A Coordinated Consensus Control Strategy for Distributed Battery Energy Storages Considering Different Frequency Control Demands

With the increasing penetration of renewable energy sources (RESs), ensuring frequency stability is becoming urgent for the power system. The distributed battery energy storage systems (DBESs) is one of the promising solutions to this problem. In this paper, a consensus control-based strategy is proposed for coordinating the DBESs to participate in the frequency regulation. Firstly, the system frequency response (SFR) model with the DBESs is introduced, and different frequency control demands are analyzed in detail, based on which the designing principles of the strategy are elaborated. Then, a revised dead band of frequency response is proposed to improve the frequency control performance under severer and more frequent RESs power fluctuation, reduce the possibility of frequency variation crossing the thresholds, and fully utilizes the DBESs' frequency regulation capability. Further, a developed consensus strategy derived from droop control is proposed, which enables the DBESs to participate in different frequency control demands simultaneously. The proposed strategy can prolong the service time when DBESs involved in frequency control as an aggregator, avoid unexpected energy exhaustion during frequency regulation, and reduce the frequency variation. The performance of the proposed control strategy is validated by the simulation cases with different operating scenarios.