Analysis and Prevention Measures of the 220 kV Step-Up Transformer
Lightning Accident in a Wind Power Plant
SONG Jia-jun, LIU Shou-bao, TONG Li, WEI Chang-wei
（Datang Hydropower Science & Technology Research Institute Co., Ltd, Nanning 530007, China）
Abstract: Locations of wind farms mostly are open and in the windward mountains where the climate and the terrain conditions are complex,and the operation of equipment is inevitably affected by the thunderstorm. This paper studied a step-up transformer lightning accident in a wind power plant. It detected the short-circuit between the transformer low-voltage coil caused by lightning which is the vital cause of the primary transformer failure after data analysis and disassembly inspection. The ATP-EMTP software helped establish the electricity line lightning electromagnetic transient analysis model. The boosting voltage became the overvoltage under the tower lightning strike had been analyzed by using that model. In addition, it indicated the existing lightning protection measures could not prevent and control the three-phase invasion wave problem caused by large amplitude lightning current. This research proposed the idea that adding a group of lightning arresters with the main transformer 35 kV casing and building the transformer trapezoidal equivalent circuit analysis model. The simulation test verified the effectiveness of lightning protection measures.It provides technical references for lightning protection in wind power plants with multiple thunder and lightning weather condition.
