Stochastic Optimal Power Flow Applied in Day-Ahead Planning of Isolated Microgrids

Due to the growing demand for energy in the last decades, the electric power system has been facing challenges to supply the power consumed by population. In this sense, isolated microgrids have emerged as a viable alternative based on the use of local energy resources to feed hard to reach areas. In this context, this paper develops a day-ahead energy based on optimal power flow for an isolated microgrid in Brazil equipped with storage system, backup generation and renewable resources. The renewable resource available in the studied microgrid is the photovoltaic solar energy, which presents an intermittent behavior, and so it is modeled by a probability density function in the proposed OPF formulation. The storage system represents approximately 52% of the total microgrid investment. Considering that, the objective function of the OPF incorporates the costs associated to the life cycle of the storage system and the fuel consumption with the backup generation, as well as, a stochastic model to estimate the costs of the photovoltaic solar energy. The proposed formulation was solved using Differential Evolution algorithm to obtain a minimal generation cost considering the load profile of a typical day.