Cooperative Control for Distributed Energy Storage Systems with Different Droop Schemes

Different types of power grids have different characteristics which require proper control methods to be implemented. Typically, droop control schemes are utilized at the primary control level due to their simplicity and quick response. Nevertheless, those droop methods can be varied depending on the power grid impedance, and hence, various secondary control protocols might be needed. This research proposes a distributed design approach for distributed battery energy storage systems (BESSs) at the higher control level corresponding to three different droop schemes implemented at the lower control level for various grid conditions. The designed controllers use multi-agent system and consensus theory to regulate the voltage/frequency and synchronize the energy level as well as active and reactive power sharing among BESSs. A modified IEEE 57-bus power system is used in the simulation for validation purpose.