Influence of GFRP Barrier Thickness on the Positive Streamer Propagation in an Air-GFRP Gap

The puncture damage of GFRP wind turbine blades poses a serious threat to the safe and steady operation of large-capacity wind turbines and the reliability of wind power supply. A coupling numerical simulation model was used to investigate the influence of GFRP thickness on the positive streamer pattern and electrical breakdown of GFRP laminate in an air-GFRP gap. The evolutions of the electron number density, electric field, and surface charge densities during streamer propagation are obtained. It is found that a thicker GFRP laminate leads to a longer upper surface streamer with a higher propagation velocity, an expanded secondary streamer region and an increased number of multiple secondary streamer branches, which are consistent with experimental results. The decrease of GFRP thickness leads to a higher electric field on the GFRP laminate, which explains that the breakdown of GFRP blade under lightning strikes mostly occurs at the blade tip.