Review of Energy Storage Systems in Regenerative Braking Energy Recovery in DC Electrified Urban Railway Systems: Converter Topologies, Control Methods & Future Prospects
Electrified urban railway systems are large consumers of energy in urban areas and thus, there is a need for energy saving measures in this transportation sector. Recuperation of train’s regenerative braking energy (RBE) is one of the best ways for attaining high levels of energy efficiency in this area. Energy Storage Systems (ESSs) prove to be the most practical and viable solution for maximizing the RBE utilization in urban railway systems. In the existing related reviews of ESSs, few papers covered the review of ESS technologies or converter interface. However, a comprehensive review is needed in this regard. This paper discusses an overview of urban railway electrification, and detail review for the three ESS components – ESS Technologies, Bidirectional DC-DC Converters (BDCs), and Controller Unit. This study concludes that among the storage technologies, supercapacitor ESS appears to be the most suitable followed by Lithium-ion batteries and flywheels. For BDC, cascaded BDC is the most suitable followed by dual active bridge. For control methods, fuzzy logic and artificial intelligent are recommended among other control strategies. Thus, the key contribution of this paper is the comprehensive review and analyses of the ESS’s components in the recovery of RBE in urban railways.