高速铁路牵引网雷害风险评估方法

Method of Lightning Hazard Risk Evaluation for Traction Electric Network of High-speed Railway

雷电灾害已成为威胁高速铁路运行安全的重要因素,建立科学、系统、规范的高铁牵引网雷电风险评估系统,合理有效地指导高铁牵引网的防雷设计、运行和改造,具有十分重要的必要性和紧迫性。为此基于风险管理的概念提出了高速铁路牵引网雷电风险评估方法,讨论了牵引网雷击损害风险源获取方法、牵引网雷击损害类型,提出了不同落点、不同雷电流雷击损害概率的计算方法和流程。提出采用雷击跳闸率作为表征雷害风险的指标,其数值等于风险源数量与雷击损害概率的乘积。通过设定风险评估等级划分标准,实现了雷害风险等级评估,并建立了全参数、全路段雷害风险量化评估流程。京沪高铁评估结果表明:2005—2013年沿线风险源特征具有明显差异性,各段地闪密度最大值约为最小值的6倍,从北往南雷电流幅值累积概率50%电流值从36.5 k A逐渐减小为22.1 k A;2005—2013年京沪高铁全线126网格段中A、B、C、D风险等级的网格段数量分别为24、38、45、19,20%网格段处在低雷害风险,15%网格段处在强雷害风险。所提出的方法可有效确定牵引网雷害风险水平和风险等级分布,发现雷害风险严重区段,为高速铁路牵引网防雷优化设计和运维检修管理提供更加科学准确的参考依据。

Lightning hazard has become an important threatening factor for the safe operation of high-speed railway. So it is of great importance and urgency to build a scientific and normative system of lightning hazard risk evaluation. Thus, it is necessary to provide an applicable guide for the designing, operating, and reconstruction of lightning performance for traction electric network of high-speed railway. For this purpose, we proposed a method of lightning hazard risk evalua- tion for traction electric network of high-speed railway based on the concept of risk management. We discussed the sources of lightning damage and the types of lightning damage for the traction electric network. Moreover, we proposed a method and flow chart to calculate the lightning damage probability for different lighting location and current, and gave the lightning hazard risk indicators which were equal to the product of the risk sources＇ number and the lightning damage probability, deriving their calculating formulas. Lastly, by setting up the partitioning criterion of risk grade, we realized the lightning hazard risk grade evaluation, and developed a quantified evaluation flow chart with many parameters and the whole railway corridor of lightning hazard risk for traction electric network. As an example, lightning hazard risk of the Beijing-Shanghai High-speed Railway was evaluated and discussed. The results show that the lightning damage sources of the different segments have obvious differences and the maximal ground flash density is 6 times of the minimum one. From the north to the south, the lightning current amplitude of the 50% lightning cumulative probability decreased from 36.5 kA to 22.1 kA. The numbers of risk grade A, B, C, D are 24, 38, 45, 19 for the 126 segments of the Beijing-Shanghai High-speed Railway in 2005--2013, and 20% of those are in lowest lightning hazard risk and 15% in highest risk. The method proposed could effectively determine the level and grade distribution of lightning hazard risk for the traction elec- tric network, and find the sections with high risk grade. The results can provide more scientific and accurate reference for the optimal design, operation and maintenance of lightning performance for the traction electric network of high-speed railway.