基于Blankman-harris窗的加窗FFT插值修正算法

The Correction Algorithm Based on the Blankman-harris Windows and Interpolated FFT

直接利用FFT进行电力系统谐波分析存在较大误差,加窗插值修正算法可以较好提高测量准确性.鉴于Blankman-harris窗在抑制频谱分析长范围泄漏方面具有很优良的性能,采用了双谱线插值修正的原理,推导了Blankman-harris窗双谱线插值修正公式,并利用MATLAB多项式逼近函数求出简洁实用的基于Blankman-harris窗的双谱线插值修正公式的逼近多项式.仿真分析表明,该修正多项式的算法实现容易,而且精度高.

The FFT has a higher error in the harmonic analysis of the power system, the utilization of window functions and interpolation algorithms can correct the measured frequency, phase and amplitude by FFI＇. Because the Blankman - harris window has better performance in reducing leakage compared with other windows. This the algorithm with which the amplitudes of harmonics can be estimated from the two neighboring spectral paper uses lines, develops the correction formulas based on the Blankman - harris window, and uses polynomial approximation method of MATLAB to obtain the polynomial approximation formulas for frequency and amplitude correction based on the Blankman - harris window. This results of the simulation verify the algorithm and shows that it is easy to be realized and is highly accurate.