When lightning strikes a transmission tower or overhead line, the lightning current generates a spherically expanding electromagnetic field. The propagation mode of an expanding electromagnetic wave is different from that of a transverse electromagnetic (TEM) wave, which is applied to the modeling of transmission lines. This paper presents an equivalent circuit model of an overhead transmission line that considers the TEM-mode formation delay. The TEM-mode formation delay is approximately represented by the first-order delay functions in surge impedances and time delays in the mutual coupling from one line to the others. The proposed circuit model of the overhead line is introduced to the Alternative Transients Program version of Electromagnetic Transients Program using the MODELS language through a formulation in the phase domain based on Dommel's method. The results of the proposed model are validated through a comparison with the results of a three-dimensional numerical electromagnetic analysis. Furthermore, the effect of the delay of the TEM-mode formation on the voltages across the insulator strings of a lightning-struck tower is described by referencing a previous experimental study conducted using an actual 500 kV transmission tower. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

中文翻译：

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考虑TEM模式形成时延的架空输电线路电路模型

当雷电击中输电塔或架空线时，雷电流会产生球形扩展的电磁场。扩展电磁波的传播模式与横向电磁波（TEM）的传播模式不同，横向电磁波用于传输线的建模。本文提出了一种考虑TEM模式形成延迟的架空传输线的等效电路模型。TEM模式形成延迟大致由浪涌阻抗中的一阶延迟函数和从一条线到另一条线的相互耦合中的时间延迟表示。提出的架空线电路模型通过基于Dommel方法的相域公式，通过MODELS语言引入到电磁暂态程序的“替代暂态程序”版本中。通过与三维数值电磁分析的结果进行比较，验证了所提出模型的结果。此外，通过参考先前使用实际500 kV输电塔进行的实验研究，来描述TEM模式形成的延迟对电击塔的绝缘子串两端电压的影响。©2021日本电气工程师学会。由Wiley Periodicals LLC发布。通过与三维数值电磁分析的结果进行比较，验证了所提出模型的结果。此外，通过参考先前使用实际500 kV输电塔进行的实验研究，来描述TEM模式形成的延迟对跨击雷塔的绝缘子串两端电压的影响。©2021日本电气工程师学会。由Wiley Periodicals LLC发布。通过与三维数值电磁分析的结果进行比较，验证了所提出模型的结果。此外，通过参考先前使用实际500 kV输电塔进行的实验研究，来描述TEM模式形成的延迟对跨击雷塔的绝缘子串两端电压的影响。©2021日本电气工程师学会。由Wiley Periodicals LLC发布。