Title :
An Over-Coupled Fused Coupler Based Acoustic Emission Sensor for Detecting Partial Discharges
Author :
Wang, Jinyu ; Min, Li ; Qi, Haifeng ; Wang, Chang
Author_Institution :
Key Lab. of Opt. Fiber Sensoring Technol. of Shandong Province, Laser Inst., Jinan, China
Abstract :
A fiber optic AE sensor system based on over-coupled fused coupler (OCFC) and intensity modulate principle is investigated to detect power transformer partial discharge effectively. The principle of a sensing heads based on OCFC for detection of acoustic emissions in power transformers is illustrated. The theory and experiment results of fiber optic AE sensor based on OCFC is described, the transmission spectrum of these OCFC sensor when applied with different strains is investigated. A distributed feedback laser was used to interrogate the sensors, optimizing the measurand readout sensitivity. The output of these AE sensors when applied with acoustic emission is shown. The sensitivity, frequency responses and the minimal discharge are experimentally obtained. Experiment show the OCFC AE sensor has the flat response from 40k to 120 kHz, the average sensitivity is about -70dB, and the minimum detection discharge quantity is 50pc.
Keywords :
acoustic transducers; distributed feedback lasers; fibre optic sensors; frequency response; measurement by laser beam; partial discharge measurement; power transformers; strain measurement; OCFC; acoustic emission sensor; distributed feedback laser; fiber optic AE sensor system; frequency 40 kHz to 120 kHz; frequency response; intensity modulate principle; measurand readout sensitivity; overcoupled fused coupler; power transformer partial discharge detection; transmission spectrum; Acoustic emission; Discharges (electric); Oil insulation; Optical fiber sensors; Partial discharges; Power transformers; Sensitivity;
Conference_Titel :
Photonics and Optoelectronics (SOPO), 2012 Symposium on
Conference_Location :
Shanghai
Print_ISBN :
978-1-4577-0909-8
DOI :
10.1109/SOPO.2012.6271075
