基于最小二乘的准同步DFT幅值线性修正方法  

Linear correcting algorithm for quasi-synchronous DFT’s harmonic amplitude based on the least squares theory

作　　者：傅中君[1] 王建宇[2] 欧云[3] 周根元[1] 赵小荣[1] 洑涵妤[1] Fu Zhongjun;Wang Jianyu;Ou Yun;Zhou Genyuan;Zhao Xiaorong;Fu Hanyu(Jiangsu University of Technology,Changzhou 213001,China;Nanjing University of Science&Technology,Nanjing 210094,China;Changzhou Foreign Languages School,Changzhou 213001,China)

机构地区：[1]江苏理工学院,常州213001 [2]南京理工大学,南京210094 [3]常州外国语学校,常州213001

出　　处：《电子测量与仪器学报》2019年第7期72-78,共7页Journal of Electronic Measurement and Instrumentation

基　　金：江苏省产学研合作项目(BY2018191)资助

摘　　要：准同步离散傅里叶变换(DFT)谐波分析频谱泄漏的主要原因是信号频偏导致的短范围泄漏。在分析准同步DFT短范围泄露特性的基础上,给出了基于最小二乘原理的准同步DFT幅值线性修正方法。该方法的具体思路是构建基波幅值误差曲线,采用最小二乘法得到基波幅值误差的线性修正方程,推广基波幅值误差线性修正方程到高次谐波,获得高次谐波幅值误差的线性修正方程。仿真实验表明,准同步DFT幅值线性修正方法既能够获得高精度的幅值分析结果,又能够降低算法复杂度,实现实时运算。Spectral leakage in the harmonic measured by quasi-synchronous DFT(QSDFT)is mainly about the short-range leakage caused by deviation in the signal frequency.By analyzing the short-range-leakage characteristic of QSDFT,a linear amplitude-correction algorithm(LACA)for QSDFT’s harmonic-analysis results is proposed.The specific ideas of LACA are:1)constructing the error curve of fundamental amplitude,2)using the least squares method to obtain the linear correction equation of the fundamental amplitude error,and 3)generalizing the linear correction equation of fundamental amplitude error to the higher harmonics.Simulation experiments show that the LACA not only obtains high-precision amplitude analysis results,but also reduces the complexity of the algorithm and realizes real-time operation.

关 键 词：谐波分析 傅里叶变换 电力系统参数估计 频谱分析 准同步采样 

分 类 号：TM711[电气工程—电力系统及自动化]