This paper details a decision model to implement direct load control (DLC) on battery charging processes at electric vehicle charging points located at parking areas. The programming model combines optimally three types of energy management decisions: grid-to-vehicle charges, vehicle-to-grid discharges, and novel vehicle-to-vehicle energy exchanges. The objective function maximizes the net energy supplied to batteries minimizing simultaneously the global energy cost. A 50-plug-in vehicle park case is analyzed for three possible mobility patterns: household, commercial and mixed. Outputs from the DLC model are compared with the ones using a dumb charging policy from the service quality and economic points of view. Finally, a sensitivity analysis has been done to evaluate the economic impact of the Depth of Discharge condition to preserve battery lifecycle of electric vehicles.
Index Terms-Charging points, direct load control (DLC), electric vehicle batteries, grid to vehicle, vehicle to grid, vehicle to vehicle.
NOMENCLATUREHere, we provide the main nomenclature used for quick reference of acronyms and elements of the programming model. Lower-case symbols denote indexes and parameters, and uppercase symbols denote variables.
A. Main Acronyms[1] EV/EVB Electric vehicle/electric vehicle battery. PHEV Plug-in hybrid electric vehicle. EVCP Electric vehicle charging point. DLC Direct load control. AU/CAU Aggregation unit/central aggregation unit.
G2VGrid-to-vehicle charging process.
V2GVehicle-to-grid discharging process.
V2VVehicle-to-vehicle energy exchange.
B. IndexesType of plug-in vehicles {EV, PHEV}.