Effect of Inductive Grounding Impedance on Lightning Transients in Wind Farm

Electric facilities operating inside wind turbine towers are damaged due to direct-and indirect-lightning, and such accidents sometimes stop operations of plants for a long time. Lightning current distributions and potential rises inside a wind farm are investigated by means of numerical analysis in this paper. The plant is expressed by equivalent circuit models of towers, grounding foundations, and interconnecting cables. Effects of each component, especially the inductive characteristics of the tower grounding, on the lightning current distributions and potential rises are discussed based on the simulated results by Electromagnetic Transients Program (EMTP). The effect of the inductive characteristic of the tower grounding on the potential rise at the lightning struck tower is large, although it is relatively small on the current distribution inside the plant.