220KV oil-immersed power transformer is designed according to IEC 60076 and GB1094.1.2-1996, GB1094.3.5-2003 with rated frequency 50Hz, applicable to power transmission and transformation in industrial and agricultural grids.
Structure and Characteristics:
Made out of excellent grain-oriented cold-rolled silicon steel, the iron core adopts whole-tilted non-porous structure. The side column are tied up with glass tape. The upper and lower iron yokes are drawn tightly with the drag bar on the clamping fixtures. With low magnetic steel sheets as drawing board, the core is connected with the upper and lower clamping fixtures tightly to form a steel framed structure so as to obtain a smaller non-load loss and lower noise.
Based on the transformer capacity, the windings adopt cylinder, spiral or continuous structure, and 110KV or higher grade windings, entangled or internal shielded structure so as to improve effectively the distribution of impulse voltage. For the purpose of reducing the additional loss of windings, the conductors are of position-changing or composite type. To use a computer to simulate and calculate the impulse characteristics of electric field and windings shall guarantee fine fine electric features and impulse strength of windings. To take effective measures technologically will ensure their safe and reliable operations.
Entirely round insulated pressing plates are used for the holding down of transformer body. By using the complete set technique, the windings are assembled in an integrating manner to improve the reliability of products.
The oil tanks are of bell-jar structure, with the tank walls to be welded with folded plate stiffening angles, thus improving the mechanical strength of the tanks. In order to lower the stray loss of the transformers, large sized transformers are equipped with magnetic shield on the inner walls of tanks.
In order to prevent transformer body from displacing in the course of transportation, the transformer body and oil tank are provided with positioning device. The oil storage tank is of hermetically sealed type to separate the oil from the air so as to avoid humidity and aging. The ends are equipped with pointer oil gauge. On the basis of oil mass of transformer, two pressure relief valves can be installed on the top of tank to guarantee safe operation of the products.