| 引用本文: | 黄方能,黄成军,陈陈,江秀臣.高精度插值FFT谐波分析[J].电力自动化设备,2007,27(9):40-43 |
| .Improved high precision interpolating FFT for harmonic analysis[J].Electric Power Automation Equipment,2007,27(9):40-43 |
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| 摘要: |
| 分析了插值快速傅里叶变换(IFFT)产生误差的原因,说明了信号的相角会对IFFT分析结果产生较大误差,指出不能直接把针对复信号的算法套用于实信号。针对这一产生误差的原因,提出一种高精度的IFFT算法,以快速傅里叶变换(FFT)为基础,对FFT分析的频谱进行修正计算,从而得到较精确的计算值。该算法利用FFT中实用的信息,并充分考虑了实信号和复信号频谱的区别,采用一系列的数学变换,可以有效克服信号相角的影响,在不明显增加计算时间的同时,提高谐波分析的精度。该算法无需采用复杂的迭代方法,对数据采样也无特殊要求,故对硬件部分要求不高,易于应用。算法的分析结果可以得到实信号中谐波精确的幅值、相角及频率。实例计算结果证实了该算法的准确性,计算精度比传统的IFFT有了显著提高。 |
| 关键词: 谐波,插值FFT,相角 |
| DOI： |
| 分类号:TM935 |
| 基金项目: |
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| Improved high precision interpolating FFT for harmonic analysis |
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HUANG Fang-neng HUANG Cheng-jun CHEN Chen JIANG Xiu-chen
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| Abstract: |
| Errors in IFFT(Interpolating Fast Fourier Transform) are analyzed and the signal phase is demonstrated as the main cause.It is pointed out that the algorithm applied to complex signal could not be applied to real signal.A high precision IFFT algorithm is thus presented,which corrects the spectrum of FFT to improve its precision based on FFT.Using the useful information of FFT and considering the spectrum difference between complex signal and real signal,it adopts a series of math transforms to overcome the influence of signal phase.As a result,the precision of harmonic analysis is improved without obvious increase of calculating time.Since the complex iteration and special data sampling are not necessary,the requirements for hardware are not strict in implementation.The precise magnitude,phase and frequency of harmonic components in real signal are achieved by analysis.An instance verifies its correctness and higher precision. |
| Key words: harmonic,IFFT,phase |
