Optimization and control method for smart charging of EVs facilitated by Fleet operator Review and classification

Electric vehicles (EV) can become integral parts of a smart grid, since they are capable of providing valuable services to power systems other than just consuming power. As an important solution to balance the intermittent renewable energy resources, such as wind power and PVs, EVs can absorb the energy during the period of high electricity penetration and feed the electricity back into the grid when the demand is high or in situations of insufficient electricity generation. However, the extra loads created by increasing EVs may have adverse impacts on grid. These factors will bring new challenges to the utility system operator; accordingly, smart charging of EVs is needed. This paper presents a review and classification of methods for smart charging of EVs found in the literature. The study is mainly executed from the control theory perspectives. Firstly, service dependent aggregation and the facilitator EV fleet operator are introduced. Secondly, control architectures and their integrations in term of electricity market and distribution grid are discussed. Then, data analysis of EVs including a battery model and driving pattern is presented. Further discussion is given on mathematical modelling and control of smart charging of EVs. Finally, the paper discusses and proposes future research directions in the area. International Journal of Distributed Energy Resources and Smart Grids, ISSN 1614-7138, Volume 10 Number 1 © 2014 Technology & Science Publishers, Kassel, Germany, http://www.ts-publishers.com 384 J. Hu, S. You, C. Si, M. Lind, J. Østergaard