Optimal operation of microgrids under conditions of uncertainty

This paper proposes a method to optimally operate microgrids under conditions of uncertainty introduced by renewable energy sources, under both grid connected and islanded mode. Uncertainty is quantified with probability distribution and confidence levels are used to establish likelihood of forecast error. The optimization problem is formulated as a quadratic programming problem and the optimality of the solution is shown mathematically by proving the convexity of the problem. The optimization is carried out with the combined objective of minimizing total operating cost and carbon emission. The proposed optimization method is then tested against a priority controller for an extended time-horizon of 24 hours. Furthermore, under islanded mode of operation, for extended time-horizon, a key decision making task of whether to provide energy to non-critical loads or to store excess energy is addressed.