| 引用本文: | 孙曙光,庞毅,王景芹,等.一种基于新型小波阈值去噪预处理的EEMD谐波检测方法[J].电力系统保护与控制,2016,44(2):42-48.[点击复制] |
| SUN Shuguang,PANG Yi,WANG Jingqin,et al.EEMD harmonic detection method based on the new wavelet threshold denoising pretreatment[J].Power System Protection and Control,2016,44(2):42-48[点击复制] |
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| 摘要: |
| 为了提升经验模态分解(EMD)用于谐波检测的效果，用集合经验模态分解(EEMD)消除了EMD谐波检测的模态混叠问题。通过研究发现采样信号中的噪声会对EEMD的分解产生较大影响，提出了一种基于新型小波阈值去噪预处理的EEMD谐波检测方法。该方法首先采用变换小波系数精确选取小波阈值，然后采取软硬阈值相结合的方式，以消除随机噪声，再将去噪后的信号进行EEMD分解。经仿真分析，所提方法可以有效地消除随机噪声对谐波检测的影响，提高了EEMD谐波检测的精度与适用性。同时与原有EEMD算法相比，所提方法在分解速率上平均提高了大约3.8倍，有效分量与原始信号的相关度平均提升了22.5%。 |
| 关键词: 谐波检测 模态混叠 集合经验模态分解 小波系数 阈值 |
| DOI：10.7667/j.issn.1674-3415.2016.02.006 |
| 投稿时间：2015-03-24修订日期：2015-05-12 |
| 基金项目: |
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| EEMD harmonic detection method based on the new wavelet threshold denoising pretreatment |
| SUN Shuguang,PANG Yi,WANG Jingqin,ZHANG Chao,DU Taihang,YU Han |
| (School of Control Science and Engineering, Hebei University of Technology, Tianjin 300130, China;School of
Electrical Engineering, Hebei University of Technology, Tianjin 300130, China;College of Electrical and
Information Engineering, Shaanxi University of Science and Technology, Xi’an 710021, China) |
| Abstract: |
| In order to promote the effect of empirical mode decomposition (EMD) for the harmonic detection, this paper uses the ensemble empirical mode decomposition (EEMD) to eliminate the modal mixing of EMD harmonic detection. After studying, it is found that the noise in the sampling signal has great influence on the EEMD harmonic decomposition. This paper proposes an EEMD harmonic detection method based on a new wavelet threshold denoising pretreatment. This method adopts transforming wavelet coefficients to select threshold accurately, then uses the combination of hard and soft threshold and finally eliminates random noise. After simulation and analysis, this method can effectively eliminate the influence of random noise on harmonic detection and improve the accuracy and applicability of EEMD harmonic detection, and meanwhile, compared with the original EEMD algorithm, the decomposition rate increases about 3.8 times and the correlation between the effective components and the original signals increases by 22.5% . |
| Key words: harmonic detection mode mixing ensemble empirical mode decomposition wavelet coefficients threshold |
