Accurate Modelling of Frequency-Dependent Transmission Lines in Electromagnetic Transient Simulations

TLDR

Transmission‑line parameters with ground return vary strongly with frequency, and accurate modeling across the full signal spectrum is essential, yet closed‑form solutions are difficult and numerical methods suffer from instability and accuracy errors. The methods presented in this paper aim to overcome these numerical difficulties.

Abstract

The parameters of transmission lines with ground return are highly dependent on the frequency. Accurate modelling of this frequency dependence over the entire frequency range of the signals is of essential importance for the correct simulation of electromagnetic transient conditions. Closed mathematical solutions of the frequency-dependent line equations in the time domain are very difficult. Numerical approximation techniques are thus required for practical solutions. The oscillatory nature of the problem, however, makes ordinary numerical techniques very susceptible to instability and to accuracy errors. The, methods presented in this paper are aimed to overcome these numerical difficulties.