±400kV直流输电线路杆塔涉鸟故障风险区域研究

青藏地区大型鸟类活动频繁,直流线路穿越冻土区沿线基本无树木,鸟类筑巢所用废弃铁丝和鸟粪掉落会引起绝缘子周围间隙气隙击穿,造成经济损失。为了减少输电线路涉鸟故障,以青藏±400kV直流输电线路为背景,首先利用有限元法分析,模拟异物下落时绝缘子周围电场分布。研究表明,异物下落时,由于自身形成悬浮电位,导致了高压端-异物、低压端-异物两段空气间隙相继击穿,此时异物能够引起绝缘子附近气隙击穿的区域称为风险区域。在此基础上,结合海拔修正方法,提出了一种高海拔地区杆塔考虑涉鸟故障的风险区域划分方法。依据电场分析结果得到了异物在竖直下落、倾斜下落和从横担下垂三种状态下的涉鸟故障风险区域。研究结果可以为±400kV直流线路防鸟害工作提供指导,并为其他相似工程提供参考。

Research on bird damage risk region of ±400kV DC transmission line

Reducing bird damage is of great significant to enhance operational reliability of DC transmission line.The method to classify the bird damage risk region of tower was exposed.The typical tangent tower model was based on altitude correction of discharge voltage in high altitude area.Three-dimensional finite element model was used to calculate the potential of bird streamer and nest material.The analysis contained three stream ways of foreign objects which were in vertical direction,inclined direction and hang from cross arm of tower.Numerical results were presented for variations of length,location and angle when external objects streamer.By utilizing the criterion of the breakdown voltage of air gap in high altitude areas,risk region of tower was able to be classified.The research on bird damage risk region is expected to provide a reference for the prevention work of bird damage.