Icing monitoring technology and application of 10 kV overhead distribution lines based on axial tension measurement

Severe ice cover on overhead distribution lines affects the safe operation of the distribution network. Aiming at the lack of icing monitoring methods for 10 kV overhead distribution lines with strain towers, especially those with small spans, in consideration of the structural characteristics of 10 kV strain towers commonly found in mountainous areas of southern China, this paper proposes a real-time monitoring technology of equivalent ice thickness (EIT) of 10 kV overhead distribution lines based on axial tension measurement of the conductors. Considering variations in vertical spans of conductors before and after icing, a calculation method for EIT of ice-covered conductors is presented. Then an icing monitoring device for ice-covered overhead distribution lines has been developed and installed in Guizhou, and typical monitoring data is used to analyze environmental impacts on tension. The validity of the monitoring technology and accuracy of the calculation method are verified through comparison with artificial ice observation results and ice-covered lines photographs. Finally, comparing the method of this paper and the method of calculating the EIT of ice-covered conductors without considering the change of vertical spans of transmission conductors adopted for voltage levels of 110 kV and above, it is found that the method of this paper, considering the changes of vertical spans of conductors, can significantly improve the accuracy of calculating the EIT under the small span, making it more suitable for application to overhead distribution lines.