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

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7248
Author(s):  
Valerio De Santis ◽  
Luca Giaccone ◽  
Fabio Freschi
Keyword(s):  
Magnetic Field ◽  
Human Exposure ◽  
Extreme Case ◽  
Wireless Power ◽  
Reference Levels ◽  
Anatomical Models ◽  
Safety Standards ◽  
Front Position ◽  
Standards And Guidelines ◽  
The Magnetic Field

In this study, the human exposure to the magnetic field emitted by a wireless power transfer (WPT) system during the static recharging operations of a compact electric vehicle (EV) is evaluated. Specifically, the influence of the posture of realistic anatomical models, both in standing and lying positions, either inside or outside the EV, is considered. Aligned and misaligned coil configurations of the WPT system placed both in the rear and front position of the car floor are considered as well. Compliance with safety standards and guidelines has proven that reference levels are exceeded in the extreme case of a person lying on the floor with a hand close to the WPT coils, whereas the system is always compliant with the basic restrictions, at least for the considered scenarios.

scholarly journals Evaluation of the Magnetic Field Leakage from Two Wireless Power Transfer Systems for EV/PHV Driven Simultaneously

2019 ◽  
Vol 10 (2) ◽  
pp. 41
Author(s):  
Toshiaki Watanabe ◽  
Yusuke Hakuta
Keyword(s):  
Magnetic Field ◽  
Human Exposure ◽  
Wireless Power Transfer ◽  
Hybrid Vehicles ◽  
Reference Level ◽  
Current Phase ◽  
Power Transfer ◽  
Wireless Power ◽  
Human Exposure Assessment ◽  
The Magnetic Field

Wireless power transfer for electric and plug-in hybrid vehicles has been developed to facilitate battery charging. In a wireless power transfer system, because the magnetic field leaks to the surroundings of the vehicle, it is important to evaluate the quantitative human exposure. The International Commission on Non-Ionizing Radiation Protection provides guidelines for human exposure assessment. In this study, we evaluate the magnetic field leakage under two parking configurations and current phase differences for two vehicles being simultaneously charged (3.7 kW at 85 kHz per vehicle). The results of the analysis show that the magnetic field leakage is lower than the reference level of the guidelines for all cases and that the leakage could be reduced by controlling the phase difference between the two wireless power transfer systems equally distributed from the single high-frequency power source for each parking configuration.

scholarly journals Wireless power transfer (WPT) system for an electric vehicle (EV): how to shield the car from the magnetic field generated by two planar coils

2017 ◽  
Vol 5 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Tommaso Campi ◽  
Silvano Cruciani ◽  
Valerio De Santis ◽  
Francesca Maradei ◽  
Mauro Feliziani
Keyword(s):  
Magnetic Field ◽  
Electric Vehicle ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Automotive Applications ◽  
Wireless Power ◽  
Safety Standards ◽  
Charging System ◽  
Weak Points ◽  
The Magnetic Field

This paper deals with the shielding of the magnetic field generated by two planar coils of a wireless power transfer (WPT) system at the frequency of tens of kilohertz used in automotive applications. Different shielding techniques using conductive and magnetic materials are examined and discussed highlighting strong and weak points of each other. Finally, the proposed shielding configuration consisting of a combined conductive and magnetic material is applied to model an electric vehicle equipped with a WPT charging system. With this configuration, compliance with the electromagnetic field safety standards can be achieved inside (passengers) or near (pedestrian) the car.

scholarly journals Active Shielding Applied to an Electrified Road in a Dynamic Wireless Power Transfer (WPT) System

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2522
Author(s):  
Silvano Cruciani ◽  
Tommaso Campi ◽  
Francesca Maradei ◽  
Mauro Feliziani
Keyword(s):  
Magnetic Field ◽  
Ionizing Radiation ◽  
Electric Vehicles ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Reference Levels ◽  
Mathematical Procedure ◽  
Active Shielding ◽  
The Magnetic Field

An active coil system is proposed to shield the magnetic field produced by a dynamic wireless power transfer (WPT) system used to power electric vehicles (EVs) in motion. The considered dynamic WPT is based on an electrified road with many short-track pads. A sophisticated mathematical procedure is developed to optimize the design of the active coils configuration and their excitation. By the proposed approach, the resulting magnetic field is compliant with the reference levels (RLs) of the ICNIRP (International Commission on Non-Ionizing Radiation Protection) 2010 Guidelines inside the cabin of EVs and on the side of the electrified road.

scholarly journals Near Field Wireless Powering of Deep Medical Implants

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2720 ◽  
Author(s):  
Tommaso Campi ◽  
Silvano Cruciani ◽  
Valerio De Santis ◽  
Francesca Maradei ◽  
Mauro Feliziani
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Near Field ◽  
Cylindrical Shape ◽  
Medical Implants ◽  
Wireless Power ◽  
Primary Coil ◽  
Fixed Position ◽  
Safety Standards ◽  
Large Primary

This study deals with the inductive-based wireless power transfer (WPT) technology applied to power a deep implant with no fixed position. The usage of a large primary coil is here proposed in order to obtain a nearly uniform magnetic field inside the human body at intermediate frequencies (IFs). A simple configuration of the primary coil, derived by the Helmholtz theory, is proposed. Then, a detailed analysis is carried out to assess the compliance with electromagnetic field (EMF) safety standards. General guidelines on the design of primary and secondary coils are provided for powering or charging a deep implant of cylindrical shape with or without metal housing. Finally, three different WPT coil demonstrators have been fabricated and tested. The obtained results have demonstrated the validity of the proposed technology.

