Abstract: By expounding the mechanism of lightning damage, establishing the lightning discharge model and evaluating the grounding grid condition of wind farm, on the basis of a comprehensive study of the grounding grid conditions of wind farms, the process of over-voltage damage caused by lightning to wind turbines and box-type substations and the equipotential connection system, an in-depth analysis is carried out on the accidents of equipment damage caused by lightning strikes in wind farms. The improvement measures, such as the improvement of grounding grid and equipotential connection, and the replacement of low-voltage side surge protector are introduced.

Key words: alpine wind power, lightning overvoltage, reconstruction of grounding network, equipotential, low pressure side surge protector