Analysis of the implementation of microgrid: case study of wide-area Bjelimići

Microgrids are increasingly put forward as key concepts of future energy supply, complementing as well as transforming the conventional, centralized energy system. Here, the aim was to construct microgrid composed of wind and solar power plants, diesel generator and battery storage which will be independent of a large, centralized electricity grid and incorporate more than one type of power source so to supply Bjelimići area. This area is taken as a case study since it has large potential considering the renewable energy sources and because this feeder is quite long which makes energy losses considerably higher. All material which were used in this project consist of real network parameters which are provided by Public Electric Utility Elektroprivreda of Bosnia and Herzegovina. For completing the project, DIgSILENT PowerFactory software (base package and Quasi-Dynamic Simulation Toolbox), HOMER (Hybrid Optimization Model for Multiple Energy Resources) software and Microsoft Excel were used. System has been modeled using minimum total cost of investment as a goal for optimization function and to cover the maximum power load with battery storage and diesel generators. Therefore, appropriate installed power of wind, solar and diesel power plants in combination with battery storage, based on real energy resource data and real load profiles of existing customers, has been chosen. In the end, using obtained data from HOMER for model in DIgSILENT PowerFactory, power flow, voltage profiles, line and transformer loading, and total grid losses were analyzed. It has been concluded that microgrids should be considered as excellent solution for such and similar areas, especially when considering the construction or significant upgrading of networks. Also, results from DIgSILENT PowerFactory have proved that system can operate with modeled microgrid. In addition, it is shown that better conditions of the network are present when operated in the island mode.