Communication Constraints for Distributed Secondary Control of Heterogeneous Microgrids: A Survey

Heterogeneous microgrids provide a promising solution for accommodating different distributed energy resources (DERs) and enhancing the system performance in terms of reliability, resilience, flexibility, and energy efficiency. With the penetration of microgrids, the cyber-enabled distributed control techniques are playing an increasingly important role in microgrids for coordinating a multitude of heterogeneous and spatially distributed DERs. To identify the influence of communication constraints on the reliability and stability operation of heterogeneous microgrids, this survey presents a comprehensive review and comparison of cyber-enabled distributed control techniques for microgrid's secondary control layer. Local controls of an unavailable state signal are calculated in a distributed and cooperative matter according to merely invoked cyber messages. Then, the recent developments in the communication constraints of distributed controlled microgrids are discussed. Specifically, the communication constraints (e.g., time-varying network topology, communication delay, noise disturbance, limited communication bandwidth, uncertainties of communication links, and cyber attacks) on the operation of the distributed controllers and the possible challenges are presented and compared. Finally, a short discussion section is contained to summarize the existing research and suggest some interesting research directions along with several open issues that are critical to further exploring the promising research area.