Most of the launched power electronics-enabled distributed generators (DGs) adopt phase-locked-loop (PLL) synchronization control. In this paper, we delve into two different autonomous operation control (AOC) strategies to ensure the frequency/voltage profile and accurate power sharing for such DGs in islanded systems. The commonly used AOC is based on the concept of active power-frequency ( $P-f$ ) and reactive power-voltage magnitude ( $Q-V$ ) droop and deployed in a decentralized way. It is frequently criticized for inaccurate reactive power sharing between DGs, subject to the mismatch in their output impedances. To cope with this issue, we first design a local AOC using the $P-f$ and $Q-\dot {V}$ (i.e., the time derivate of $V$ ) droop concept, where the desired reactive power sharing can be achieved at the expense of a marginal and allowable $V$ excursion. Then, we develop an optimization-based AOC that is implemented through a continuous-time alternating direction method of multipliers (ADMM) algorithm and neighborhood communication. Equilibrium analysis and local asymptotic stability of the proposed AOC strategies are both established using a Lyapunov method. Finally, simulations are carried out in two islanded systems to validate the improvement in power sharing under a wide range of possible system conditions.

中文翻译：

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优化的自主运行控制，可为孤岛系统中的DG维持频率，电压和准确的功率分配

大部分已推出的支持电力电子技术的分布式发电机（DG）均采用锁相环（PLL）同步控制。在本文中，我们研究了两种不同的自主运行控制（AOC）策略，以确保孤岛系统中此类DG的频率/电压曲线和准确的功率共享。常用的AOC基于有功功率频率（ $ Pf $ ）和无功功率-电压幅度（ $ QV $ ）下垂并以分散方式部署。由于DG之间的输出阻抗不匹配，经常会批评DG之间的无功功率分配不正确。为了解决这个问题，我们首先使用 $ Pf $ 和 $ Q- \点{V} $ （即，时间的导数 $ V $ ）下垂概念，在这种情况下可以牺牲边际和可允许的能量来实现所需的无功功率共享 $ V $ 游览。然后，我们开发一种基于优化的AOC，该AOC通过乘数（ADMM）算法和邻域通信的连续时间交替方向方法实现。所提出的AOC策略的平衡分析和局部渐近稳定性均使用Lyapunov方法建立。最后，在两个孤岛系统中进行了仿真，以验证在各种可能的系统条件下功率共享的改进。