Optimal Planning and Scheduling of Battery Energy Storage Systems for Isolated Microgrids

Abstract

Balancing the energy demand in isolated microgrids is a critical issue especially in the presence of intermittent energy sources. Battery Energy Storage Systems (BESS) can be installed in such circumstances to supply the demand and support the reserve requirements of the isolated microgrid. However, due to the high installation costs of BESS, there is a need for proper mechanisms to select such systems and size them optimally. Furthermore, since BESS are often installed to serve multiple applications, these should be properly modeled to coordinate their different functionalities.

In this thesis, a multi-year operational planning model is developed to determine the BESS optimal power rating and energy capacity along with the year of installation taking into account its coordinated operation. The model includes unit commitment formulation with renewable energy and BESS operational constraints. The optimal planning decisions are obtained for different BESS technologies under several scenarios of ownerships.

The uncertain patterns of solar and wind resources and system demand are considered and several microgrid operational scenarios are created. A stochastic optimization model is developed to determine the optimal BESS size and installation year including the different states of the uncertain microgrid variables. The stochastic optimization model is solved using a decomposition based two-stage iterative approach to cope with the large computational burden of such problems.