用于谐波/间谐波分析的奇数频点插值修正法  

An Approach for Harmonic/Inter-harmonic Analysis Based on the Odd Points Interpolation Correction

作　　者：惠锦[1] 杨洪耕[1] 

机构地区：[1]四川大学电气信息学院,四川省成都市610065

出　　处：《中国电机工程学报》2010年第16期67-72,共6页Proceedings of the CSEE

基　　金：国家自然科学基金项目(50677041)~~

摘　　要：用离散傅里叶变换进行电力系统谐波、间谐波分析时,采样窗口长度的有限性和采样的非同步性是引起分析误差的根本原因;在频域信号中各成分会发生频谱干扰,产生栅栏效应。不同于传统的加窗方法,提出一种抑制频谱干扰的新方法,其特点是在插值的同时抑制旁瓣泄漏。该方法首先根据离散傅里叶变换的相位特性,对变换结果进行相位旋转调整,使信号中各成分旁瓣对应的相邻谱线共线且相位相反;结合调整后旁瓣对应谱线的相位及幅值特点,利用谐波、间谐波频点附近最大及其左右相邻谱线,插值求得对应成分的幅值、频率和相位。对谐波和间谐波信号进行仿真计算,结果表明,该方法不仅能有效地抑制信号间的频谱干扰,并能准确地提取出信号中的微弱成分。The limited window width and the asynchronous sampling are the two radical factors which make the harmonic/inter-harmonic analysis incorrect by discrete Fourier transform （DFT）. In the frequency domain, the two factors would cause spectral leakage and fence effect on each component of the signal. Different from the approaches which use specific window with better spectrum characteristic, a new method was presented to reduce the leakage while interpolating According to the phase characteristics of the DFT results, the phase angles of adjacent lines of side lodes could be against by phase rotation adjustment. By considering the new features of the phase angles and amplitudes of the spectral lines; the amplitudes, frequencies and phase angles of each harmonic/ inter-harmonic could be well estimated according to the local largest spectral line and its neighboring lines by interpolated calculation. The simulation results indicate that the approach presented is not only adapted for leakage elimination, but also adapted for the extraction of weak components in the signal.

关 键 词：谐波分析 间谐波分析 离散傅里叶变换 快速傅里叶变换 

分 类 号：TM71[电气工程—电力系统及自动化]