基于3F–C法的局部放电脉冲信号能量最大似然估计  

Maximum Likelihood Estimation of Energies in Partial Discharge Pulse Signals Based on 3F-C Method

作　　者：陈孝信[1] 钱勇[1] 许永鹏[1] 盛戈皞[1] 江秀臣[1] 

机构地区：[1]上海交通大学电气工程系,上海200240

出　　处：《高电压技术》2017年第2期460-467,共8页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2014CB239506)~~

摘　　要：为抑制白噪声和窄带干扰对局部放电脉冲信号能量测量的影响,提出了一种基于噪声参数的能量估计方法。研究了现场信号模型和信号能量谱系数的概率分布,得到噪声参数已知条件下脉冲信号能量的最大似然估计。同时为获得噪声参数,将采样数据划分成信号帧和噪声帧,采用3F–C法估计了白噪声和窄带干扰参数。通过仿真实验和实测数据处理,与传统小波包降噪方法的结果进行了对比。数据分析结果表明:无论是针对单一白噪声环境还是存在窄带干扰的混合噪声环境,该能量估计方法的准确性均优于传统小波包降噪方法,且随着信噪比的降低和信号时间窗口长度的增加,该方法表现出更明显的优势。在信噪比为–8 d B的条件下,使用该方法对实测局部放电脉冲信号进行能量估计的相对误差仅为4.07%,而使用小波包降噪方法时相对误差则达到44.12%。To suppress the influence of white noise and narrowband interference on the energy measurement of partial discharge pulse signals, we proposed an energy estimation method based on noise parameters. Furthermore,we investigated the field signal model and the probability distribution of the energy spectral coefficients, and obtained the maximum likelihood estimation of the pulse energy with known noise parameters. Meanwhile, to acquire the noise parameters, the sampled data were divided into signal frames and noise frames, and the 3F-C method was adopted to estimate the param- eters of the white noise and narrowband interference. Through simulation experiments and field data processing, the results of the proposed method were compared with those of the conventional wavelet packet de-noising method. The data analysis results show that, compared with the wavelet packet de-noising method, the proposed method has a better accu- racy in energy estimation for either white-noise environment or mixed-noise environment with narrowband interference. With the decrease of the signal-noise ratio and the increase of the signal time window length, the advantage of the proposed method becomes more significant. For measured partial discharge pulse signals with a signal-noise ratio of -8 dB, the relative error of energy estimation using the proposed method is only 4.07%, while that of the wavelet packet de-noising method is 44.12%.

关 键 词：局部放电 脉冲 能量 白噪声 窄带干扰 参数估计 最大似然估计 3F–C法 

分 类 号：TM855[电气工程—高电压与绝缘技术]