山区220 kV新型错层横担直线塔防雷性能研究

针对山区地形坡度影响输电线路杆塔防雷性能的问题,为降低山区输电线路的雷击跳闸率,设计了一种220 kV新型错层横担直线塔。分析了错层横担直线塔在不同坡度条件下的防雷性能,确定了错层横担杆塔在山区地形的可行性,建立了新型错层结构杆塔的多波阻抗模型及其接地体等效电路模型。基于PSCAD软件搭建了错层横担杆塔的整体模型,仿真计算出了杆塔的反击跳闸率;建立了适用于新型错层杆塔求解绕击跳闸率的电气几何模型,并推导了求解的计算公式;分析比较了错层横担杆塔在几种坡度条件下的雷击跳闸率的数据结果。通过常规杆塔和错层杆塔的雷击跳闸率对比发现,错层横担结构有效地提高了杆塔的耐雷水平。研究结论可为山区错层横担杆塔输电线路防雷设计、防雷改造以及线路运行和维护提供参考。

Research on Lightning Performance of 220 kV Split-Level Cross Arm Tower in Mountainous Area

Aiming at the problem in mountainous terrain slope affect lightning protection performance of a tower, a new type of 220 kV split-level cross arm tower is designed to reduce the lighting trip-out rate of mountain transmission lines. Lightning protection performance of split-level cross arm tower under different slope conditions are analyzed to determine the feasibility of split-level cross arm tower in mountainous area. Multi-wave impedance model of the tower and equivalent circuit model of grounding electrode are established; the complete model for the tower is built based on PSCAD, and the rate of lightning back striking is calculated; modified electrical geometry model is established for solving the shielding failure rate of the new tower, and the calculation formulation is derived based on the geometric model; lightning trip-out rate of split-level cross arm tower under several slope conditions are analyzed and compared. Compared with the conventional tower, the new type split-level cross arm tower can improve the lightning withstand level of the tower effectively. Research results can provide references and basis to lightning protection in the design period and the reconstruction of transmission line in mountainous area.