TY - JOUR
AU - Garca-Souto, J A
AB - The main problem in power transformers is the degradation of the isolation, andpartial discharges are a major contribution to this shortcoming. Partial dischargesinside medium-and high-power transformers generate ultrasonic pressure waveswhich are usually detected by using acoustic piezoelectric sensors placed outsidethe transformers. In this paper we describe an optical fibre interferometric sensorwe are developing for the detection and location of partial discharges bymeasuring inside the power transformers. This non-intrusive optical fibre sensorallows a high level of sensitivity to be achieved for the typical small pressurevariations created by partial discharges, specially if compared with theresults obtained by acoustic piezoelectric external sensors. We presentinterferometrically detected levels of partial discharge. These results indicate thatthe developed optical fibre sensor is able to detect a partial discharge inthe range of 103 pC that produces an optical phase shift of about 2 radwith a resolution of 30 pC in charge means. Finally, the wavelet analysisis used to identify the acoustic patterns instead of the more commonlyused Fourier analysis. When transforming the measured signal to thefrequency domain, the temporal information disappears. But the acousticsignals really contain numerous transitory pieces of information to beconsidered. By looking at a Fourier-transformed signal it is impossible tostate when a particular event took place. The wavelet analysis helps tosolve this problem, and some results are presented here to show this.
TI - Detection and wavelet analysis of partial discharges using an optical fibre interferometric sensor for high-power transformers
JF - Journal of Optics A: Pure and Applied Optics
DO - 10.1088/1464-4258/5/1/310
DA - 2002-12-13
UR - https://www.deepdyve.com/lp/iop-publishing/detection-and-wavelet-analysis-of-partial-discharges-using-an-optical-JlPMGfmLiI
SP - 66
EP - 72
VL - 5
IS - 1
DP - DeepDyve
ER -