Transient analysis on wind farm suffered from lightning

Wind power generators are often struck by lightning because of their special shape of a very high construction in open space. Although some reports, e.g., IEC TR61400-24 and NREL SR-500-31115, indicate those accidents and the problem, there seems to be room for more work to be done in this area. The authors focus on, and have investigated, surge analysis on a wind farm connected to a power system. Under the conditions of several values of earth impedance (considering inductivity as well as resistivity) around a lightning-struck wind turbine, sensitivity analysis was performed using the digital transient simulator, ARENE. The result of the analysis shows that the surge propagating from the lightning-struck wind turbine to the next turbine may become large depending on the conditions of earthing. The result suggests possibilities of serious accidents to electrical and electronic devices in wind farms due to surge propagation, as well as to direct lightning strikes.