Thermal protection of overhead lines in different ambient conditions

This paper introduces an approach for a more effective thermal protection of overhead electrical lines. Starting from thermal model of overhead line, its thermal behaviour has been simulated resolving thermal balance equation thanks to the dynamic simulation program, MATLAB. Then, knowing simulated behaviour of the conductor, time-current curve has been obtained, that adapts itself, in each simulation interval, to the new working conditions of the line. The knowledge of the real thermal behaviour together with a completely automatic thermal protection could guarantee full exploitation of existing overhead lines without reducing safety and quality.