| 引用本文: | 张宇华,赵晓轲,申庆祥,方艺翔.基于ESMD和HT相结合的谐波检测新方法[J].电力系统保护与控制,2018,46(23):52-59.[点击复制] |
| ZHANG Yuhua,ZHAO Xiaoke,SHEN Qingxiang,FANG Yixiang.New method in harmonic detection based on ESMD and HT[J].Power System Protection and Control,2018,46(23):52-59[点击复制] |
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| 摘要: |
| 针对现有的电力系统谐波信号检测方法精度不高的问题，以及研究较多的经验模态分解(Empirical Mode Decomposition, EMD)在谐波检测中出现的模态混叠问题，结合极点对称模态分解(Extreme-point Symmetric Mode Decomposition, ESMD)理论和算法，提出基于ESMD和希尔伯特变换(Hilbert Transform, HT)相结合的谐波检测新方法。首先对信号进行极点对称模态分解，得到一系列不同特征尺度的固有模态函数(Intrinsic Mode Function, IMF)，再对IMF分量进行希尔伯特变换得到各谐波瞬时幅值和瞬时频率信息。该方法能够根据信号自身特征进行自适应分解，理论上由于扩展了IMF定义并采用内部插值方法，使得该方法具有简单、精度高的优势。仿真结果表明，该方法在谐波检测中自适应分解能力强，检测精度高，实时性好，并且能够在不添加噪声的情况下有效避免EMD方法在谐波检测中出现的模态混叠现象。 |
| 关键词: 极点对称模态分解 经验模态分解 谐波检测 模态混叠 固有模态函数 |
| DOI：10.7667/PSPC171577 |
| 投稿时间：2017-10-25修订日期：2018-03-01 |
| 基金项目:上海市自然科学基金项目资助(15ZR1418000) |
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| New method in harmonic detection based on ESMD and HT |
| ZHANG Yuhua,ZHAO Xiaoke,SHEN Qingxiang,FANG Yixiang |
| (School of Electrical Engineering, Shanghai University of Electric Power, Shanghai 200090, China) |
| Abstract: |
| The problem of low accuracy in harmonic signal detection method of power system and mode aliasing in harmonic detection based on Empirical Mode Decomposition (EMD) is studied, a new method of harmonic detection based on Extreme-point Symmetric Mode Decomposition (ESMD) and Hilbert Transform (HT) is proposed according to the theory of ESMD algorithm. Firstly, the mode decomposition of the signal is carried out, and a series of Intrinsic Mode Functions (IMF) with different scale characteristics are obtained. Then, the instantaneous amplitude and instantaneous frequency of IMF are obtained by Hilbert Transformation (HT). This method can be used to decompose signal according to the characteristics of the signal itself. In theory, it has advantages of simple and high precision due to the expansion of IMF definition and internal interpolation method. The simulation results show that the method is adaptive in harmonic detection, better in accuracy and real-time. What’s more, it avoids the EMD aliasing in harmonic detection without adding noise. This work is supported by Natural Science Foundation of Shanghai (No. 15ZR1418000). |
| Key words: extreme-point symmetric mode decomposition empirical mode decomposition harmonic detection mode aliasing intrinsic mode function |
