The Hierarchical Structure and Control Signal Transmission of Microgrid Hierarchical Control: A Review

Microgrids, as an important component of modern power systems, have garnered significant attention due to their ability to operate flexibly, enhance power supply reliability, and improve the integration of renewable energy sources. As distributed generation and renewable energy continue to merge, microgrid operation faces significant challenges, including intermittency in generation and load, power balance issues, as well as frequency and voltage stability. Hierarchical control has become an effective strategy to address these complexities. This paper provides a comprehensive review of the structure and control objectives of microgrid hierarchical control, analysing in depth the differences and interrelationships between control levels in terms of timescale, hardware components, control tasks, decision-making mechanisms, and communication methods. By systematically organizing the responsibilities and coordination between control layers, this paper clarifies the pathways for control signal transmission and feedback mechanisms. By integrating the relationships between different hierarchical control strategies, this paper lays a theoretical foundation for the efficient and stable operation of microgrids, offering researchers an overall perspective on the interactions and coordination between control layers.