Distributed Cooperative Control of Battery Energy Storage Systems in DC Microgrids

The control of battery energy storage systems (BESSs) plays an important role in the management of microgrids. In this paper, the problem of balancing the state-of-charge (SoC) of the networked battery units in a BESS while meeting the total charging/discharging power demand is formulated and solved as a distributed control problem. Conditions on the communication topology among the battery units and the accessibility of the knowledge of the desired power are established under which a control law is designed for each battery unit based on distributed average power estimators and distributed average unit state estimators. We show that, under the proposed control laws, SoC balancing of all battery units is achieved and the total charging/discharging power of the BESS tracks the desired power. A simulation example is presented to verify the theoretical results.