Interleaved Four Quadrant Converter-Based Active Traction Substation for Recuperating Regenerative Braking Energy in DC Railway Line

This study addresses limitations in the Italian 3 kV DC railway system, proposing a bidirectional or reversible traction substation (TSS) configuration using interleaved four quadrant converters (4QC). Focusing on regenerative braking energy (RBE), the paper addresses the potential of bidirectional traction substations with interleaved 4QCs, allowing bidirectional power flow and promoting RBE revert to the main grid. The results coming from the case study highlights the limitations of the existing configuration and underscores the need for a transformative solution. This research models and simulates a new reversible substation design for the case study system using MATLAB/SIMULINK. Different load scenarios and system configurations are tested, comparing traditional and modern substation typologies. The analysis evaluates various substation features, aiming to identify the most efficient design in terms of key indicators such as voltage ripple, passive components stress, total harmonic distortion, voltage and current unbalance, and unity power factor operation. This investigation offers valuable insights into the potential of interleaved 4QCs for bidirectional TSS, advancing the field toward sustainable and energy-efficient rail transport solutions. The research contributes to practical advancements in the rail transport sector.