Electric Railway System Integrated with EV Charging Station Realizing Train-to-Vehicle Technology

In recent years, the development of electric vehicle (EV) infrastructure and efforts to achieve more sustainable transportation systems have increased. The enhanced utilization of EVs will require fast charging systems, which will overload utility power grids and require high-cost additional installations and equipment. However, a significant amount of regenerative braking energy (RBE) is available in electric railway systems (ERSs), which needs to be properly stored and accommodated. The integration of ERSs and EV charging stations (EVCS) at strategic points, such as parking areas close to ERS stations or rail freight intermodal terminals where EVs are parked most hours of the day, can be a promising solution to save RBE in the dedicated internal EV batteries. In this paper, a new method is proposed to charge EVs by transferring RBE from ERSs to EVCSs, taking advantage of a combined power management scheme based on stationary hybrid energy storage systems (HESSs) integrated with railway power flow controllers (RPFCs). A coordinated hierarchical control (CHC) method collaborating with an internal model predictive control (IMPC) strategy is presented to manage an optimal power flow paradigm for various operating system modes. The effectiveness of the proposed strategy is confirmed through simulations executed with the desired precision representing real system behavior.