Microgrids: Architectures, Controls, Protection, and Demonstration

—In the recent years, there has been a growing interest in the concept of microgrids to integrate distributed generation systems and to provide higher reliability for critical loads. Several microgrid demonstration projects have been implemented to investigate further and advance this emerging concept. This article provides a detailed review of microgrid systems. It describes different architectures, including AC, DC, and hybrid systems. Various microgrid components, including sources, converters, and loads, are illustrated. Microgrid management and controls are discussed, and a modified natural droop control is described in detail. Both physical layers and standard protocols are explained for communication in the microgrid structure. The unique protection complexities have been raised and discussed in the presence of distributed generations and bidirectional power flow. A demonstration of a military microgrid system at Fort Sill is illustrated, and the experiment of a typical microgrid operation scenario is provided.