Electrical Power Infrastructure for Modern Rolling Stock with Regard to the Railway in Poland

Implementing high-speed trains on Polish railway lines requires a new approach to the issue of power and energy supply via a 3 kV DC power system. Due to the control systems used, modern rolling stock equipped with asynchronous drive allows maintaining a set speed, as far as a locomotive’s power and voltage in a catenary allow it. Characteristics of traction vehicles with asynchronous drives enables run at voltage lower than the rated voltage, however, it entails decrease of consumed power (required for locomotives with power above 2 MW) and loss of motion dynamics. Modernisation of a railway power supply system conducted in Poland since the mid-1990s of the 20th century has intensified in the past couple of years (so-called MUZ-I program) due to the purchase of Pendolino trains, and it primarily include the main lines. A number of modernisation investments (lines E65, E20, E30) are implemented with co-financing from the EU funds. Due to the predicted trains’ speed (200 km/h and above), in order to fulfill the requirements specified in TSI, a power supply system on these lines should ensure achieving high parameters, that is supply of trains with current up to 3.2 kA, while the so-called mean useful voltage should not be lower than 2.8 kV. The article presents solutions introduced on Polish railway and aiming at adjusting the power supply used to the TSI requirements. The range of conducted modernisation works allows for conclusion that the process is in fact a re-electrification of railway power supply systems.