减小地线保护角对改善线路防雷性能的效果  

Effects of Reducing Shielding Angle on Improving Lightning Performance of Transmission Lines

作　　者：王志勇[1,2] 余占清[1] 李雨[1] 梁曦东[1] 

机构地区：[1]清华大学电机工程与应用电子技术系电力系统及发电设备控制和仿真国家重点实验室,北京100084 [2]南方电网公司广州供电局,广州510620

出　　处：《高电压技术》2011年第3期622-628,共7页High Voltage Engineering

摘　　要：雷电绕击是影响高压输电线路安全稳定运行的关键因素之一,减少地线保护角是降低绕击跳闸率的重要手段。为此,介绍了基于先导发展模型的超高压线路雷电绕击跳闸率分析方法,利用该方法对不同地形条件下各种塔型减小保护角对改善线路防雷性能的效果进行计算和对比,提出减小保护角的改造方案,对杆塔的力学性能进行校核,评估了减小保护角的经济费用,对比了减小保护角与其他防雷措施的技术经济性。研究表明,绕击跳闸率与塔型和地形关系密切,一般来说同一塔型保护角越小绕击跳闸率也越小,但不同塔型相同保护角跳闸率差异可能很大;减小保护角对改善线路防雷性能的效果受地形影响明显;对比不同防雷措施的效果和成本可见,将地线水平宽度增加对改善跳闸率的综合效果较好。Lightning shielding failure is a key problem affecting operation safety of transmission lines,and reducing shielding angles is an important measure to restrain shielding failure rate.The shielding failure rate analyzing method for very high voltage transmission lines based on the leader progress model was introduced.By this method,effects of reducing shielding angles on different types of towers in various terrains were calculated and compared.An improved scheme of reducing shielding angles was proposed,and mechanical properties of the tower were analyzed.The cost of reducing shielding angle was evaluated,and its technical economy was compared to other lightning protection measures.Results show that shielding failure rate is closely related with tower types and terrains.In general,for the same tower,the shielding failure rate decreases with the decreasing of shielding angle,while for different towers,the shielding failure rates under the same shielding angle can be quite different.Effects of reducing shielding angle depend on the terrains.By comparing effects and costs of different lightning protection measures,it can be seen that increasing the distance of the ground lines is the optimal choice.

关 键 词：先导发展模型 输电线路 绕击 保护角 技术经济分析 雷电防护 

分 类 号：TM863[电气工程—高电压与绝缘技术]