Coordinated Control of DC Distribution System Based on Three‐Level Energy Interaction

Abstract

AbstractWhen compared to the AC distribution system, the DC distribution system can better adapt to the integration of large‐scale distributed generations (DGs), but it also has some challenges and limitations due to its complex control. This paper investigates the coordinated control of a DC distribution system containing multiple DC microgrids and proposes a coordinated control strategy for energy interaction at the microgrid, cluster, and main grid‐levels to address this problem. To begin, the interaction at the microgrid‐level employs a decentralized control strategy that only requires local voltage information and adjusts the operation modes of each unit within the microgrid based on the bus voltage information. Second, a new power equalization optimization control is added to the cluster‐level interaction based on the decentralized control strategy to achieve power equalization among microgrids with different line impedances. Furthermore, at the main grid‐level, the interaction uses one‐way communication of time‐of‐use (TOU) price to optimize system economy, ensuring that even if communication fails, the system's operation reliability is not compromised. Finally, simulation results demonstrate that the proposed three‐level energy interaction and switching meet the system's reliability requirements. Furthermore, the proposed coordinated control strategy reduces the system's reliance on communication while maintaining economic efficiency. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.