Microgrid Operation and Control: Challenges and expected functionalities

This article considers several functionalities expected from the emerging microgrids and systems of microgrids. These performance objectives are then related to several modeling- and controlrelated challenges and open R&D questions that must be studied. The challenges are illustrated on Sheriff and Banshee microgrids, which are IEEE standards for testing microgrid control. I suggest that an extended ac optimal power flow (AC OPF) can be used to increase ranges of intermittent resources and responsive demand that can be used in a reliable way and without requiring excessive load shedding. The emphasis is on optimizing voltage-controlled equipment available at the inverter-controlled diverse distributed energy resources (DERs), including electric vehicle (EV) control of small residential end users, and the grid itself. The second question concerns enabling stability of microgrids over broad ranges of system inputs, and I briefly present a novel multilayered interactive modeling in transformed energy state space for stable control design. The article closes by revealing the importance of operating and control paradigm change from today's hierarchical control to interactive dynamic multilayered protocols, which also would provide financial incentives for reliance on control.