基于改进DFT和时域准同步的间谐波检测算法

发布时间：2018-02-28 02:05

本文关键词： 频谱干扰改进DFT 时域准同步间谐波检测谱峰搜索谐波分析　出处：《电力自动化设备》2017年04期 　论文类型：期刊论文

【摘要】：快速傅里叶变换(FFT)在非同步采样时存在频谱泄漏和栅栏效应,由此产生的谐波与间谐波之间的频谱干扰会严重影响间谐波参数测量的准确度。为减小谐波与间谐波之间的频谱干扰,提出一种基于改进离散傅里叶变换(DFT)和时域准同步的间谐波检测算法,采用改进DFT算法精确估计基波频率,利用三次样条插值重构准同步采样序列,用FFT算法对单个周期重构序列进行处理,得到基波和谐波的参数,并将基波和谐波成分从重构序列中减去,再次用FFT算法和最大谱峰搜索法对剩余序列进行处理,确定每一个间谐波成分的参数。仿真结果表明,该算法不仅能提高频率分辨率,还可以有效排除谐波和间谐波的频谱干扰,且间谐波检测的准确度高、稳定性好、运算量小。
[Abstract]:Fast Fourier transform (FFT) has spectrum leakage and fence effect in asynchronous sampling. The spectral interference between harmonics and interharmonics will seriously affect the accuracy of the measurement of inter-harmonic parameters. In order to reduce the spectral interference between harmonics and interharmonics, An interharmonic detection algorithm based on improved discrete Fourier transform (DFT) and time domain quasi-synchronization is proposed. The improved DFT algorithm is used to accurately estimate the fundamental frequency and the cubic spline interpolation is used to reconstruct the quasi-synchronous sampling sequence. The parameters of fundamental wave and harmonic are obtained by using FFT algorithm, and the fundamental and harmonic components are subtracted from the reconstructed sequence, and then the residual sequence is processed by FFT algorithm and maximum spectral peak search method. The simulation results show that the algorithm can not only improve the frequency resolution, but also effectively eliminate the spectral interference of harmonics and interharmonics, and the detection accuracy of interharmonics is high, the stability is good, and the computation is small.
【作者单位】：国网新疆电力公司电力科学研究院;湖南大学电气与信息工程学院;
【基金】：国家自然科学基金资助项目(51377049,51277058) 国网新疆电力公司、湖南大学合作项目(SGXJDK00JLJS1400231)~~
【分类号】：TM935

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