OPGW Icing Monitoring Method Based on Phase Difference Between Temperature Curves

To obtain the criterion of whether the optical fiber composite overhead ground wire (OPGW) is iced and to estimate the ice thickness, this letter establishes a three-dimensional temperature field model for OPGW under icing conditions and validates it through the experiments. Based on this, sine function is used to simulate the time-varying ambient temperature, and the lag characteristics of the optical fiber temperature are discovered through the simulation and also the experiment. The concept of phase difference in the curves between optical fiber temperature and ambient temperature is proposed, and the relationships between the phase difference and the mean ambient temperature, fluctuation amplitude of ambient temperature, ice thickness are investigated. It reveals that the influence of mean value and fluctuation amplitude of ambient temperature on the phase difference can be neglected, and the relationship between the phase difference and the ice thickness is obtained. The criterion for determining transmission line icing based on the phase difference is proposed, along with a formula for ice thickness estimation.