摘要
首先讨论了谐波分析的频谱混叠影响,提出了从时域构造一类新窗函数的谐波分析方法。该类新窗函数构造简便,具有更快的旁瓣衰减速率,能够更好地抑制频谱长泄漏的影响。仿真实验表明,加双汉宁窗时,强谐波信号的幅值相对误差为10-4数量级,相位的绝对误差优于0.003°。弱谐波信号的幅值相对误差可达到3.4%,相位绝对误差为2.4°。上述两种情况下,谐波分析误差都远优于目前的加窗插值谐波分析算法。因而,新窗函数谐波分析方法特别适用于分数次谐波分析,且能提高弱谐波信号的分辨能力和准确度。
The paper analyzes the leakage error between harmonics, and proposes a novel harmonic analysis algorithm based on constructing new windows in the time domain. The new windows has advantages of easy construction and have lower attenuation and little inhibit the leakage error. Simulation shows that the relative error of ampli- tude of strong harmonic component is less than 10^-4 and the absolute error of phase is less than 0.003°, moreover the relative error of amplitude of weak harmonic component is less than 3.4% and the absolute error of phase is 2,4° with two hanning windows in the algorithm. The results show that the new algorithm is much better than the algorithm of interpolating windowed FFT. So it can be applied to fractional-harmonics analysis more preferably, and therefore improve the resolution capability of weak harmonic component and accuracy of harmonic analysis.
出处
《电测与仪表》
北大核心
2005年第10期1-4,共4页
Electrical Measurement & Instrumentation
关键词
频谱混叠
窗函数
谐波分析
分数次谐波
energy leakage
window function
fourier transform
fractional-harmonics
