Investigating suitable features for Partial Discharge localization in power transformer

It has been shown in the literature that partial discharge (PD) pulses can be localized in transformer windings successfully using sectional winding transfer functions. But it is necessary to have the transformer design data to use this method. So the method can not be employed in the cases that transformer design data are not available. Another method for estimating PD location in transformers is based on using extracted features from single PD pulse waveforms. This method does not need transformer design data. In this paper it is tried to find suitable features for PD localization. For this purpose, a specially prepared research transformer is employed and different type of PD are generated and applied to different points along the winding and are measured by means of a modern VHF PD measuring system. The features extracted from different transforms like KLT, DST, DCT and HADAMARD transforms are investigated and PD localization results are analyzed.