Nuttall 窗加权谐波分析算法及其在电能计量中的应用.doc

Nuttall窗加权谐波分析算法及其在
电能计量中的应用*
温和,滕召胜,李聪聪,贺静丹,魏双双
(湖南大学电气与信息工程学院长沙 410082)
摘要:采用FFT进行电网信号谐波参数分析时存在频谱泄漏,准确度较低。研究提出了一种基于Nuttall窗函数的频谱相位差校正算法,分析了Nuttall窗函数的时域、频域特性,建立了频谱相位差校正算法的流程,推导了信号谐波参数计算式,给出了算法在三相谐波电能计量中的实现方法。采用Nuttall窗对电压、电流信号进行加权,利用Nuttall窗旁瓣电平低、旁瓣衰减快的特点可有效减少频谱泄漏;运用频谱相位差校正方法进行信号频谱校正与分析,不必求解高次方程即可实现电网信号谐波参数分析。仿真与实际运行结果表明,非同步采样情况下,本文算法可以准确地实现电网信号谐波分析,实现电能的准确计量。
关键词:Nuttall窗;谐波分析;频谱泄漏;相位差;电能计量
中图分类号:TN911 TM714 文献标识码:A 国家标准学科分类代码:
Harmonic analysis algorithm based on Nuttall window and
its application in power measurement
Wen He, Teng Zhaosheng, Li Congcong, He Jingdan, Wei Shuangshuang
(College of Electrical and Information Engineering, Hunan University, Changsha 410082, China)
Abstract:The precision of harmonic analysis is affected by spectral leakage when using FFT in electrical signals. A new phase difference revision algorithm of discrete spectrum for Nuttall window weighted signal is proposed in this paper. The characteristics of Nuttall window are studied, and the workflow of the new algorithm is given. The application of the algorithm in power measurement is introduced. Nuttall window has optimal side lobe levels and the side lobes of the Nuttall window decay at a fast rate. Hence, spectral leakage can be reduced when the voltage and current signals are weighted by Nuttall window. The phase difference revision algorithm has the advantages putational e