Ricerc@Sapienza

The AC power supply systems represent one of the most considered technical solutions for high-speed railway lines. This paper analyses these systems by utilization of numerical simulation models, to determine current voltage and power flows under realistic operating conditions. The proposed models are implemented in two ways: As a model for the well-known Electro-magnetics transient program ATP, and as a model written in the standard modelling language Modelica, and used inside a Modelica-capable simulation tool.

The paper shows the typical architecture of a 2×25 kV-50 Hz traction system, and the details that need to be considered and approximations that can safely be done, for power frequency studies. Power frequency models are important to allow simulations of long timespans, such as those needed when evaluation of trains acceleration/braking, for instance to analyse active and reactive power flows, voltages and currents. The proposed models are implemented in two ways: as data to be inputted to the well-known ATP Program, and as specific models written in the standard Modelica language.