Temperature measurements in power plant equipment using distributed fiber optic sensing

A special optical fiber is described which can measure local temperature from 0 to 150/spl deg/C in electrical power equipment with an accuracy of /spl plusmn/5/spl deg/C. Changes in Rayleigh backscattered light from the fiber cladding indicates changes in local temperature at points along the fiber using an optical time domain reflectometer approach. This distributed fiber optic temperature sensor (DFOTS) had a spatial resolution of 10 cm using fiber sensors up to 100 m long. Field test data were successfully obtained for several electrical power system applications. Switchgear finger cluster, stator winding, and rotor shaft temperatures were all measured in operating power plants. Results show that the Rayleigh DFOTS approach can provide valuable information about thermal performance of operating electrical equipment.<
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