Energy Storage Application Strategy on DC Electric Railroad System using a Novel Railroad Analysis Algorithm

Abstract

-There is an increasing interest in research to help overcome the energy crisis that has been focused on energy storage applications in various parts of power systems. Energy storage systems are good at enhancing the reliability or improving the efficiency of a power system by creating a time gap between the generation and the consumption of power. As a contribution to the various applications of storage devices, this paper describes a novel algorithm that determines the power and storage capacity of selected energy storage devices in order to improve upon railroad system efficiency. The algorithm is also demonstrated by means of simulation studies for the Korean railroad lines now in service. A part of this novel algorithm includes the DC railroad powerflow algorithm that considers the mobility of railroad vehicles, which is necessary because the electric railroad system has a distinct distribution system where the location and power of vehicles are not fixed values. In order to derive a more accurate powerflow result, this algorithm has been designed to consider the rail voltage as well as the feeder voltage for calculating the vehicle voltage. By applying the resultant control scheme, the charging or discharging within a specific voltage boundary, energy savings and a substation voltage stabilization using storage devices are achieved at the same time.

Evaluation of Strategies to Reducing Traction Energy Consumption of Metro Systems Using an Optimal Train Control Simulation Model

“…Compared to the on-board ESSs, one of the advantages for the application of the wayside ESSs is that they can recover regenerative energy from multiple braking trains at the same time, and their installation has little influence the operation and maintenance. However, wayside ESSs are usually less efficient due to the transmission losses on the power line [28,29]. According to experimental results [30][31][32], the rate of energy reduction with ESSs ranges from 12%-20% for different lines.…”

Regenerative Energy Control of DC Electric Railway Based on Solid State Transformer

“…Thus, many studies have investigated about the installation of the regenerative inverter to improve the regenerative energy efficiency [5][6]. Also, other studies have been carried out with EDLC which is installed on DC electric railway systems [7][8][9]. EDLC stores regenerative energy generated from the deceleration intervals of the train and uses the stored regenerative energy when the train departs or accelerates.…”

Development of a Novel Charging Algorithm for On-board ESS in DC Train through Weight Modification

“…The TPS calculates the electrical traction drive of each vehicle on the basis of the input data, and the power supply in each substation can be estimated through a power-flow analysis. In a previous study, power-flow analysis was performed to check the power consumption at each substation, and the peak-power measurement or the operation of energy storage devices could be simulated for system research [15][16]. However, the simulation process was disabled in checking the weight variation at each station; thus, the ESS optimization process was difficult because of the inexactitude of the power consumption pattern.…”