One of the challenges of electromagnetic modeling on systems (aircraft, wind turbines, etc.) is understanding the induced transients on individual pins. It is reasonably straightforward to model the currents that are induced on overall cable bundles. However, it is the current and voltage on individual conductors that often matters to system designers.
The geometry is not very simple. There can be branches of cables, multiple shield levels, and multiple conductors in a bundle that can complicate this effort. We have put a great deal of work into creating a customized transmission line solver that can handle these complications (MHARNESS). This approach works very well for EMI, HIRF, and EW. However, for lightning coupling, the traditional transmission line modeling approach is not accurate in all cases.
In order to remedy this deficiency, we developed a low-frequency mode for our transmission line solver, MHARNESS. We have carefully validated the approach on actual cable levels injected with lightning-like pulses in our lab. The details of the simulation and experimental validation are presented in the document below.