Abstract
Energy storage systems (ESSs) represent an established solution for energy saving and voltage regulation in DC urban railway systems. In particular, ESSs can store the braking energy of light rail vehicles (LRVs) and support the DC feeder system during traction operations. Moreover, ESSs can significantly improve the operating conditions of the AC supply system by reducing voltage drops and current spikes. This paper investigates the impact on the bus voltages and branch currents of the AC grid of wayside and on-board ESSs supporting the DC railway infrastructure. An iterative algorithm solves the decoupled AC/DC power flow considering the 3-phase bridge rectifier model of traction substations. The work presents a novel mathematical formulation of the optimization problem to solve the positioning and sizing of supercapacitor-based wayside ESSs, considering both DC and AC network constraints. The effectiveness of the proposed method is proved through numerical simulations on a real Italian DC railway system. Obtained results are presented and discussed comparing the proposed methodology to several existing literature solutions.
Highlights
Up to 2050, passenger mobility will increase by 300%, as stated by the International Transport Forum [1]
This paper investigates the impact of wayside SC-based Energy storage systems (ESSs) supporting the DC railway system on the bus voltages and the branch currents of the AC power grid
Electric models of SC modules and DC/DC power converter with its controller are used to calculate the state of charge (SoC) variation related to the value of the ESS/on-board energy storage systems (OBESS) current
Summary
Up to 2050, passenger mobility will increase by 300%, as stated by the International Transport Forum [1]. ESSs installed along the track or supporting the TPS could be beneficial to the AC supply system They could improve the AC operating conditions by reducing peak values of absorbed current and voltage drops and mitigating the negative impact of the railway system on other users connected to the same AC power grid [25]. ESSs could become a smart grid asset capable of providing emergency power or demand response services to the local energy distribution company if the TPS is reversible [11], [28] For these reasons, it is important to evaluate the impact of the railway feeder system on the local distribution network to quantify the benefit introduced by wayside ESSs. a new design of the whole light railway power supply network from the AC supply to the DC network is needed.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call