BSI PD IEC/TR 62905:2018
$215.11
Exposure assessment methods for wireless power transfer systems
| Published By | Publication Date | Number of Pages |
| BSI | 2018 | 106 |
This document describes general exposure assessment methods for wireless power transfer (WPT) at frequency up to 10 MHz considering thermal and stimulus effects. Exposure assessment procedures and experimental results are shown as examples such as electric vehicles (EVs) and mobile devices.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | undefined |
| 4 | CONTENTS |
| 9 | FOREWORD |
| 11 | INTRODUCTION |
| 12 | 1 Scope 2 Normative references 3 Terms and definitions |
| 14 | 4 Symbols and abbreviations 4.1 Physical quantities 4.2 Constants 4.3 Abbreviations |
| 15 | 5 Overview of WPT systems 5.1 General 5.2 WPT systems whose frequency range is less than 100 kHz Figures Figure 1 โ Wireless power kitchen appliances [1] |
| 16 | Figure 2 โ Use cases of the LCD and semiconductor product lines andkitchen WPT systems [1] |
| 17 | Figure 3 โ Example of a WPT system for EV/PHEV [1] |
| 18 | Figure 4 โ Example of an online electric vehicle [1] Figure 5 โ Technical characteristics of an online electric vehicle [1] |
| 19 | 5.3 WPT systems whose frequency range is from 100 kHz to 10 MHz Tables Table 1 โ Summary of application, technology and specificationof WPT systems whose frequency range is less than 100 kHz. |
| 20 | Figure 6 โ Example magnetic induction WPT system block diagram [1] Figure 7 โ Example magnetic resonance WPT system block diagram [1] |
| 21 | Figure 8 โ Capacitive coupling WPT system block diagram [1] Figure 9 โ Typical structure of the capacitive coupling system [1] |
| 22 | 6 Basic assessment methods 6.1 General 6.2 Basic assessment methods considering direct effect 6.2.1 General Table 2 โ WPT systems whose frequency range is from 100 kHz to 10 MHz |
| 23 | 6.2.2 Evaluation based on transmit power or current 6.2.3 Evaluation of incident fields against reference levels 6.2.4 Evaluation of incident fields against basic restrictions |
| 24 | 6.2.5 Evaluation of induced E-field and SAR against basic restrictions |
| 25 | 6.2.6 Assessment procedure 6.3 Basic assessment method considering indirect effect Figure 10 โ Flowchart of assessment procedure considering the direct effect |
| 26 | Figure 11 โ Two exposure situations for ungrounded and grounded metal objects Figure 12 โ Flowchart of assessment procedures for indirect effects |
| 27 | Annex A (informative)WPT systems whose frequency range is over 10 MHz |
| 28 | Table A.1 โ Classification of WPT applications Table A.2 โ Characteristics of beam WPT applications |
| 29 | Annex B (informative)International exposure guidelines B.1 ICNIRP guidelines Table B.1 โ Basic restrictions up to 10 GHz of ICNIRP1998 |
| 30 | Table B.2 โ Basic restrictions of ICNIRP2010 |
| 31 | Table B.3 โ Reference levels for electric and magneticfields (unperturbed rms values) of ICNIRP1998 Table B.4 โ Reference levels for electric and magnetic fields (unperturbed rms values) of ICNIRP2010 |
| 32 | B.2 IEEE standards Table B.5 โ Reference levels for contact currents of ICNIRP1998 and ICNIRP2010 Table B.6 โ Basic restrictions up to 5 MHz of IEEE C95.6 and IEEE C95.1 |
| 33 | Table B.7 โ Basic restrictions between 100 kHz and 3 GHz of IEEE C95.1 Table B.8 โ Magnetic field MPE up to 5 MHz of IEEE C95.1 and IEEE C95.6 Table B.9 โ Electric field MPE for whole-body exposure upto 100 kHz of IEEE C95.1 and IEEE C95.6 |
| 34 | Table B.10 โ MPE for electric and magnetic field over 100 kHzfor whole-body exposure of IEEE C95.1 and IEEE C95.6 Table B.11 โ Contact current MPE of IEEE C95.1 and IEEE C95.6 |
| 35 | Annex C (informative)Assessment methods C.1 Exclusion based on transmit power or current Table C.1 โ Basic restrictions regarding SAR (unit is W/kg) |
| 36 | C.2 Measurement of incident electromagnetic fields C.2.1 Equipment for electric field measurement C.2.2 Equipment for magnetic field measurement Table C.2 โ Possible exclusion power level regarding local SAR |
| 37 | C.2.3 Measurement method |
| 38 | C.3 Coupling factor |
| 39 | C.4 Generic gradient source model |
| 40 | Table C.3 โ Coupling transformation matrix to estimateinduced E-field for compliance with ICNIRP 2010 Table C.4 โ Coupling transformation matrix to estimate inducedcurrent density for compliance with ICNIRP 1998 |
