同步挤压小波变换在电力系统低频振荡模态参数提取中的应用

针对电力系统低频振荡的非平稳、非线性特性,将一种新的时频分析方法——同步挤压小波变换(SWT),应用于低频振荡分析。该方法克服了大多数分析方法抗噪性差的缺点,结合了经验模态分解(EMD)和小波的优点,具有EMD的自适应性,同时提高了抗模态混叠能力。利用该算法可实现具有多分量的低频振荡模式分离,得到其瞬时幅值和频率,并计算阻尼比。仿真和实测信号的计算结果证明了SWT的有效性,优于传统的HHT方法。

Application of Synchrosqueezed Wavelet Transform for Extraction of the Oscillatory Parameters of Low Frequency Oscillation in Power Systems

For the non-stationary and nonlinear characteristics of low frequency oscillation in power system, a new time-frequency analysis method, namely synchrosqueezed wavelet transform (SWT), is used in the analysis of low frequency oscillation. The method overcomes the disadvantage of poor noise immunity, which is the drawback of most analysis methods. At the same time, it combines the advantages of empirical mode decomposition (EMD) and wavelet, which has the adaptability of EMD, and improves the ability of anti mode mixing based on EMD and wavelet. The SWT algorithm can be used to realize the separation of the low frequency oscillation mode with a single frequency component, and the instantaneous amplitude and frequency are obtained,then the damping ratio is calculated. Simulation and measured data results show that the SWT is effective and stronger than the traditional HHT method.