Design of a Greedy V2G Coordinator Achieving Microgrid-Level Load Shift

This paper designs a microgrid-level V2G (Vehicle-to-Grid) coordinator capable of controlling the electricity flow from EV (Electric Vehicle) batteries to a grid, aiming at achieving temporal and spatial load shift in energy consumption. A bidding request specifies earliest and latest arrival times, amount to sell, and plug-in duration, while the controller creates an on-off schedule by which EVs are connected or disconnected to the grid on each time slot. After defining the search space made up of all feasible solutions, a greedy scheduler traverses the space to find an optimal slot allocation, which can enhance the demand-supply balance by means of minimizing the amount of surplus and lacking energy. The schedule also tells EV owners when to come and be connected to the microgrid. The performance evaluation result obtained from a prototype implementation shows that the proposed scheme reduces the energy lack by 49.0 % and the energy waste by 63.7 %, compared with the uncoordinated scheduling strategy.