Event-Triggered Secondary Frequency Control for Islanded Microgrid Suffering From Communication Delays: A New Adaptive Threshold Mechanism

This paper mainly explores the secondary frequency control (SFC) for the islanded microgrid (MG) with communication delays. First, a new SFC scheme based on adaptive event-triggered (ET) mechanism is proposed against frequency fluctuations of the islanded MG caused by the uncertainty of renewable energy sources (RESs). Second, the state space model of SFC for the islanded MG encountered from communication delays is established. Based on adaptive thresholds, an adaptive event-triggered secondary frequency control (ET-SFC) scheme is proposed which can be adjusted continuously according to the real-time system state. Then, the stability condition of the islanded MG system is derived using the Lyapunov-Krasovskii functional method. Moreover, Zeno behavior can be excluded through theoretical derivation. According to the simulation results, the proposed adaptive ET-SFC scheme not only guarantees the frequency stability of the system, but also further reduces the communication burden.