Jean-Philippe Parmantier

Susceptibility analysis of wiring in a complex system combining a 3-D solver and a transmission-line network simulation

This paper deals with the application of electromagnetic field-to-transmission-line coupling models for large cable systems analysis. It emphasizes the use of Agrawals (1980) model applied here in a numerical simulation of an electromagnetic susceptibility problem up to 500 MHz. Based on the concepts of EM topology, the proposed methodology consists in calculating the incident fields with a three-dimensional (3-D) computer code and the coupling on cables with a multiconductor transmission-line network computer code. In order to validate the efficiency of this methodology in an industrial context, an experiment has been performed on a prototype wiring installed in a Renault Laguna car, stressed by an EM plane wave. Numerous validation configurations have been carried out. First, the prototype cable network under study has been tested on a ground plane to validate the coupling model but also, to validate the cable-network topology itself. Second, EM fields have been measured onto the structure and inside the structure. Then, they have been compared to 3-D calculations, performed with an FDTD code. Third, comparisons between measurements and calculations of bulk currents and voltages on 50 /spl Omega/ loads on the wiring have been achieved.

Numerical coupling models for complex systems and results

The paper gives a status of present electromagnetic (EM) coupling modeling capabilities. Starting from topologically designed systems, it shows how formal rules of the EM topology approach can provide guidance for EM coupling analysis or the development of protection against intentional electromagnetic interference (EMI)- related threats, even in the case of a poorly shielded system. After a review of currently available mature numerical techniques, a strategy allowing one to chain different numerical tools (including three-dimensional analysis tools, cable-networks tools, and circuit analysis procedures) is proposed in order to achieve EM coupling assessments on real complex systems. The paper also gives a status on several scientific trends likely to enhance modeling capabilities in the future.

A Network Formulation of the Power Balance Method for High-Frequency Coupling

This paper deals with a network formulation of the power balance approach in order to estimate high frequency coupling mechanisms in complex systems. After giving the general principles of this approach found in the scientific literature, the network development of the method is presented, based on an electromagnetic topology analysis. Finally, the network formulation of this approach is applied on a simple two contiguous cylindrical structure by easily adapting a computer code initially dedicated to electromagnetic topology on cable networks.

Application of a hybrid finite difference/finite volume method to solve an automotive EMC problem

In this paper, we present a hybrid finite difference/finite volume method and we apply it to solve an automotive electromagnetic compatibility (EMC) problem. The principles of the hybrid method and the numerical schemes are described. Simple examples are used to compare this method with the finite difference and finite volume methods alone in terms of accuracy and computing speed. The automotive EMC problem and its modeling are then presented. Finally, sample comparisons between measurements and calculations of both electric fields and S-parameters between an antenna and cables are given.

Multiconductor Reduction Technique for Modeling Common-Mode Currents on Cable Bundles at High Frequency for Automotive Applications

This paper presents the fundamentals of the so-called ldquoEquivalent Cable Bundle Methodrdquo for the calculation over a large frequency range of common-mode currents induced on cable bundles by an electromagnetic (EM) perturbation. In particular, the method aims at overcoming the limitation of the multiconductor transmission line theory (MTLN), which is based on the propagation of the quasi-transverse EM (TEM) mode and efficiently used only at ldquolow frequencies.rdquo The purpose of the method described here is to reduce the computation time by reducing the complexity of the cable bundle models. After a short presentation of the ldquohigh frequencyrdquo coupling problem, first, the theoretical basis of the method, and, second, the numerical and experimental validations performed on prototypal cable bundles, in order to illustrate the efficiency and the advantages of the method, are presented. The method described in this paper is considered as a required first step in order to prepare wider applications on real systems in the near future.

Extension of the “Equivalent Cable Bundle Method” for Modeling Electromagnetic Emissions of Complex Cable Bundles

This paper presents an extension of the so-called ldquoequivalent cable bundle methodrdquo for the computation over a large frequency range of the electromagnetic radiation of complex cable bundles. The purpose of the method is to reduce the complexity of the problem by grouping together the conductors according to their terminal load configuration and their excitation to reduce the required computation time for the complete cable bundle modeling. As far as the use of the method on emission problems is concerned, a new five-step procedure is established to define the electrical and geometrical characteristics of the reduced cable bundles. After the description of the adjustments required for the application of the method to emitting cases, some numerical and experimental validations performed on simple cable bundles illustrate the efficiency and the advantages of the method. The research described in this paper is considered as a new step in the study of the modeling of complex cable bundles at ldquohigh frequenciesrdquo.

