Windfarms are every day increasing in number. So wind turbines are an easy aim for cloud-to-ground lightning for two main reasons: high isokeraunic level over windfarm locations and the height and sharp of the wind turbine structure and blades. Then the turbine should facility current flowing through its main parts: blades, rotor brushes and tower without dangerous overvoltages. Grounding should be design to derive current efficiently, but in many situations grounding is conditioned to particular location aspects such as: extension and soil resistivity. Both aspects are strongly related with grounding performance. This paper presents an analysis of a wind turbine overvoltages. It is modelled as a transmission line with different grounding models: a constant resistance, a nonlinear model based on soil ionisation, and a windfarm interconnected grounding model. Besides not only first lightning return strokes current are considered if not, subsequent return stroke current is included too.

Lightning current parameters derived from Lightning Location Systems (LLS) have been used in the past to assess their influence in the local performance of the Network. The paper presents an analysis of the statistical parameters for negative peak current strokes and flashes in different areas of Catalonia (32 000 km2) for two different LLS operating in this area.Peer ReviewedPostprint (published version

Wind turbines emit lightning flashes upwards,\ud producing these electrical discharges at regular\ud intervals relative to the turbine’s rotation, and\ud can do so tens of kilometres away from an active\ud thunderstorm area.Peer ReviewedPostprint (published version