Dynamic Circuit-Based Unified Power Regulation for Hybrid AC/DC/DS Microgrids: A Comprehensive Approach to Static and Transient Control
Pengfeng Lin, Qingzuo Meng, Miao Zhu, Amer M. Y. M. Ghias, Frede Blaabjerg
Abstract
Power regulation in hybrid ac/dc microgrids (MGs) is a critical concern, both in static and transient states. Static power regulation involves optimizing the dispatch of distributed energy resources (DERs) to meet the global load in proportion to their capacities, while transient power regulation requires each DER to manage load fluctuations based on their respective inertia during transients. However, the existing literature typically addresses these regulations separately focusing on static control often leads to the oversight of transient performance, and vice versa. To bridge this gap, this article introduces a unified modeling framework that integrates both static and transient power regulation, providing a comprehensive, full time-scale control strategy for hybrid systems. This approach visualizes the power regulation process through a dynamic equivalent circuit model, where power flow is represented as current variables on respective circuit elements. Furthermore, distributed energy storage systems are deployed centrally forming a distributed storage (DS) subgrid so that DS can be uniformly managed and participate in full time-scale regulation within the hybrid ac/dc/DS MG. The proposed unified model is validated through simulation and experiments, demonstrating its feasibility and effectiveness in achieving seamless static and transient power regulation.