Caracterização e desenvolvimento de sensores ópticos de corrente elétrica para aplicações em linhas de alta tensão

Abstract

This thesis, titled "Characterization and development of electric sensors for electrical applications in high voltage lines" was developed in a PhD program in Electrical Engineering. Fix the devices and characterized the magneto-optical current sensors for measurement applications and protection in high power systems, namely, prism sensor and photonic glass fiber (PCF) sensor. Both are based on the Faraday effect, using a double quadrature polarimetric configuration. This work was then divided in two moments. In the first, a prism sensor, consisting of a portable sensor head for anchoring in the transmission line was developed, in Portugal, for an industrial application. In this case, no prism sensor prototype was used in a Schott SF57 glass prism 8cm in length with high Verdet constant and low birefringence. It has been incorporated into a Nylon casing suitable for fastening applications in the power line. The operation of the sensor is characterized and compared using Super Luminescent Diodes (SLD) as a source of 650, 830 and 1550 nm. Class 1 precision sensor for nominal currents of 900 ARMS or higher and classes 0,1 and 0,2 for nominal currents of 1,2 kARMS and 0,3 kARMS, respectively, and the possibility of detecting impulses in the network of 10 Μs. Second, another type of wrapping, the use of optical fibers as a transition element, using highly rotated fibers at 4, 6, 9, and 11 revolutions per second, developed by the group of the Laboratory of Special Fibers and Photonic Materials - LaFE, from the Institute of Physics Gleb Wataghin of UNICAMP, Brazil. In particular, these lines were tested as a whole on an electric conductor using three winding sizes of 6, 12 and 18 cm in diameters with different turns, with currents of up to 800 ARMS using an SLD source at 650 nm. Parameters, such as sensitivity and linearity of the sensor, were investigated. A symbolic analysis was also performed to quantitatively analyze the fiber sensitivity value with respect to the number of turns and with respect to the diameter of the support, there is no conclusion that there is a compromise between these two parameters in order to obtain a better response in the signal of sensor output.