Title: Acoustic emission method as a tool of partial discharges indication

Authors: Marta Korenska; Lubos Pazdera; Monika Manychova

Addresses: Department of Physics, Faculty of Civil Engineering, Brno University of Technology, Veveri 95, 602 00 Brno, Czech Republic. ' Department of Physics, Faculty of Civil Engineering, Brno University of Technology, Veveri 95, 602 00 Brno, Czech Republic. ' Department of Building Structures, Faculty of Civil Engineering, Brno University of Technology, Veveri 95, 602 00 Brno, Czech Republic

Abstract: The present paper deals with a method of tracking the partial discharges using the acoustic emission method. The quantity under study was the overshoot counting rate in acoustic emission signals. The subject of the experiment was a high-voltage generator rod, which had been provided with Relanex insulation. Acoustic signals, which were generated in the Relanex insulation layer, were picked up by wide-band sensors. Measurement results proved that electric discharges in a cavity are accompanied by the generation of mechanical oscillations, which in turn act as a source of standing waves in the cavity and standing waves in the rod and the insulator. The frequency spectrum therefore extends from the rod fundamental oscillation mode (i.e., 3 kHz) up to the cavity natural frequencies (in the order of several MHz).

Keywords: acoustic emission; insulated material; electric discharge; cavity; standing waves; amplitude; average frequencies; acoustic signal duration; partial discharges; high-voltage generator rods; wideband sensors; mechanical oscillations.

DOI: 10.1504/IJMPT.2011.045468

International Journal of Materials and Product Technology, 2011 Vol.42 No.3/4, pp.209 - 218

Published online: 07 Mar 2015 *

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