The increasing penetration of distributed energy resource DER, distributed generation DG and energy storage system ESS units in distribution grids leads to the emergence of the concepts of active distribution networks ADNs, microgrids, and virtual power plants. Nowadays, the use of electronically-coupled distributed energy resources is of great interest that can provide the power of demand side alone or in a small electricity grid. A microgrid is a small-scale power grid in low voltage network that must be able to locally solve energy issues and enhance the flexibility and can operate either in grid-connected or islandedautonomous mode of operation. To study them, researchers need an appropriate set of methods, software tools, analogous to those exist for large interconnected power systems. pThe book iMicrogrids and Methods of Analysisi addresses systematic analysis, controlprotection systems design, and optimal operation of a distribution system under high penetration of DERs analogou