Multi-functional grid-tied inverters (MFGTIs) have been investigated recently for improving the power quality (PQ) of microgrids (MGs) by exploiting the residual capacity (RC) of distributed generators. Several centralized and decentralized methods have been proposed to coordinate the MFGTIs. However, with the increasing number of the MFGTIs, it demands a method with improved reliability and flexibility, which are characteristics of distributed framework that has not been introduced into the PQ improvement (PQI) field before. In this paper, we propose a distributed consensus method to undertake the PQI task. The task is proportionally shared among the MFGTIs according to their instant RCs. Besides, most of the existing methods assume that the RCs of the MFGTIs are sufficient for tackling the PQ problem (PQP), which is not always true. In the case of insufficient RC, the active power output of each MFGTI is scaled down by the same factor determined by a proposed leader-follower protocol to make room for the task. In summary, the PQP is dealt with in both cases of sufficient and insufficient RC under the distributed control framework. Finally, simulations and hardware-in-the-loop experiments of an MG consisting of three 10kVA MFGTIs are presented to verify the effectiveness of the proposed methods.

中文翻译：

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用于电能质量改善的多功能并网逆变器的分布式控制

最近研究了多功能并网逆变器 (MFGTI)，以通过利用分布式发电机的剩余容量 (RC) 来改善微电网 (MG) 的电能质量 (PQ)。已经提出了几种集中和分散的方法来协调 MFGTI。然而，随着MFGTI数量的增加，它需要一种具有更高可靠性和灵活性的方法，这是以前没有被引入PQ改进（PQI）领域的分布式框架的特性。在本文中，我们提出了一种分布式共识方法来承担 PQI 任务。根据它们的即时 RC，任务在 MFGTI 之间按比例分担。此外，大多数现有方法都假设 MFGTI 的 RC 足以解决 PQ 问题（PQP），这并不总是正确的。在 RC 不足的情况下，每个 MFGTI 的有功功率输出按由提议的领导者-跟随者协议确定的相同因素按比例缩小，以便为任务腾出空间。总之，在分布式控制框架下，在RC充足和不足两种情况下都处理PQP。最后，给出了由三个 10kVA MFGTI 组成的 MG 的仿真和硬件在环实验，以验证所提出方法的有效性。