Power-synchronization control (PSC) is a promising control strategy to improve the stability and performance of voltage-source converters (VSCs) in ultra-weak AC grids. However, evaluation of PSC to date has investigated performance only at single controller operating points, rather than holistically varying multiple controller gains. This paper develops a new methodology, based on small-signal eigenvalue analysis, to comprehensively analyze PSC-VSC stability. The maximum active power transfer of PSC is established across a broad range of controller tunings and the two-way and three-way couplings between the power-synchronization control, AC voltage control and high-pass current filter gains are quantified. A new stable tuning region is introduced, which represents the controller parameter space for stable operation. It is shown that PSC can achieve rated power transfer into an AC grid (short circuit ratio(SCR)=1) at multiple controller operating points, but dynamic performance varies significantly within this region. The robustness of this operating region to SCR changes is also investigated. The stability boundary and dynamic performance are validated using control hardware-in-the-loop experiments with a real-time digital simulator. Practical recommendations arising from this work are a set of controller gains that provide stability and good dynamic performance at high power transfer for ultra-weak grid-connected VSCs employing PSC.

中文翻译：

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超弱交流网络的功率同步控制：综合稳定性和动态性能评估


功率同步控制（PSC）是一种很有前景的控制策略，可提高超弱交流电网中电压源换流器（VSC）的稳定性和性能。然而，迄今为止的 PSC 评估仅研究了单个控制器工作点的性能，而不是整体改变多个控制器增益。本文开发了一种基于小信号特征值分析的新方法来全面分析 PSC-VSC 稳定性。 PSC 的最大有功功率传输是在广泛的控制器调谐范围内建立的，并且对功率同步控制、交流电压控制和高通电流滤波器增益之间的两路和三路耦合进行了量化。引入了一个新的稳定调节区域，它代表稳定运行的控制器参数空间。结果表明，PSC 可以在多个控制器工作点实现额定功率传输到交流电网（短路比（SCR）=1），但动态性能在该区域内变化很大。还研究了该运行区域对 SCR 变化的稳健性。使用实时数字模拟器进行控制硬件在环实验来验证稳定性边界和动态性能。这项工作提出的实用建议是一组控制器增益，可为采用 PSC 的超弱并网 VSC 在高功率传输时提供稳定性和良好的动态性能。