Optical fiber and integrated optics accelerometers for real-time vibration monitoring in harsh environments: in-lab and in-field characterization

Abstract

The reliability of rotating machines such as electrical generator is critical to the overall reliability and operation of electrical power plants. The very high cost of these machines, makes it necessary to improve the lifetime of a wide set of currently installed hydrogenerators around the world and avoid costly maintenance. Vibration monitoring is essential in maintenance and protection programs. However, due to the harsh environment and the very low frequency spectrum of the vibrations, the above mentioned machines cannot be appropriately monitored by piezoelectric sensors. Several combination of optical fiber with silicon microstructures or in integrated optics, but because of technical or economic reasons, up to now, these sensors are not fully suited for the above-mentioned applications. In this paper both optical fiber and integrated optics accelerometers developed in order to satisfy specifications required for these applications are presented. Their developments were a part of a European project dedicated to real time defect detection and predict forthcoming failures of a generator group in an electric power plant in Spain. In-laboratory and in-field test are reported.