An Experimental Validation of the Bergeron Transmission Line Model Applied to Rotor Blades During Lightning

Composite materials application in modern wind turbine rotor blades, such as carbon fiber-reinforced polymer (CFRP) and glass fiber-reinforced (GFRP) polymer composites, are dominating the blade manufacturing process. Carbon pultruded blades, which are widely implemented in blades with lengths above 50 m, can be seen as a multi-conductor cable, where the carbon spar caps and the lightning current down-conductor cable do form a multiple phase model. The aim of this research work is to adapt the Bergeron transmission line model to a carbon pultrusion blade and validate its transient response against impulse currents measured in the high voltage lab. Bergeron's transmission line modeling shows an acceptable alternative concerning transient response compared to the oscillographs obtained in the lab.