改进小波降噪方法在水电机组振动信号降噪中的应用  

Application of Improved Wavelet Denoising Method in Vibration Signal Denoising of Hydroturbine Units

作　　者：孙召辉 陈鑫[1] 夏鑫[1] 李新煜[1] 刘小明 SUN Zhaohui;CHEN Xin;XIA Xin;LI Xinyu;LIU Xiaoming(Shandong Taishan Pumped Storage Station Co.,Ltd.,Tai'an,Shandong,271000)

机构地区：[1]山东泰山抽水蓄能电站有限责任公司,山东泰安271000

出　　处：《红水河》2021年第2期21-25,共5页Hongshui River

摘　　要：针对小波降噪法中传统硬阈值函数的不连续特性和软阈值函数存在恒定误差的缺陷会对降噪效果产生不良影响,提出了一种改进阈值函数的小波降噪方法,并用该方法和传统阈值函数降噪法对模拟振动噪声信号进行降噪处理。结果表明,所提出的方法得到的降噪后信号的信噪比和均方根误差均较优。同时,采用不同阈值函数的小波降噪法对水电机组真实振动信号进行降噪处理,并比较高频噪声分量残留程度和信号特征能量的保留程度,可以得出,改进阈值函数的小波降噪方法能够取得较好的降噪效果,证明了该方法的有效性。Aiming at the defect of discontinuity of traditional hard threshold function and constant error of soft threshold function in wavelet denoising method,which will have adverse effect on denoising effect,a wavelet denoising method based on improved threshold function is proposed,and the simulated vibration noise signal is.denoising processed by this method and traditional threshold function denoising method.The results show that the signal-to-noise ratio and root-mean-square error of the denoised signal obtained by the proposed method are better.At the same time,wavelet denoising methods with different threshold functions are used to denoise the real vibration signals of hydroturbine units,and the residual degree of high-frequency noise components and the retention degree of signal characteristic energy are compared.It can be concluded that the wavelet denoising method with improved threshold function can achieve better denoising effect,which proves the effectiveness of the method.

关 键 词：水电机组 小波降噪 阈值函数 信噪比 

分 类 号：TN911.7[电子电信—通信与信息系统]