A new single-phase PLL based on discrete fourier transform
A new single-phase PLL based on discrete fourier transform
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DOI：
10.1109/apec.2015.7104399
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发表时间：
2015-03
期刊：
影响因子：
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通讯作者：
Huawu Liu;Yongheng Sun;Haibing Hu;Y. Xing
中科院分区：
文献类型：
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作者：
Huawu Liu;Yongheng Sun;Haibing Hu;Y. Xing
提出了一种新的单相同步参考框架锁相环。实现单相SRF-PLL的关键是如何准确地产生正交信号，即使在含有谐波和直流分量的污染电网中也是如此。本文利用离散傅里叶变换(DFT)滤波器实现了正交信号的产生。与传统的SRF-PLL相比，提出的基于DFT的锁相环(DFT-PLL)具有更好的抗谐波能力和直流分量抑制能力。此外，该方法通过根据估计的频率调整DFT的采样周期来考虑电网频率的变化。此外，DFT-PLL的数字实现简单明了，计算量小。这些优点使得所提出的DFT-PLL特别适合于谐波失真和频率变化的应用。给出了实验结果，并与另两种广泛使用的SRF-PLL进行了比较，验证了该方法的有效性和优越性。
A new single-phase synchronous reference frame phase-locked loop (SRF-PLL) is proposed in this paper. The key point to implement single-phase SRF-PLL is how to generate the orthogonal signal accurately, even under polluted grids with harmonics and DC components. In this paper, the generation of the orthogonal signal is achieved by the discrete Fourier transform (DFT) filter. Compared with conventional SRF-PLLs, the DFT-based PLL (DFT-PLL) proposed offers better harmonics immunity and DC component rejection capacity. Besides, the proposed method incorporates grid frequency variations by adjusting the sampling period of DFT according to the estimated frequency. Also, digital implementation of DFT-PLL is simple and straightforward with low computational burden. These advantages make the proposed DFT-PLL especially suitable for harmonically distorted and frequency-varying applications. Experimental results and comparisons with two another widely used SRF-PLLs are given to validate the effectiveness and advantages of the proposed method.