基于DFT和DSC提取电压基频正序分量的方法

A Method for Extracting the Fundamental-frequency Positive-sequence Voltage Vector Based on DFT and DSC

针对三相电网电压可能含有谐波和不对称分量的情况,通过离散傅里叶变换(DFT)算法提取其中基频信号的幅值和相位,重构出基频信号后,再通过延时信号消除算法(DSC)提取基频信号中的正序分量,最后通过同步参考轴锁相环(SRF-PLL)完成对基频正序信号的相位跟踪,同时该PLL还能给定基频正序分量(FFPS)的频率估计值,该频率的获取使得DFT和DSC具有频率自适应性,能准确提取相应信息。最后通过实验验证了这种信号提取方法的可靠性和正确性。

For the case of three-phase grid contains harmonic and unbalanced components, discrete Fourier transform （DFT） algorithm is used to extract the amplitude and phase of the fundamental-frequency component so that the signal can be reconstructed, delayed signal cancellation （DSC） algorithm is used to extract positive-sequence components from the fundamental-frequency signal, and synchronous reference frame phase-locked loop （SRF-PLL） is used to trail the phase,the estimated frequency which is determined by SRF-PLL can make DFT and DSC frequency adaptive so that correlative information can be distilled accurately.The experiments validate its reliability and feasibility.