Wind farm Collector Cable Network Protection against Direct Lightning Strokes

Abstract

Wind farms are often located in regions with high keraunic levels. The high rate of lightning occurrence together with the high resistance of the soil can negatively affect wind farms or individual wind turbines. Therefore, a proper protection system against direct lightning strokes is essential for wind farms. In this paper, by modeling the wind farm in EMTP software, the protection of the collector cable network of wind farms against direct lightning strokes is investigated. To do that, the metallic sheath of the Collector cable and sheath bonding are modeled in the EMTP environment, and the overvoltages on the collector cable caused by direct lightning strokes to wind turbines are calculated. Also, different topologies of wind farms are considered to determine the effect of wind turbine arrangements on lightning protection of collector cables. To this aim, the best method to protect against direct lightning strokes is selected by implementing different sheath bonding methods in collector cables. Then, various sheath grounding methods and grounding systems are examined. Finally, the proper protection scheme to protect the wind farm collector cable against direct lightning strokes is proposed owing to the wind turbine topology