Selection of the Lateral Distance for the Assessment Area in a Monte Carlo Procedure Under Indirect Lightning for Overhead Distribution Lines

Monte Carlo procedures are commonly adopted to evaluate the lightning flashover rate on overhead lines due to indirect lightning. This letter presents a discussion on selecting a lateral distance of the assessment area, in which a lightning stroke would cause a flashover. An inappropriate choice would either cause unexpected assessment errors or incur an extra computational burden. Unfortunately, in the literature, there is no systematic discussion on this issue. In this letter, the influence of this lateral distance on the flashover rate evaluation is discussed. The utmost lateral distance is introduced, beyond which indirect lightning events would not cause a flashover. A general procedure is provided to determine this utmost lateral distance. With this selected utmost lateral distance, the computational burden could be relieved while the assessment accuracy preserved.