Recuperation of railcar braking energy using energy storage at station level

Abstract

This paper investigates the effect of adding energy storage to a metro DC microgrid in order to recuperate otherwise dissipated energy produced through regenerative braking. For this, a power load profile is constructed for a metro station using existing measured railcar data, which is then used to derive the requirements for storing regenerative braking energy. It is found that introducing a storage can lead to an almost complete recuperation of otherwise dissipated energy. The derived requirements for the storage are then used to investigate a selection of possible scenarios more in depth. These scenarios include both smart controlled and uncontrolled scenarios, and with the usage of an ideal storage device as well as a (non-ideal) flywheel. Simulation results confirm that all braking energy can be recuperated through the addition of energy storage to the microgrid.