±400 kV青藏直流线路防雷特性研究

Study on Lightning Protection Characteristics of ±400 k V Qinghai-Tibet DC Transmission Lines

随着特高压直流输电项目的大量建设,直流输电线路的安全稳定运行越来越受到人们的重视,而雷电防护是直流线路安全稳定运行的重要环节。青藏直流线路全线海拔高度在3 000 m以上,恶劣的气候和地形条件都为防雷工作带来了巨大的挑战。文中对±400 k V青藏直流线路的雷电参数、防雷措施等进行了调研,对该线路上典型杆塔的反击和绕击特性进行了计算分析,在目前的绝缘配置情况下,全线的雷击闪络率为0.170 7次/(100 km·a)。文中根据计算的结果,从减小保护角、加强绝缘、降低接地电阻等方面对高海拔地区直流线路防雷提出了针对性的建议,以期为线路的防雷建设提供参考。

Along with the construction of UHV DC transmission project,the safety and stable operation of DC trans-mission line has got more attention. The lightning protection is an important part of the stable operation of the DCtransmission lines. The Qinghai-Tibet DC transmission line is located on the plateau whose altitude is over 3 000 m.Terrible weather and geography conditions have brought great challenges to the lightning protection of the transmis-sion line. The paper has carried on the investigation to 400 k V Qinghai-Tibet DC lines,such as lightning parametersand lightning protection. On the basis of this,the characteristics of some typical towers are analyzed. The lightningflashover rate is about 0.170 7 for 100 km per year. Some corresponding suggestions are put forward to give a refer-ence for the construction of lightning protection like reducing the protecting horn,increasing insulation and decreas-ing the grounding resistor.