Investigation of damage to wind turbine blades caused by atmospheric discharges in Croatia

Abstract:
The paper shows damages of wind turbine blades despite the implemented lightning protection system and overvoltage protection. The classification of the blade damage in accordance with the norm and examples of actual damage of the wind turbine blades are presented. The recorded damage of the wind turbine blades at individual wind power plants in Croatia, which occur because of lightning strike to the wind turbine blade, is presented in detail. The strategy of inspection and maintenance of the wind turbine blades and their changes over time is explained. Systems for measuring lightning currents are briefly explained, and examples of recorded values of lightning stroke parameters in the wind turbine with the measuring system installed at the Voštane wind power plant in Croatia are presented. The waveform of the lightning current that strikes the wind turbine is also shown.