Design and Development of Control Algorithm for a DC Microgrid System

DC microgrid technology provides a promising alternative to the currently existing AC microgrids, owing to ease of integration of renewable energy sources, lesser number of grid variables in need of control, and the rapid developments in DC energy storage technologies. The availibility of DC lighting loads, DC motors, and high efficiency DC-AC converters for high power applications make a strong case for the implementation of DC microgrids. This paper proposes a DC microgrid system, and a control algorithm for operating the aforementioned microgrid in Hybrid Mode. The microgrid integrates a PV array with MPP tracking, AC grid interfacing, a Battery Energy Storage System with CC-CV charging and cell balancing using a proposed cell balancing algorithm. Each component is studied and designed individually, and finally all are integrated to form the DC microgrid, whose operation in Hybrid Mode is demonstrated through simulated results.