An Improved Solution for Simultaneous Measurement of Current and Temperature on Terfenol-D FBG Optical Sensor

This article presents a proposal for an alternative approach for simultaneous measurement of electric current and temperature using an optical sensor based on magnetostrictive material that employs a single Fiber Bragg Grating (FBG). The sensor head is of simple design and allows easy installation on the existing conductors of the underground distribution network. This proposal measures the root mean square (RMS) current from 50 to 600 A at any temperature between 10°C to 60°C, real values for a distribution network. The approach consists of obtaining surface curves of two key parameters of the sensor’s waveform response,
$\lambda ({t})$
. The main parameters are the peak-to-peak and minimum wavelengths as a function of temperature and current. When determining these parameters from the waveform, the crossing point of the contour graphics is used to uniquely determine the current and temperature in the sensor head in real-time, without the need for any correction process.