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This paper presents the results obtained from measurements and analyses of acoustic emission (AE) signals generated by partial discharges (PD) in a model of power capacitors during experiments carried out under laboratory conditions. A remotely-controlled mobile unit (RCMU) has been used in experimental tests, allowing the safe execution of measurements in hazardous conditions. The measurement set-up and construction of the RCMU is presented. The study confirmed that it is possible to use a remotely-controlled mobile unit for carrying out measurements under high voltage. The most significant contribution of the paper lies in the idea that the PD of a condenser for electric power is detected using a mobile system, which can also be applied for other purposes related to the non-destructive diagnosis of power equipment systems working under difficult operating conditions. [ABSTRACT FROM AUTHOR]

The article presents the issue modelling the partial discharge phenomenon in engineering and scientific environments using hardware-based computer cluster. The authors present the results of research work on the phenomenon of acoustic emission from partial discharge occurring in power capacitors for power factor correction. The work includes the issues presentation and explanation of solutions enabling to create 3D spatial model of power capacitor. The authors proposed a simplified model of an acoustic test object aimed at improving the process of calculating the results. [ABSTRACT FROM AUTHOR]

The paper presents some observations of ultrasound induced cavitation phenomenon in a mineral insulating oil. The acoustic cavitation phenomenon was generated at different signal frequencies and rms voltage value supplied to round piezoelectric transducers. Used transducers have created a high energy acoustic field in prepared insulating oil samples. The acoustic emission signal contains a broad-band noise and a fundamental frequency component and its harmonics, produced by the direct driving acoustic field. The paper presents the spectral analysis of acoustic emission signal observed during acoustic cavitation in insulating oils. To emphasize the changes in acoustic cavitation intensity also time-frequency analysis was used and some spectrograms were evaluated. The measurement uncertainty of some frequency-rms voltage pairs was very unfavorable. The main application expected with created cavitation measurement system is to develop a diagnostic tool for the aging of oil, based on the hypothesis that the measured cavitation intensity and spectrum could be affected by aging. Previous published measurements showed some relationship between insulating oil aging process and changes of acoustic emission of cavitations. [ABSTRACT FROM AUTHOR]

Paper presents definition of a mathematical model describing acoustic emission signals generated by partial discharges occurring in oil immersed electric power transformers. Time runs, power spectral density graphs and spectrograms of acoustic emission signals generated in experiments, performed under laboratory conditions, and of equivalent signals, calculated on the basis of the mathematical model, are presented. Furthermore, results of numerical simulations of acoustic pressure distribution inside a tank filled with insulation oil are presented in the paper. In the center of the tank acoustic emission wave sources were placed, each generating signals described by the model developed. [ABSTRACT FROM AUTHOR]

Results of a numerical simulation of an acoustic wave that propagates in a spherical object filled with insulating oil are presented in the paper. The sinusoidal acoustic wave is generated by an electro-acoustic transducer mounted in the middle of the object. Presented results depict acoustic pressure distribution within the transient and the steady states in a two-dimensional object. Furthermore, comparison of short time simulations adapting different mesh element size is presented. [ABSTRACT FROM AUTHOR]

Presents a study which attempted to apply spectral analysis tools in processing acoustic emission (AE) pulses generated by partial discharge (PD). PD types and their generation systems; Selection of descriptors for PD generated by AE pulses; Selection of measuring systems.