采用改进连续小波变换的电力系统短信号阻尼参数识别

Damping Parameter Identification of Power System Short Signals by Improved Continuous Wavelet Transform

连续小波变换的端点效应给电力系统短信号的阻尼参数识别带来了极大困难,由于振荡模式的能量在信号末端已接近于0,小波变换在信号末端端点效应的影响已经很小,为此提出了改善信号首端端点效应的改进小波变换方法。在小波系数的每个卷积时刻,该方法强制位于小波函数左半平面的信号为0,改善了短信号阻尼参数识别效果。算例结果验证了该方法的有效性。

The edge effect of wavelet transform brings great difficulty in damping parameter identification of power system short signals. In view of the fact that the energy of oscillation mode at the end of the signal is close to zero, the influence of edge effect of wavelet transform at the signal end is very weak, for this reason an improved confmuous wavelet transform method, which forcibly make the signal that is located in the left half plane of wavelet function at the moment of convolution equal to zero, is proposed to improve the edge effect of beginning of the signal, thus the effect of identification of short signal damping parameter is improved. Results of calculation example show that the proposed method is effective.