This book presents a detailed description of the transition from the traditional power system to the microgrid (MG) system. The authors introduce the basic concepts of an MG system along with its different operating modes and classifications.The various benefits, challenges, and technical aspects of an MG are highlighted.They demonstrate different control strategies that are applied at different levels of the control hierarchy, particularly the distributed secondary control architecture.Furthermore, the adaptive techniques-based distributed schemes, a distributed architecture-based synchronization controller, and a delay-independent buffer-free distributed controller are proposed for the MG system. This book can be useful for senior undergraduate students, postgraduate students, and researchers of electrical power engineering and system control.