雷击是高压及超高压输电线路的主要事故之一，反击跳闸发生的概率很低，绕击是发生故障跳闸的主要原因。可以在地线上架设水平侧向短针的分布式绕击防治措施以有效提高地线引雷能力，防止绕击跳闸。以西昌220 kV输电线路N148号杆塔为例，分析并比较了杆塔附近地线上安装防绕击侧针前后，线路绕击率、绕击跳闸率以及绕击雷电流幅值的变化情况。通过实例计算发现，防绕击侧针安装以后明显改善了线路的防绕击能力，可见安装防绕击侧针作为输电线路的防雷改造措施，具有较好的实用性。%Lightning stroke is one of the major accidents in HV and EHV transmission lines .The trip-out accidents are main-ly caused by shielding failure and rarely caused by back flashover .In order to prevent the trip-out by shielding failure , the lightning rod against shielding failure can be installed on the lightning conductor that can improve the triggered lightning capac -ity of the ground wires .Taking N148 tower in 220 kV transmission line of Xichang for example , the differences of shielding failure rate, shielding failure trip-out rate and shielding failure lightning peak current of the transmission line which has in -stalled the lightning rod against shielding failure near N 148 tower are analyzed .With the help of calculation analysis , it is found that after installing the lightning rod against shielding failure , the ability against shielding failure of transmission lines has been improved obviously .Therefore, it is in high practicality to use lightning rod against shielding failure as the improve-ment measures of the protection against lighting in transmission lines .
展开▼
