Calculation and analysis of ampacity and stress of overhead transmission line

Abstract

To ensure the safe operation of a transmission line, it is necessary to study the radial temperature rise and the stress and strain distribution of the transmission line under on-load state. A three-dimensional solid finite element model of reinforced aluminum conductor steel was established, and the temperature and stress distribution of the conductor were calculated. The effects of operating tension, wind speed, and radial temperature difference on the temperature and stress distribution were analyzed. The radial temperature difference increases about 1.40–3.16 °C with the rise of the mean temperature of the conductor. When the ambient temperature decreases from 20 to −40 °C, the mean temperature of the conductor decreases from 50.34 to −9.31 °C, and the external layer stress increases from 44.59 to 60.19 MPa. At the same time, the external layer stress of the conductor increases with the increase in wind speed and operating tension. The stress of the outermost aluminum conductor of the conductor under the radial temperature difference load increases with the rise in the temperature difference, and the stress of the inner aluminum conductor and the inner steel core decreases with the rise in the temperature difference.