Modelling EM-Coupling on Electrical Cable-Bundles with a Frequency-Domain Field-to-Transmission Line Model Based on Total Electric Fields

Abstract

This article deals with modelling of EM-coupling on cable-bundles installed in 3D structures. It introduces a modified-Field-to-Transmission-Line model for which the specificity is to account for the reciprocal interaction between EM-fields and induced currents by considering equivalent total field sources. The first part of the paper is devoted to the derivation of this model starting from Agrawal’s classical Field-to-Transmission-Line applied on a two-wire Transmission-Line and leads to a Transmission-Line model in which the signal-wire is now referenced to a fictitious surrounding cylinder acting as a return conductor. The modified-Field-to-Transmission-Line model is then obtained by modifying this derived-model in such a way that is made compatible with numerical approaches and tools based on Agrawal’s Field-to-Transmission-Line model. This modification involves a kL coefficient equal to the ratio of the two per-unit-length inductances of the classical and derived Field-to-Transmission-Line models. Validations of this modified formulation clearly show the capability of this model to predict precise wire responses including EM-radiation losses. The second part of the paper is devoted to its extension to Multiconductor-Transmission-Line-Networks. The process relies on the capability to define an equivalent wire model of the cable-bundle in order to derive the kL coefficient and to numerically evaluate equivalent total field sources. Validation of this extrapolation is presented on a real aircraft test-case involving realistic cable-bundles in order to assess the potentiality of the method for future problems of industrial complexity.