Distributed Economic Coordination Controller for Parallel DC–DC Converters in Shipboard DC Microgrids Based on Prescribed-Time Consensus Observer
Yuji Zeng, Qinjin Zhang, Herbert Ho‐Ching Iu, Heyang Yu, Yancheng Liu, Haohao Guo, Zifan Lin, Siyuan Liu
Abstract
Conventionally, the centralized energy management strategy (EMS) is commonly used as the power allocation method between different dispatchable power sources (DPSs) in shipboard dc microgrids, and the EMS optimization and converter control are performed on different time scales, resulting in high-power generation cost, low reliability, poor scalability, and disconnection between optimization and control. In this article, a distributed economic coordination (DEC) controller based on a prescribed-time consensus (PTC) observer is proposed to realize optimal power allocation and flexible bus voltage regulation for parallel dc–dc converters of fuel cells and batteries (BATs) in shipboard dc microgrids with a fully distributed manner. Compared with the centralized EMS, the proposed DEC controller unifies the optimal power allocation and bus voltage regulation in the converter control layer for real-time implementation, and the designed PTC observer ensures the convergence of the average combined state variables at arbitrary prescribed settling time while not relying on the initial system conditions. The integration of the PTC observer and the DEC controller not only provides a unified framework for economic dispatch and voltage regulation of the multisource hybrid power systems in shipboard dc microgrids but also provides the advantages of minimizing the total power generation cost of the parallel DPSs, the excellent plug-and-play performance of the converters, the robust system scalability, and the dynamic state-of-charge balancing of BATs. The stability of the PTC observer and DEC controller is verified by Lyapunov stability analysis and system steady-state analysis, respectively. Finally, the experimental results based on StarSim demonstrate the feasibility and effectiveness of the proposed method for shipboard dc microgrids under various test scenarios.