基于相空间重构的电能质量扰动特性提取方法

Power quality disturbance feature extraction based on phase space reconstruction

将相空间重构方法引入电能质量领域,对电压暂降、电压瞬升、电压中断、电压尖峰、谐波及闪变6类电能质量扰动事件进行研究.利用相空间重构将实域的扰动信号映射到二维相平面,构造不同扰动的信号轨迹.将轨迹幅值归一化进行编码,将信号轨迹转变为二进制图像.针对该图像,定义了最大偏差、载体相似度、扰动覆盖区域和平均幅度4项特性指标.对6类扰动波形分别进行特性计算,结果表明,尖峰波形的最大偏差、谐波波形的载体相似度、闪变的扰动覆盖区域特性明显与其它扰动不同,利用平均幅度特性可以分辨暂降、瞬升和中断.通过提出的4项指标可以有效提取特性扰动进行识别.

Phase space reconstruction method was introduced to power quality research field to investigate the disturbances including voltage sag, voltage swell, voltage interruption, voltage spike, harmonic and flicker. Disturbance signals in time domain were mapped into 2-D phase plane to construct different trajectories, which were converted to binary images after amplitude normalization and coding process. Four indices of trajectory image were defined to be maximum deviation （MD）, carrier similarity ratio （CCS）, disturbance overlay area （DOA） and mean amplitude （MA）. The feature indices of the six disturbances were calculated to show that MD of voltage spike, CCS of harmonic and DOA of flicker were dramatically different from those of other disturbance. The value of MA can be utilized to distinguish among sag, swell and interruption. By the four indices, features of different disturbances can be extracted effectively.