Multi-pulse Active Substation for Power Quality Improvement and Recuperation of Regenerative Braking Energy in DC Railway

This paper investigates the potential of active traction substations (ATSS) equipped with interleaved PWM rectifiers to enhance regenerative braking energy (RBE) utilization in bidirectional power systems. By comparing modern ATSS with conventional diode-bridge rectifier traction power substation (TPSS) in a bilateral DC railway setup, the study utilizes the operational context of the Italian 3 kV DC railway line as a case study. Various power quality parameters are analyzed to determine the optimal design, including overhead contact line voltage fluctuation, stress on passive components, total harmonic distortion in primary side of TPSS, voltage and current imbalances, and power factor. Real-world data from the Italian railway system ensures the relevance and accuracy of the findings, providing valuable insights for the implementation of ATSS in similar railway infrastructures.