Real-Time Energy Storage System Control Strategies for Urban Rail Transit with Renewable Energy

Abstract

The energy storage system (ESS) and renewable energy source (RES) have been applied in some urban rail transit (URT), aiming to reduce energy consumption from the utility grid. However, the SOC of ESS highly affects the performance of ESS in supporting urban rail transit. Thus, this research proposes a real-time control strategy of ESS in urban rail transit with RES, which can dynamically control substations to charge ESS to support the peak shaving function of ESS. The mathematic model of the URT and ESS was established first. Then, the power flow method of URT with ESS and RES is introduced to analyze the energy distribution. Besides, a real-time SOC control strategy is designed to ensure ESS has enough stored energy to shave the peak power of the substation. The case study based on the Merseyrail line shows that the proposed real-time SOC control strategy can remain the SOC of ESS above the target value.