基于三次样条插值时域采样重构的间谐波检测新算法  

A New Algorithm for Interharmonics Measurement Based on Time Domain Sampling and Reconstruction by Cubic Spline Interpolation

作　　者：金维刚 刘会金[2] 

机构地区：[1]国家电网华中电力调控分中心,湖北省武汉市430077 [2]武汉大学电气工程学院,湖北省武汉市430072

出　　处：《电网技术》2012年第7期74-80,共7页Power System Technology

基　　金：国家自然科学基金项目(50677045;51177112);Supported by National Natural Science Foundation of China(50677045;51177112)

摘　　要：首先用加汉宁窗的插值快速傅里叶变换(fast Fouriertransform,FFT)算法确定准确的基波频率,并且根据基波频率和时域原始采样序列,利用三次样条插值方法重构一个新的等间隔序列,重构序列是严格整基波周期截断的,而且在每基波周期内包含整数个重构点;然后用FFT算法对重构序列进行处理,计算出所有基波和谐波的参数;接着,将基波和谐波成分从重构序列中减掉,则剩余序列中只包含间谐波成分;最后,再次用加汉宁窗的插值FFT算法和最大谱峰搜索法对剩余序列进行处理,每确定一个间谐波成分的参数就将该间谐波成分从剩余序列中减掉,如此循环,直至确定每一个间谐波成分的参数。该算法排除了基波和谐波对间谐波的影响,也避免了大幅值间谐波对小幅值间谐波的泄漏影响,因而对基波、谐波和间谐波参数的检测均有很高的精度,仿真和实验证明了该算法的正确性和有效性。Firstly,the accurate fundamental frequency is determined by Hanning windowed interpolated fast Fourier transform（FFT） algorithm,and according to the fundamental frequency and original time-domain sampled sequence a new equal interval sequence is reconstructed by cubic spline interpolation.The reconstructed data sequence is strictly truncated by whole fundamental period and each fundamental period contains integral number of reconstruction points.Secondly,the reconstructed data sequence is processed by FFT algorithm to compute parameters of fundamental and all harmonics,and then in the reconstructed data sequence the components of fundamental and all harmonics are subtracted,thus the residual reconstructed data sequence contains interharmonics only.Finally,residual reconstructed data sequence is re-applied by Hanning windowed interpolated fast Fourier transform（FFT） algorithm and spectrum peak searching method,once the parameters of an interharmonic component are determined,in the residual data sequence this interharmonic component is subtracted and this process is cyclically performed till the parameters of each interharmonic component have been determined.In the proposed algorithm,the influences of fundamental and harmonics on interharmonics are gotten rid of and the influences of leakage effect of interharmonics with higher amplitudes on interharmonics with lower amplitudes can be avoided,thus the measurement of fundamental,harmonics and interharmonics by the proposed method is accurate.Results of simulation and experiments show that the proposed algorithm is available and correct.

关 键 词：加窗插值快速傅里叶变换 时域 三次样条插值 重构序列 最大谱峰搜索 间谐波参数 

分 类 号：TM714[电气工程—电力系统及自动化]