DC Nano-Grid with Power Management System

The DC residential nano-grid is typically a combination of renewable energy sources (RES) like solar panels, fuel-cells, micro wind together with batteries (EES), and DC loads for isolated buildings. For solar and fuel cell DC-DC Boost converter is used, bi-directional converter is used for ESS however buck/boost converter are required for loads. The maximum benefit of multi-source can only be achieved by optimal load and source scheduling whereas priority load and non-priority load needs to be distinguished and controlled using appropriate power management algorithm. In this paper, a new algorithm is developed for the central controller to manage the power flows between the RES, ESS and priority and non-priority loads. The real-time data is sent to the central controller to operate DC nano-grid in different modes based on power generation and load information. The proposed central controller and power management system is implemented and validated using the MATLAB Simulink platform that it effectively maintains the DC bus voltage at 48 V, adjust the voltage and power of every unit and balance what energy flows in the system irrespective of variations in switching functioning ways, radiation and climate, and loads.