Some Studies on Carrier Propagation in Overhead Transmission Lines

The effectiveness of a carrier channel on a power line under various power frequency load conditions is studied. The effect of increase of load current results in an increase of conductor temperature, line length and sag. Therefore, the resistivity of the ACSR conductor material increases and the effective height of the conductor above the earth level decreases. A mathematical model of series-impedance and shunt-admittance which takes into account the above effects is used to evaluate the carrier signal attenuation on a line. Further, for the case of a bundle conductor line, the effect of subconductor deflections on the carrier attenuation has been studied. The effects of earth resistivity and earth wires on the actual carrier attenuation have also been studied.