Hierarchical Control for Isolated Microgrid Clusters Under Renewable Variability

This paper presents a novel hierarchical control for a microgrid cluster (MGC) operating in islanded mode, integrating renewable energy technologies (RETs), energy storage systems (ESSs), and variable demands. The control strategy dynamically manages power distribution by introducing the real-time available power concept, enabling proportional allocation of power among microgrids (MGs) based on their operational capacity. The proposed configuration includes MGs with grid-forming (GFM) inverters for voltage and frequency control and MGs with grid-following (GFL) inverter for power control. Unlike conventional methods that oversimplify the dynamics of RETs and ESSs, this approach ensures adaptive and reliable power sharing while addressing the challenges of intermittency and demand variability. Time-domain simulations across various operating scenarios validate the effectiveness of the proposed strategy, demonstrating its ability to maintain stable voltage and frequency in isolated MGCs. The results confirm the robustness and adaptability of the proposed hierarchical control framework, making it a viable solution for improving operational reliability and resilience in high-RETs penetration systems. This innovative approach advances the state of the art by providing a dynamic solution to manage the complexities of islanded MGC operations. Key words. Isolated, microgrid-cluster, hierarchical, control, dynamic.