许鸿飞,张姣姣,庞思睿,于然,赵子兰.基于汉宁双窗apFFT单谱线插值的电力谐波和间谐波检测算法[J].电测与仪表,2017,54(10):. Xu Hongfei,Zhang Jiaojiao,Pang Sirui,Yu Ran,Zhao Zilan.An electric power harmonic and inter-harmonic detection method based on single-spectrum-line interpolation of double hanning windows apFFT[J].Electrical Measurement & Instrumentation,2017,54(10):.
基于汉宁双窗apFFT单谱线插值的电力谐波和间谐波检测算法
An electric power harmonic and inter-harmonic detection method based on single-spectrum-line interpolation of double hanning windows apFFT
When FFT is applied to analyze the harmonic or inter-harmonic signal of electric power, due to the non-integral multiple relationship between the real frequency and the frequency resolution, spectral leakage will occur. As a result of that, the estimation accuracy of the harmonic or inter-harmonic parameters will degrade. To solve such a problem, a discrete signal spectrum line interpolation correction method based on double hanning windows apFFT is proposed in this paper. The principle of the algorithm is as following. After the signal was processed by double hanning windows apFFT, the modified values of each theory frequency point were deduced by the ratio of the side spectral line and main spectral line amplitudes. Then, according to these frequency modified values and hanning window mode function, and the LTI of apFFT to correct the corresponding amplitudes. Because the phase spectrum of apFFT has nothing to do with the frequency deviation, the initial phase of each frequency point was the phase of the main spectral line. Simulation examples show that the harmonic and inter-harmonic parameters estimated by the single-spectrum-line interpolation based on double hanning windows apFFT are more accurate, the total errors are smaller, and the algorithm is more robust against white noise.
