Accelerated Secondary Frequency Regulation and Active Power Sharing for Islanded Microgrids with External Disturbances: A Fully Distributed Approach

Abstract

Islanded microgrids face some challenges in maintaining stable frequency and sharing proper power among distributed generators (DGs) in the presence of external disturbances. This paper develops a novel fully distributed approach to achieve accelerated secondary frequency regulation (FR) and active power sharing (APS) in islanded microgrids, which enhances system performance and robustness against external disturbances. The proposed control strategy combines advanced consensus algorithms with distributed secondary control loops, eliminating the requirement for a central control unit thereby improving the scalability. Particularly, the fully distributed feature of the proposed control strategy can be understood from two aspects. On one hand, the controller itself is not using global information of (1) communication topology, such as the second smallest eigenvalue of its Laplacian matrix; and (2) the total number of DGs in the microgrid. On the other hand, the estimated settling time is independent of the aforementioned global information. Therefore, the proposed fully distributed control scheme has the potential of becoming a promising solution for the resilient and efficient management of large-scale islanded microgrids. The effectiveness of the designed controllers is validated through numerical examples, demonstrating superior performance in terms of FR, APS, and transient response under various operating conditions.