联合VMD与改进小波阈值算法的GIS局部放电信号去噪

GIS partial discharge signal denoising based on VMD and improved wavelet threshold algorithm

针对气体绝缘开关设备(GIS)因其内部缺陷而产生的局部放电(PD)信号含有白噪声干扰的问题,提出联合变分模态分解(VMD)与改进小波阈值算法进行去噪。首先运用VMD将含有噪声的PD信号拆解为多个本征模态分量;然后在现有的小波阈值去噪算法的基础上,克服传统软硬阈值函数的缺点,构造新阈值函数,并采用改进小波阈值算法对每个本征模态分量进行处理,将处理得到的信号重构;最后得出去噪后的局部放电信号。将所提出的方法与小波阈值去噪、VMD算法进行比较分析,通过仿真结果表明,所提方法去噪效果更好,为GIS设备内部PD信号去噪提供参考。

Aiming at the problem of white noise interference in partial discharge(PD)signals generated by gas insulated switchgear(GIS)due to its internal defects,a denoising method combining variational mode decomposition(VMD)and improved wavelet threshold function is proposed.Firstly,the PD signal containing noise is decomposed into multiple intrinsic mode components by VMD.Secondly,on the basis of the existing wavelet threshold denoising algorithm,overcome the shortcomings of soft and hard threshold.A new threshold function is constructed.The improved wavelet threshold algorithm is used to process each intrinsic mode component,and the processed signal is reconstructed.Finally,the PD signal after denoising is obtained.The proposed method is compared with wavelet threshold denoising and VMD algorithm.The results show that the denoising effect of this method is better and provides a reference for PD signal denoising in GIS equipment.