基于全相位Fourier变换的电力系统相量测量新方法

摘要

A novel vector measurement method for PMUs in power system is proposed in this paper, which is based on all-phase fast Fourier transform (apFFT). Due to excellent performance of apFFT in suppressing spectral leakage and the property of phase invariance, this method can realize the fast and accurate estimation of PMU phase angle, and then, the time-shift phase difference spectrum correction is adopted to estimate the frequency and amplitude parame-ters. The calculation flow of this algorithm is proposed, and the hardware of new PMU measuring device is designed based on ARM9 microprocessor. Simulation results show that the proposed method is close to unbiased estimation for noise-free case, and the algorithm in this paper can obtain 7dB signal-to-noise ratio gain compared with the conven-tional method.%提出了一种基于全相位Fourier变换(apFFT)的电力系统相量测量新方法.该方法利用apFFT良好的抑制频谱泄露能力以及"相位不变性",实现了PMU装置快速、准确的相位估计,然后采用时移相位差谱校正法实现了频率以及幅度参数的估计.文中给出了算法具体的计算流程,并采用ARM9微处理器完成了新型PMU测量装置硬件设计.仿真实验表明,在无噪情况下本文方法接近于无偏估计,在参数估计的RMSE相同时,与传统算法相比,本文算法可提供7 dB左右的信噪比增益.