A sample application of supercapacitor storage systems for suburban transit

The advance in energy storage technologies allows to improve significantly the performances of electrified light transportation systems. This is aligned with the massive requirement of competitiveness compared to other transportation technologies in terms of sustainable energy and high reduction of environmental impact. The installation of stationary storage devices, as widely recognized, allows the recovery of the braking energy for increasing the energy efficiency as well as lower line voltage drops. In the paper, the storage system under investigation is based upon a bidirectional dc-dc converter with supercapacitors, characterized by high power density. The main parameters of the storage system are determined by employing an optimization technique, which in a quite general way is capable of taking into account contemporaneously several aspects in an integrated manner. Some simulations of lines of a suburban railways in Southern Italy managed by Sepsa Company are presented, pointing out how supercapacitors can be practically designed with the proposed technique.