Design of an optical sensor with varied sensitivities for overhead line sag, temperature and vibration monitoring

This paper reports on the design of a fiber-optic sag, temperature, and vibration sensor to implement overhead line (OHL) dynamic rating and health monitoring in electrical power networks. The proposed sensor is based on the fiber Bragg grating technology for compatibility with a suite of photonic voltage and current sensors previously developed by the authors. A range of different strain transfer and attachment structures for an FBG-based strain sensor that facilitate varied strain transfer from the conductor to the FBG are considered and the expected sensor performance is evaluated through software simulations and the finite element analysis. The results suggest that the proposed sensor, when fabricated, should be a valuable tool for the conductor sag, temperature, and vibration monitoring. The choice of a strain transfer and attachment structure to achieve desired sensitivity can be tailored based on the requirements of a given application.