Abstract:
The heavy icing on the optical fiber composite overhead ground wire (OPGW) seriously affects the power supply reliability of power grids. In order to study the temperature-rise characteristics of OPGW during DC ice-melting and its influencing factors, this paper establishes a dynamic numerical calculation model for OPGW DC ice-melting, and simulates the temperature field distribution of OPGW during ice-melting and after complete ice-melting. The influencing factors of OPGW fiber temperature change are analyzed from the aspects of environmental temperature, wind speed, ice-melting current, etc. The accuracy of the model results is verified in an artificial climate room. The results show that the elliptical air gap between OPGW and the inner surface of the ice layer impedes heat transfer to the ice layer. After ice-melting, the steady-state temperature distribution of OPGW varies significantly depending on the type of ice-melting conductor and its location. The maximum temperature of the optical fiber during ice-melting increases with the increase of ice-melting current and ice cover thickness, independent of wind speed and ambient temperature. After complete ice-melting, the optical fiber temperature increases with rising ambient temperature, decreasing wind speed, and increasing ice-melting current. The moment when the optical fiber reaches its highest temperature is related to wind speed; when the wind speed is between 0 to 3 m/s, the optical fiber temperature continues to rise after ice melting. Thus, DC ice-melting technology for OPGW is only suitable for high-temperature-resistant optical cables predominantly made of metal materials. The relative error between the model calculation values proposed in this paper and experimental values is no more than 10%, validating the accuracy of the model.