±400kV青藏直流线路鸟粪闪络故障分析及治理

Fault Analysis and Treatment of Bird Dropping Flashover on ±400kV Qinghai-Tibet DC Transmission Line

青藏±400 kV柴拉直流输电线路自2011年11月投运后,截至2017年9月,共发生了115次对地短路故障。首先分析上述故障原因和特点并在西藏高海拔试验基地开展了模拟鸟粪闪络试验研究,在此基础上提出了相应的治理措施。研究结果表明:青藏线大部分短路故障是由鸟粪闪络所引起,涉鸟故障的主要鸟种有大鵟、高山兀鹫、秃鹫、金雕等猛禽类鸟类。故障多发生在海拔4500~5000m地区,春季和冬季的鸟粪闪络故障相对高发,故障时段主要集中在21:00—次日凌晨8:00之间,耐张杆塔的故障数高于直线杆塔,正极性的故障数略高于负极性。结合前期治理经验和模拟鸟粪试验,提出了综合性的治理措施:在横担3.5m防护半径内规范布置防鸟刺和针板,适当增加垂直方向上间隙距离。青藏线经上述措施治理后,大幅降低了线路鸟粪闪络故障率。

Since Qinghai-Tibet Chaila±400 kV DC transmission line was put into operation in November 2011,until September 2017,115 short-circuit faults occurred.Firstly,fault causes and characteristics were analyzed in this paper,and simulation experimental study of bird dropping flashover was carried out in Tibet’s high altitude test base.Based on this,treatment measures were put forward.Research shows that most of the short-circuit faults are caused by bird dropping flashover,and the main related bird species are raptors,such as big buzzard,mountain vulture,vulture,golden eagle,etc.Most bird dropping flashover faults occur in areas of altitude 4500 m^5000 m.The faults are relatively frequent in spring and winter,and the fault period is mainly between 21:00 p.m.and 8:00 a.m.of the next day.The number of faults on tension tower is higher than that on suspension tower,and the faults on positive polarity line is slightly higher than that on negative line.Based on previous experience and bird dropping flashover experiment,following comprehensive treatment measures are proposed.Bird prevention thorn and needle board should be regularly arranged within 3.5 m radius on the cross arm,and the gap distance in vertical direction should be appropriately increased.After Qinghai-Tibet line is treated with above measures,the bird dropping flashover failure rate is greatly reduced.