密集输电通道雷击风险多参量融合预警方法研究

In recent years, China's power grid has formed a number of transmission corridors with high transmission load and compact layouts. In comparison with traditional transmission lines, compact transmission corridor have complex lightning shielding characteristics and lightning triggering ability, and lightning faults in corridors are different, especially, one single lightning flash may cause simultaneous or successive trip-out happened in multi-circuit transmission line can lead to critical power grid accident. In this project, lightning detecting network was used to detect massive lightning data in a long time, then by researching on lightning shielding characteristic and ability of triggered lightning, an identification method of risk source of lightning simultaneous trip-out in corridor was proposed, still, multiple dimensions, non-linear calculation of length of exposure arc projection in complex transmission line of compact transmission corridor. By building calculation models of lightning trip-out risk, distribution features of risk of lightning simultaneous trip-out were acquired. By optimizing wide-area and multiple-parameter lightning detection analysis platform, the relationship between each parameter and every phase of the development of lightning(generation-development-diminish) was established, then multiple-parameter models which show the dynamic characteristic of lightning in compact transmission corridor. Combining the model with lightning risk real-time evaluation, lightning risk warning method in compact transmission corridor was proposed, and the verification and correction were carried out.

近年来，我国电网形成了一些输送容量大、线路排列紧密的密集输电通道。与传统线路相比，密集通道雷电屏蔽特性和引雷能力复杂，在雷击故障特征及分布上存在较大差异，特别是一次雷暴活动可能造成通道中多回线路同跳或相继故障，从而导致严重的电网事故。现有防雷技术研究无法完全适用于密集输电通道，且缺乏针对雷击故障的主动预警防控方法。本项目利用电网雷电监测网长期海量监测数据，研究通道雷电屏蔽特性和引雷能力，提出通道雷击同跳风险源辨识方法，研究密集通道复杂空间结构线路暴露弧投影距离多维度非线性计算方法，建立通道雷击跳闸风险计算模型，获得雷击同跳风险等级分布特征；通过优化广域多参量雷电监测同步分析实验平台，建立各参量与雷暴过程产生-发展-消亡各阶段相互对应关系及定量函数，提出适用于密集通道的雷暴全过程动态特征多参量融合模型；基于该模型并结合通道雷击风险实时评估，提出密集通道雷击风险预警方法，并进行验证与修正。

我国电网密集输电通道每年雷击跳闸百余次，占比高达50%。随着电网日益复杂，现有依靠事中监测和事后治理的雷击故障应对技术，在面临短时突发、持续大面积雷暴时，无法避免密集输电通道因雷击引发电网重大事故的风险，近年来也已发生多起密集通道雷击导致的大型能源基地切机、电力输送中断等事件。电网亟需通道级雷害风险评估及雷击风险预警技术，以在雷暴来临和经过前主动采取措施规避关键断面负荷损失和社会影响。针对国内外尚无成熟可用技术，项目重点攻克了以下4个难题：.（1）采用数据挖掘方法获取密集通道不同线路组合下雷电特征参数(雷击位置、次数、间隔、强度等)分布规律，采用时空间隔平移搜索法研究可引起通道多条线路雷击同跳的风险源辨识方法，确定通道雷击同跳风险源量化特征。.（2）提出了密集通道复杂空间结构线路暴露弧投影距离的多维度呈现方法，定量获取不同线路导地线、通道间距、绝缘水平配置下暴露弧的非线性关系，建立考虑雷电屏蔽影响后雷害风险评估模型，通道风险评估准确度提升50%。.（3）构建了由雷电磁场探测装置、关联气象参数以及大数据采集组成的雷电多源资料同步分析平台，提取了大气电场、雷达回波等资料特征和雷电预警阈值，实现了融合多源雷电数据“时-空”协同的线路通道区域全过程雷电发展趋势预测。.（4）建立了雷电时间、空间、强度动态过程与线路拓扑结构、运行特性、绝缘性能相耦合的输电线路雷击灾害风险预警模型，结合特高压历史跳闸数据进行预警效果评价和模型修正，预警精度从千米级提升至百米级，准确率达85%。.通过本项目研究，揭示了密集输电通道雷击同跳风险源产生过程及发展机理，构建了通道复杂拓扑结构组成下的雷害风险量化评估模型，创新性提出了基于雷电多源观测资料融合处理与协同分析的输电通道雷电活动趋势预警，实现了考虑密集通道引雷特性、雷击同跳规律的雷击灾害风险预警。项目研究成果开拓了密集通道关键断面雷害主动性防御理念，推进了电网防灾减灾技术水平。