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Kato Y.,Electromagnetic Systems Laboratory | Hasegawa H.,Cryogenic Systems Laboratory
Quarterly Report of RTRI (Railway Technical Research Institute) | Year: 2015

In Japan, regulations on low-frequency magnetic fields came into force. Initial regulations in 2011 applied to power equipment in general, but the scope of regulatory control was expanded in 2012 to cover track-side railway power equipment. Although railway vehicles are not included in the scope of the regulation at the moment, it thought that it is necessary to assess magnetic fields in railway vehicles. As such a series of studies have been launched to develop a method to measure and predict low-frequency magnetic fields in railway vehicles.


Azizi H.,University of Science and Technology Houari Boumediene | Tahar Belkacem F.,Electromagnetic Systems Laboratory | Moussaoui D.,Electromagnetic Systems Laboratory | Moulai H.,University of Science and Technology Houari Boumediene | And 2 more authors.
Journal of Electromagnetic Waves and Applications | Year: 2014

Apertures in a rectangular enclosure can be the coupling path of electromagnetic interference. This paper is devoted to the development of approximating phenomenological models in order to estimate the electromagnetic energy coupling through apertures into enclosures. The effect of apertures on shielding effectiveness (SE) of the enclosure is studied with both circuit modelling method and the finite-difference time-domain (FDTD) method. The results of SE predictions obtained by the analytical formulation and FDTD method are compared and validated with full-field simulations using the software CST/EMC. The software code is based on the finite integration technique. The investigation includes accurate calculation of both magnetic and electric shielding as a function of frequency, enclosure dimensions, apertures shapes, position within the enclosure, plane wave incidence mode and the "loaded aperture" approach. © 2014 Taylor & Francis.


Tahar Belkacem F.,Electromagnetic Systems Laboratory | Tahar Belkacem F.,Ecole Superieure dIngenieurs en Genie Electrique | Boutar A.-G.,Electromagnetic Systems Laboratory | Bensetti M.,Ecole Superieure dIngenieurs en Genie Electrique | And 2 more authors.
Proceedings - 2011 International Conference on Electromagnetics in Advanced Applications, ICEAA'11 | Year: 2011

In this paper; the problem of evaluation the shielding effectiveness of a rectangular box containing a rectangular aperture, irradiated by a plane wave is investigated. In the proposed model [1], [2] the aperture is treated as a two-wire transmission line, and the enclosure is modeled as a length of a rectangular waveguide back-ended by a short. The distribution of the electric field on the aperture is used to give a first estimate of the modal excitation of the box [1], [2]. In this work, it is our idea, to use a simple formula developed by [3] and [4] to calculate the voltage distribution on the aperture (without cavity) in order to evaluate the electric field distributed on this aperture. This approach is useful to achieve a fast evaluation of electric shielding effectiveness (SE) and magnetic shielding effectiveness (SM). The obtained results are in good agreement with the results given by other theoretical models [2], [5], also compare well with full-field simulations using the finite-difference time-domain technique (FDTD). © 2011 IEEE.


Tahar Belkacem F.,Electromagnetic Systems Laboratory | Tahar Belkacem F.,Ecole Superieure dIngenieurs en Genie Electrique | Bensetti M.,Ecole Superieure dIngenieurs en Genie Electrique | Boutar A.-G.,Electromagnetic Systems Laboratory | And 3 more authors.
IET Science, Measurement and Technology | Year: 2011

This study presents an approach which combines an analytical model developed by Robinson et al. and a model which analyses the shielding effectiveness (SE) of enclosure loss with an off-centre aperture. It is based on the analytical model of transmission lines theory and aims at predicting the SE of a metallic enclosure with apertures. The combined model is more general than other analytical methods and proposes to consider the enclosure with numerous small apertures and the incident wave with varied angles of polarisation. It is therefore far quicker to calculate the SE with the combined model which on the other hand enables the impact of design parameters to be investigated. This investigation is often difficult via numerical methods because they require high computational times and memory in order to model a problem with sufficient details. This combined model is validated by comparing the SE predictions with full-field simulations using the finite-difference time-domain technique, CST Microwave Studio simulation tools and experimental investigations of the SE in a semi-anechoic chamber. © 2011 The Institution of Engineering and Technology.


Belkacem F.T.,Electromagnetic Systems Laboratory | Bensetti M.,IRSEEM | Laour M.,Electromagnetic Systems Laboratory | Boutar A.,Electromagnetic Systems Laboratory | And 3 more authors.
2010 IEEE 9th International Conference on Cybernetic Intelligent Systems, CIS 2010 | Year: 2010

The development and investigation of approximate phenomenological models used to estimate the electromagnetic energy coupling through apertures into enclosures is presented in this paper. Some theoretical aspects of the electromagnetic field penetration into a rectangular enclosure through apertures are reviewed. It is shown that for a simple system topology analytical formulations based on a transmission line model give good predictions of the shielding effectiveness of a rectangular enclosure with apertures. Both the magnetic and electric shielding may be calculated as a function of frequency, enclosure dimensions, apertures dimensions and positions within the enclosure. This analytical approach is validated by comparing the shielding effectiveness predictions with full-field simulations using the finite-difference time-domain technique, software CST and experimental investigations of the shielding effectiveness in a semi anechoic chamber. Industrial needs in terms of EMC require that the experimental results of the shielding effectiveness are accurate for large frequency intervals. To meet this requirement, a neural network based model is used for the implementation of inverse models in order to estimate physical and geometrical parameters of enclosures. In this context an application is considered. It Concerns the evaluation of the shielding effectiveness (SE) parameter as a function of the frequency. During experimental measurements of the SE parameter we did not get enough resolution for intermediate frequencies [17]. © 2010 IEEE.

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