基于改进不完全S变换的电压暂降源分类方法

Voltage sags classification based on modified incomplete S-transform

为了快速准确地判别引起电压暂降的扰动源类型,提出一种基于改进不完全S变换的电压暂降源分类方法。该方法对电压暂降信号进行FFT提取信号的主要频率点f;然后对主要频率点f进行改进S变换得模时频矩阵,再对模时频矩阵进行尺度缩放,构造各类暂降源的标准模板;对待测电压暂降信号进行同样改进S变换和尺度缩放,计算其与标准模板的平均相似度,按照相似度最大原理实现电压暂降源的分类。MATLAB仿真计算结果表明,该方法可以快速准确地识别引起电压暂降的扰动源,无需添加分类器、计算量小、抗干扰能力强。

In order to quickly detect voltage sag disturbance in condition of voltage sags,this paper proposes a new voltage sags classification based on modified incomplete S-transform.The fast Fourier transform of the voltage sags signal is made to obtain the main frequency of signal.Then modified S-transform of the main frequency gets modulus matrixes and standard templates established by scale transform.The same modified S-transform and scale transform deal with test sags,then calculates the similarity between standard and test sags,classification is accomplished according to the principle of maximum similarity.MATLAB simulation results indicate that the proposed method can quickly and accurately identify the source of the disturbance caused by voltage sags,without extra classification process,low computational complexity and high accuracy and noise robustness.