新型窗函数四谱线插值的谐波分析方法

Harmonic Analysis of Power System Based on New Window Function and Four-Spectrum-Line Interpolation Method

针对在非同步采样及非整周期截断的情况下,采用快速傅里叶变换分析电力谐波时谐波检测精度不够高的问题,提出了一种8阶三角自卷积窗的新型四谱线插值谐波检测算法。首先,分析了不同阶窗的时域和频域特性;然后,分析了四谱线插值算法,并推导出基于新算法的参数估计公式;最后,通过模拟谐波环境进行了算法的仿真实验,并与三谱线插值算法进行对比,其精确度要高于三谱线插值算法。实验结果表明,8阶三角自卷积窗具有旁瓣特性和栅栏效应的明显优势,可以更好地抑制频谱泄漏,并且随着谱线数目的增多,计算精度也有所提高,计算结果误差大多数小于10-7,所提出的算法可以更准确地计算每个谐波的参数。

Aiming at the problem that the accuracy of harmonic detection is not high enough when using fast Fourier transform to analyze power harmonics,a new four-spectral line of 8-order self-convolution triangular window(TSCW)is proposed.First,the time domain and frequency domain characteristics of different order windows are analyzed,then,analyze the four-line interpolation algorithm.The parameter estimation formula based on the new algorithm is derived.Finally,the experiment of the algorithm is realized by simulating the harmonic environment,and compared with the three-line interpolation algorithm,the accuracy is higher than the three-line interpolation algorithm.The experimental results show that the 8-order self-convolution triangular window has obvious advantages of sidelobe characteristics and fence effect,which can better suppress the influence of spectral leakage,and with the number of spectrum lines increasing,the computing accuracy of the algorithm is improved.And the proposed algorithm can calculate the parameters of each harmonic more accurately.