基于DRSC窗递推DFT算法的电力谐波检测

Power System Harmonic Parameters Estimation Based on Recursive DFT Algorithm with DRSC Window

提出了一种基于离散矩形自卷积(DRSC)窗的递推离散傅里叶变换(DFT)校正算法,并应用于电力谐波的高精度实时检测。将加DRSC窗的DFT看成一有限脉冲响应(FIR)数字滤波器,通过将其转化为无限脉冲响应(IIR)滤波器的形式,推导出加DRSC窗的DFT递推计算公式;在此基础上,采用相位差DFT校正算法,获得电网谐波参数的实时估计。算法利用DRSC窗的频谱特性,最大限度地减小基波及各次谐波相互间的频谱泄露影响,提高了频谱分析精度,同时通过递推算法大幅度降低了谐波实时分析计算量。仿真分析结果验证了本文算法的可行性和有效性。

A recursive, discrete Fourier transform（DFT） algorithm with discrete rectangular self-convolution（DRSC） window is proposed in this paper, and used for high-precision real-time power harmonic parameter estimation. By converting the recursive DFT from finite impulsse response（FIR） filter to infinite impulse responsec（IIR） filter form, the recursive DFT formula with DRSC window is deducted. Furthermore, the real-time estimation of electrical harmonic parameters is implemented by use of the phase difference DFT correction algorithm. The harmonic estimating algorithm uses the spectral characteristics of the DRSC window, which can not only minimize inter spectrum leaks effect on fundamental and harmonic components to improve the accuracy of spectral analysis, but also significantly reduce the computation burden of harmonic real-time analysis by recursive algorithm. Simulation results have showed the feasibility and effectiveness of the proposed algorithm.