Modeling and Analysis of a Micro-Grid System Powered by Renewable Energy Sources

Renewable source based micro-generations such as wind and hydro offer the best potential for emission free power in future power systems. This paper investigates the technical issues related to stable and autonomous operation of a micro-grid system consisting of renewable power sources. A small hydro generation unit and a wind farm are the main renewable power generation units in the proposed micro-grid system. The system under investigation represents a case study in Newfoundland and Labrador, Canada. The availability of the utility grid and the intermittent nature of wind power generation are taken into consideration when identifying the operational modes of the proposed micro-grid system. The investigations are carried out through dynamic modeling and simulation of the proposed micro-grid system in different operational modes. The components models of the proposed micro-grid system are also presented in this paper. The investigations reveal that appropriate control techniques are required to be developed depending upon the operational modes of the proposed system with some additional arrangements. Such arrangements include the type of energy storage unit, reactive power compensation, the management of excess power in the system due to the wind generator etc. The control concepts with additional necessities are also outlined in this paper. This paper concludes that the development of such control concepts is essential to ensure stable and automatic operation of the proposed micro-grid system while maintaining the system voltage and frequency in their rated values.