Lightning Incidence on Transmission Overhead Lines

The paper deals with an estimation of lightning strike incidence to transmission overhead lines in the context of line outages gathered from an automatic monitoring system. The statistics of the Czech transmission system's line outages caused by lightning strikes are presented and analyzed. Lines with significantly higher outage rates are identified, and the electrogeometric model is used for lightning incidence calculation. The estimation that the lightning strikes the phase conductor, ground wire, or tower constructions of overhead line is performed. Finally, the ratio of lightning strikes that caused line outage to the total number of lightning strikes to phase conductors is evaluated and compared with the values obtained from the monitoring system.