Wavelet de-noising method of all-fiber optical current transformer based on variational mode decomposition
LIU Mei1,2, NIU Chunping1,2, JI Zhongxiao1,2, DIAO Zhaowei1,2, NIU Lizhuang1,2
1. School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049; 2. State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049
Abstract：In order to improve the signal-to-noise ratio of the all-fiber optical current transformer (FOCT) and improve the measurement accuracy, this paper proposes a variational mode decomposition (VMD) method combined with wavelet. The detrended fluctuation analysis (DFA) is used to determine the number of VMD layers to make the decomposition more accurate, and the mutual information method is used to determine the relevant modes, while the uncorrelated modes with a large amount of noise are processed by sym8 wavelet. Signal reconstruction is carried out on this basis to ensure signal characteristics and integrity. The simulated data FOCT data are processed using this method to testify the efficiency compared with conventional VMD, empirical mode decomposition (EMD) and local mean decomposition (LMD), and the root mean square error (RMSE) and signal to noise ratio (SNR) are used as indicators to measure the denoising effect. It is proved that this method can better reduce the noise of the output signal of FOCT through test results.
2021, Vol. 22 
