应用双峰谱线插值法进行谐波分析的改进与优化方法

he windowed interpolation fast Fourier transform (FFT) has been widely used for harmonic analysis in the electric power system. Double-spectrum-line interpolation could effectually decrease the frequency spectral leakage caused by non-synchronized sampling and non-integral period truncation; besides, this arithmetic is not complicated and facilitates the realization of embedded system. In this paper, the theory of windowed Double-spectrum-line interpolation is analyzed, and some parameters of interpolation polynomials are given along with a developed formula of phase. Also proposed in the paper is an optimized method which enhances real-time performance by decreasing periods of sample. In addition, a program flow chart is provided in this paper, which is improved to inhibit the precision range under frequency variation. The simulation of a complex signal with 21 order harmonics verifies the effectiveness of the method.