State Grid Ningdong Electric Power Supply Company Strengthens Engineering Quality Control to Enhance Ice Resistance of Transmission Lines

On December 10th, State Grid Ningdong Electric Power Supply Company completed the anti-icing renovation of the 110kV Nanfeng Transmission Line. This upgrade significantly enhances the safety and capacity of the dedicated renewable energy line for users, ensuring greater grid reliability and stability during the peak winter season.

The 29.35-kilometer Nanfeng Line, commissioned in 2011, runs from State Gird Mahuangshan 110kV Booster Station to the Nanxinzhuang 110kV Substation at an altitude of 1,537 to 1,952 meters above sea level. The segment between towers 1 and 19, located in the micro-terrain and microclimate zone of Mahuangshan in Yanchi County, has historically been vulnerable to ice accretion during extreme winter weather. Past ice storms have caused conductor galloping and line tripping, jeopardizing grid stability. To substantially enhance the line’s resilience to rain, snow, and freezing disasters, Ningdong Company initiated the anti-icing upgrades of this section on November 20th, ensuring grid reliability throughout the winter.

The renovation project involved constructing ten new reinforced ice-resistant towers along the original line path, dismantling eight existing towers, and installing 10 “Ice Elf” ice monitoring devices. The newly constructed towers feature an enhanced anti-icing design, incorporating anti-theft and anti-loosening measures, and the average span length has been reduced to 293 meters. These improvements, including reduced span lengths, enlarged tower heads, optimized ice monitoring, and the exploration of new anti-icing materials, substantially improve the line’s ice resistance. Furthermore, a comprehensive inspection and maintenance effort addressed 42 defects and added 1,560 bird spikes to 52 towers, enhancing overall equipment reliability and power supply stability.

Throughout the project, State Grid Ningdong Electric Power Supply Company rigorously enforced quality control measures across all phases, from planning and site surveys to risk assessment, plan formulation, work execution, and personnel deployment. Its strict adherence to construction and acceptance protocols ensured the highest quality standards for the renovated line.(By Wang Yushuo from State Grid Ningdong Electric Power Supply Company)