基于六项余弦窗函数插值FFT的谐波分析方法  

Harmonic analysis algorithm based on six-term cosine window interpolation FFT

作　　者：周琍[1] 

机构地区：[1]解放军汽车管理学院装备技术系,安徽蚌埠233011

出　　处：《机电工程》2011年第8期1015-1018,共4页Journal of Mechanical & Electrical Engineering

摘　　要：在分析电网谐波时,很难实现同步采样和整周期截断,因此采用傅里叶方法必然存在频谱泄露和栅栏效应。加窗插值FFT算法是减小频谱泄露和栅栏效应的有效方法。为减小长范围泄露,将六项余弦窗函数应用于电力系统谐波分析,并且推导出了谐波参数的插值修正公式,其插值系数具有简单的显示表达式,计算量小。对该算法与Hanning窗和Blackman-Harris窗插值FFT算法进行了Matlab仿真对比研究,验证了该算法具有更高的分析精度。对微波炉电流实测数据的分析结果进一步验证了所提算法的有效性。It is very difficult to achieve synchronous sampling and integrated-cycle truncation when power system harmonics are analyzed.Therefore,there inevitably exists spectral leakage and fence effect.The windowed interpolation FFT algorithm is the effective method to reduce spectral leakage and fence effect.In order to reduce long range leakage,a 6-term cosine window function was applied to harmonics analysis of power system.The interpolation estimation formulas of harmonics parameters were derived,moreover its interpolation coefficient has explicit expression and computation load is low.Comparison with the Hanning and Blackman-Harris interpolation FFT method was conducted by Matlab simulation.The result verifies the higher analysis accuracy of the proposed algorithm.The analysis results to testing data of microwave oven current further demonstrate the validity of the proposed algorithm.

关 键 词：谐波 同步采样 六项余弦窗 插值快速傅里叶变换 电力系统 

分 类 号：TM714[电气工程—电力系统及自动化]