacturers are different in shape, but they are similar in structure. It has the following features:

1) Due to the rate of transformer winding aluminum foil, coil conductor than the cylindrical void space occupied less effective working area increased, the result is: epoxy dry-type transformer with transformer winding aluminum foil can realize the miniaturization and lightening.

2) Restrain thermal stress. When the coil of epoxy dry type transformer is running, the temperature change will happen because of the change of load. At this point, thermal stress will occur due to the different thermal expansion coefficients of the epoxy resin and the conductor in the coil. The use of transformer winding aluminum foil can reduce the thermal stress. Compared with copper, the thermal expansion coefficient of aluminum is closer to the thermal expansion coefficient of epoxy resin, which reduces the thermal stress and improves the anti cracking performance of epoxy transformer.
3)  High insulation reliability. The transformer winding aluminum foil adopts the pouring method of one layer and one layer, and the turn to turn voltage is generally only the potential of each turn. Therefore, the inter turn voltage can be controlled to a minimum, and the insulation strength of transformer winding aluminum foil is better than that of cylindrical coil.
4) The safety of impact. When a vacuum switch is used in a transformer, the closing of the switch will produce shock. Especially when the Liz inrush current of the transformer and the light load current are cut off, the electromagnetic energy stored in the transformer coil will be released, resulting in the impact voltage.
There is a capacitance between the coil and the iron core and other coils, and there is also a direct capacitance between the conductors in the coil. Therefore, the potential fluctuation can be generated when the shock wave is affected by the impulse voltage. Compared with the general coil, the capacitance between conductors increases, and the potential fluctuation can be suppressed, which is beneficial to the insulation safety.
 
Conclusion
 
The coil of epoxy dry type transformer is manufactured by using aluminum foil conductor, which is not only technically reliable, but also economical. The choice of epoxy dry-type transformer with transformer winding aluminum foil can reduce investment and reduce operating costs.