基于DFT滑窗迭代算法与小波变换的谐波检测方法.pdfVIP

学兔兔 总第48卷 第541期 电测与仪表 2011年 第O1期 Electricai Measurement Instrumentation 基于DFT滑窗迭代算法与小波变换的谐波检测方法 李益华，段虎，周黎明 (长沙理工大学电气与信息工程学院，长沙410114) 摘要：为解决非线性负载大量使用所产生的谐波电流对电力系统所造成的影响，提出了将DFF(Discret。Fourie Transform)滑窗迭代算法和小波变换相结合的谐波检测新方法。该方法利用滑窗迭代检测出信号的基波分量 和总谐波分量，提高系统的实时眭和目标跟随特性；然后利用小波变换对总谐波信号进行再次分解，对DFr滑 窗迭代算法进行补充与改善，从而得到更加精确的基波和各次谐波的含量。利用MATLAB进行实验仿真表明， 较之傅里叶变换和DFT滑窗迭代算法，该算法具有更高的实时眭和准确性。 关键词：谐波检测；滑窗迭代；DFT；小波变换 中图分类号：TM714 文献标识码：A 文章编号：1001—1390(201 1)O1—0006—04 Harmonic Detection Based on Sliding—windows Iterative of Discrete Fourier Transform and Wavelet Transform U Yi—hua，DUAN Hu，ZHOU Li—ruing (College of Electrical and Information Engineering，Changsha University of Science and Technology，Changsha 410114，China) Abstract：For solving the effect of harmonic current formed by non—liner loads in power system，the method based on combined sliding—windows iterative of discrete fourier transform(SWIDFT)and wavelet transform(WT)is proposed in this paper．The first step is to use SWIDFT to obtain the fundament component and total harmonic component，which improves the system S real—time and tracing characteristic．The total harmonic component was decomposed once again using WT，making the detection results more accurate and giving a supplement and improvement to SWIDFr．The simu— lation result with MATLAB shows that the detection of frequency and amplitude based on SWIDFY and WT reached a more reasonable real—time and accuracy than F订 and SWIDFT． Key words：harmonic detection，sliding—window iterative，DFT，wavelet transform 0 引 言 口的大小，是一种自适应的时一频分析方法