Proposal of New Zoning Concept Considering Lightning Protection of Wind Turbine Blades

Abstract

Lightning protection of wind turbines has gained increased interest during the past ten years. The characteristics of a modern wind turbine exhibiting overall heights of 150m, moving blades with a tip velocity of 60-80 m/s, a wide use of insulating and conducting composite materials dictates the challenges faced by the lightning protection engineer. The present paper discusses a new method of dividing wind turbine blades in different zones, to argue for a principle of differentiating the lightning protection system. The methodology counteracts the traditional interpretation of the Electro Geometrical Model (EGM) for blades in IEC TR 61400-24 (2002) but follows the needs for new approaches given in the IEC 61400-24 (2010). The argumentation is based on experiences gathered during the past five years, consisting of laboratory testing, numerical modeling and gathering of field data. Finally the conclusions are correlated with the requirements in the new standard concerning lightning protection of wind turbines; IEC 61400-24