Stochastic Analysis of Transient Overvoltages at Substations by Applying the Monte Carlo Method Integrated with ATP

The present paper proposes a methodology for stochastic analysis of electromagnetic transients caused by lightning and switching in substations. Such methodology consists on computer-aided simulations using the Alternative Transients Program (ATP) and employing the Monte Carlo Method (MCM) to reproduce the probabilistic phenomena of the aforementioned events. For atmospheric discharges, the method was used to estimate parameters such as amplitude, front time and tail time, considering their statistical features, while for switching it was used to generate commutations in different time instants. Since the original ATP does not provide the resources to perform such simulations, the authors present a procedure to incorporate them through the use of foreign models, available in the software mentioned above. Some examples are shown in order to demonstrate the use of the methodology.