The performances of an active filtering and regenerative system for DC railway traction substations This paper presents the performances of filtration and regeneration system for DC traction substations equipped with 12 pulse series rectifier, that allows connection of the system directly to the secondary of the traction transformer. Modeling of the whole system and vehicle – DC line assembly was done inMatlab-Simulink, and on this basis, were determined the performances, both as filtering and in regeneration mode.