ABSTRACT
Jingbo Yang & Fengli Yang China Electric Power Research Institute, Beijing, China
ABSTRACT: The safety and reliability of the UHV transmission towers were analyzed in many aspects. Load considerations, tower types, calculating model in structural design, prototype tests. Capacities of resisting natural disasters were evaluated on UHV transmission towers according to the analysis results. The return period of is valued as 100 years in the design of UHV transmission towers. Wind loads on UHV transmission towers are higher than 500 kV transmission towers by 14.5 percent. Therefore the anti-wind capacity and the reliability level are enhanced. The vibration analysis based on the random vibration theory and the tunnel tests for UHV transmission tower were carried out. The results show that the value of wind vibration coefficient in the design of UHV transmission towers is conservative and the towers are safe. Tubular towers are used in UHV transmission towers. Tubular towers have some advantages including high bearing capacity and good stability. Effects of the end moments were considered in the structural analysis of tubular towers. The member forces can be computed more precisely. The typical UHV towers all passed the prototype tests under design load cases. In general, comparing with the transmission towers of regular voltage grades, capacities of resisting natural disasters for UHV transmission towers are higher. Safety and reliability of UHV transmission towers can be fully assured.
