DC-DC converter-based multi-bus DC microgrids (MGs) in series have received much attention, where the conflict between voltage recovery and current balancing has been a hot topic. The lack of models that accurately portray the electrical characteristics of actual MGs while is controller design-friendly has kept the issue active. To this end, this paper establishes a large-signal model containing the comprehensive dynamical behavior of the DC MGs based on the theory of high-order fully actuated systems, and proposes distributed optimal control based on this. The proposed secondary control method can achieve the two goals of voltage recovery and current sharing for multi-bus DC MGs. Additionally, the simple structure of the proposed approach is similar to one based on droop control, which allows this control technique to be easily implemented in a variety of modern microgrids with different configurations. In contrast to existing studies, the process of controller design in this paper is closely tied to the actual dynamics of the MGs. It is a prominent feature that enables engineers to customize the performance metrics of the system. In addition, the analysis of the stability of the closed-loop DC microgrid system, as well as the optimality and consensus of current sharing are given. Finally, a scaled-down solar and battery-based microgrid prototype with maximum power point tracking controller is developed in the laboratory to experimentally test the efficacy of the proposed control method.

中文翻译：

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通过全驱动方法实现孤岛直流微电网的最优协同二次控制

基于DC-DC变换器的多母线串联直流微电网（MG）备受关注，其中电压恢复与电流平衡之间的冲突一直是热门话题。由于缺乏能够准确描绘实际 MG 电气特性且控制器设计友好的模型，导致该问题一直存在。为此，本文基于高阶全驱动系统理论，建立了包含直流电机综合动力学行为的大信号模型，并在此基础上提出了分布式最优控制。所提出的二次控制方法可以实现多母线直流MG的电压恢复和电流共享两个目标。此外，所提出方法的简单结构类似于基于下垂控制的方法，这使得该控制技术可以在具有不同配置的各种现代微电网中轻松实现。与现有研究相比，本文的控制器设计过程与 MG 的实际动力学密切相关。这是一个突出的功能，使工程师能够定制系统的性能指标。此外，还对闭环直流微电网系统的稳定性以及均流的最优性和一致性进行了分析。最后，在实验室开发了具有最大功率点跟踪控制器的小型太阳能和电池微电网原型，以通过实验测试所提出的控制方法的有效性。