Using plug-in electric vehicles to implement ancillary services in smart distribution grids

Abstract

Plug-in Electric Vehicles (PEVs) will remain connected to the grid a high percentage of their life-time. During these connections, idle-time will be considerably longer than battery charging time. This fact turns PEV idle-time into a suitable candidate to help in the distribution grid management by implementing active distribution grid functions, leading to the future Smart Grids. In this chapter, conventional ancillary services for distribution grids are presented, including their development in the new context of Distributed Energy Resources (DER), micro grids, smart grid and either in connected or isolated modes. Later, the coordination of the previously discussed services with PEVs is analyzed, mainly considering them as Energy Storage Systems. Then, the optimization problem is presented, empathizing the indexes and constriction that could be taken into account. From the optimization procedure, reference operation setpoints are generated for each individual PEV. Then, the coordination of charger operations for maximizing global impact on the whole distribution grid is developed. Control strategies are presented and analyzed in terms of their operation setpoints in normal and abnormal grid states, when they are expected to control active, reactive and harmonic power. Finally, some examples on how the described strategies can be used for controlling active, reactive and harmonic power using a PEV charger, when the PEV is following the given operation references, are discussed.