Transient Analysis and Prevention Measures of Lightning Strikes on Step-up Transformers in Wind Farms

Abstract

Wind farms are mainly located in open and windy mountainous areas with complex climatic and topographic conditions, and the operation of equipment is inevitably affected by thunderstorms. In this paper, an electromagnetic transient analysis model for lightning strikes on collector lines is established with the use of the ATP-EMTP software. The overvoltage situation of step-up transformers subjected to lightning strikes on towers is analysed, and it is pointed out that existing lightning protection measures cannot effectively prevent the three-phase invasion caused by large current lightning, and a lightning protection strategy of installing a set of lightning arresters in the 35 kV bushing of the main transformer is proposed. A transformer trapezoidal equivalent circuit analysis model is established, and the effectiveness of the lightning protection measures are verified through simulation calculations, providing a technical reference for lightning protection in wind farms in multi-thunderstorm areas.