基于FFT与形态加权动态时间规整的电压暂降源辨识新方法

A novel method of voltage sag source identification based on FFT and shape-based weighted dynamic time warping

电压暂降源的准确辨识,有助于合理解决电压暂降问题和公正处理供用电纠纷。提出了一种基于快速傅里叶变换(FFT)与形态加权动态时间规整(SWDTW)的电压暂降源辨识新方法。首先分析了系统中可能出现的单一暂降源与复合暂降源所引起电压暂降波形特征。其次通过FFT方法分析信号谐波特征,构建并划分了特征波形库。然后针对传统的动态时间规整(DTW)方法中存在的不足之处,采用了一种基于形态特征的加权动态时间规整方法(SWDTW),用于对一维波形数据的相似度匹配。最后通过仿真证明,所述方法能有效实现电压暂降源的辨识,为电压暂降的有效治理以及相关纠纷问题的合理解决提供有力支持。

The accurate identification of voltage sag source helps to solve the problem of voltage sags and to fairly deal with the disputes of power supply.In this paper,a new identification method of voltage sag source is proposed,which combines fast Fourier transform(FFT)and a shape-based weighted dynamic time warping(SWDTW).Firstly,the waveform characteristics of voltage sags caused by single sags and composite sags are analyzed.Secondly,the characteristics of the signal harmonic are analyzed by FFT method,and the feature waveform library is constructed and divided.Then,in view of the shortcoming of traditional dynamic time warping(DTW)method,a shape-based weighted dynamic time warping(SWDTW)method is applied to match the one-dimensional waveform data.Finally,the simulation shows that the proposed method can effectively realize the identification of voltage sags and provide strong support for the effective control of voltage sags and the resolution of related disputes.