Study of an FBG-FP Cascaded Optical Fiber Current Transformer Based on Electrostrictive Material Coupling

Area of Science:

• Sensor Technology
• Optical Physics
• Materials Science

Background:

• Traditional optical fiber current transformers suffer from low sensitivity and susceptibility to environmental interference.
• Magnetostrictive sensors present structural complexity, limiting their practical application.
• Existing solutions lack the required precision and adaptability for modern power systems.

Purpose of the Study:

• To develop a novel fiber-optic current sensor with enhanced sensitivity and environmental stability.
• To overcome the limitations of traditional current transformers and magnetostrictive sensors.
• To provide a compact, high-precision, and scalable solution for current detection in power systems.

Main Methods:

• Integration of a high-sensitivity electrostrictive piezoelectric ceramic sensor with an FBG-FP cascaded fiber-optic sensor.
• Utilization of orthogonal intensity demodulation to improve detection sensitivity.
• Implementation of a multi-cycle waveform-averaging method for DC output light intensity calculation.
• Temperature calibration and compensation based on the correlation between DC output light intensity and operating points.

Main Results:

• The designed sensor achieves a detection bandwidth of 0-7 kHz, suitable for power-frequency current detection.
• A wide current measurement range of 0.15-42 mA was demonstrated.
• A minimum measurable current as low as 150 μA was achieved, indicating high sensitivity.
• The sensor structure was significantly optimized, offering compactness and scalability.

Conclusions:

• The developed fiber-optic current sensor effectively addresses the limitations of conventional methods.
• The sensor demonstrates high precision, excellent sensitivity, and robust performance under varying conditions.
• This technology offers significant engineering value and adaptability for current detection in power systems.