An integrated diagnostic tool based on PD measurements

A new diagnostic tool based on partial discharge (PD) measurements is presented in this paper. Unlike conventional PD detectors, which record PD pulse height, the tool described is based also on the shape of PD pulses. PD pulses are digitised and recorded in fast RAM banks. The diagnostic tool uses a fuzzy interface to separate firstly PD pulses in classes according to their shape, then applies statistical analysis of PD pulse height and phase on the pulses recorded in each class. A fuzzy logic inference engine is then employed to provide indications on the nature of the defects generating PD. In the paper, a short description of the proposed diagnostic tool is presented along with its application to different insulating systems, i.e., cable joints, cables and high frequency transformers