Temperature Sensing by Rubi Fluorescence
Temperature is a very important parameter for the electric power industry because insulators, copper conductors, core iron of transformers, insulator oil, and other equipment are very sensitive to temperature, which has to be kept under strict control at all times. Nevertheless, when dealing with high voltage, conventional electric sensors are not applicable since they need to be kept away from high voltage energized parts. For this reason, optical fiber sensors can offer many advantages over conventional sensors such as high immunity to electromagnetic interference, electrical isolation, no need of electric power to work, and ability to be directed installed over electric potentials. This chapter reports the development of a temperature sensor field prototype using the ruby fluorescence when pumped by a pulsed ultra-bright green LED. The prototype with four probes was installed on a substation harmonic filter at 75 kV for temperature monitoring. The system performed well during several months monitoring four temperatures together with ambient temperature, sending data to the substation control room, and promising to be a good solution for high voltage energized parts.