Field-to-Wire Coupling in an Electrically Large Cavity: A Semianalytic Solution

This paper proposes a semianalytic solution to the problem of high frequency coupling on a wire running in electrically large enclosures. This model is basically derived from the transmission-line (TL) theory in which the electromagnetic (EM) environment, represented as a random plane-wave spectrum, is characterized by its statistical parameters. The results are compared to those obtained by randomly generating elementary plane-wave samples and numerically calculating their EM coupling through a TL model.

Evaluation of the Modeling of an EM Illumination on an Aircraft Cable Harness

This paper describes the approach developed in order to model the electromagnetic response of a cable bundle, part of the electrical wiring interconnection system of a real aircraft, submitted to an external electromagnetic excitation. The aim of this study is to highlight the main challenges in the synthetic modeling and validation of a fully real setup, from the electromagnetic compatibility point of view. Both conducted and radiated excitations have been considered in the electromagnetic global model. The solution is obtained through a cooperative simulation approach involving one 3-D full-wave solver and a multiconductor transmission line solver. The results are compared with measurements and specific tools, such as feature selective validation and integrated error against log frequency, are used to assess the adequacy of the results.

The 'Equivalent Cable Bundle Method': an Efficient Multiconductor Reduction Technique to Model Industrial Cable Networks

In automotive electromagnetic (EM) compatibility (EMC), the cable bundle network study is of great importance. Indeed, a cable network links all the electronic equipment interfaces included the critical ones and consequently can be assimilated both to a reception antenna and to an emission antenna at the same time. On the one end, as far as immunity problem is concerned, where an EM perturbation illuminates the car, the cable network acts as a receiving antenna able to induce and propagate interference currents until the electronic equipment interfaces and potentially induce dysfunction or in the worst case destruction of the equipment. At low frequency, the interference signal propagating on the cable network is generally considered as more significant than the direct coupling between the incident field and the equipment. On the other end, as far as emission problem is concerned, the EM field emitted by the cable network may disturb itself the electronic equipments by direct coupling. To avoid these problems, automotive manufacturers have to perform normative tests before selling vehicles. These tests are applied on electronic equipments outside and inside the car first to verify that the equipments are not disturbed by an EM perturbation of given magnitude and second to ensure that the EM emission of each equipment does not exceed a limit value at a given distance. Obviously, these tests are not exhaustive and fully representative of real conditions. For example, in immunity tests, two polarizations (vertical and horizontal polarizations) of the EM perturbation are generally tested in free space conditions. In reality, the EM perturbation due for example to a mobile phone outside the car could happen from any direction of space and be reflected by all the scattering objects located in the close environment of the vehicle (ground, other vehicles, buildings,...). Consequently, the contribution of EM modelling is a great tool for automotive manufacturers in order to proceed to numerical normative, additional and also parametric tests at early stages of the car development on numerical models and for a reasonable cost. Moreover, numerical modelling will reduce the number of prototypes built during the

Lightning-Induced Current Simulation Using RL Equivalent Circuit: Application to an Aircraft Subsystem Design

Full-wave EM simulation techniques such as finite-difference time domain (FDTD) are generally used for the calculation of lightning-induced current redistribution on complex 3-D geometries. For slow lightning waveforms, such techniques are not compatible with sensitivity analysis due to heavy preprocessing and calculation constraints. As an alternative, this paper presents an equivalent electric circuit method in which the 3-D geometry is described by conductive segments only on which resistance, self-inductance, and mutual inductance are calculated with analytical formulas. Here, this method, once known as “stick model” method, has been applied for the calculation of the lightning-induced currents on an A320 aircraft landing gear. The results have been compared with an FDTD simulation and with laboratory measurements. They demonstrate that the overall simulation cost is extremely reduced compared to FDTD while they maintain the same degree of accuracy. This paper shows how this equivalent circuit method is appropriate for design processes in which parametric calculations performed in a reasonable time are required.