Abstract
In this paper, mixed integer programming (MIP) formulations are proposed to obtain the optimal capacity of the battery energy storage system (BESS) in a power system. Two optimization problems will be investigated: (1) When the BESS is owned by a utility, the operation cost of generators and cost of battery will be minimized. Generator on/off states, dispatch level and battery power dispatch level will be determined for a 24-h period. (2) When the BESS is owned by a community for peak shaving, the objective function will have a penalty component for the deviation of the imported power from the scheduled imported power. The battery sizing parameters, power limit and energy limit, are treated as decision variables in the optimization problems. In both cases, switchable loads are considered. Further, constrains of switchable loads are included in the optimization problem to show their impact on battery sizing. MIP problems are solved by CPLEX. The simulation results present the effect of switchable load penetration level on battery sizing parameters.