Design of a Future Residential DC Microgrid

Sammanfattning: In the search for environmentally friendly methods to implement renewable energy in the power system residential microgrids have been proposed and proven. The direct current (DC) microgrid topology is a promising implementation of a microgrid system due to the increasing amount of DC-operated loads and production units expected in the near future. In this project, the proposed DC microgrid consists of a solar photovoltaic (PV) power source, a battery, a DC load, and an interlinking bidirectional converter to connect the microgrid to the external three-phase power grid. The PV system is controlled with a Maximum Power Point Tracking (MPPT) algorithm to maximise the power production in all weathers. The DC bus voltage is stabilised by the battery controller and a coordinated control scheme considering the electricity price and battery State of Charge (SOC) is implemented to govern the power exchange with the utility grid. Simulations of the system are shown to validate the functionality of the microgrid and the performance of the controllers in multiple scenarios. The proposed DC microgrid is proven to function in both utility grid-connected mode and in isolation from the utility grid.