Abstract This paper introduces a frequency-based control strategy to minimize the total generation cost in low-voltage dc microgrids. In dc microgrids, although the voltage is the only variable for controlling the outputs of sources, it is not a common variable for all sources due to the different line resistances. Hence, applying the conventional voltage-based droop control will not be able to share the load among the sources accurately. Within the context alluded above, to realize an accurate load sharing in dc microgrids, the communication-based approaches are employed. However, any link failure in these approaches may impair the controller functionality and consequently, render the whole system inoperable. To cope with the associated problems of the communication-based approaches, the frequency-based control strategy has been introduced for accurate load sharing in dc microgrids which operates without any communication network. This study proposes a frequency-based economical-sharing control strategy that has the capability to minimize the total generation cost and regulate the voltage of sources. The main advantage of this strategy over the previously addressed frequency-based strategies is providing an optimal combination of dispatchable sources to supply the required load on the grid. Through the employed control strategy, the incremental costs of all dispatchable sources will be equal in the steady state which causes the optimal operation of the dc microgrid. The small-signal modeling of the proposed strategy is also carried out to analyze the system stability and parameter sensitivity. A complete set of simulation studies is provided in PLECS software to verify the effectiveness of the proposed control strategy.

中文翻译：

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一种基于频率的低压直流微电网经济共享策略

摘要 本文介绍了一种基于频率的控制策略，以最小化低压直流微电网的总发电成本。在直流微电网中，虽然电压是控制电源输出的唯一变量，但由于线路电阻不同，它不是所有电源的通用变量。因此，应用传统的基于电压的下垂控制将无法准确地在源之间共享负载。在上面提到的上下文中，为了在直流微电网中实现准确的负载分配，采用了基于通信的方法。然而，这些方法中的任何链路故障都可能损害控制器功能，从而导致整个系统无法运行。为了应对基于通信的方法的相关问题，引入了基于频率的控制策略，以便在没有任何通信网络的情况下运行的直流微电网中实现精确的负载分配。本研究提出了一种基于频率的经济共享控制策略，该策略能够最大限度地降低总发电成本并调节电源电压。与之前提到的基于频率的策略相比，该策略的主要优势在于提供可调度源的最佳组合，以供应电网所需的负载。通过采用的控制策略，所有可调度源的增量成本在稳态下将相等，从而导致直流微电网的优化运行。还进行了所提出策略的小信号建模以分析系统稳定性和参数敏感性。