Autonomous Distributed Frequency Control for the Management of Energy Storage Systems in Microgrid

This paper proposes a novel frequency control method based on autonomous distributed control scheme. The operating frequency is controlled by battery energy storage systems (BESSs) in AC microgrid (MG) where an efficient coordination of BESS’s state-of-charges (SOCs) is performed without communications. The BESS-SOCs of the individual prosumers are automatically managed to a same value, while the frequency is deviated in a specified bandwidth as a function of the total BESS-SOCs in MG. The proposed method can increase the reliability of MG operation specially in emergency state where communication is lost. The method is useful not only for the management of BESS-SOCs but also for any distributed generations (DGs) with limited energy storages. The simulation results show that the effectiveness of the proposed method where the MG survives until all energy storages are consumed.