Operation modes of battery chargers for electric vehicles in the future smart grids

This paper presents an on-board bidirectional battery charger for Electric Vehicles (EVs), which operates in three different modes: Grid-to- Vehicle (G2V), Vehicle-to-Grid (V2G), and Vehicle-to-Home (V2H). Through these three operation modes, using bidirectional communications based on Information and Communication Technologies (ICT), it will be possible to exchange data between the EV driver and the future smart grids. This collaboration with the smart grids will strengthen the collective awareness systems, contributing to solve and organize issues related with energy resources and power grids. This paper presents the preliminary studies that results from a PhD work related with bidirectional battery chargers for EVs. Thus, in this paper is described the topology of the on-board bidirectional battery charger and the control algorithms for the three operation modes. To validate the topology it was developed a laboratory prototype, and were obtained experimental results for the three operation modes.FEDER Funds, through the Operational Programme for Competitiveness Factors – COMPETE, and by National Funds through FCT – Foundation for Science and Technology of Portugal, under the project FCOMP-01-0124- FEDER-022674, and QREN project AAC n.º36/SI/2009 – 1384

Long term individual load forecast under different electrical vehicles uptake scenarios

More and more households are purchasing electric vehicles (EVs), and this will continue as we move towards a low carbon future. There are various projections as to the rate of EV uptake, but all predict an increase over the next ten years. Charging these EVs will produce one of the biggest loads on the low voltage network. To manage the network, we must not only take into account the number of EVs taken up, but where on the network they are charging, and at what time. To simulate the impact on the network from high, medium and low EV uptake (as outlined by the UK government), we present an agent-based model. We initialise the model to assign an EV to a household based on either random distribution or social influences - that is, a neighbour of an EV owner is more likely to also purchase an EV. Additionally, we examine the effect of peak behaviour on the network when charging is at day-time, night-time, or a mix of both. The model is implemented on a neighbourhood in south-east England using smart meter data (half hourly electricity readings) and real life charging patterns from an EV trial. Our results indicate that social influence can increase the peak demand on a local level (street or feeder), meaning that medium EV uptake can create higher peak demand than currently expected

Electric Vehicles as a Mobile Storage Device

International audienceElectricity is a quite recent energy (150 years old) that has developed very much as it allows a flexible use through converters (electrical machines and power electronics). At the beginning, the main use was for lighting and metro. Now, electricity is a major energy for developed countries: 17.7% of the world final energy consumption and 22% for the ECD countries (IEA, 2013a; b, Figure 1), and an economic growth is always linked to an electric consumption growth. Electricity has improved our daily life: washer, dryer, dishwasher, microwaves, internet, TV, air-conditioning, and so on. Humans have become very dependent on electricity consumptions. Nevertheless, electricity is a specific product in the sense that it is a nonmaterial energy, and thus it can only be stored through a costly transformation. Electricity can be classified as a tertiary or secondary energy produced from thermal, potential, hydro (see Volume 5, Chapter XX), wind hces137, or solar energy. For a thermal plant, the primary energy (coal, gas, or uranium) is converted into mechanical energy (secondary energy) by a turbine and is transmitted to the generator to be converted into electricity (tertiary energy). As electricity is difficult to store, it needs an infrastructure to be delivered to consumers: the electrical grid that makes the link between power plants and the consumers through transformers and overhead or cabled lines. At the beginning of the twentieth century, all countries made the choice of the alternating current technology as it allowed—thanks to a key device (the transformer) transmission of high power at high voltages to reduce losses. In the context of emissions reduction (CO2, NOx, etc.), objectives have been given for cleaner energies and the use of more efficient ones. In Europe, there are the “20–20–20” targets: 20% reduction for CO2 emissions, 20% reduction in energy consumption, and 20% increase in efficiency by 2020 (see Volume 6, Chapter XX). To reach these policy goals, electricity is an appropriate vector: it is a flexible energy that can be produced from renewable or CO2-free sources, electrical converters have high efficiency (80–90% for an electric motor) and are bidirectional what makes energy recovery possible for applications such as breaking (trains, vehicles, etc.). Transportation (cars, autobuses, and trucks) is often considered a major contributor to local pollution. Then, constraints for CO2 emissions reduction are more and more severe, especially in Europe. Automakers and their suppliers have optimized their engines with innovations such as start&stop starter/generator, kinetic energy recovery ystems, hybrid systems, and full battery electric vehicles (EVs) and plugin hybrid vehicles. For the two last cases, the energy stored in the batteries will totally or partially come from the electric grid