Symmetrical Wavelet Construction and Its Application for Electrical Machine Fault Signal Reconstruction

Symmetrical wavelet and anti-symmetrical wavelet have characteristics of linear phase and generalized linear phase respectively. They are very important to signal decomposition and reconstruction, because they can avoid signal distortion. Daubechies wavelets and Symlets wavelets have being used widely. Unfortunately, they aren´t symmetrical. In this paper, firstly, general symmetrical wavelet construction method based on Db4 and Sym4 have been presented. The computational complexity of constructed symmetrical wavelets is just half as primitive wavelets. Secondly, Db4 based symmetrical wavelet packets are used to decompose and reconstruct fault signals of electric machines. The experiment illustrates that symmetrical wavelets have less frequency leakage and more energy concentration than primitive mother wavelets do