Smart Charging of EV Batteries for Load Balancing Strategies

Abstract: This thesis analyzes the economic potential of increased charging control of Plug-in Electric vehicles (PEVs) and resulting potential for evening peak shaving and load shifting. The analysis in this body of work considered a building in Hammarby Sjöstad with four Plug-in hybrid electric vehicles (PHEVs). A model was developed in Matlab which, with the help of linear programming tools, calculated the lowest possible charging cost for three different charging modes with added charging control for both a single night, and throughout a whole year. The “Reference mode” considers no charging control, the “Smart Charging mode” considers day-ahead electricity prices to calculate the least expensive charging profile, and the “vehicle-to-grid (V2G) mode”, which facilitates the selling of excess energy to the grid. The conclusions of this study are twofold. As presently constituted, the smart charging mode is the least expensive charging mode available, because it decreases overall charging costs without incurring an increase in battery degradation. Nevertheless, V2G is promising, because with the constant improvements in battery development, larger batteries will allow for a larger amount of energy to be sold to the grid at a profit, without a steep increase in battery degradation costs.