Mast transformer
A distribution transformer is on a pylon -mounted transformer . Due to the high weight of transformers, mast transformers are only used in Germany in the area of medium-voltage networks with electrical voltages of up to around 30 kV . They mostly serve to supply a regional, small-scale low - voltage network from the medium-voltage network. Standard oil-insulated transformers up to a nominal power of 160 kVA can be used as mast transformers . With the appropriate mast load-bearing capacity, transformers with a nominal power of 250 and - although not common in Germany - 400 kVA are possible.
In Italy, mast transformers are also used for high voltages up to 60 kV. A mast transformer is mounted on the high-voltage pylon. A field of a medium-voltage overhead line runs from the high-voltage pylon to a medium-voltage pylon station. Another mast transformer is installed there. This feeds into the low-voltage network .
If the transformer is mounted in a weatherproof cover, a cast resin transformer can also be used. In water protection areas, a cast resin transformer or a transformer filled with a non-hazardous liquid (such as synthetic ester ) must be used.
As a rule, mast stations are used for supply outside of built-up areas and remote consumers, such as farms . In many cases, however, living spaces with z. B. 50 houses, i.e. larger hamlets, are supplied with electrical energy from the medium-voltage network via mast stations . When pole transformers of emigrants courts can on the low voltage side zigzag connection be used, which is less in unbalanced loads unbalanced load means. Another application is the supply of electrical equipment from the overhead contact line of AC- powered railways . These include railway signals , point heaters , train preheating systems and, in the case of smaller or remote stations, their equipment, such as B. the lighting or ticket machines . In this case, single-phase mast transformers are used.
There are also mast transformers without overhead line outlets.
literature
- A. Senner: Electrical engineering. 4th edition. Verlag - Europa-Lehrmittel, 1965
- Wilfried Knies, Klaus Schierack: Electrical systems engineering. 5th edition, Carl Hanser Verlag, Munich and Vienna, 2006, ISBN 3-446-40574-7
