伊穆±500kV直流输电线路雷击事故分析及防雷改造

Analysis of Yimu ± 500kV DC Transmission Line Lightning Accident and the Protection for the Lightning Flash

伊穆±500 k V直流输电线路横跨内蒙古东部地区,输电走廊占地面积大且地形复杂,2013年6月发生两起雷击跳闸事故,雷害问题较大。采用EMTP软件计算反击耐雷水平,研究其反击耐雷性能;基于改进的电气几何模型编程求解绕击跳闸率并分析绕击跳闸率与工作电压以及地面倾角的关系,研究其绕击耐雷性能。结果表明,该线路反击耐雷性能较好,两起跳闸事故均为雷电绕击所致;加装线路避雷器是降低绕击跳闸率的有效方法,在该线路故障杆塔正极性导线侧加装一组避雷器,绕击耐雷水平提高超过2倍,超过最大绕击屏蔽雷电流,绕击耐雷性能明显提高。

Yimu ±500kV DC transmission lines come through the eastern region of Inner Mongolia.The transmission corridor occupies large area and the terrain is more complex. Transmission lines are easily struck by lightning.There were two lightning accident in June 2013.In order to ensure the stable operation,the paper does some research on lightning protection. The simulation with EMTP software could calculate the counter attack lightning withstand level,which is a good model for analysis of the back flashover performance; Based on the simulation results,Yimu DC back flashover performance is better.Two lightning flash accidents are the performance of shielding failure. By the shielding failure flashover rate calculation program analyzes the shielding failure flashover rate with wire polarity,voltage and ground inclination relationship. Installation of the line arrester is an effective method of reducing the shielding failure trip. The paper recommends installing 1 arrester on positive line of the Yimu ±500kV DC transmission line.The lightning shielding level is increased more than 2 times under the arrester protection and greater than the maximum shielding failure lightning level. Lightning protection performance improved significantly.