1995 Volume 115 Issue 9 Pages 1070-1075
Various preventive measures are taken against lightning faults in power transmission facilities to decrease their occurrence frequency and improve transmission reliability. However, how much they enhance the power carrying capability of a transmission line has not been quantitatively defined so far. To solve this issue rationally, it is useless to adopt the conventional deterministic approach which is widely used in power utilities as a general rule for power system planning.
This paper proposes a new method for numerical evaluation of the transfer capability by means of lightning measures. The proposed method is based on a probabilistic approach in which several fault patterns are considered with their occurrence frequency and maximum transferable power. This paper also applys the developed method to a trunk transmission model system and shows numerically the effect of 3 ground wires on the increase of carrying capability of a 500 kV transmission line.