Decomposition of frequency characteristics of acoustic emission signals for different types of partial discharges sources

The Application of the Selected Time-Frequency Descriptors Detection of the Acoustic Emission Signals Generated by Multisource Partial Discharges

“…Within graphic presentation of the results obtained there are shown, respectively: time run of the AE pulses measured, approximation A at the seventh decomposition level, runs of details D1-D7 and a column diagram visualizing the size of energy transferred by the particular details. Based on the investigations carried out in single-source systems, the results of which have been presented, among others, in papers [5][6][7][8][9][10], it was demonstrated that it is possible to assign a characteristic frequency band to the particular discharge forms:…”

Analysis of Properties Characteristic for Acoustic Emission Signals Recorded On-Line in Power Oil Transformers

“…Recorded AE signals have been put to filtration within the band of 110-200 kHz, and next basic characteristics, amplitude distributions and AE descriptor with an acronym ADC [1][2][3][4][5] were worked up. Basing on kriging method, the descriptor maps on lateral walls of trans- Positions of measuring points in the measuring network are also marked on the maps.…”

“…Author's method used to analyze AE signals [1][2][3][4][5][6], applied to signals recorded in power oil transformers, enables us to elaborate the method how to investigate AE signals in power oil transformers which includes successively: recording of signals, calculation of amplitude distributions of signals, calculation of defined AE descriptors, working up of descriptor maps on lateral walls of transformer tanks, location of AE sources according to these maps by means of the method of maximum loudness (modified by the authors), and analysis of properties characteristic for signals recorded at points lying in the vicinity of identified sources. Presented stages of analysis are realized repeatedly within different frequency bands which enable to distinguish signals coming from different types of sources such as partial discharges (PD), Barkhausen's effect, oil circulation, and outer acoustic interferences.…”

“…In order to investigate transformers an author's measuring system called AE DEMA-COMP [1][2][3][4][5][6] was applied; such a system has been equipped with AE sensors D9241A type, produced by Euro Physical Acoustic Corporation. Investigations concern two oil power transformers with transformer ratio of 120/20/6 kV and rated power of 25 MVA.…”

The Application of the Correlative Analysis and the Regression Function for Determining Correlations οf the Measurement Results of Acoustic Emission Generated by Partial Discharges

“…The paper describes the dependence between the changes of the voltage supplying the spark-gap modeling partial discharges (PDs) on indeterminate potential particles moving in insulation oil and the values of selected descriptors calculated for the amplitude spectrum of the acoustic emission (AE) pulses generated [1][2][3][4][5][6][7][8][9][10]. It is a simple type relation, which is characteristic of a unilateral influence of the cause, which is the voltage changes, on the result, which are the value changes of the descriptors under study.…”