Efficient magnetic biasing scheme for a Bragg-grating-based magnetostrictive alternating current sensor

In this work, the authors describe in detail the development of an efficient magnetic biasing scheme for FBG-based magnetostrictive current transducers intended to be used in innovative transmission line monitoring systems. A Fiber Bragg grating is attached to a giant magnetostrictive rod, and a DC magnetic field is created by a magnetic circuit in order to enable the magnetostrictive material operate in its linear region. Design stages, including simulations using the Finite Element Method, and the proposed sensor configuration are presented. The sensor prototype, which is assembled in laboratory, is tested by employing an arrangement built to simulate the current in a transmission line, showing the efficiency of the proposed magnetic biasing set-up.