Abstract :
The decision to electrify the railways in Finland was taken in 1965. The author shows how the use of power electronics on tractive stock made it possible to choose the 25 kV 50 Hz electrification system. As a result, the feeding system could be made as simple as possible. Energy is fed to electrified lines by means of single-phase transformers connected directly between two phases of the national grid. Thus the railways need no power stations or energy transmission lines of their own
