The presence of single-phase distributed generators unevenly injecting active power in three-phase microgrids may create undesired upstream current unbalance. Consequently, voltage asymmetry and even active power curtailment may occur in such networks with negative economic impact. Thus, this paper proposes an optimal multiobjective approach to regulate the active and reactive power delivered by distributed generators driven by a three-layer hierarchical control technique in low-voltage microgrids. This method does not require previous knowledge of network parameters. The multiobjective algorithm is implemented in the secondary level achieving optimal dispatch in terms of maximizing the active power generation, as well as minimizing the reactive power circulation and current unbalance. By the existence of a utility interface three-phase converter placed at the point-of-common-coupling, the proposed control can regulate the power circulating among the microgrid phases, and the microgrid structure can withstand grid-connected and islanded operating modes. The path for interphase power circulation through the DC-link of the utility interface allows the multiobjective algorithm to achieve better results in terms of generation and compensation compared to the system without utility interface. The proposed method is assessed herein by computational simulations in a three-phase four-wire microgrid under realistic operational conditions.

中文翻译：

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低压交流微电网的最优多目标控制：潮流调节和无功及不平衡补偿

单相分布式发电机的存在会在三相微电网中不均匀地注入有功功率，这可能会导致不希望的上游电流不平衡。因此，在这种网络中可能发生电压不对称甚至有功功率削减，并对经济产生负面影响。因此，本文提出了一种最优的多目标方法来调节低压微电网中由三层分层控制技术驱动的分布式发电机的有功和无功功率。此方法不需要事先了解网络参数。多目标算法在次要级别实现，从而在最大化有功功率，最小化无功功率循环和电流不平衡方面实现了最佳调度。通过在公用耦合点处放置一个公用接口三相变频器，所提出的控制可以调节微电网相之间的功率循环，并且微电网结构可以承受并网和孤岛运行模式。与没有公用接口的系统相比，通过公用接口的直流链路进行相间功率循环的路径使多目标算法在发电和补偿方面获得更好的结果。本文通过在实际操作条件下的三相四线微电网中的计算仿真来评估提出的方法。微电网结构可以承受并网和孤岛运行模式。与没有公用接口的系统相比，通过公用接口的直流链路进行相间功率循环的路径使多目标算法在发电和补偿方面获得更好的结果。本文通过在实际操作条件下的三相四线微电网中的计算仿真来评估提出的方法。微电网结构可以承受并网和孤岛运行模式。与没有公用接口的系统相比，通过公用接口的直流链路进行相间功率循环的路径使多目标算法在发电和补偿方面获得更好的结果。本文通过在实际操作条件下的三相四线微电网中的计算仿真来评估提出的方法。