Compensação de temperatura para sensores de corrente elétrica baseados em redes de Bragg em fibras ópticas

Abstract

Study and the development of temperature compensation for electrical current sensors based on fiber Bragg gratings using the twin gratings technique. The measurement of electric current by opto-mechanical sensors is very well described in the literature, as well as techniques that propose the compensation of thermal variation effects on the output signal of the system. However, the compensation method employing twin gratings using the method proposed herein has not yet been reported in the literature. The temperature compensation in systems that employ as sensor element the fiber Bragg grating is necessary due to the fact that temperature variations also induce changes in the Bragg wavelength, exerting negative influence on the characteristics of the sensor. In this sense, temperature compensation was achieved by the addition of a second fiber Bragg grating in the system, called fixed filter, in order to interrogate the output signal from the sensing grating. Once both gratings have been attached to the Terfenol-D rods close to each other and subjected to the same temperature variations inside a paper box, the separation of magnetostrictive strain from those related to temperature in the signal of sensor output could be obtained.