采用小波技术的几种电能质量扰动的测量与分类方法

WAVELET-BASED MEASUREMENTS AND CLASSIFICATION OF SHORT DURATION POWER QUALITY DISTURBANCES

提出了一种新的短时电能质量扰动(SDPQD)的测量与分类方法:SDPQD的位置与范围用差变信号实时确定;幅度用小波变换(WT)方法确定;WT用新设计的复小波,采用塔式二进快速算法即可达到移动不变效果;分类用的特征量为极容易在时域与WT域提取的新定义的二进数,用简单的二-十进制转换方法即可得到毫无歧义的正确的分类结果。对5种SDPQD的仿真结果表明,该方法快速,正确,扩展到分析更多的SDPQD时极为方便。

This paper introduces a wavelet-based method for measuring and classifying short duration power quality disturbances (SDPQDs). A difference signal is formed for detection and localization in real-time. Wavelet transform (WT) with a new complex wavelet is utilized to quantify SDPQDs. It can take the fast dyadic scheme not the time consuming shift-invariant scheme and just need the detail version at one scale not at many scales. Novel binary features are defined and extracted from time or WT domain, and then a simple binary-decimal conversion is sufficient for classification purpose. This benefits the method both fast and accurate. Simulation results for five types of SDPQDs show that the proposed method is much better than others.