Fiber Bragg Grating Vibration Sensing Technology for Operational Condition Monitoring in the Transformer

The long-term operation of large-scale equipment in power systems is subject to electrical, thermal, and mechanical stresses, leading to aging, wear, and increased fault rates. Vibration signals can effectively reflect failure state information in the power system. This work presents a vibration sensing system based on fiber Bragg grating (FBG) interferometric dynamic demodulation, addressing challenges posed by electromagnetic interference in traditional electrical signal sensors. The system integrates an FBG acceleration sensor and a dynamic demodulation unit, demonstrating high sensitivity (100 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{pm} / \mathrm{g}$</tex>) and immunity to electromagnetic disturbances. Experimental deployment on a 500 kV main transformer revealed accurate vibration measurements consistent with piezoelectric sensors, effectively capturing vibration signals within the main transformer's operational frequency range of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$50-600 ~\text{Hz}$</tex>. These results emphasize the potential of this technology as a reliable supplement for transformer condition monitoring, and it is expected to provide strategies in terms of the real-time monitoring and security guarantee of power systems operations in high-voltage environments.