Contribution of Wayside Energy Storage Systems to Short Circuit Currents in DC Railway Traction Power Systems

As a consequence of the growing demand for mobility and the requirements for reduced environmental pollution, railway traction systems are receiving increasing interest. Researches are analyzing new technologies and managing solutions to increase energy efficiency in the railway infrastructures. Many studies proposed the oppor-tunity to introduce the technology of energy storage systems (e.g., Wayside Energy Storage Systems - WESS) in traction infrastructures. WESS can be able to: i) reduce voltage drops; ii) save braking energy; iii) support Traction Power Substations in supplying traction power peaks. A relevant topic in using WESSs in railway infrastructure is to verify their impact in case of faults. Studies on short circuit analyses are required to verify the correct rating of the protection devices and the opportunity to use new protection devices and mode of operating, when the new technology is integrated. In this paper, the typical Italian DC railway power system is investigated. Specifically, the contribution of WESS to the short circuit currents is assessed by examining transient and steady-state conditions.