An Assessment of Shielding Failure Rates in Transmission Lines: A Comparative Analysis Between EGM and the LPM

This article presents a proposed model for the estimation of the shielding failure rate. This model is rooted in a modified version of the Leader Progression Model (LPM) that incorporates stochastic attributes, resulting in a reduction in the computational resources required for describing the downward leader in lightning phenomena. The integral discharge channel model is employed to evaluate the shielding failure rate, and its outcomes are juxtaposed with those derived from the conventional electrogeometric model, applied to a 220 kV overhead transmission line spanning from Canutillar to Puerto Montt. Both the Shielding Failure Rate (SFR) and the Shielding Failure Flashover Rate (SFFOR) are computed for both models, facilitating a comprehensive comparative analysis. It is noteworthy that the values obtained from the LPM tend to be higher, primarily due to the LPM’s consideration of the tortuous and branching characteristics inherent in the lightning channel.