StatisticalEvaluation of Lightning Performances of Distribution Lines

voltage and of tbc cbange of coupling factor among tbe linc conductors and tbe ground at tbe location where f1ashov~ 0CC1D'. In Section 3, we shall compare om metbod with tbe ODe proposed by tbe IEEE Guide Std 1410 [2] for tbe ~ purpose. Tben in Section 4, we sball perfonn a first assesSJnent of tbe lightning perfonnance of a typical Italian distn"bution linc. Section 5 is devoted to tbc conclusions. Abstracl-Flashover rata or overbead muldconductor distribution ~nes witb realistic confipntions, due to ligbtning-induced overvoltages are estimated by means or a statistical procedure based on the Monte Carlo method. Tbe goal is the estimation or tbe number of events exceeding. ror a given ground flash density, a certain voltage value or-pro\ided tbe voltage-time characteristic or tbe insulators is knOWD-the 'classical' flasbover rate vs CFO (criticai flashover voltage) curves. For each ligbtning event, the evaluation or tbe induced overvoltage aIong the line is perfonned using the LIOV program, developed in the framework or an Italian-Swiss research collabontion. Tbe procedure is first compared witb tbe ODe proposed in tbe IEEE Guide Std 1410 ror the lame purpose, .nd tben appUed to a typicaJ ItaJian Une confignration.