电网技术2012，Vol.36Issue(6)：141-147,7.
基于改进小波系数奇异值分解和小波去噪的低频振荡时变模式辨识
A Method to Identify Time-Varying Mode of Low Frequency Oscillation by Continuous Wavelet Transform Based on Raising Singular Value Decomposition of Wavelet Coefficient and Wavelet Denoising
摘要
Abstract
Based on the combination of continuous wavelet transform （CWT） with singular value decomposition （SVD）, a new algorithm to identify oscillation frequency of signal, extract mode information and denoise signal by raising SVD of wavelet coefficient is proposed. The condition that under high noise level or closely spaced mode of noise, the wavelet ridges are unsharp and even the frequency is hard to extract due to the aliasing and intersection of wavelet ridges can be overcome by the proposed method, and the frequencies of oscillation modes in different orders can be identified according to frequency vectors of the raised SVD of wavelet coefficients. Meanwhile the wavelet energy coefficient is chosen to identify the dominant oscillation mode, and signal denoising is performed by use of wavelet soft-thresholding denoising and restructured matrix after the SVD of wavelet coefficient. CWT can be used to deal with time-varying low-frequency oscillation signals containing time-varying oscillation mode, and the identification accuracy of mode parameters is high. Both effectiveness and applicability of the proposed algorithm are verified by simulation results.关键词
连续小波变换（CWT）/奇异值分解（SVD）/时变振荡：小波能量系数/主导模式/小波软阂值去噪Key words
continuous wavelet transform (CWT)/singularvalue decomposition (SVD)/time-varying oscillation/waveletenergy coefficient/dominant modes/wavelet soft-thresholdingdenoising分类
信息技术与安全科学引用本文复制引用
栾某德,刘涤尘,廖清芬,董超,欧阳利平..基于改进小波系数奇异值分解和小波去噪的低频振荡时变模式辨识[J].电网技术,2012,36(6):141-147,7.基金项目
国家自然科学基金项目（51077103）. （）
