Abstract
The temperature of a transmission line conductor is one of the important factors used to determine its current carrying capacity. There are several standards and methods by IEC, IEEE, CIGRE and ICS on the calculation of conductor temperature. Apart from heat dissipation by convection where some differences exist, almost the same formulae are used in these standards and methods in calculating the other terms of the heat equation that is used in determining the conductor temperature.
In this paper, a comparison of how the heat dissipation by convection is assessed using these standards and methods is reported. In order to compare the conductor temperature obtained by calculation and that measured experimentally, laboratory experiment of temperature measurement of ACSR conductors was carried out under several currents, surface and wind conditions. In the calculation, CIGRE method is used because it is virtually adopted worldwide. Under low wind velocity, however, the difference between calculated and measured conductor temperatures is quite significant. A new equation is proposed in order to narrow the differences between the measured and calculated temperatures under low wind velocity conditions. By applying the probabilistic technique or approach, the proposed equation and the CIGRE method were then employed to assess conductor temperature using actual climatic and current data. This is to provide a wider basis for comparison.
