Adaptive protection proposal to interconnect isolated microgrid to main electric grid: Case study of Pedernales province

With the introduction of the Cabo Rojo project the province of Pedernales will see unprecedented growth in economic activity, population and consequently energy consumption. For that matter it is of great importance that the energy supply matrix is sufficiently expanded to address the future needs of its inhabitants and the soon thriving local tourism industry. This expansion should see greater use of distributed energy resources, especially renewables, to improve the resiliency of the energy sources and its power distribution grid. Being currently isolated from the main national grid, the Pedernales grid provides a special opportunity to study the performance of a small traditional grid to smart microgrid conversion, with presence of multiple types distributed energy resources and the application of an adaptive protection strategy in the Dominican Republic. The intent of this research is to analyze the viability of interconnecting the Pedernales grid to the main grid, increase the distributed energy resources with renewables and battery storage, while maintaining adequate electrical protection. The main grid, the Pedernales microgrid and battery models were simulated using the PowerFactory DIgSILENT software. The results of the study show the response of the adaptive protection as compared to the non-adaptive solution. Here the adaptive protection strategy provided greater grid stability than the traditional approach by preventing frequency increases above 62Hz.