• Uilian José Dreyer
  • Erlon Vagner da Silva
  • André Biffe Di Renzo
  • Felipe Mezzadri
  • Hypolito José Kalinowski
  • Valmir de Oliveira
  • Cicero Martelli
  • Jean Carlos Cardozo da Silva


Temperature measurement, Fiber Bragg gratings, High power generator


This work presents the design and tests results for two temperature sensors based on quasi-distributed Fiber Bragg gratings (FBG) applied to bearings and heat exchangers of hydro generators. The temperature increase in the bearing is generally due to excessive shaft misalignment, low oil level or dirt in the lubricant oil. The heat exchanger suffer mostly because the onset of biological fouling decreasing its efficiency and increasing the generator temperature. The bearing sensor has four FBG to monitor the vertical temperature gradient in the lubricant oil. Temperature stability tests were carried out lasting twenty two hours in laboratory with bearing sensor. The calculated uncertainty of each FBG matches the requirements for temperature monitoring in hydroelectric generator bearings. Longer the heat exchanger is monitored with fifteen FBG to map the temperature of the air that comes from the generator stator and passes through the heat exchanger. A preliminary installation in the heat exchanger inside a power plant is reported. The biggest temperature reached by the fifteen FBG was 38 °C during the generator operating at 180 MW. The tests have proven that the temperature measured is associated with the generator load condition.


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How to Cite

Uilian José Dreyer, Erlon Vagner da Silva, André Biffe Di Renzo, Felipe Mezzadri, Hypolito José Kalinowski, Valmir de Oliveira, Cicero Martelli, & Jean Carlos Cardozo da Silva. (2015). FIBER OPTIC TEMPERATURE SENSING IN HEAT EXCHANGERS AND BEARINGS FOR HYDRO GENERATORS. Journal of Microwaves, Optoelectronics and Electromagnetic Applications (JMOe), 14, SI–35 to SI. Retrieved from

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