Monte Carlo analysis of wind farm surge arresters risk of failure due to lightning surges

• Monte Carlo procedure for wind farm arresters risk of failure assessment.
• EMTP-ATP wind farm el. system lightning-associated transient simulation.
• Arrester absorbed energies approximated with a Weibull distribution.
• Risk of arrester failure as a means of optimizing arrester selection procedure.
• Introduction of the risk management into arrester selection procedure.

This paper presents a Monte Carlo procedure intended for the assessment of the metal-oxide (MO) surge arresters risk of failure in onshore wind farms. It focuses on the energy withstand (absorption) capability of the MO surge arresters in relation to lightning surges and in terms of their risk of failure assessment. Presented methodology accounts for the fact that the lightning itself is stochastic in nature and that the MO surge arrester energy capability is a statistical quantity. The well-known backsurge phenomenon is employed as a means for studying the MO surge arresters energy stresses due to lightning surge transients (in onshore wind farms), where the associated transient (i.e. high-frequency) models of particular wind farm components feature prominently. Necessary numerical simulations are carried-out with the well-known EMTP-ATP software package. This procedure could be seen as beneficial in selection of the optimal MO surge arrester energy withstand capability for wind farm projects situated in areas marked with high keraunic levels and/or having high soil resistivity.