1,721,000 research outputs found
Deterministic algorithm for optimizing energy storage systems along railway lines
No full textThe paper carried out a methodology to design stationary energy storage system (ESS) employing a deterministic algorithm. The primary scope is to maximizing economic benefits arriving to define an optimal siting and sizing of the ESS utilizing deterministic algorithm. The objective function of the algorithm is set on the net present value (NPV) calculation. Numerical simulation of a d.c. railway line with new high-speed trains has been presented to assess power flow between trains, leading to the identification of suitable locations and sizes for electrical substations and storage systems within the railway network.The main scope of the proposed approach lies in using an optimization algorithm to maximize the economic advantage of installing an energy storage system in a railway line also minimizing the energy purchase from the grid with low computational effort, versatility and easy implementation features. The methodology proposed has been applied to a case study
A preliminary design of a hybrid train’s on-board batteries for a 25 kV-50 Hz high speed railway line
No full textThe paper reports a technical-economic comparison for a Turkey high-speed railway line, between 25 kV AC electrification and the use of hybrid trains with on-board storage systems. On-board battery storage systems have been designed to operating in specific parts of the line. Different types of technologies have been taken into account, evaluating the use of high specific power/energy lithium-ion electrochemical cells. The models of the battery pack have been designed in the MATLAB/Simulink environment, in order to carry out the complete operation check, also evaluating the time and power required for recharging. An economic evaluation and comparison have been carried out in order to evaluate the convenience of using a hybrid train on specific part of a real line in order to not totally electrified the line
Energy storage systems for voltage regulation: Analysis for the railway junction of Rome
No full textThe paper reports a preliminary evaluation concerning the design of a stationary storage system for voltage regulation in the railway junction of Rome. In particular the case study concerns the 3 kV dc 'Trastevere-Cesano' railway line. The constant increase in railway traffic, together with the improvement of comfort, has led to an increase of the energy required in the railway sector, causing larger voltage drops along the line. The growth of the railway traffic needs solutions to manage and analyze the capability of the railway junction. Power systems simulations of a railway junction requires high computational effort and the present work reports a methodology to simulate a railway line belonging to a complex railway junction, taking into account network equivalents
A MILP methodology to optimize sizing of PV - Wind renewable energy systems
No full textThis paper proposes a methodology that is based on mixed-integer linear programming (MILP) to calculate the optimal sizing of a hybrid wind-photovoltaic power plant in an industrial area. The proposed methodology considers the: i) load requirements; ii) physical and geometric constraints for the renewable plants installation; iii) operating and maintenance costs of both wind and PV power plants; and the iv) electric energy absorbed by the public network. The power demand variation associated with the production cycles is considered by using a stochastic simulation tool. To consider both the load and seasonality variability, and to adapt the methodology to the actual operational use of the power plant, the optimization is performed separately for each month of the year. Then, an integrated economic analysis is discussed. The methodology is adopted to analyze an industrial plant in the Rome area used as a train depot and for maintenance purposes. The results, which combine the needs of the plant activity with the availability of renewable energy, enabled the determination of optimal solutions and the relevant savings achievable
Eco-friendly urban transport systems. Comparison between energy demands of the trolleybus and tram systems
No full textA computational code implementing experimentally tested mathematical models was used to conduct a study on an urban center of southern Italy comprising the cities of Cosenza and Rende that, seat of the University of Calabria, has recorded a systematic and significant expansion in recent years in terms of both urban and demographic development. In Italy the first electric tramway was built in Florence in 1890 and it linked Florence to Fiesole. In 1920 major tramway development was reached. In Europe, North America, South America and Australia, almost all medium and large size cities had urban and intercity networks. In the late 20s, North America first and then Europe reduced the tramway systems replacing them with trolleybuses and buses. The traction electric motor used in most new vehicles is the four-pole three-phase asynchronous motor, that with its control systems, has introduced a number of advantages compared to the DC motor in terms of reliability, less maintenance, high efficiency and control
The integration of a PV system for 3 kV dc railway electrical substation: The case study of Cagliari — Oristano line
No full textThe paper describes a technical and economic analysis of photovoltaic system integration for a 3 kV dc railway line. The study has been conducted on a electrical substation (ESS) place on Cagliari - Oristano railway line. The analysis has been taken into account two different railway timetables and the size of PV system, according to electric power supplied by the ESS, has been defined in order to enhance the self-consumption, taken into account the space available near the electrical substation. Finally, an economic analysis and the possibility of providing an energy system storage to store the excess energy produced has been evaluated
An environmental sustainable transport system: A trolley-buses Line for Cosenza city
No full textIn the present paper, a comparison among different types of urban mass transport systems, which can be implemented for medium-sized cities, is reported. For each mobility system, advantages and disadvantages, in terms of transport capacity and environmental impact, are highlighted. Then the focus is pointed on the trolley-bus solution. A real case study of deployment of this type of mobility system, for a medium size Italian city, is analyzed. The results of traffic and electrical simulations of the proposed trolley-buses system are exposed, including energy performance and economic evaluations. © 2012 IEEE
Energy storage application in trolley-buses lines for a sustainable urban mobility
No full textThe focus of the present paper is pointed on trolley-buses lines, as solution for the urban mass transport in medium size cities. After a comparison in terms of economic and environmental features, with other mobility systems, the potential upgrading actions on trolley-buses line, that would improve its energy performance, are highlighted. In particular the energy storage application in power supplying system and on board the vehicles is deeply analyzed. To identify which of the two solutions involves in the highest energy saving, a study has been performed on the case of a trolley-buses line proposed for Cosenza city. © 2012 IEEE
O.Si.Si: Optimal SIzing and SIting of stationary storage systems in railway electrical lines using a blackbox integer model
No full textThe paper reports a methodology to define the optimal sizing and positioning of energy storage system (ESS) in a railway line, based on supercapacitors technologies and accounting for economic benefits. The problem of the optimal siting and sizing of an ESS is addressed by a bi-objective nonlinear mathematical model involving only discrete variables. A novelty is considering the siting ESS on wayside, imposing the constraint of siting in correspondence with the electrical substations. This reduces the possible choices for siting and it is advantageous in the real case both for cost and for management. The Pareto frontiers are obtained by a fully enumerative algorithm which is viable when the problem has a small dimension. The feasible solutions have been analyzed from an economic point of view, taken into account the least part energy to be taken from the primary network, on the basis of the purchase price of energy. A real Italian underground railway line, using a standard working day timetable, has been simulated using a simulation toolbox in order to estimate the power flow between the trains. Real energy storage systems, available on market, have been considered in the simulation. Analyzing a good Pareto solution, we got that the installation of 4 storage systems allows an energetic saving of 1730 kWh, equivalent to about 11% of profit each year for the case study
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