Methodological Framework for Conductor Lifetime Estimation Using Optical Sag Sensors

This letter proposes the methodological framework for estimating overhead line (OHL) conductor lifetime using optical sag sensors. The sensors utilize fiber Bragg grating (FBG) technology to monitor static and dynamic mechanical parameters of the conductor in real time, including direct measurements of strain and temperature that can be translated into the sag, force, and stress readings. The signals acquired by the sensors in a field trial were used to analyze vibration and dynamic stress load experienced by the monitored conductor to predict its cumulative damage by means of the rainflow-counting algorithm combined with Miner's rule. The results suggest that the proposed methodology allows for the online estimation of the remaining lifetime of the conductor under dynamic operating conditions in ambient environments.