基于小波变换的电网畸变信号检测的研究

The Study of Power Grid Distortion Signal Detection Based on WF

短时谐波、暂态扰动、电压剧变等畸变信号常常危害电网系统安全运行,因此对该类信号进行检测分析有很大的现实意义。提出了基于Mallat算法的小波变换方法,利用其分解算法将原信号分为高频和低频两部分,通过分析第一、二层高频系数来判断信号是否发生畸变,进而求出畸变持续时间,对于低频部分采用重构算法依次提取出各次谐波,再利用FFT实现对各次谐波的精确分析。Matlab仿真结果验证了该方法的准确性和有效性。

As to prevent distortion signals such as short-term harmonic, transient fluctuation and voltage up- heaval from harming the grid system＇s operation, the distortion signals shonld be monitored. Wavelet transform based on Mallat algorithm to deal with the signals is proposed. The signal is divided into high frequency part and low frequency part, the 1 st and 2nd HF coefficient are analyzed to judge the signal and the lasting time of distortion is gotlell. For LF part, extract the harmonics is extracted by using the reconstruction algorithm, and FFT is used to realize accurate measurement of the harmonics. The simulation results prove that the method is accurate and effec- tive.