Stochastic optimization of microgrids with renewable and storage energy systems

The microgrids can function as a single controllable system in a grid-connected or islanded operation mode. The transition from grid-connected mode to islanded mode can result in microgrid excess generation or demand, which must be spilled or curtailed. This paper proposes an optimization model for optimizing the microgrid operations accounting for distributed energy resources (stochastic generation and time-varying demand), as well as microgrid operation constrains. The objective is to minimize the microgrid operational costs considering the classical generation capacities and exchanged power with the upstream grid, as well the operational constraints. The analyzed microgrid is composed of a thermal engine, a photovoltaic system, an electrochemical storage system, critical and interruptible loads. The deterministic and stochastic optimization model were formulated, and each optimization model is tested in various case studies considering the different operational states of the microgrid.