China Three Gorges University
The National Natural Science Foundation of China (General Program, Key Program, Major Research Plan)
Ultra-high voltage transmission lines inevitably pass through mountainous areas with high altitude and heavy icing. Unbalanced tension and conductor jump caused by ice-shedding of large elevation transmission lines will have an important impact on their electrical and mechanical properties. In this paper, a five-span conductor-insulator ice-shedding jump model is established for three typical 500 kV transmission lines in mountainous areas, such as hill climbing, cross-mountain and valley crossing. The influence of elevation difference form on the amplitude of conductor jump height and unbalanced tension is obtained by the additional force method. The results show that the unbalanced tension on the higher side of the insulator is larger than that on the lower side when the height difference exists in the ice-shedding gear. With the increase of the height difference angle, the unbalanced tension on the lower side of the insulator decreases rapidly, and the unbalanced tension on the higher side of the insulator at 30° is 3.06 times that on the lower side. Compared with the valley-crossing model, the unbalanced tension on both sides of the ice-shedding model is larger. With the increase of elevation angle, the unbalanced tension and jump height of the mountain-crossing model and the valley-crossing model show the opposite trend. At 30 °, the unbalanced tension of the mountain-crossing model reaches the maximum value of 30454.6 N, and the jump height reaches the minimum value of 10.02 m. At this time, the unbalanced tension of the valley-crossing model reaches the minimum value and the jump height reaches the maximum value. By analyzing the relationship among sag difference, jump height amplitude and line height difference angle, the calculation formula of ice-shedding jump height of transmission line conductor with large elevation difference is fitted, which has important engineering value for line design and maintenance.
张斌,许正涛,江全才,等. 山区大高差500kV输电线路脱冰跳跃高度的计算方法研究[J]. 科学技术与工程, , ():复制