Two-Level Coupling-Based Frequency Control Strategy with Adaptive Distributed Frequency Consensus and Dynamic Compensation

This paper highlights the inefficiency of most distributed control methods in dealing with dynamic enhancement while coordinating DGs, leading to poor frequency dynamics. To address this concern, a two-level coupling-based frequency control strategy for microgrids is developed in this paper. At the lower level, an adaptive dynamic compensation algorithm is designed to tackle short-term and long-term frequency fluctuations caused by the uncertainties of renewable energy resources (RESs). At the upper level, an adaptive distributed frequency consensus algorithm is developed to address frequency restoration and active power sharing. Furthermore, to account for the potential control interaction of the two designed levels, a nonlinear extended state observer (NESO) is introduced to couple their control dynamics. Simulation tests and hardware-in-the-loop (HIL) experiments confirm the improved frequency dynamics.