Investigation of partial discharges in power oil transformers by AE

Oil power transformers are an integral part of electrical power systems. The main cause of failure of such transformers are damages to the insulation system caused by the harmful phenomena of partial discharges (PDs). Examination and diagnosis of PDs in oil power transformers (necessary for safety reasons and for economic reasons) includes their detection, measurement and location. The acoustic emission method (AE) provides such possibilities. The book contains selected works from this subject published by the research group from the Silesian University of Technology in Poland. Within individual chapters there are presented applied/constructed measurement systems and analyses of recorded signals in domains of time, frequency, time-frequency and discrimination threshold. As part of the analysis in the domain of discrimination threshold, the authors defined descriptors with the acronyms ADC, ADP and have proposed patented research methodology allowing for determining descriptors maps on lateral walls of the tank of tested transformer. Such calculated descriptors maps in selected frequency bands are the base for the location of the various types of EA wave sources, especially for PDs.