Investigating the energy handling capability of low voltage surge arresters in a wind farm under direct lightning strikes on wind turbine blades

Surge arresters provide effective protection against transient overvoltage in wind turbine networks, especially in wind farms located in areas with high lightning activity and high soil resistivity. The burnt out of arresters are prevalent in such areas, which are caused by backflow current during direct lightning strikes on wind turbines. The survival of surge arresters during lightning strikes on wind turbines is dependent on their energy handling capabilities. The energy handling capability of low voltage surge arresters in wind farms has not been fully established, hitherto. This paper investigates the energy handling capability of low voltage surge arresters in a wind farm, modeled as a test system under various lightning strikes, and compares manufacturer´s datasheet with simulated results from the test wind farm. The study employed the electromagnetic Transient Program-Alternative Transient Program EMTP-ATP to model a section of an existing wind farm that has been exposed to various lightning wave shapes. The results show that the longer the lightning wave-tail, the greater is the energy being absorbed by the arresters.