Four Consecutive Samples Based Frequency Estimation for Single-Phase Grids With DC Offsets
Four Consecutive Samples Based Frequency Estimation for Single-Phase Grids With DC Offsets
复制标题
具有直流偏移的单相电网基于四个连续样本的频率估计
DOI：
10.1109/tie.2020.3028805
复制
发表时间：
2021-10
影响因子：
7.7
通讯作者：
Du Guifu
中科院分区：
文献类型：
--
作者：
Fan Mingdi;Dai Zhiyong;Yang Yong;Xie Menxi;He Liqun;Du Guifu
直流偏移的存在导致频率估计中的基频振荡，这在单相电网中是一个具有挑战性的问题。在这篇文章中，四个连续的样本（4CS）的基础上，提出了一种方法来估计电网频率具有较强的直流偏移抑制能力。详细地说，一个4CS模型建立的基础上，电网电压，直流偏移量，以及它们的连续采样信号之间的关系。与传统的3CS模型不同，所提出的4CS模型可以完全抑制直流失调的负面影响。基于所得到的模型，提出了一种频率估计和稳定性分析提供了根据自适应控制理论。与传统的3CS依赖于前置滤波器，所提出的方法是无滤波器，它仍然有很强的抑制能力，对直流偏移。理论分析和实验结果表明，该方法具有较高的频率估计精度和良好的直流偏移抑制能力。
The presence of dc offsets results in fundamental frequency oscillations in the frequency estimation and it is a challenging problem in single-phase grids. In this article, a four consecutive samples (4CSs) based method is proposed to estimate grid frequency with strong dc offset rejection capability. In details, a 4CS model is established based on the relationship among the fundamental grid voltage, dc offsets, and their consecutive sample signals. Different from the traditional 3CS model, the proposed 4CS model can reject the negative effects of dc offsets completely. Based on the obtained model, a frequency estimation is proposed and stability analysis is provided according to the adaptive control theory. Unlike the traditional 3CSs relying on prefilters, the proposed method is filter-free and it still has strong suppression capability against dc offsets. The theoretical sound and experimental results indicate that the proposed method achieves accurate frequency estimation with good dc offset rejection capability.