基于小波变换和LMS自适应滤波器的单相接地选线方法

综合应用小波变换理论和最小均方误差(LMS)自适应滤波器技术,提出了一种小电流接地系统单相接地故障选线方法.该方法对故障发生后的零序电流信号进行小波变换,通过LMS自适应滤波器对小波系数进行滤波去噪,利用去噪后的信息进行选线.该方法能有效地从被噪声干扰的信号中得到有用的信息,克服了故障信号信噪比低的缺点,并能够充分利用故障信息连续判断.应用现场故障录波数据对该方法进行了验证,结果表明该方法能够满足实用要求.

SELECTION OF SINGLE-PHASE TO GROUND FAULT LINE BASED ON WAVELET TRANSFORM AND LMS ADAPTIVE FILTER

This paper proposes a method for the fault line selection in small current fault networks based on the wavelet transform theory and LMS adaptive filter technology. This method selects the fault line by analyzing the zero sequence currents of all lines by use of the wavelet transform and removing the noise disturbance from wavelet coefficients by the LMS adaptive filter. It can derive the useful information effectively from the signals disturbed by noise so that the difficulty of low signal noise ratio can be overcome, and takes full advantage of fault information to select the line continuously. The results of field record data reveal that this method can meet the practical requirements.