One of the main issues that has to be faced when evaluating lightning-induced overvoltages on a realistic network configuration is to implement the algorithm that solves the field-to-line coupling problem into an electromagnetic simulator that is able to represent with a high level of detail all the power system components. On one hand, numerical stability conditions of the finite-difference time-domain schemes have been deeply investigated in the presence of boundary conditions known analytically; on the other hand, there is not so much literature on the situations in which such conditions are provided in a numerical way through an external electromagnetic simulator. The study reveals that the commonly used linear extrapolation of currents at the line extremities might rise to numerical instabilities. An efficient solution using the method of characteristics is presented and validated.

中文翻译：

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基于FDTD的数字代码评估架空输电线路雷电过电压的稳定性

在实际网络配置上评估雷电感应过电压时必须面临的主要问题之一是将解决场到线耦合问题的算法实施到能够以高水平表示的电磁模拟器中详细介绍所有电力系统组件。一方面，在存在解析已知边界条件的情况下，已经深入研究了有限差分时域方案的数值稳定性条件；另一方面，关于通过外部电磁模拟器以数值方式提供此类条件的情况的文献并不多。研究表明，常用的线路末端电流线性外推法可能会导致数值不稳定性。