局部放电信号检测的HHT-MDL自适应阈值算法  

A new adaptive threshold algorithm to partial discharge processing based on HHT-MDL criterion

作　　者：赵妍[1] 董爽[1] 李天云[1] 

机构地区：[1]东北电力大学输变电技术学院,吉林吉林132012

出　　处：《电力系统保护与控制》2010年第5期45-50,共6页Power System Protection and Control

摘　　要：基于局部放电信号特征,将HHT与信息论的MDL判据相结合应用于局部放电信号的提取。该算法以多分辨率的EMD为基础,结合MDL判据自适应地确定EMD得到的IMF的阈值,来提取局部放电信号,同时还得到局部放电信号的时间-相位-幅值谱。对于强周期窄带干扰,提出了先用FFT预处理后,再用HHT和MDL消噪的简单算法。该算法综合了这两种方法的优点:无需定义任何基函数,无需事先知道噪声的水平,不需要预置阈值、不需要选择阈值行为方式,有较强的自适应性。仿真结果表明,本方法能够有效地消除局部放电中的噪声,其效果优于基于小波和MDL准则的消噪算法,为局部放电信号的消噪提供了一种新思路。According to the characteristics of partial discharge（PD）, a new method using Hilbert-Huang transform（HHT） and Minimum Description Length （MDL） criterion is applied to extract PD signals from excessive noises. Firstly PD signals are decomposed by Empirical Mode Decomposition, the most appropriate coefficients are obtained by MDL Criterion, finally the corresponding coefficients are reconstructed to achieve de-noised PD. And time-phase-amplitude spectrum can be obtained. For narrow-band interference, FFT is put forward to suppress the interference based on the differences between the PD and interference. The algorithm has wonderful virtues such as free from any parameters estimation about noise, free from presetting threshold and threshold choosing behavior, so the algorithm is highly adaptive. Large mount of simulation proves that this method can wipe off narrow-band interference and white noise efficiently, prior to the de-noising algorithm of wavelet and MDL, so it provides a new way for PD de-noising.

关 键 词：局部放电 HILBERT-HUANG变换 MDL 自适应阈值算法 

分 类 号：TM835[电气工程—高电压与绝缘技术]