OPGW雷击破坏的数值分析及结构优化

OPGW因雷击而断股,不仅会影响到输电线路的安全运行,而且会威胁到电力系统通信和继电保护的可靠性。因此,对OPGW雷击断股的分析和研究就显得尤为重要。笔者采用有限单元法(FEM)分析OPGW遭雷击时的高温情况。首先在对OPGW遭雷击时的能量转换和传递过程分析的基础上建立了温度场的数学模型,并进一步阐述了使用有限单元法对该温度场进行数值求解的空间域和时间域离散过程。分析了雷电电弧弧根的能量功率函数及其影响因素,以此作为OPGW分析温度场的外热源。雷击点的热流分布采用高斯热源模型,计算过程考虑了材料热物性参数的温度相关性、相变潜热以及综合表面散热系数等影响因素。最后对现有OPGW的结构进行了优化,分析结果表明,优化后结构的抗雷击性能明显提升。该数值分析方法克服了传统的理论分析和模拟试验在数据定量研究方面的不足,进而可以为OPGW的优化设计提供参考。

Numerical Analysis of OPGW Damage by Lightning and Structural Optimization

The finite element method(FEM)is employed to analyze the temperature field of OPGW struck by lightning.Based on the analysis of the energy conversion and transfer process of lightning strike on OPGW,a mathematical model of the temperature field of lightning strike on OPGW is constructed,and the discretization in time domain and space domain with FEM are discussed.Then lightning arc root energy,which is taken as the external heat source of OPGW,and the influencing factors of the energy are investigated.Gaussian heat source is adopted as lightning heat source,and such factors as material's thermo-physical parameters,phase change latent heat,and integrated surface heat transmission coefficient.Finally,the existing structure of OPGW is optimized,and the results show that its anti-lightning performance has enhanced significantly.This method can overcome the deficiency of conventional theoretical analysis and simulation test in quantitative research,and benefit optimization design of OPGW.