【摘要】 基于改进电气几何模型并充分考虑了雷击避雷线与大地的不同,引入击距系数。提出了利用暴露距离计算线路绕击跳闸率,以500 kV输电线路为例,采用该方法计算绕击跳闸率比规程法计算更准确。并且结合实例研究分析了输电线路避雷线保护角和导线高度、地面倾角、线路绝缘强度对绕击跳闸率的影响。结果表明绕击跳闸率与保护角、地面倾角、杆塔高度有关,随着保护角、地面倾角、杆塔高度的增加而增加,当避雷线保护角为-6.24°时,绕击闪络率从0.213 5(100 km·a)-1降到0。更多还原

【Abstract】 "The striking distance factor" is introduced based on the improved electric-geometry model and by fully considering difference of electric intensity between lightning stroke on the transmis-sion line and the ground.The " unshielded distance" is put forward to be adopted to calculate line shielding failure flashover rate.Taking 500kV transmission line as example,this method is more accu-rate compared with the regulation method.At the same time,the influence of the shielding angle,the height of tower,the grounding obliquity and the electrical stress of insulators on shielding failure flashover rate is analyzed.The results of studies show that the shielding failure tripping rate is a func-tion of the shielding angle,ground obliquity angle and the height of tower.It will increase with the in-crease of the grounding obliquity,protection angle and the height of tower.And when the shielding an-gle is-6.24 degrees,the shielding failure flashover rate reduces from 0.2135(100km·a)-1 to 0.更多还原