Asynchronous Switched Event-Triggered Load Frequency Control Considering Dynamic Participation Behaviors of Energy Storage Systems

The rapid response ability of energy storage systems (ESSs) can provide additional regulation capacities for load frequency control (LFC) in power systems. However, the dynamic participation/exit behaviors of ESSs caused by unplanned maintenances, unexpected failures or other reasons may lead to structural uncertainties in LFC systems. This paper investigates an asynchronous switched event-triggered LFC scheme to address the uncertain participation behaviors of ESSs. Firstly, a novel event-triggered control (ETC) scheme has been proposed, in which the triggered conditions depend not only on control performance but also on the participation states of ESSs. Secondly, considering the climbing constraints of frequency regulation equipment, the dynamic closed-loop characteristic of LFC is described by a nonlinear saturated model. Thirdly, given the asynchronous adjustment nature of ETC parameters lagging behind the ESS behavior changes, the design constraints and ETC parameter update criteria are strictly derived based on Lyapunov theory and average dwell time (ADT) technique. Finally, the effectiveness of the proposed scheme has been verified by a series of case studies.