Energy management in islanded DC microgrid using fuzzy controller to improve battery performance

Large integration of Distributed Energy Resources (DERs) has led to the concept of microgrid. Microgrid allows integration of renewable energy sources, storage devices, loads etc. Islanded mode is where the microgrid is disconnected from the utility grid. Energy balance is the main issue in islanded mode because of intermittency in DERs. Storage devices are used because of fluctuation in renewable sources. Since battery has to undergo high number of charge and discharge cycles under fast varying load, ultracapacitor is used to reduce the weight on battery. The main aim of this work is to develop and implement prototype model of the energy management system of DC microgrid in islanded mode consisting of battery with ultracapacitor forming Hybrid Energy Storage System (HESS) to extend the life of battery. The micro grid is implemented with dc-dc converters, with closed loop control. The control is achieved with fuzzy logic scheme implemented in microcontroller. The switching action of the converter is based on the power balancing to meet the load demand.