Strength Loss of Single Line of Transmission Line Conductors under Condition of Long Time and High Temperature Operation

In order to ensure the normal operation of transmission line conductors under high temperature 80-150℃ conditions, the variation of tensile strength of single wire under different temperature and duration was studied. The high temperature tests of the galvanized steel wires and the hard-drawn aluminium wires were carried out around three factors of temperature, time and diameter. The high temperature environment was simulated by high temperature oven, and the tensile strength was tested by microcomputer controlled electronic universal material testing machine. Orthogonal test method was used to analyze the significant influencing factors of the tensile strength loss rate. The results show that the tensile strength loss rate of galvanized steel wire was small when the temperature was less than 150℃ and the heating time was less than 1 000 h. The tensile strength loss rate of the hard-drawn aluminium wires increased as increasing heating temperature and heating time, and the temperature was the significant factor affecting the tensile strength loss rate, time was the next significant factor, and the influence of the diameter was the smallest.