Depletion of natural resources to meet power demands has revolutionized the use of Renewable Energy Sources (RESs).The paradigm shift from the centralized to distributed control is witnessed due to the Microgrids. Different configurations using smart grids and Microgrids are expected to ensure grid stability and security.Eventually, electricity market is subjected to change due to the projected changes in the grid architecture. This paper is a review on the Microgrids, its elements and the controllability. This paper discusses the major issues in the Microgrids, the factors affecting the choice of the Microgrid type and also various generation sources and their combination for reliable power quality and control. Recent developments with future trends are also addressed in this paper.

The world is shifting towards Renewable Energy Sources (RES) to meet the increasing demand. With proportionally high penetration of RES, the inertia of the grid tends to fall due to the incapability of these sources to participate in control mechanism. Also, due to the indeterminacy in the generation pattern, they tend to feed small signal disturbances in the grid due to the imbalance of generation and demand, which affects the frequency stability. In this paper, the affect of inertia emulation (IE) in the grid is presented to mitigate the small signal disturbances caused due to the change in load or due to the penetration of the RES. This work has considered Electric Vehicles for the application of vehicle to grid (V2G) towards frequency control. A cooperative control method, with V2G and synchronous power controller (SPC) based HVDC links, has been proposed towards the control of the fluctuations and a considerable decrease in the deviations have been observed. Several case studies are conducted and the results are presented to proof the concept.