Probabilistic Optimal Power Flow for Balanced Islanded Microgrids

This paper presents a Probabilistic Optimal Power Flow (POPF) for losses minimization in balanced islanded microgrids considering load uncertainties following a normal distribution. The peculiarities of the islanded operation, like the absence of infinite bus and frequency variation in the face of load and loss variations, are adequately considered. The constraints deal with the power balancing, angular reference, droop control mode of generators (P-f e Q-V), and the probability of satisfying the limits of microgrid frequency, nodal voltages, and power generation. As the main contribution, the Differential Evolution method and the Unscented Transformation solve the POPF, reducing the computational time and providing accurate results compared with the Monte Carlo Simulation. The proposed approach is evaluated using a 33-bus islanded microgrid.