Fundamental Key Issues and Analysis of Symmetrical Current Components in Micro-Grids

Micro-grids are becoming increasingly popular to consumers and as such in the future, a great number of them will be installed at consumer's sites. In this way, conventional distribution grid structures that accept distributed generation connections may face serious problems when their grid control and protection functions become more complicated. These problems have led to a new trend of generation power locally at distribution voltage level by using non-conventional sources like wind power, fuel cells, micro-turbines and biogas and their integration into the utility distribution system. Micro-grids can cause several fundamental problems in its system and grid control when operate as autonomous mode. This paper is a review of fundamental key issues on micro-grids with respect to voltage and frequency flow grid control and protection of micro-grids. Moreover, in the paper the symmetrical current components are analyzed on a larger system of distribution network. All of the studies are simulated using DIgSILENT PowerFactory to establish claims in this paper.