改进阈值函数的小波熵方法抑制局部放电白噪声的研究

Suppressing white noise research in PD signal based on wavelet entropy and improved threshold function

针对传统硬阈值法和软阈值法的缺陷,提出了改进阈值函数的小波熵方法。该方法对含噪局放信号进行小波分解,基于小波熵自适应选取阈值,并引入一种改进阈值函数对小波系数进行处理,最后重构得到去噪后信号。典型仿真信号和实测信号的去噪结果表明,提出的方法能够有效去除局放信号中的白噪声。

Aiming at the shortcomings of traditional hard threshold method and soft threshold method, this paper puts forward a wavelet de-noising method based on wavelet entropy and improved threshold function. Firstly, the noisy par- tial discharge （PD） signals are processed by wavelet decomposition, and then, the wavelet coefficients are processed by a new improved threshold function using adaptive selection of threshold based on wavelet entropy, finally, the de- noised signal can be obtained by reconstruction. The de-noising results of typical simulation signals and the field sig- nals reveal that this proposed method can effectively remove white noise in partial discharge.