Fiber Bragg grating temperature sensing system for large air cooled hydrogenerators

This paper describes the research, project, construction, calibration, installation and operation of a fiber Bragg grating based fiber-optic system applied to a hydro-electric generator to perform a continuous monitoring of temperature. After being deployed for two and a half years, the system has proved itself to be capable of reliably and accurately measuring and monitoring temperatures inside the generator, while taking into consideration the harsh environment of the stator. The results were considered satisfactory, demonstrating the usefulness of the fiber-optic system in power generation equipment.