Reversible Traction Substations in DC Railway Systems: A Comparative Study of Approaches

In line with the overall goals of EU climate commitment and railway operators, reducing CO2 emission and eco-friendly transport systems together with increased energy efficiency have received more attention during the last years. In this context, a significant contribution of studies is dedicated to the capabilities and potentials of utilizing regenerative braking energy (RBE). Among different methods of recuperating RBE, adopting reversible/bidirectional substations to feed back the RBE into the upstream grid is a promising solution. In this paper, different methods and configurations regarding the implementation of reversible substations (RSS) with bidirectional power flow capability are discussed and compared. Meanwhile, the challenges of transforming the existing traditional traction substations (TSS) into reversible substations together with their impacts on the energy efficiency of the electric railway system (ERS) are outlined