Sizing Battery Energy Storage Systems for Microgrid Participating in Ancillary Services

The installation of battery energy storage systems (BESS) does not only provide reliability, security and flexibility of renewable sources to microgrids, but can also generate a considerable revenue by providing several ancillary services to the main grid such as frequency regulation. Using BESS for ancillary services results in reducing the total expansion cost of connected microgrids. In this paper an optimal BESS sizing model is developed to minimize the total operation cost and investment cost by determining the optimal BESS power rating and energy capacity and by participating in ancillary services markets. Additionally, the model aims to investigate the effect of the frequency regulation reserved capacity on the size of BESS and the total operation cost. The model in this paper is demonstrated on a microgrid system using historical price data from PJM. A mixed integer linear programming (MILP) is used in this work to formulate the optimization problem.