| 41 | Table C.5 โ Coupling transformation matrix to estimateinduced E-field for compliance with IEEE 2005 Table C.6 โ Coupling transformation matrix to estimate SAR (pSAR10g and wbSAR)for compliance with ICNIRP 1998 and IEEE 2005 |
| 42 | C.5 Induced E-field or SAR C.5.1 Measurement Table C.7 โ Dielectric properties of the tissue equivalent liquid defined in IEC 62209-2 Table C.8 โ Dielectric properties of the tissue equivalent NaCl solution |
| 43 | C.5.2 Calculation |
| 44 | Table C.9 โ Human models and source models |
| 45 | C.6 Contact current C.6.1 Equipment Table C.10 โ Computational methods Table C.11 โ SAR evaluation method based on numerical simulation |
| 46 | Figure C.1 โ Frequency characteristics of impedanceof adult male and IEC equivalent circuit Figure C.2 โ IEC equivalent circuit Figure C.3 โ Example of contact current measurement equipment |
| 47 | C.6.2 Measurements |
| 48 | Annex D (informative)Case studies D.1 WPT system for EV D.1.1 General |
| 49 | D.1.2 Assessment procedures for WPT system for EV Figure D.1 โ Example for areas of protection, for ground mounted systems [37] |
| 50 | Figure D.2 โ Area 3 measurement position [37] Figure D.3 โ Area 4 measurement position [37] |
| 53 | Figure D.4 โ Assessment flow of Part 1 |
| 54 | Table D.1 โ Uncertainty of H-field measurements for WPT systems in Area 3 |
| 55 | Table D.2 โ Numerical uncertainty of the exposure of anatomicalhuman models to WPT systems for EV |
| 56 | Table D.3 โ Uncertainty of EMF measurements for WPT systems in Area 4 |
| 57 | Figure D.5 โ Assessment flow of Part 2 |
| 58 | Figure D.6 โ Assessment flow of Part 3 |
| 59 | Table D.4 โ Uncertainty of contact current measurements |
| 60 | D.2 Experimental assessment results for EV D.2.1 General D.2.2 Electromagnetic field measurement results Table D.5 โ ICNIRP2010 guideline at 85 kHz Table D.6 โ Specification of DUT |
| 61 | Figure D.7 โ Example measurement layout for Area 3 surrounding area of vehicle Table D.7 โ Measured incident H-fields and E-fields of Area 3 Table D.8 โ Measured incident H-fields and E-fields of Area 4 |
| 62 | D.2.3 Contact current measurement Figure D.8 โ Example measurement layout for Area 4 car interior Figure D.9 โ Contact current meters used in the measurement |
| 63 | D.3 WPT system for mobile devices D.3.1 General Figure D.10 โ Measurement of contact current Table D.9 โ Measurement results of contact current [mA] |
| 64 | D.3.2 Assessment procedures for WPT system for mobile |
| 66 | Annex E (informative)Numerical and experimental studies E.1 Exposure evaluation of WPT for EV E.1.1 Research in Japan Figure E.1 โ Geometry of vehicle model |
| 67 | Figure E.2 โ Measured and simulated magnetic field strength leaked from wireless power system in an electric vehicle [46] Figure E.3 โ Distance dependence of peak inducedelectric field strength in human body model |
| 68 | Figure E.4 โ Analysis of induced electric field strength in the human bodyfor different human positions relative to the vehicle [41] |
| 69 | Figure E.5 โ Relationship between the maximum induced electric field in the human body and the magnetic field strength [41] |
| 70 | E.1.2 Research in Korea Figure E.6 โ The induced electric field distributions in a humanbody model lying on the ground with his right arm stretched [48] Table E.1 โ Estimated permissible power for WPT system for EV |
| 71 | Figure E.7 โ EMF human exposure condition from the power lineand pickup coils of OLEV system |
| 72 | Figure E.8 โ The model in the field generated by OLEV |
| 73 | Figure E.9 โ The calculated magnetic field distributions at each distance from OLEV |
| 74 | E.2 Exposure evaluation of WPT for mobile device E.2.1 WPT system in 140 kHz band Figure E.10 โ Photograph of magnetic field measurement for transmitting andreceiving pads of wireless charging system Figure E.11 โ Measurement results of magnetic field value for two cases oflow voltage output (case 1) and high voltage output (case 2) |
| 75 | Figure E.12 โ Transmitting and receiving coils, and magnetic sheet Figure E.13 โ Simulated magnetic field strength distribution (Charging (a) xy plane, (b) yz plane; Standby model (c) xy plane, (d) yz plane) and measured value (Charging (e) xy plane, (f) yz plane; Standby mode (g) xy plane, (h) yz plane) |
| 76 | E.2.2 WPT systems in MHz band Figure E.14 โ Position of human body and coil (left), exposure point in chest (right) Table E.2 โ Local SAR and induced electric field inin a human body on the chest surface |
| 77 | Figure E.15 โ Realistic human body model and system position |
