基于Blackman窗全相位FFT双谱线校正的同步宽频相量测量方法研究

Development of Wide-frequency Measurement Device based on BlackmanWindow ApFFT and Double-spectrum-line Correction

为进一步分析电网电力电子化特征日益明显所带来的影响,电网运行状态监视向间谐波和高次谐波方向延伸,对同步宽频测量提出了更高要求。同步宽频测量广泛采用的加窗插值频谱分析方法存在频谱泄露,当基波频率发生偏移或信号中存在邻近信号时会导致较大误差。针对此问题,文中提出采用基于Blackman窗全相位FFT双谱线校正的改进宽频相量测量方法,结合全相位FFT和Blackman余弦窗对宽频信号进行频谱分析,并利用双峰谱线进行参数校正。文中方法可以有效提升频谱泄露的抑制效果,降低邻近频谱干扰,提升基波频偏或邻近频谱的复杂运行工况宽频信号参数测量精度。

In order to further analyze the influence brought by the increasingly obvious characteristics of power network electronization,the monitoring of power network operation condition extends to the direction of interharmonics and higher harmonics,and puts forward higher requirements for synchronous wide-frequency measurement.The windowed interpolation spectrum analysis method widely used in synchronous wide-frequency measurement has spectrum leakage,which will lead to large errors when the fundamental frequency is shifted or there are neighboring signals in the signal.To solve this problem,an improved wide-frequency phasor measurement method based on Blackman window all-phase FFT bispectrum line correction is proposed in this paper.The spectrum of wide-frequency signals is analyzed by combining all-phase FFT and Blackman cosine window,and the parameters are corrected by using bimodal spectral lines.This method can effectively improve the suppression effect of spectrum leakage,reduce the interference of adjacent spectrum,and improve the measurement accuracy of wide-frequency signal parameters in complex operating conditions of fundamental wave frequency offset or adjacent spectrum.