Control strategy research of wayside supercapcitor energy storage system for urban rail transit

An energy storage system based on supercapcitor (SC) for metro network regenerative braking energy is investigated. A control strategy are proposed to manage the energy and optimize the power supply system performance according to the various power requirement in metro line and differing characteristics of these storage devices. In order to estimate the required ESS (energy storage system), a useful method is proposed to predict the instantaneous regenerative energy which is delivered to each substation before applying ESS and based on the ESS configuration for each substation is determined. A simplified mathematical model of the whole metro network has been developed and the main features of the control strategy have been developed. Numerical simulations show the efficacy of suggested control strategy and the energy saving obtained for metro trains.