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 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.

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 Design and Optimization of a Wireless Power Transfer (WPT) System for Automotive

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5575
Author(s):  
Silvano Cruciani ◽  
Tommaso Campi ◽  
Francesca Maradei ◽  
Mauro Feliziani
Keyword(s):  
Magnetic Field ◽  
Optimization Procedure ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Design And Optimization ◽  
Gradient Descent Algorithm ◽  
Active Shielding ◽  
Shielding Design ◽  
The Magnetic Field

This study deals with the optimization of a shielding structure composed by multiple active coils for mitigating the magnetic field in an automotive wireless power transfer (WPT) system at 85 kHz. Each active coil is independently powered and the most suitable excitation is obtained by an optimization procedure based on the Gradient Descent algorithm. The proposed procedure is described and applied to shield the magnetic field beside an electric vehicle (EV) equipped with SAE standard coils, during wireless charging. The obtained results show that the magnetic field in the most critical area is significantly reduced (i.e., approximately halved) with a very limited influence on the electrical performances (i.e., WPT efficiency decreases by less than 1 percentage point compared to the case without active shielding).

scholarly journals In vitro exposure system using magnetic resonant coupling wireless power transfer

2014 ◽  
Vol 1 (2) ◽  
pp. 97-107 ◽  
Author(s):  
Kohei Mizuno ◽  
Junji Miyakoshi ◽  
Naoki Shinohara
Keyword(s):  
Magnetic Field ◽  
Cell Culture ◽  
Wireless Power Transfer ◽  
Reference Level ◽  
Power Transfer ◽  
Wireless Power ◽  
Exposure System ◽  
Resonant Coupling ◽  
In Vitro Exposure

Wireless power transfer (WPT) technology using the resonant coupling phenomenon has been widely studied. However, possible relationships between WPT exposure and human health have not been experimentally evaluated. In this study, we developed a new in vitro exposure system to evaluate the biological effects of magnetic resonant coupling WPT. The WPT was carried out using a self-resonant helical coil, which was designed to transfer the power with 85.4% efficiency at a 12.5 MHz resonant frequency. The magnetic field at the positions of the cell culture dishes is approximately twice the reference level for occupational exposure as stated in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. The specific absorption rate (SAR) at the positions of the cell culture dishes match the respective reference levels stated in the ICNIRP guidelines. In this paper, the coil design for the magnetic resonant coupling in the in vitro exposure system and characteristics, such as power transfer efficiency, electric field and magnetic field distributions, and SAR of the exposure system, are described.

scholarly journals Research on Coil Identification Algorithm of Wireless Power Transfer System Based on Magnetic Field Features

2021 ◽  
Vol 12 (3) ◽  
pp. 140
Author(s):  
Feng Wen ◽  
Chen Han ◽  
Qiang Li ◽  
Zhoujian Chu ◽  
Wenhan Zhao ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Wireless Power Transfer ◽  
Structure Type ◽  
Image Feature ◽  
Identification Algorithm ◽  
Power Transfer ◽  
Wireless Power ◽  
Energy Transmission ◽  
Coil Structure ◽  
The Magnetic Field

In the practical application of wireless power transfer (WPT), the identification of the secondary coil and the analysis of the space magnetic field of the coil will affect the matching scheme of the coil, which will further affect the performance of energy transmission. At present, the establishment of the coil space magnetic field model mainly adopts the finite element method (FEM). The accuracy of the results is limited by the computer performance and the specific settings during calculation, which usually takes a long time. Additionally, it can only analyze and establish the space magnetic field of the coil with specific parameters. Especially when the coil structure and parameters change, it is difficult to quickly establish the spatial magnetic field. This paper presents a secondary side coil identification method of a wireless charging system based on the magnetic field cloud image characteristics. The image feature extraction algorithm is used to extract features of a certain height magnetic field cloud image of an unknown structure type coil obtained by FEM. Further, by matching with the characteristics of the magnetic field cloud image of the known coil, the identification of the unknown coil structure type is realized. The effectiveness and accuracy of the proposed method is verified by an example. This algorithm is helpful to extract the characteristics of the coil space magnetic field, and can establish coil space magnetic field models with different structure types and different coil parameters combined with deep learning to guide the matching scheme of the primary and secondary coils, and realize efficient energy transmission.

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