Study on the insulation damage characteristics of wind turbine transformers caused by lightning overvoltage based on electrical geometry mod

With the development of the trend of large-scale wind turbines, the transformer-mounted solution has gradually become popular. However, insulation breakdown and fire accidents caused by lightning overvoltage of the mounted transformers are frequent, causing serious losses to power companies. Based on the leading development theory and the electrical geometry model method, this paper proposes an electrical geometry model of the wind turbine and establishes an analysis method. The research content includes the calculation of the lightning resistance level of the transformer in the cabin environment, the analysis of the lightning-affected area of different parts of the wind turbine, and the calculation of the insulation damage rate caused by lightning currents higher than the lightning resistance level. Finally, combined with the actual wind turbine verification calculation, a lightning insulation damage rate evaluation method for wind turbine mounted transformers based on the electrical geometry model is proposed, which provides a theoretical basis for wind turbine scheme design and transformer lightning performance improvement.