Recognition of partial discharge signals in GIS using dual-tree complex wavelet transform

In this paper, a new method of feature extraction of UHF PD signal which is on basis of dual-tree complex wavelet is proposed and the principle, formulas and algorithm of the method are presented in detail. UHF PD signals which are acquired in lab are analyzed by translation and scaling. The feature space is constructed on basis of the energy on all frequency bands and modulus maxima on all scales. And then feature space is inputted into a component classifier of combined neural network classifier. It is proved that this method are effective way of recognition of UHF PD signals and the recognition rate of UHF PD signals is about 86%.