摘要
雷电定向定位仪测量的雷击跳闸时的雷电流幅值分布为500kV线路防雷提供了宝贵的运行经验,它表明绕击是造成500kV线路雷击跳闸的主要原因,而不是传统观念中的反击。而地面倾斜角对绕击率又有较大的影响。在研究防雷措施时要适当地修正思维方式,要特别重视防止绕击跳闸。我国现有规程推荐的雷击跳闸率计算方法存在有待改进的地方。
The distribution of lightning current amplitude, which are measured by LLS and caused the 500 kV transmission line trip, provides valuable operation experiences for 500 kV transmission line lightning protection. It proves that shield fail is the main reason to cause line trip and it is not the back strike, which is considered as the main reason from traditional point of view. However the ground incline angle has great effect on the ratio of shield fail. The thought way of lightning protection research should be modified. Protecting line from shield fail trip should be specially paied attention to. The calculation methods of lightning trip ratio recommended by current standard in China are need to be improved.
