Management of a photovoltaic-battery-based microgrid in a prosumer context

Prosumers are households that are both producers and consumers of electricity. In this paper, an Energy Management System (EMS) for a DC-microgrid-based prosumer is designed and simulated, whose aim is to coordinate operation of a photovoltaic (PV) system and a battery for supplying a DC load; interaction with the utility grid - modelled as an infinite-power source - is minimized, such that power is either injected or drawn only when strictly necessary. The PV system and the battery are paralleled on a common DC-link by means of a boost converter and a synchronous buck converter, respectively, while an inverter ensures connection to the utility grid. In order to design and simulate the individual components of the microgrid, MATLAB®/Simulink® tools were used. During the study, different operating scenarios were created with respect to the PV power, load and the state of charge (SoC) of the battery. Thus, the following operation modes were identified: following mode, discharge mode, charging mode - referring to the battery operating modes that depend of its SoC. The aim of the EMS is to ensure the requirements of a prosumer application and switch between these different modes. Simulation results have shown that the developed EMS can achieve effective coordination within the microgrid, and all goals are reached.