A Comprehensive Review on Control Sterategies in Microgrids

A microgrid is an aggregation of multiple distributed generators (DGs), energy storage systems, and loads. A microgrid can be operated in both islanding mode or grid-connected mode. Microgrid’s control is necessary to provide power quality, system stability, and also reliability. Most DG technologies, which can be installed in the microgrid, are not suitable to direct connection to the grid because of their power generation characteristics. Therefore, for the installation of these units in the microgrid, we need the power electronic converters. Hence, the main concern in the operation of the microgrid is to control the power electronics units. Microgrid’s control methods are different with respect to its structure that is mean that what type of microgrid exist for study, DC or AC microgrid or consolidation of them that is called hybrid microgrid. It is noticeable that control methods in the microgrid are also different from the point of view of control functions. For example, output power control of DGs, islanding detection, synchronization with the upstream grid, power quality, participation in the energy market and etc. Moreover, control methods of microgrid can be divided into two general categories such as control methods based on communication infrastructure and without communication link.In this chapter, various control methods of the microgrid with respect to microgrid’s structure, functions control, and types of power electronic converter will be categorized and analyzed. In addition, their advantage and disadvantage are noted in each section describing control methods.