Dosimetry for Resonance-Based Wireless Power Transfer Charging of Electric Vehicles

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  • ABSTRACT

    This paper presents the dosimetry of a resonance-based wireless power transfer (RBWPT) system for electric vehicles applications. The compact RBWPT system is designed to transfer power at 150-mm distance. The electric and magnetic fields generated by the RBWPT system and the specific absorption rate in the human body model, which stands around the system, are calculated. These analyses are conducted in two cases: the alignment and the misalignment between the transmitter and the receiver. The matching loops are adjusted to maximize the power transfer efficiency of the RBWPT system for the misalignment condition. When the two cases were compared for the best power transfer efficiency, the specific absorption rates (SAR) in the misalignment case were larger than those in the alignment case. The dosimetric results are discussed in relation to the international safety guidelines.


  • KEYWORD

    Dosimetry , Electric Vehicles , FDTD , Wireless Power Transfer

  • 1. Kurs A., Karalis A., Moffatt R., Joannopoulos J. D., Fisher P., Soljacic M. 2007 "Wireless power transfer via strongly coupled magnetic resonances," [Science] Vol.317 P.83-86 google doi
  • 2. Sample A. P., Meyer D. A., Smith J. R. 2011 "Analysis, experimental results, and range adaptation of magnetically coupled resonators for wireless power transfer," [IEEE Transactions on Industrial Electronics] Vol.58 P.544-554 google doi
  • 3. Cheon S., Kim Y. H., Kang S. Y., Lee M. L., Lee J. M., Zyung T. 2011 "Circuit-model-based analysis of a wireless energy-transfer system via coupled magnetic resonances," [IEEE Transactions on Industrial Electronics] Vol.58 P.2906-2914 google doi
  • 4. Awai I., Ishida T. 2010 "Design of resonator-coupled wireless power transfer system by use of BPF theory," [Journal of the Korean Institute of Electromagnetic Engineering and Science] Vol.10 P.237-243 google doi
  • 5. Nagaoka T., Watanabe S., Sakurai K., Kunieda E., Watanabe S., Taki M., Yamanaka Y. 2004 "Development of realistic high-resolution whole-body voxel models of Japanese adult males and females of average height and weight, and application of models to radio-frequency electromagnetic field dosimetry," [Physics in Medicine and Biology] Vol.49 P.1-15 google doi
  • 6. Gabriel C., Gabriel S. 1996 "Compilation of the dielectric properties of body tissues at RF and microwave frequencies," google
  • 7. Park S., Wake K., Watanabe S. 2013 "Incident electric field effect and numerical dosimetry for a wireless power transfer system using magnetically coupled resonances," [IEEE Transactions on Microwave Theory and Techniques] Vol.61 P.3461-3469 google doi
  • 8. Park S., Kim E., Wake K., Watanabe S. 2014 "Dosimetry for two modes of resonance-based wireless power transfer system," [in Proceedings of International Symposium on Electromagnetic Compatibility (EMC’14)] P.210-213 google
  • 9. 1998 "Guidelines for limiting exposure to timevarying electric, magnetic, and electromagnetic fields (up to 300 GHz)," google
  • [Fig. 1.] Side view of an anatomically realistic model of the human body positioned with respect to the resonance-based wireless power transfer system for electric vehicle charging.
    Side view of an anatomically realistic model of the human body positioned with respect to the resonance-based wireless power transfer system for electric vehicle charging.
  • [Fig. 2.] Configuration of a compact resonance-based wireless power transfer system. The transmitter and receiver are aligned, and the system is matched for only one resonant mode (case 1).
    Configuration of a compact resonance-based wireless power transfer system. The transmitter and receiver are aligned, and the system is matched for only one resonant mode (case 1).
  • [Fig. 3.] Configuration of a misaligned resonance-based wireless power transfer system. The matching loop is adjusted to obtain the best power transfer efficiency (case 2).
    Configuration of a misaligned resonance-based wireless power transfer system. The matching loop is adjusted to obtain the best power transfer efficiency (case 2).
  • [Fig. 4.] The xz-plane distributions of the electric field strength around the RBWPT system in the alignment condition (a) and in the misalignment condition (b). The black solid lines represent the reference level. The rectangular area is the space occupied by the human model.
    The xz-plane distributions of the electric field strength around the RBWPT system in the alignment condition (a) and in the misalignment condition (b). The black solid lines represent the reference level. The rectangular area is the space occupied by the human model.
  • [Fig. 5.] The results of the magnetic field distributions in the alignment condition (a) and in the misalignment condition (b). The black solid lines represent the reference level. The rectangular area is the space occupied by the human model.
    The results of the magnetic field distributions in the alignment condition (a) and in the misalignment condition (b). The black solid lines represent the reference level. The rectangular area is the space occupied by the human model.
  • [Fig. 6.] Specific absorption rate (SAR) distribution in the alignment condition (a) and the misalignment condition (b).
    Specific absorption rate (SAR) distribution in the alignment condition (a) and the misalignment condition (b).
  • [Table 1.] SAR results in the human body model exposed to the RBWPT system with 1 W input power in case 1 and case 2
    SAR results in the human body model exposed to the RBWPT system with 1 W input power in case 1 and case 2
  • [Fig. 7.] Maximum allowable power satisfying the basic restriction. SAR=specific absorption rate, 10 g SAR=the localized SAR average of any 10 g cubical volume of tissue, WB SAR=the whole-body average SAR.
    Maximum allowable power satisfying the basic restriction. SAR=specific absorption rate, 10 g SAR=the localized SAR average of any 10 g cubical volume of tissue, WB SAR=the whole-body average SAR.