基于提升小波的电能质量高效定位算法.pdfVIP

学兔兔 第34卷 第2期 仪 器 仪 表 学 报 Vo1．34 No．2 2013年2月 Chinese Journal of Scientific Instrument Feb．20l3 基于提升小波的电能质量高效定位算法冰 李 涛 ，何怡刚 ，张 宇 (1．湖南大学计算机与通信学院 长沙 410082；2．湖南大学电气与信息工程学院 长沙 410082) 摘 要：针对暂态电能质量扰动信号的检测和定位，提出了一种基于提升复小波的高效定位算法。首先对扰动信号基于(max— imum posteriori，MAP)最大后验估计的双树复小波进行去噪预处理，对不同分解层次的细节系数的噪声方差和信号方差进行估 计运算，同时计算各分解层的阈值，得到去噪阈值。扰动信号进行去噪预处理后，利用提升小波对去噪后的扰动信号进行定位， 并与传统实小波进行了定位准确度和算法耗时的比较。仿真实验结果表明，所提去噪预处理定位算法步骤简单，效果理想定位 运算速度快且易于实现，实用性强，两者结合具有良好的应用前景。 关键词：电能质量；最大后验估计；双树复小波；提升小波 中图分类号：TN911．23 文献标识码：A 国家标准学科分类代码：470．4017 H high efficient location algorithm for power quality signals with lifting wavelet transform Li Tao ，He Yigang ，Zhang Yu ( ．School ofComputer and Communication，Hunan University，Changsha 410082，China； 2．School of Electrical and Information Engineering Hunan University，Changsha 410082，China) Abstract：In order to accurately detect and locate the disturbance signal from real power quality signal in actual pow— er line，a high—efficient power algorithm is presented with lifting wavelet transform．A dual—tree complex wavelet de— noising method based maximum posteriorim(MAP)estimation is used to preprocess power quality disturbance signa1． Noise variance and signal variance for the detail coefficients of dual tree complex wavelet at different levels are esti- mated and thresholds of each layers are calculated to denoise．The denoised power quality disturbance signal is detec— ted and located by using lifting wavelet．The proposed algorithm is compared to the traditional real wavelet denoising method based on the accuracy of location and the time-consuming performance．Simulation results show that