Distributed convex optimization of energy flows: The two-microgrid case

In this paper, a distributed convex optimization framework is developed to manage energy flows between is-landed microgrids. More specifically, the problem consists of two islanded microgrids with the additional capability of selling energy to one another. In order to avoid a central controller and to reduce communications requirements, a subgradient-based cost minimization algorithm is proposed that converges to the centralized solution in a practical number of iterations. Furthermore, this approach allows for a very intuitive, economics interpretation that explains the algorithm iterations in terms of “supply-demand model” and “market clearing”. Finally, numerical results show that microgrid cooperation brings a benefit, both globally (system level) and locally (microgrid level).