| 78 | Figure E.16 โ Position of the human body model: (a) the human body is movedin the horizontal direction, (b) the coils are moved in vertical direction Figure E.17 โ Peak of 10 g average SAR movedin (a) horizontal direction, (b) vertical direction |
| 79 | Figure E.18 โ Peaks of 10 g average SAR |
| 80 | Figure E.19 โ Wireless power transfer system configurations Figure E.20 โ Electric field and magnetic field distributionsaround the coil when an input power is 1 W Figure E.21 โ Exposure conditions for WPT system |
| 81 | E.3 Coupling factor E.3.1 WPT system for EV Table E.3 โ Simulated result of local SAR and whole-body average SAR by Nagoya Institute of Technology (NITech) / NTT DOCOMO and NICT (input power is 40 W) |
| 83 | Figure E.22 โ Top and birdโs-eye views of (a) solenoid type and (b) circular spiral type coupling coils, and (c) geometry of electric vehicle with a wireless power transfer system [13] Table E.4 โ Dimensions of WPT systems for electric vehiclesconsidered by different groups [13] |
| 84 | E.3.2 WPT system for mobile device Table E.5 โ Coupling factor for internal electric field of WPT systems for EV [13] |
| 85 | E.3.3 Evaluation example of CF and GGSM using a cylinder model Figure E.23 โ A numerical model of dielectric cylinder used in the calculation Table E.6 โ Coupling factor for peak 10 g SAR for WPT systemsat 6,78 MHz (implemented on the desk) [13] Table E.7 โ Coupling factor for internal electric field for WPT systemsat 6,78 MHz (implemented on the desk) [13] |
| 87 | Figure E.24 โ Distribution of induced electric field strength insidethe cylinder in the vicinity of a one-turn loop with 1 A current Figure E.25 โ A two-line current model |
| 88 | Figure E.26 โ Decay profile of incident magnetic field for each component Figure E.27 โ Profile of incident magnetic field for Gn = 13 (left) and 80 (right) Figure E.28 โ Distribution of induced electric field for x-, y-, and z-componentsof the incident magnetic field profiles generated by GGSM |
| 89 | E.4 SAR measurement Table E.8 โ NICT and ITโIS results of induced electric field and local peak 10 gaverage SAR in the dielectric cylinder using GGSM |
| 90 | Figure E.29 โ Solenoid-type WPT system (left) and flat-spiral-type WPTsystem (right) used for SAR measurement Figure E.30 โ SAR distribution in a liquid phantom, calculated by MoM (above) and measured by the developed measurement system (below) Table E.9 โ Experimental and numerical results of spatial peak 10 g average SAR (input power = 10 W) |
| 91 | E.5 Contact current E.5.1 WPT system for EV Figure E.31 โ Two conditions of contact current measurement |
| 92 | E.5.2 WPT systems for mobile (MHz) Figure E.32 โ Contact currents with ungrounded condition Figure E.33 โ Contact currents with grounded condition |
| 93 | Figure E.34 โ Contact current with ungrounded metal Figure E.35 โ Contact current with grounded metal |
| 94 | Annex F (informative)Medical implants F.1 Background F.2 Medical implant enhancement factor |
| 95 | Table F.1 โ Preliminary medical implant enhancement factorsfor nerve stimulation up to 10 MHz Table F.2 โ Preliminary medical implant enhancement factorsfor tissue heating up to 10 MHz (โT) |
| 96 | Figure F.1 โ Model of the insulated perfectly conducting wire with non-insulated bare tips used as generic implantable medical device Table F.3 โ Dielectric and thermal properties assignedto the muscle tissue and to the generic implants |
| 97 | Table F.4 โ Induced E-field in the homogeneous tissuewithout the implant to reach J-BR of ICNIRP 1998 Table F.5 โ Induced E-field in the homogeneous tissue without the implantto reach SAR-BR of ICNIRP 1998 and IEEE 2005 for f โฅ 100 kHz |
| 98 | Figure F.2 โ pSAR0,1g (W/kg) at the lead tip as a function of frequency in the range100 kHz to 10 MHz for each lead length (100 mm, 200 mm, 500 mm and 800 mm) |
| 99 | F.3 Numerical evaluation of medical implant enhancement factor F.3.1 General F.3.2 Numerical setup Figure F.3 โ Induced E-field tangential to the implant, embedded in the homogeneous tissue, in the absence of the implant, to reach ICNIRP2010 BRs in the frequency range 10 kHz to 10 MHz and as a function of the lead length, when the implant is present |
| 101 | Bibliography |
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BSI PD IEC/TR 62905:2018
Exposure assessment methods for wireless power transfer systems Published By Publication Date Number of Pagesโฆ
