Chassis Influence on the Exposure Assessment of a Compact EV during WPT Recharging Operations

Abstract

In this study, the external magnetic field emitted by a wireless power transfer (WPT) system and the internal electric field induced in human body models during recharging operations of a compact electric vehicle (EV) are evaluated. The magneticfield is calculated with a hybrid scheme coupling the boundary element method with the surface impedance boundary conditions in order to fit the multiscale open-boundary characteristics of the problem. A commercial software is then used to perform numerical dosimetry. Specifically, two realistic anatomical models, both in a driving position and in a standing posture, are considered, and the chassis of the EV is modeled either as a currently employed aluminum alloy and as a futuristic carbon fiber composite panel. Aligned and misaligned coil configurations of the WPT system are considered as well. The analysis of the obtained results shows that the International Commission on Non-Ionizing Radiation Protection (ICNIRP) reference levels are exceeded in the driving position, especially for the carbon fiber chassis, whereas the system is compliant with the basic restrictions, at least for the considered scenarios.

Influence of Posture and Coil Position on the Safety of a WPT System While Recharging a Compact EV

“…The compact vehicle considered in this paper is the FIAT 500, as described in [15] and freely accessible at this link https://github.com/cadema-PoliTO/vehicle4em (accessed on 26 October 2021). Once again, onlythe chassis of the car was considered and modeled as a surface mesh in order to exploit the capabilities of the numerical formulation, which is based on the hybrid BEM/SIBC method [18].…”

“…The exposure assessment of static and dynamic EV-WPT systems has been widely investigated [7][8][9][10][11][12][13][14][15]. However, while the influence of the car chassis material has been investigated in [14,15], the effect of the human posture and related positions against the WPT coils has not rigorously been addressed. Such an influence is therefore investigated in this work for a large variation of anatomical models, postures and WPT coil position/configurations.…”

“…The compliance assessment of EV-WPT systems is not straightforward. Indeed, while the standalone design of the recharging system could be easily performed with classical numerical approaches, the presence of the car body, which is more difficult to take into account, has been shown to play an important role [14,15]. However, the presence of the human body does not affect the source field up to some megahertz [16,17], making it possible to separate the overall compliance procedure into two steps: (1) the simulation of the magnetic field source (WPT system and car body) and (2) numerical dosimetry (human body subject to the previously evaluated IF field).…”

Special Issue: Advances in Computational Electromagnetics

“…Recent advances in computational electromagnetics (CEMs) have made the full characterization of complex magnetic materials possible, such as superconducting materials, composite or nanomaterials, rare-earth free permanent magnets, etc. Such advances are found in the collection of papers from this Special Issue, where vector properties and the non-linearity of ferromagnetic materials are investigated in [1][2][3][4], while new composite materials for automotive and aircraft are envisaged in [5,6], respectively. Finally, novel deposition techniques for nanomaterials using nonuniform magnetic fields are addressed in [7].…”

“…Advances in CEMs for innovative materials in automotives have been exploited in [5]. Specifically, the safety compliance of a wireless power transfer (WPT) system aimed to recharge a compact electric vehicle (EV) has been evaluated.…”