发表机构
ETH Zurich; Eindhoven University of Technology（苏黎世联邦理工学院; 埃因霍温理工大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出一种单次主动非参数频域方法，通过局部有理模型拟合谱线，从1秒随机激励记录中以1Hz分辨率恢复dq阻抗的复传递函数，在控制器硬件在环平台上验证了其有效性。
AI 中文摘要
dq坐标间的交叉耦合使得不对称电网阻抗的识别成为一个具有挑战性的问题，尤其是在基波频率附近，此时不对称耦合最强。现有方案通常要么通过依次扰动两个坐标来处理，这会延长测量时间；要么使用带有全局参数模型的时域方法，而该模型的阶数必须调整。本文提出了一种单次主动非参数频域方法，避免了上述两种方法的缺陷。等效阻抗由一对单输入单输出复传递函数参数化；每条谱线都用局部有理模型拟合，同时估计泄漏和瞬态贡献，因此不需要周期稳态激励，也不需要重复激励周期。本文给出了共轭耦合复信号模型的精确有限时间离散傅里叶变换关系，并分析了在派克变换前放置的静止帧滤波器对识别出的阻抗对造成的失真。该方法在控制器硬件在环平台上，针对解析推导的小信号模型进行了验证，验证场景包括对称电网以及添加了并网换流器（使电网变为不对称）的同一电网。从随机激励的单次1秒记录中，以1Hz的分辨率在宽频带上恢复了这对复传递函数，以及dq阻抗的全部四个实传递函数。
英文摘要
Cross-coupling between the $dq$ coordinates makes the identification of asymmetric grid impedances a challenging problem, particularly near the fundamental frequency where the asymmetric coupling is strongest. Existing schemes usually handle it either by perturbing the two coordinates sequentially, which lengthens the measurement, or by using a time-domain method with a global parametric model whose order must be tuned. This paper develops a single-shot active non-parametric frequency-domain method that avoids both. The equivalent impedance is parameterized by a pair of single-input single-output complex transfer functions. Each spectral line is fitted with a local rational model; the leakage and transient contributions are estimated, so that neither periodic steady-state excitation nor repeated excitation cycles are required. We give the exact finite-time discrete Fourier transform relation for the conjugate-coupled complex-signal model, and analyse the distortion that a stationary-frame filter placed ahead of the Park transform imposes on the identified pair. The method is validated on a controller hardware-in-the-loop platform against an analytically derived small-signal model, for a symmetric grid and for the same grid with an added grid-following converter that renders it asymmetric. Both complex transfer functions and all four real transfer functions of the $dq$ impedance are recovered over a wide band from a single one-second record of a random excitation, at 1 Hz resolution.
