重庆电网输电线路防雷计算中参数的选取

为搞好重庆电网线路耐雷水平评估,针对现有规程中对地面落雷密度选取的建议和重庆地区的实际情况,提出了按照国际大电网会议推荐的公式和50个雷电日计算地面落雷密度。根据雷电定位系统在重庆地区2003~2005年所测数据统计得到了重庆地区雷电流幅值的概率分布公式;采用新的雷电参数计算了重庆电网的雷击跳闸率。通过与线路实际运行数据的比较对重庆地区雷电参数的选取提出了建议,为输电线路防雷计算中参数的选取提供了新的思路。

Parameters Selection for Lightning Protection Calculationfor Transmission Line in Chongqing Grid

Lightning parameters are the important factors in lightning protection evaluation.Considering the recommendation in the regulation and the actual condition of Chongqing municipality synthetically,the formula to calculate the ground flash density recommended by CIGRE and 50 thunderstorm days in one year was chosen for lightning protection calculation in Chongqing grid.Meanwhile,on the basis of the lightning data picked up by the Lightning Location System working from 2003 to 2005 in Chongqing,the formula to calculate the distribution probability of lightning current amplitude was obtained by computing the value of the lightning current.The breakdown rate of transmission line in Chongqing grid caused by lightning stroke also was calculated by using this new lightning parameters presented in this paper.According to the comparison of the practical data with calculating data theoretically,the selection of the lightning parameters for lightning protection calculation was presented.And this method would be a new idea in lightning parameters selection for lightning protection calculation.