3 or 25 kV? Comparison of power supply systems of overhead lines

The ProKolej Foundation together with the Railway Transport Institute presented a report «3 or 25 kV? Comparison of power supply systems of the railway catenary». This is the latest expert study showing optimal energy solutions for Polish railways, reports the railway magazine «Railway Supply» citing Nakolei.

power supply systems of overhead lines
Picture PKP PLK SA

The introduction of a new power supply system on Polish railways, based on the use of 25 kV alternating current, is justified primarily in the case of the construction of new, separate lines with a speed of more than 250 km/h or on not electrified sections with a length of at least 100 km.

It should be borne in mind that there are almost 12 thousand kilometers of electrified railway lines in Poland powered by DC 3 kV and more than 500 traction substations, – reminds Dr. Arthur Royek from the Institute for Rail Transport – Therefore, the discussion of energy supply should be as broad as possible. Considering not only the railway infrastructure, but also external power supply and the characteristics of the rolling stock used.

The growing importance of transit routes (China – Western Europe), the rapid development of intermodal transport and the European strategy of building a single, standardized rail market are arguments in favor of introducing alternating current on the Polish railroad. Authors of the report «3 or 25 kV? Comparison of power supply systems of the railway catenary» show the benefits of AC power for high speed railways and the planned connections served by the Central Communications Port.

The simulations and calculations described in the report were carried out for four different routes, separately for passenger and freight trains. The results were compared for the most commonly used traction power systems in Europe.


Four powerful traction substations equipped with the most modern Pluton equipment operate in the Minsk metro