摘要
为实现对±800 k V直流输电线路雷害风险快速、准确的评估,从绕击计算模型及评估参数计算方法等方面进行研究,确定杆塔雷击最小放电路径应为导线到横担和塔身距离中的较小者;采用左/右地面倾角值多点、独立计算提高地形地貌参数精度;提出以6 km×6 km网格大小对±800 k V线路雷电参数进行分块,来获取正、负极性地闪密度值NGP、NGN,并推荐以雷电地闪2 000次为阀值拟合获得雷电流幅值累积概率分布计算式,其较单一分布公式更加精细;提出单基杆塔计算模型中"极性效应"权重系数值αN=0.91、βN=0.09,αP=0、βP=1;提出的±800k V直流输电线路雷害风险评估方法可达到全长2 058.6 km、4 240基杆塔线路的快速评估要求,评估结果表明特高压直流线路雷击跳闸率计算值和实际运行值虽均满足实际雷击跳闸率控制参考值,但仍存在雷害风险高、雷害防御能力相对薄弱区段。其中,高风险杆塔共649基,占比15.3%,此类杆塔应作为后期运维及治理的主要对象。
In order to evaluate the lightning hazard risk of±800 kV DC transmission line quicky and accurately, we study on the the shielding failure trip-out calculation model and evaluation parameter calculation methods. We ensure the min- imum discharge that the path is the smaller one of the distances between line-to-arm and line-to-tower body, use left/right ground angle values to improve parameter accuracy of landform, suggest a method that lightning parameters of ±800 kV line can be divided by 6 km×6 km grid to obtain the positive/negative ground flash density, and propose a formula of cu- mulative distribution of lightning current amplitude by 2 000 times ground flashes. We propose the polarity effect weight coefficient in the calculation model of single-base tower as αN=0.91,βN=0.09,αP=0,βP=1. And the proposed lightning hazard risk evaluation method of DC ±800 kV transmission line can completely meet the rapid assessment requirements of a line which is 2 058.6 km long and has 4 240 towers. The result shows that the lightning trip-out rate of calculated value and actual value is all meet the actual lightning trip-out rate control reference value, but it is still has high risk ex- tents. There are 649 high-risk towers of this line accounting for 15.3%.Such towers shall be concerned in the future.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2016年第12期3781-3787,共7页
High Voltage Engineering
基金
国家电网公司科技指南项目(重要输电通道雷击同跳机理与主动防护基础技术研究)~~
关键词
特高压
直流输电线路
绕击
参数提取方法
雷害风险评估
UHV
DC transmission line
shielding failure
parameter extraction method
lightning hazard risk evaluation
