小波熵自适应阈值的电能质量信号去噪新方法

针对电能质量信号去噪问题，提出改进的小波熵自适应阈值去噪法。利用小波变换分解电能质量信号，计算小波分解后信号子带区间的小波熵，将小波熵和自适应阈值相结合确定高频系数阈值门限，采用改进折中指数阈值函数对电能质量信号去噪处理，最后重构降噪后的电能质量信号。通过对四种典型带噪电能质量信号（电压突降信号、暂态振荡信号、电压中断信号、谐波信号）去噪处理，并与无偏风险阈值、极大极小阈值的去噪性能比较，对比可知在输入信噪比为20dB 时，对于不同的电能质量信号，改进的小波熵自适应阈值去噪法的输出信噪比是最大的。...

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Bibliographic Details
Published in电测与仪表 Vol. 51; no. 15; pp. 68 - 73
Main Author 陈晓娟 王文婷 李楠
Format Journal Article
LanguageChinese
Published 东北电力大学 信息工程学院,吉林 吉林,132012 2014
Subjects
去噪
小波熵
电能质量信号
自适应阈值
阈值函数
power quality signal
denoising
wavelet entropy
电能质量信号
threshold function
去噪
自适应阈值
小波熵
阈值函数
adaptive threshold
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ISSN1001-1390

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Summary:针对电能质量信号去噪问题，提出改进的小波熵自适应阈值去噪法。利用小波变换分解电能质量信号，计算小波分解后信号子带区间的小波熵，将小波熵和自适应阈值相结合确定高频系数阈值门限，采用改进折中指数阈值函数对电能质量信号去噪处理，最后重构降噪后的电能质量信号。通过对四种典型带噪电能质量信号（电压突降信号、暂态振荡信号、电压中断信号、谐波信号）去噪处理，并与无偏风险阈值、极大极小阈值的去噪性能比较，对比可知在输入信噪比为20dB 时，对于不同的电能质量信号，改进的小波熵自适应阈值去噪法的输出信噪比是最大的。
Bibliography:23-1202/TH
CHEN Xiao-juan, WANG Wen-ting, LI Nan （ College of Information Engineering, Northeast Dianli University, Jilin 132012, Jilin, China）
power quality signal;denoising;adaptive threshold;wavelet entropy;threshold function
An improved denoising method for power quality signal based on wavelet entropy adaptive threshold has been presented in this paper..The power quality signal is decomposed by wavelet transformatioin , so as to calculate the wavelet entropy after the decomposition.The wavelet entropy and adaptive threshold are combined to determine the threshold of high frequency coefficients.An improved trade -off exponent threshold function is adopted to denoise the power quality signal in order to obtain the reconstructed signal .Through denoising four typical power quality signals （voltage sag signal, voltage transient oscillatory signal, voltage interruption signal and harmonic signal ） and compared with the methods of unbiased risk threshold and the max -min threshold method, the simulation results b
ISSN:1001-1390