Optimized Planning for Hybrid Micro-grid in Grid-connected Mode

Abstract

The emergence of the Distributed Generation (DG) units along with their application in the distribution system level has led to the establishment of microgrids. microgrids are a part of the distribution network in which, in addition to the loads, there are micro sources operating in two modes, i.e. grid-connected mode and island also known as standalone mode. In the grid-connected mode, the load is supplied through local DG units, and if necessary, power is exchanged with the upstream grid, concerned as well. Considering the development of DG units technology in recent years which in turn, has led to the expansion of microgrid concept, microgrid planning meaning determining the capacities of local DG units assumes an extraordinary significance, taking the technical, economic and environmental considerations into account. This research tries to study the optimized planning for a grid-connected hybrid microgrid. The case study was conducted in Razi University in Kermanshah, Iran (34°23'Nlatitude and 47°6'E longitude). Due to the stochastic behavior of renewable energies based DG units, the uncertainties about the amount of generated power from these resources are considered using appropriate probability density functions. The problem is a Mixed Integer Non-linear Program (MINLP), to be solved by means of GAMS software. In order to bring about optimized results, microgrid simulation is processed in assorted scenarios, both in probabilistic and deterministic modes. In the end, the results are compared to those resulted from Homer Energy software. KeywordsOptimized Planning, Hybrid microgrid, Probability Functions, Uncertainty, Distributed Generation