Active filtering of low frequency harmonics in DC/DC converters for traction applications

The line-side DC/DC converter used for ETR500P traction train by ANSALDO Trasporti SpA (Italy) is considered. A new active filtering technique is proposed in order to compensate for undesired input current harmonics. The compensation technique does not require any additional power converter and it is based on an on-line detection of the undesired harmonic to be eliminated. The controller is designed by using an equivalent circuit of the DC/DC converter, obtained by means of a proper transformation of its state space model. Simulation results show the effectiveness of the proposed technique.