On Possible Influence of Corona Discharge on the Propagation Speed of Lightning Surges Along a Tall Grounded Object
On Possible Influence of Corona Discharge on the Propagation Speed of Lightning Surges Along a Tall Grounded Object
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DOI：
10.1109/temc.2020.2995311
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发表时间：
2021-02
影响因子：
2.1
通讯作者：
Takuro Okada;Y. Baba;T. Tran;V. Rakov
中科院分区：
文献类型：
--
作者：
Takuro Okada;Y. Baba;T. Tran;V. Rakov
在本文中，我们提出了敏感性分析，以显示在什么条件下垂直导体上的电晕可能变得显着。使用柱坐标系中的二维时域有限差分 (FDTD) 方法，并考虑物体侧面的电晕放电，模拟了完美导电地面上 600 米高的接地金属物体（塔）的雷击。高物体由半径为 0.1、1 或 5 m 的圆柱体表示（这些值代表塔顶，而不是整个塔），其中径向电晕的范围最显着。电晕放电由高物体周围径向扩展的高电导率区域表示。物体顶部的电晕半径最大（可达约 5 m），而底部没有电晕。从FDTD模拟可以看出，雷电流浪涌的波前会显着畸变，并且视在传播速度会降低。随着雷电流强度的增加，传播速度的降低变得更加显着。
In this article, we present a sensitivity analysis to show under what conditions corona on vertical conductors may become significant. A lightning strike to a 600-m-tall grounded metallic object (tower) on a perfectly conducting ground is simulated using the 2-D finite-difference time-domain (FDTD) method in the cylindrical coordinate system and taking into account corona discharge from the lateral surface of the object. The tall object is represented by a cylinder having a radius of 0.1, 1, or 5 m (these values are representative of tower top, not the entire tower), where the extent of radial corona is most significant. The corona discharge is represented by a radially expanding higher conductivity region around the tall object. The corona radius is largest (up to about 5 m) at the object top with no corona at its bottom. It follows from the FDTD simulations that the wavefront of lightning current surge can be distorted significantly and the apparent propagation speed can be reduced. The reduction in propagation speed becomes more significant as the magnitude of lightning current increases.