风偏角与杆塔结构对500 kV同杆双回线路绕击耐雷性能的影响

分析500kV双回输电线路的绕击耐雷性能，对EGM进行了改进。在计算过程中为考虑风的影响，引入风偏角；同时引入了雷击避雷线与雷击地面击穿强度比值随杆塔高度h变化的系数β。用暴露弧法计算每根导线绕击跳闸率，以暴露弧为0时对应的雷电流作为雷电的最大绕击电流，并分析了风偏角、杆塔结构等因素对500kV双回输电线路各导线绕击跳闸率的影响。结果表明，风偏角增大，绕击跳闸率增大；总绕击跳闸率随避雷线横担增长而减小；各导线绕击跳闸率与杆塔结构间的关系复杂，需具体计算分析。理论分析和计算验证了该方法的实用性和有效性，具有一定的工程指导意义。

The Effects of Wind Deviation Angle and Tower Structure on the Lightning Protection Performance of Shielding Failure for 500kV Double-circuit Transmission Line

For analyzing the lightning protection performance of shielding failure for 500kV double-circuit transmission line, the EGM is improved by using wind deviation angle to consider the effect of wind in the course of calculation. At the same time, a coefficient β, which varies with tower height h and is the ratio of two electric intensities when lightning strike on transmission line and on ground, is introduced in this paper. The uncovered-arc-method is adopted to calculate every line＇ s rate of shielding failure. It takes the current of lightning when the length of uncovered arc is zero as the largest thunder current of shielding failure. The effects caused by wind deviation angle, transmission tower structure, etc. On the rate of 500kV double-circuit structure is complicated, so it is needed to calculate and analyze concretely. Theory analysis and calculation verify that this method is practical and efficient and has engineering instruction meanings to some degree.