Charging Electric Vehicles Using Regenerated Energy from Urban Railways
Nowadays transport system is one of the most important producers of air pollution in cities. Urban railways and electric vehicle will play a fundamental role to accomplish the sustainability of cities. Urban railways are right now an efficient mode of transport. However it is necessary to continue improving its energy efficiency in view of the demand growth. On the other hand, electric vehicles need a charging infrastructure to support their market penetration. In this context, the use of the railway electrical infrastructure to charge electric vehicles could bring several benefits. First of all, there is a cost reduction effect because of the use of an existing installation. Besides, part of the regenerated energy that cannot be accepted by other trains can be used to charge electric vehicles, improving the efficiency of the global system. In this paper, a new system for the global energy management between the railway infrastructure and the electric vehicles is proposed. Besides, the global energy savings that can be obtained using railway electrical infrastructure to charge electric vehicles has been assessed.
On board accumulator model for power flow studies in DC traction networks
Abstract This paper presents a detailed model of a DC train to be applied to an unified AC/DC power flow analysis. The model will consider the regenerative braking of the train and the squeezing control that derives part or all regenerated power to the rheostatic braking system depending on the catenary voltage. The model also considers an on board accumulator (ACR) that can be charged with the regenerated power, depending on the network and train parameters. When the train is in traction mode, both the network and the ACR can contribute in feeding the train traction system.
Battery Energy Storage System
This chapter discusses the various technical components of battery energy storage systems for utility-scale energy storage and how these technical components are interrelated. The introduction lists the basic types of large-scale storage and how storage can be used to mitigate the variability associated with renewable generation. It also provides an overview of how to define storage applications as primarily “power” or “energy” based. A basic description of how battery energy storage works is provided with several examples to illustrate how battery energy storage can be used in large-scale applications. A brief discussion of the various battery chemistries that are suited to large-scale applications is provided, as well as guidance on what factors to look for when trying to select an appropriate chemistry for a given application. An overview of how the storage system’s power electronics work is followed by a more detailed description of possible power electronic topologies and power electronic controls that are used to ensure that the system can be properly integrated with the generation source and, if necessary, the load. Battery management and battery monitoring via the power electronic controls is discussed briefly. This chapter concludes with a detailed example of battery energy storage system integration that is summarized with data obtained in the field.