Interaction between supply system and EMU loco in 15 kV-16/sup 2/3/ hz AC traction systems

The paper analyzes the interaction between the EMU locomotives and the 15 kV-16 2/3 Hz AC supply system. To this aim the power converters on board of the EMU locomotive have been modeled and then included into the model of the whole traction system. In particular the power converters have been simulated by ATP implementing two models with different level of accuracy; the accuracy of the obtained results have been verified with tests performed on the Ansaldo EMU-NSB locomotive at the Ansaldo Vehicle Test Room. The most significant results regard the equivalent impedance at the pantograph of the locomotive and the amplification of the frequency components of the current along the line. Several parallel resonance conditions have been ascertained; they, in case of only one locomotive along the track, do not cause excessive level of voltage distortion. Critical conditions can arise for detected local amplifications of the current along the line. This result indicates that electromagnetic interference have to be evaluated not only at the locomotive pantograph but overall along the line track.