摘要
随着输电电压等级的提高,电晕放电已成为影响高压、特高压输电线路安全稳定运行的重要因素。鉴于此,提出了基于经验模式分解(empirical mode decomposition,EMD)的电晕放电辐射信号阈值降噪处理方法,首先利用EMD算法对采集到的电晕放电辐射信号做分解处理,得到不同的基本模态分量,然后利用阈值函数和给定阈值对各分量做降噪处理,并对处理后的分量重构,得到降噪后的信号。研究结果表明:与小波降噪和EMD时空降噪相比,基于EMD的阈值降噪方法不存在基函数选取和分解层数选取等问题,其降噪过程是完全由信号特征决定的自适应降噪,同时该方法保留了小波降噪中对各分量进行阈值处理来降噪的优点,并且在对信号的降噪过程中去除了可能存在于信号中的趋势项干扰,因而该方法更有利于对电晕放电辐射信号的降噪处理。
High voltage and ultra high voltage transmission have become the development trend of power transmission. With the improvement of the transmission voltage level, corona discharge has become an important factor affecting safety and stability of high voltage system. In this paper, the threshold de-noising method of signal radiated from corona discharge based on empirical mode decomposition (EMD} was proposed. Firstly, the signal radiated from corona discharge was decomposed by EMD algorithm into different modal components, then each component was de-noised by using the threshold function and a given threshold, finally the de-noised signal was acquired by reconstructing the de-noised components. The results show that the threshold de-noising method based on EMD is more advantageous than the spatial and temporal de-noising method and the wavelet de-noising method. This method was self-adaptive based on the signal characteristics, and the problems of the selection of wavelet function and decomposition layers in the wavelet de noising did not exist, while the threshold de-noising of wavelet was retained in this method. In this method trend interference in signal was given up. In conclusion, this method was more conducive to the de-noising of the signal radiated from the corona discharge than other methods.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2012年第9期2280-2285,共6页
High Voltage Engineering
基金
国家自然科学基金(61172035)~~
关键词
经验模式分解(EMD)
时空降噪
小波降噪
电晕放电
高压输电
阈值降噪
empirical mode decomposition (EMD)
spatial and temporal de-noising
wavelet de-noising
corona discharge
high-voltage transmission
threshold denoising