Full Scale Test Study on Sag Characteristics of Augmented Capacity Conductors for Transmission Line

With the diversification of the demand for new construction and reconstruction of transmission lines, the capacity increasing conductor will be gradually applied to AC/ DC transmission lines of various voltage levels. In existing transmission line design, the sag of transmission line are evaluated by empirical formula, which is verified merely in a 60 meters small span test in laboratory, and is quite different from the actual project. To understand the temperature rise and sag characteristics of typical conductors and provide basis for the selection of transmission line conductor, the first 200 m large span transmission line on actual strain tower for full scale test is built in Kunming UHV engineering technology lab to study on the temperature rise and sag characteristics of 4 kinds of conductors, including 1 kind of ordinary aluminum clad steel conductor and 3 kinds of typical augmented capacity conductor: carbon-fiber aluminum conductor composite core (ACCC), aluminum clad invar core aluminum alloy wire, and aluminum clad steel core aluminum alloy wire. The results show that ACCC and aluminum clad invar core aluminum alloy wire have better arc sag characteristics, and there are obvious temperature transfer points. The temperature transfer point of ACCC is about 75°C, and the transfer point of aluminum clad invar core aluminum alloy wire is about 105°C.