The Use of Energy Storage Systems for Supporting the Voltage Needs of Urban and Suburban Railway Contact Lines

Abstract

Abstract:The paper aims to contribute to the use of electric double layer capacitor (EDLC) sets for boosting voltages of contact lines in urban and suburban railway traction systems. Different electrical configurations of contact lines are considered and investigated. For each of them, proper mathematical models are suggested to evaluate the electrical performances of the contact lines. They give rise, also, to sample design procedures for the sizing of the most appropriate energy storage systems, to be distributed along the lines, for boosting line voltages and avoiding undesired voltage drops. A numerical example based on the "Cumana" suburban Naples railway network is presented to give an idea of the weights and sizes of electric double layer capacitors needed to boost the voltage of a sample contact line. In particular, three different EDLC systems, for a overall installed energy of 9.6 kWh, have been placed nearby the stations presenting the highest voltage drops during the most representative situation of trains' service. The new voltage drop is equal to 32% of that obtained in absence of EDLCs.

Stationary Charging Station Design for Sustainable Urban Rail Systems: A Case Study at Zhuzhou Electric Locomotive Co., China

“…In the former case, the ESS is called the onboard ESS, which is used to recover the braking energy and to smooth the electric power peak of hybrid vehicles. In the latter case, the ESS is called the stationary ESS, which is used to recover the braking energy of conventional vehicles and to support the line voltage at weak points [8]. However, in these studies, neither the stationary ESS nor onboard ESS work as the main power source.…”

“…The ESS stores energy using storage devices with good power density and a high number of cycles, such as an electric double-layer capacitor (EDLC), flywheels and superconducting magnetic energy storage (SMES) [11]. The ESS can be either installed onboard the vehicle [6,10,16,17] or installed at the substation level or along the track [8][9][10][11][12][13][14][15]. In the former case, the ESS is called the onboard ESS, which is used to recover the braking energy and to smooth the electric power peak of hybrid vehicles.…”

“…In the literature [8][9][10][11][12][13][14][15], several ESS sizing and positioning methods have been proposed for EDLC-based stationary ESSs. While the stationary charging station design in this paper is quite a different problem.…”

“…Recent studies have indicated that an energy storage system (ESS) will be helpful in improving the energy efficiency of conventional urban rail systems; see [6,[8][9][10][11][12][13][14][15][16][17]. The ESS stores energy using storage devices with good power density and a high number of cycles, such as an electric double-layer capacitor (EDLC), flywheels and superconducting magnetic energy storage (SMES) [11].…”

A New Control Method for a Bi-Directional Phase-Shift-Controlled DC-DC Converter with an Extended Load Range

“…Researchers have conducted lots of work to improve the performance including a high efficiency, less harmonics, and fast response. For example, the use of electric double layer capacitor sets for boosting voltages of contact lines in different kinds of railway traction systems is investigated [1] to better adopt the energy storage systems to reduce voltage drops and improve the stability. The popular wireless power transfer technology is also enhanced and utilized in high power applications, especially electric railway systems [2], where the power capacity, fast response, and reliability are all guaranteed.…”