Estimation of the shielding performance of transmission lines: Comparison of deterministic and probabilistic methods

The shielding performance of transmission lines is generally evaluated through deterministic methods, e.g. Anderson´ simplified method, which is implemented on IEEE Flash program. However, more accurate results may be observed with a probabilistic approach, e.g. with Monte Carlo Method, at what all random variables associated with lightning interactions with transmission systems are considered by means of probability density functions, e.g. the lightning strike position, leader angle, power frequency voltage, etc. This paper is aimed at contrasting the estimation of the shielding failure flashover rate (SFFOR) resulting from these two procedures, with especial attention on analysing the representativity of the results obtained with IEEE Flash program.