Simultaneous AC and DC measurement based on an FBG-magnetostrictive fiber sensor

Area of Science:

• Optoelectronics
• Materials Science
• Sensor Technology

Background:

• Accurate simultaneous measurement of alternating current (AC) and direct current (DC) is crucial in various applications.
• Existing fiber sensors face challenges with cross-talk and temperature sensitivity.

Purpose of the Study:

• To develop a novel fiber sensor capable of simultaneously measuring AC and DC currents.
• To investigate the potential of the proposed sensor for reducing temperature cross-talk.

Main Methods:

• A new fiber sensor was designed, integrating fiber Bragg gratings (FBGs) with giant magnetostrictive materials (GMMs).
• The sensing structure was placed within a solenoid to apply DC and AC currents.
• The differential deformation of GMMs under DC and AC was analyzed by monitoring FBG central wavelength shifts.

Main Results:

• The sensor successfully demonstrated simultaneous AC and DC current measurement.
• The central wavelength shift of the FBG exhibited a periodic harmonic variation, enabling separate demodulation of AC and DC values.
• AC current sensitivity reached 0.090576 nm/A (0-1 A range), and DC current sensitivity reached 0.2378 nm/A.
• The method showed potential for mitigating temperature cross-talk.

Conclusions:

• The developed fiber sensor offers a promising solution for simultaneous AC and DC current sensing.
• The unique response of FBGs to GMM deformation under varying currents allows for distinct signal demodulation.
• This technology has implications for improved sensor accuracy and reduced environmental interference.