Enhanced online PD evaluation on power transformers using wavelet techniques and frequency rejection filter for noise suppression

Abstract

In this contribution different digital filtering algorithms, which use new approaches like the wavelet transform as well as a new introduced adaptive frequency rejection filter in the frequency domain, are investigated concerning their ability to suppress different kinds of noise as they appear during online partial discharge (PD) measurements on power transformers. Therefore various investigations on measured PD signals in the laboratory superimposed by synthetically generated noises have been performed leading to recommendations how different noise types can be efficiently suppressed.