Related Experiment Video
Updated: Apr 29, 2026
16:11
Implementation of a Reference Interferometer for Nanodetection
Published on: April 26, 2014
8.8K
A fiber optic PD sensor using a balanced Sagnac interferometer and an EDFA-based DOP tunable fiber ring laser
Lutang Wang1, Nian Fang2, Chunxu Wu3
1Key Laboratory of Specialty Fiber Optics and Optical Access Networks, School of Communication and Information Engineering, Shanghai University, No.149, Yanchang Road, Shanghai 200072, China. ltwang@mail.shu.edu.cn.
Sensors (Basel, Switzerland)
|May 15, 2014
Summary
This study introduces a novel fiber-optic acoustic sensor for detecting partial discharge in power transformers. The sensor utilizes a tunable laser and Sagnac interferometer to achieve high sensitivity and frequency response.
Area of Science:
- Optoelectronics
- Sensor Technology
- Power Systems
Background:
- Partial discharge (PD) in power transformers poses a significant risk to grid reliability.
- Existing acoustic sensing methods face challenges with noise and sensitivity.
Purpose of the Study:
- To propose and demonstrate a novel fiber-optic acoustic sensor for PD detection.
- To investigate the impact of fiber birefringence on sensor performance.
- To enhance signal-to-noise ratio (SNR) and suppress noise in acoustic sensing.
Main Methods:
- Utilizing an erbium-doped fiber amplifier (EDFA)-based fiber ring laser for tunable polarization.
- Employing a balanced Sagnac interferometer for noise elimination and inherent quadrature operation.
- Deriving operational principles and relevant formulas for sensor analysis.
Main Results:
- Demonstrated continuous tuning of the laser's degree of polarization (DOP) from 0.2% to 100% with minimal power fluctuation (<0.05 dBm).
- Achieved a high-frequency response up to 300 kHz.
- Verified high sensing sensitivity for detecting weak corona and partial discharges.
Conclusions:
- The developed EDFA-based fiber ring laser with a balanced Sagnac interferometer offers effective acoustic sensing of PD.
- The sensor system exhibits robust performance, high sensitivity, and broad frequency response suitable for power transformer monitoring.
