Voltage stabilization and efficiency improvements on DC railways by stand alone energy storage systems

Stand Alone Energy Storage Systems (ESS) can be placed along railway lines to stabilize the catenary voltage and perform braking energy savings; this action reduces line power losses and saves energy normally wasted by train rheostats. The global result is both economic and technical, lower consumptions and a better utilization of the traditional substation rectifiers. This work analyzes a portion of a regional 3 kV DC railway; system efficiency and power savings are simulated with and without a stand alone ESS. Equipment is placed inside a passengers stop, so also infrastructures costs are low.