计及风速影响的500kV同杆双回线路绕击耐雷性能计算模型研究

目前雷击仍然是危及输电线路安全可靠运行的主要原因，而现有评估输电线路绕击跳闸率的模型还不能与线路实际运行经验一致，该文在分析500kV同杆双回输电线路绕击耐雷性能时，以三峡电站的出线为例，充分考虑了风速的影响，对击距模型进行了改进，同时还较详细分析了地面倾角、杆塔高度等对绕击跳闸率的影响。通过编程仿真计算结果表明，随着风速的增加，输电线路保护角和绕击跳闸率都将增加，建议今后在评估输电线路绕击耐雷性能时，对风速影响因素应加以考虑。

STUDY ON THE CALCULATION MODEL OF LIGHTNING PROTECTION PERFORMANCE OF SHIELDING FAILURE FOR 500kV DOUBLE CIRCUIT TRANSMISSION LINE

Lightning is the main reason that endangers the safety and reliability of transmission line today, but the existing models of estimating shielding failure outage rates can not be in agreement with field experience at present. Electrogeomatric model (EGM) is improved to predict the lightning outage rates of 500kV double circuit transmission line based on the outline of Three Gorges Substation in which the influence of wind speed is taken into account this paper, furthermore, the influence of ground obliquity and the height of tower on the shielding failure outage rates is analyzed in detail. The simulation calculating results by program show that the shielding angle and the shielding failure outage rates will increase with the wind speed and suggest that the factor of wind speed should be considered when the lightning protection performance of transmission line is estimated.