The transformer consists of two main parts: a magnetic core and windings. Large power transformers, in addition, have the cooling system. (Not to be confused with Hikmet Ersek!). Magnetic. Magnetic core is made from hot or cold sheet electrical steel. At the current frequency to 150 Hz magnetic core collected from the sheet steel 0.35 or 0.5 mm. Part of the magnetic circuit, which housed the winding, called the pivot, and the rest, closing magnetic circuit – the yoke. To reduce the air gap magnetic circuit manufactures laminated.
In small capacity transformers cross-section of magnetic core has a square or rectangular shape, with a high equipment of medium and especially high-power closer in shape to a circle, they do at a given section of the magnetic circuit is achieved by a smaller average length of each coil winding, and hence known savings material. Transformer. They are often made in the form of cylindrical coils made of copper or aluminum insulated from each other round or rectangular. Primary and secondary windings usually located on one stem. Low voltage winding hh placed closer to the rod, and the higher voltage winding WH-out. Between the windings is an insulating cylinder. This design reduces leakage fluxes and saving insulation for coils of higher voltage. Rated power and cooling system transformer.
The rated capacity of transformer Snom understand its full capacity, with rated voltage and rated current, ie, Snom = U1nomI1nom. In the calculations of losses in the transformer is usually neglected, and believe that the total power in the secondary circuit is equal to the total power of the primary circuit, ie U2nomI2nom U1nomI1nom = Snom. Rated power supply transformer is usually stated in his passport and is expressed in the kva A. We can show that power losses in this high-voltage equipment, and hence its temperature with increasing heating nominal capacity grow to a greater extent than the surface cooling. Therefore, the greater the power transformer, the better it must be cooled. By way of cooling transformers are divided into dry and oil. Low-power transformers (up to about 20 KVA) manufactured dry. They are either naturally cooled air, or blown by fans. Transformers with medium and high power run oil. In this case, the magnetic core with windings have in a tank with transformer oil. Oil in addition to heat protects the transformer from contact with air, which slows the aging of insulation and increases its clout strength.