A Fiber-optic Current Sensor Based on FBG and Terfenol-D with Magnetic Flux Density Concentration

This paper presents a compact fiber-optic current sensor (FOCS) based on fiber Bragg gratings and Terfenol-D as the magnetostrictive material for monitoring of high-voltage transmission lines. Using finite-element-method (FEM) simulations and magnetic flux density concentration techniques, the proposed FOCS was manufactured with only 2,2 g of Terfenol-D, a reduction of more than 94% compared to previous works on this field. The developed FOCS was characterized in laboratory with a.c. current in the range of 50–800 A
rms
. The experimental results showed that not only a significant reduction in the amount of Terfenol-D was implemented, reducing the cost and fragility of the sensor head, but also the developed FOCS presented a linear response with an error of 1.298%, and a sensitivity of 0.197 pm/A were achieved.