Development of a novel high-frequency reciprocal structure fiber optical pulsed current sensor

Area of Science:

• Optoelectronics
• Sensor Technology
• Electromagnetics

Background:

• Accurate measurement of large transient currents is critical in high-voltage, high-power systems.
• Existing current sensing technologies often face limitations in terms of insulation, noise, and frequency response.

Purpose of the Study:

• To design and validate a novel all-fiber optic current sensor (FOCS) for measuring large transient currents.
• To leverage the Faraday effect for high-performance current sensing in demanding environments.

Main Methods:

• A reciprocal symmetric structure was incorporated into the optical sensing loop.
• Passive optical fiber couplers and homodyne detection were used for phase demodulation.
• Bench-testing involved a fast capacitor discharge current source and various laser sources.

Main Results:

• The FOCS demonstrated high linearity, low noise (1.4 × 10⁻³ rad phase noise), and excellent frequency response.
• Performance was independent of laser wavelength and linewidth.
• Sensitivity was calibrated against a commercial Rogowski sensor, showing precise measurements.

Conclusions:

• The developed FOCS offers a robust, adaptable solution for high-precision current sensing in challenging high-voltage, high-frequency environments.
• The reciprocal sensing loop design ensures stable performance regardless of loop length.
• The sensor exhibits superior, stable performance with minimal dependence on laser parameters.