An Evaluation of Potential Rise in a Wind Turbine Generator Earthing System During a Direct Lightning Strike

A reliable and robust earthing system design is critical for the lightning protection system of a wind turbine. This paper presents an analysis of the wind turbine earthing impedance and potential rise for a horizontal multi-layer soil model in the event of a direct lightning strike on the wind turbine generator. The influence of soil resistivity and lightning current wave shapes on the wind turbine grounding impedance are analysed. The results show that the wind turbine earthing system is more vulnerable to high frequency components of the lightning strikes. The other findings highlight the impact of soil resistivity values and frequencies over the impedance and potential distribution of the wind turbine generator earthing system.