Análise dos efeitos de sobretensão causados por descargas atmosféricas em aerogeradores

Abstract

This work presents a theoretical approach about the effects of overvoltage caused by lightning strikes in wind turbines, focusing in the presentation of the main variables and methods involved for the protection of the wind turbines, to ensure the safety and the reliability of the system and its users. The discussion about the frequency of lightning strikes and the level of protection against it, agrees with the IEC 61400 standard. The physical concepts of lightning strikes are approached, the disturbance caused by them, the statistical data related to the damages, whether by direct or indirect impact, describing as well the protection system recommended by the literature. The study analyzed the influence of the voltage transient in a wind turbine system impacted by lightning strikes, using the digital simulation software ATPDraw. It was noted the importance of the correct dimensioning of the ground resistance of the installation to make this renewable energy more and more safe and reliable.