快速傅里叶变换在非同步采样和非整数周期截断的情况下存在较大的误差，无法得到准确的谐波参数。加窗插值快速傅里叶变换算法广泛用于电力系统谐波，可改善因非同步采样和非整数周期截断造成的频谱泄露，提高分析精度。文章分析了Blackman-Harris窗的频谱特性，提出了基于Blackman-Harris窗插值的分析算法，运用多项式拟合求出实用的插值修正公式。仿真结果表明， Blackman-Harris窗插值FFT方法设计实现灵活，抑制频谱泄露效果好。%There is a great error in situation of non-synchronous sampling and non-interger cycle truncation for the fast Fourier transform ( FFT) so as hard to obtain the exact harmonic parameters. Widely used in the electric power sys-tem, the windowed interpolation FFT algorithms could compensate the spectral leakage in frequency domain caused by non-coherent sampling and non-integral period truncation in order to improve the analysis accuracy. The spectral char-acteristics of Blackman-Harris window are analyzed and an approach for harmonic analysis based on Blackman-Harris window interpolation FFT has been proposed. The applicable rectification formulas of the interpolation are obtained by fitting of a polynomial. Simulation results indicate that the approach based on Blackman-Harris window interpolation FFT can be designed and realized easily which will restrain the spectral leakage effectively.
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