scholarly journals Effect of Loudspeakers on the In Situ Electric Field in a Driver Body Model Exposed to an Electric Vehicle Wireless Power Transfer System

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3635
Author(s):  
Junqing Lan ◽  
Akimasa Hirata
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Electric Vehicle ◽  
Wireless Power ◽  
Body Model ◽  
Maximum Electric Field ◽  
The Magnetic Field

This study computationally evaluates the effect of loudspeakers on the in situ electric field in a driver body model exposed to the magnetic field from a wireless power transfer (WPT) system in an electric vehicle (EV), one with a body made of carbon fiber reinforced plastic (CFRP) and the other made with aluminum. A quasi-static two-step approach was applied to compute the in situ electric field. The computational results showed that the magnetic field distribution generated by the WPT is significantly altered around the loudspeakers, and shows obvious discontinuity and local enhancement. The maximum spatial-average magnetic field strength in the driver’s body was increased by 11% in the CFRP vehicle. It was 2.25 times larger than the reference levels (RL) prescribed in the International Commission of Non-Ionizing Radiation Protection (ICNIRP) guidelines in 2010. In addition, we found that the in situ electric field computed by the line- and volume-averaging methods were stable if the top 0.1% voxels are excluded. The maximum value was well below the basic restriction (BR) of the ICNIRP guidelines. Nevertheless, the presence of the loudspeaker led to increments in the electric field strength in parts of the human body, suggesting the potential influence of permissible transmitting power in the WPT system. The maximum electric field strength in the thigh and buttock with the woofer, increased by 27% in the CFRP vehicle. The arm value was up to 3 times higher than that obtained without the tweeter in the aluminum vehicle. Moreover, this study found that the maximum electric field strength depended on the location of the loudspeaker with respect to the WPT system and the separation from the driver model. Therefore, the loudspeaker should be considered when evaluating the maximum in situ electric field strength in the vehicle body design stage.

scholarly journals Shielding the magnetic field of wireless power transfer system using zero-permeability metamaterial

2019 ◽  
Vol 2019 (16) ◽  
pp. 1812-1815 ◽  
Author(s):  
Conghui Lu ◽  
Xiutao Huang ◽  
Cancan Rong ◽  
Zhaoyang Hu ◽  
Junfeng Chen ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Wireless Power Transfer ◽  
Transfer System ◽  
Power Transfer ◽  
Wireless Power ◽  
Wireless Power Transfer System ◽  
The Magnetic Field

scholarly journals Wireless Power Transfer Using Double DD Coils

Electronics ◽  
2021 ◽  
Vol 10 (20) ◽  
pp. 2528
Author(s):  
Nataša Prosen ◽  
Jure Domajnko ◽  
Miro Milanovič
Keyword(s):  
Magnetic Field ◽  
Wireless Power Transfer ◽  
Transfer System ◽  
Power Transfer ◽  
Wireless Power ◽  
Novel Structure ◽  
Higher Power ◽  
Wireless Power Transfer System ◽  
The Magnetic Field

This paper deals with a wireless power transfer system where a novel structure of transmitting/receiving double DD coils is applied. This system uses two identical double D (DD) transmitter coils stacked on each other to transfer power to two stacked receiver coils. The power is transmitted simultaneously and independently through both transmitter coils to the receiving coils. The magnetic field of the first coil does not interfere with the second coil. Both transmitter and receiver coils are placed on each other and occupy the same footprint, so there is no need for increased space. This can lead to an interesting wireless power transfer system—from single load to double the load and higher power transfer density.

scholarly journals A Defected Metasurface for Field-Localizing Wireless Power Transfer

2021 ◽  
Author(s):  
Sarawuth Chaimool ◽  
Chawalit Rakluea ◽  
Yan Zhao ◽  
Prayoot Akkaraekthalin
Keyword(s):  
Magnetic Field ◽  
Electromotive Force ◽  
Wireless Power Transfer ◽  
Unit Cell ◽  
Transfer Efficiency ◽  
Two Dimensional ◽  
Power Transfer ◽  
Wireless Power ◽  
Commercial Applications ◽  
The Magnetic Field

The potential of wireless power transfer (WPT) has attracted considerable interest for various research and commercial applications for home and industry. Two important topics including transfer efficiency and electromotive force (EMF) leakage are concerned with modern WPT systems. This work presents the defected metasurface for localized WPT to prevent the transfer efficiency degraded by tuning the resonance of only one-unit cell at the certain metasurface (MTS). Localization cavities on the metasurface can be formed in a defected metasurface, thus fields can be confined to the region around a small receiver, which enhances the transfer efficiency and reduces leakage of electromagnetic fields. To create a cavity in MTS, a defected unit cell at the receiving coils’ positions for enhancing the efficiency will be designed, aiming to confine the magnetic field. Results show that the peak efficiency of 1.9% for the case of the free space is improved to 60% when the proposed defected metasurface is applied, which corresponds to 31.2 times enhancements. Therefore, the defected MTS can control the wave propagation in two-dimensional of WPT system.

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