频域谐波分析算法的新解释及其推广

发布时间：2018-02-01 01:21

本文关键词： 离散傅里叶变换近似模型递推公式加窗插值算法谐波分析　出处：《电力系统自动化》2017年20期 　论文类型：期刊论文

【摘要】：在电力系统谐波分析的频域方法中,加汉宁窗插值算法应用较为广泛,其某些实现具有相似结构,只是选取的插值点数不同。为深入理解其内在本质,文中利用汉宁窗和矩形窗之间的关系,将已有的两种加汉宁窗算法转化成未加窗的等价形式,找出其中规律,并将其推广到通用的未加窗p点插值算法。在推导过程中,首先建立了多分量信号的未加窗离散傅里叶变换(DFT)值的近似模型,接着利用此近似模型分析出算法系数所需满足的两个条件,最后设计了满足条件的一组系数。当插值点数p为4或5时,所提算法等价于已有的两种加汉宁窗算法;p的最小允许值为3,此时算法具有最高的频域分辨率,并且不存在对应的基于汉宁窗的等价形式。结合改进后的DFT递推公式,所提算法所需计算量仅和插值点数p呈线性关系,因此能够大幅降低计算量,并为电网信号提供实时估计。仿真部分比较了算法采用不同插值点数p时的表现,实验部分将算法应用于三相电机电流信号的实时估计。
[Abstract]:In the frequency domain method of harmonic analysis of power system, the interpolation algorithm of the Gahanning window is widely used. Some of its implementations have similar structure, but the number of interpolation points selected is different. By using the relationship between the Hanning window and the rectangular window, the two existing algorithms with Hanning window are transformed into the equivalent form without the window, and the rules are found out. In the process of derivation, the approximate model of the unwindowed discrete Fourier transform (DFTT) value of multi-component signals is established. Then using the approximate model to analyze the two conditions needed to satisfy the algorithm coefficients and finally design a set of coefficients satisfying the conditions when the interpolation point p is 4 or 5:00. The proposed algorithm is equivalent to two existing algorithms with Hanning window. The minimum allowable value of p is 3. In this case the algorithm has the highest resolution in frequency domain and there is no equivalent form based on Hanning window. The improved DFT recursive formula is used. The computational cost of the proposed algorithm is only linearly related to the interpolation point p, so it can greatly reduce the computation cost and provide real-time estimation for the power network signal. The simulation part compares the performance of the algorithm with different interpolation points p. In the experiment part, the algorithm is applied to the real-time estimation of three-phase motor current signal.
【作者单位】：浙江大学电气工程学院;
【基金】：浙江省重点研发计划资助项目(2017C01039) 国家自然科学基金资助项目(51377142)~~
【分类号】：TM711
【正文快照】： 上网日期:2017-08-11。0引言随着电力电子装置在电力系统中的广泛应用,电网的谐波问题日益严重。在谐波和噪声的干扰下,如何快速准确地分析电网信号具有重大意义[1]。目前,电力系统谐波分析的常用算法为快速傅里叶变换(FFT)[2]。其具有频谱泄漏和栅栏效应两个缺陷,这两个缺陷

【相似文献】