Computation of standard sag of overhead lines for power grid based on mathematical model of iterative technique

The computation of the sag for overhead lines plays a significant role in design and construction of lines. The common way to obtain the sag value is to lookup the curves provided by the design departments, but the standard sag obtained by this way is prone to make a personal error. Aimed at above problems, this paper proposes a computing method of standard sag for overhead lines based on iterative technique. The method establishes a mathematical model by computing theory of the stress sag. The model makes use of high-speed iterative of computer to compute standard sag of any given span through state equation of stress and judgment principle of control climate conditions. The method possesses many advantages, such as, clear thinking, easy to understand and without considering complex logic judgment to solve critical span. Finally, an example proved that the method to solve the stress is rapid and high accuracy.