On the Interactions Between Plug-in Electric Vehicles and the Power Grid

Growing concerns over climate changes have driven regulatory pressures to reduce urban pollution, emissions from CO₂ and other particulate matters, and city noise, which have motivated intense activity in the search for alternative road transportation propulsion systems. In this context, plug-in electric vehicles (PEVs), either as purely electric vehicles or as plug-in hybrid vehicles, have become a significant fraction of the overall transportation fleet in many countries worldwide. This ever-increasing penetration level of PEVs is posing significant challenges to the existing power grids' infrastructures, as a significant load in terms of the required energy (e.g., during night charging of the vehicles connected for charging) or in terms of the required power (e.g., during fast charging events). The uncertainty of the charging events (in terms of time, space and required energy) further challenge the ability of the power grids to seamlessly handle such new electrical loads in addition to the already existing base load. At the same time, however, the ability of PEVs to operate in a vehicle-to-grid (V2G) mode may be also exploited to provide ancillary regulatory services to facilitate the general operation of the power grid. The optimal trade-off between these two contrasting aspects of the charging problem is still a subject of intense study in the power research community. Accordingly, this chapter reviews the most recent research and technological advances in the charging process of PEVs; it presents through simple simulations the importance of controlled charging, and the advantages of utilizing decentralized schemes for practical implementation; also, it identifies some particularly interesting new trends that can be observed at the intersection between the transportation and the power networks, and it outlines interesting future directions in the context of electric vehicles.