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.<\/p>\n
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| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 4<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 4 Symbols and abbreviations 4.1 Physical quantities 4.2 Constants 4.3 Abbreviations <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 5 Overview of WPT systems 5.1 General 5.2 WPT systems whose frequency range is less than 100 kHz Figures Figure 1 \u2013 Wireless power kitchen appliances [1] <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | Figure 2 \u2013 Use cases of the LCD and semiconductor product lines andkitchen WPT systems [1] <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | Figure 3 \u2013 Example of a WPT system for EV\/PHEV [1] <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | Figure 4 \u2013 Example of an online electric vehicle [1] Figure 5 \u2013 Technical characteristics of an online electric vehicle [1] <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 5.3 WPT systems whose frequency range is from 100 kHz to 10 MHz Tables Table 1 \u2013 Summary of application, technology and specificationof WPT systems whose frequency range is less than 100 kHz. <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | Figure 6 \u2013 Example magnetic induction WPT system block diagram [1] Figure 7 \u2013 Example magnetic resonance WPT system block diagram [1] <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | Figure 8 \u2013 Capacitive coupling WPT system block diagram [1] Figure 9 \u2013 Typical structure of the capacitive coupling system [1] <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 6 Basic assessment methods 6.1 General 6.2 Basic assessment methods considering direct effect 6.2.1 General Table 2 \u2013 WPT systems whose frequency range is from 100 kHz to 10 MHz <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 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 <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 6.2.5 Evaluation of induced E-field and SAR against basic restrictions <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 6.2.6 Assessment procedure 6.3 Basic assessment method considering indirect effect Figure 10 \u2013 Flowchart of assessment procedure considering the direct effect <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | Figure 11 \u2013 Two exposure situations for ungrounded and grounded metal objects Figure 12 \u2013 Flowchart of assessment procedures for indirect effects <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | Annex A (informative)WPT systems whose frequency range is over 10 MHz <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | Table A.1 \u2013 Classification of WPT applications Table A.2 \u2013 Characteristics of beam WPT applications <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | Annex B (informative)International exposure guidelines B.1 ICNIRP guidelines Table B.1 \u2013 Basic restrictions up to 10 GHz of ICNIRP1998 <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | Table B.2 \u2013 Basic restrictions of ICNIRP2010 <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | Table B.3 \u2013 Reference levels for electric and magneticfields (unperturbed rms values) of ICNIRP1998 Table B.4 \u2013 Reference levels for electric and magnetic fields (unperturbed rms values) of ICNIRP2010 <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | B.2 IEEE standards Table B.5 \u2013 Reference levels for contact currents of ICNIRP1998 and ICNIRP2010 Table B.6 \u2013 Basic restrictions up to 5 MHz of IEEE C95.6 and IEEE C95.1 <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | Table B.7 \u2013 Basic restrictions between 100 kHz and 3 GHz of IEEE C95.1 Table B.8 \u2013 Magnetic field MPE up to 5 MHz of IEEE C95.1 and IEEE C95.6 Table B.9 \u2013 Electric field MPE for whole-body exposure upto 100 kHz of IEEE C95.1 and IEEE C95.6 <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | Table B.10 \u2013 MPE for electric and magnetic field over 100 kHzfor whole-body exposure of IEEE C95.1 and IEEE C95.6 Table B.11 \u2013 Contact current MPE of IEEE C95.1 and IEEE C95.6 <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Annex C (informative)Assessment methods C.1 Exclusion based on transmit power or current Table C.1 \u2013 Basic restrictions regarding SAR (unit is W\/kg) <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | 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 \u2013 Possible exclusion power level regarding local SAR <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | C.2.3 Measurement method <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | C.3 Coupling factor <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | C.4 Generic gradient source model <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | Table C.3 \u2013 Coupling transformation matrix to estimateinduced E-field for compliance with ICNIRP 2010 Table C.4 \u2013 Coupling transformation matrix to estimate inducedcurrent density for compliance with ICNIRP 1998 <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | Table C.5 \u2013 Coupling transformation matrix to estimateinduced E-field for compliance with IEEE 2005 Table C.6 \u2013 Coupling transformation matrix to estimate SAR (pSAR10g and wbSAR)for compliance with ICNIRP 1998 and IEEE 2005 <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | C.5 Induced E-field or SAR C.5.1 Measurement Table C.7 \u2013 Dielectric properties of the tissue equivalent liquid defined in IEC 62209-2 Table C.8 \u2013 Dielectric properties of the tissue equivalent NaCl solution <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | C.5.2 Calculation <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | Table C.9 \u2013 Human models and source models <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | C.6 Contact current C.6.1 Equipment Table C.10 \u2013 Computational methods Table C.11 \u2013 SAR evaluation method based on numerical simulation <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | Figure C.1 \u2013 Frequency characteristics of impedanceof adult male and IEC equivalent circuit Figure C.2 \u2013 IEC equivalent circuit Figure C.3 \u2013 Example of contact current measurement equipment <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | C.6.2 Measurements <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | Annex D (informative)Case studies D.1 WPT system for EV D.1.1 General <\/td>\n<\/tr>\n | ||||||
| 49<\/td>\n | D.1.2 Assessment procedures for WPT system for EV Figure D.1 \u2013 Example for areas of protection, for ground mounted systems [37] <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | Figure D.2 \u2013 Area 3 measurement position [37] Figure D.3 \u2013 Area 4 measurement position [37] <\/td>\n<\/tr>\n | ||||||
| 53<\/td>\n | Figure D.4 \u2013 Assessment flow of Part 1 <\/td>\n<\/tr>\n | ||||||
| 54<\/td>\n | Table D.1 \u2013 Uncertainty of H-field measurements for WPT systems in Area 3 <\/td>\n<\/tr>\n | ||||||
| 55<\/td>\n | Table D.2 \u2013 Numerical uncertainty of the exposure of anatomicalhuman models to WPT systems for EV <\/td>\n<\/tr>\n | ||||||
| 56<\/td>\n | Table D.3 \u2013 Uncertainty of EMF measurements for WPT systems in Area 4 <\/td>\n<\/tr>\n | ||||||
| 57<\/td>\n | Figure D.5 \u2013 Assessment flow of Part 2 <\/td>\n<\/tr>\n | ||||||
| 58<\/td>\n | Figure D.6 \u2013 Assessment flow of Part 3 <\/td>\n<\/tr>\n | ||||||
| 59<\/td>\n | Table D.4 \u2013 Uncertainty of contact current measurements <\/td>\n<\/tr>\n | ||||||
| 60<\/td>\n | D.2 Experimental assessment results for EV D.2.1 General D.2.2 Electromagnetic field measurement results Table D.5 \u2013 ICNIRP2010 guideline at 85 kHz Table D.6 \u2013 Specification of DUT <\/td>\n<\/tr>\n | ||||||
| 61<\/td>\n | Figure D.7 \u2013 Example measurement layout for Area 3 surrounding area of vehicle Table D.7 \u2013 Measured incident H-fields and E-fields of Area 3 Table D.8 \u2013 Measured incident H-fields and E-fields of Area 4 <\/td>\n<\/tr>\n | ||||||
| 62<\/td>\n | D.2.3 Contact current measurement Figure D.8 \u2013 Example measurement layout for Area 4 car interior Figure D.9 \u2013 Contact current meters used in the measurement <\/td>\n<\/tr>\n | ||||||
| 63<\/td>\n | D.3 WPT system for mobile devices D.3.1 General Figure D.10 \u2013 Measurement of contact current Table D.9 \u2013 Measurement results of contact current [mA] <\/td>\n<\/tr>\n | ||||||
| 64<\/td>\n | D.3.2 Assessment procedures for WPT system for mobile <\/td>\n<\/tr>\n | ||||||
| 66<\/td>\n | Annex E (informative)Numerical and experimental studies E.1 Exposure evaluation of WPT for EV E.1.1 Research in Japan Figure E.1 \u2013 Geometry of vehicle model <\/td>\n<\/tr>\n | ||||||
| 67<\/td>\n | Figure E.2 \u2013 Measured and simulated magnetic field strength leaked from wireless power system in an electric vehicle [46] Figure E.3 \u2013 Distance dependence of peak inducedelectric field strength in human body model <\/td>\n<\/tr>\n | ||||||
| 68<\/td>\n | Figure E.4 \u2013 Analysis of induced electric field strength in the human bodyfor different human positions relative to the vehicle [41] <\/td>\n<\/tr>\n | ||||||
| 69<\/td>\n | Figure E.5 \u2013 Relationship between the maximum induced electric field in the human body and the magnetic field strength [41] <\/td>\n<\/tr>\n | ||||||
| 70<\/td>\n | E.1.2 Research in Korea Figure E.6 \u2013 The induced electric field distributions in a humanbody model lying on the ground with his right arm stretched [48] Table E.1 \u2013 Estimated permissible power for WPT system for EV <\/td>\n<\/tr>\n | ||||||
| 71<\/td>\n | Figure E.7 \u2013 EMF human exposure condition from the power lineand pickup coils of OLEV system <\/td>\n<\/tr>\n | ||||||
| 72<\/td>\n | Figure E.8 \u2013 The model in the field generated by OLEV <\/td>\n<\/tr>\n | ||||||
| 73<\/td>\n | Figure E.9 \u2013 The calculated magnetic field distributions at each distance from OLEV <\/td>\n<\/tr>\n | ||||||
| 74<\/td>\n | E.2 Exposure evaluation of WPT for mobile device E.2.1 WPT system in 140 kHz band Figure E.10 \u2013 Photograph of magnetic field measurement for transmitting andreceiving pads of wireless charging system Figure E.11 \u2013 Measurement results of magnetic field value for two cases oflow voltage output (case 1) and high voltage output (case 2) <\/td>\n<\/tr>\n | ||||||
| 75<\/td>\n | Figure E.12 \u2013 Transmitting and receiving coils, and magnetic sheet Figure E.13 \u2013 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) <\/td>\n<\/tr>\n | ||||||
| 76<\/td>\n | E.2.2 WPT systems in MHz band Figure E.14 \u2013 Position of human body and coil (left), exposure point in chest (right) Table E.2 \u2013 Local SAR and induced electric field inin a human body on the chest surface <\/td>\n<\/tr>\n | ||||||
| 77<\/td>\n | Figure E.15 \u2013 Realistic human body model and system position <\/td>\n<\/tr>\n | ||||||
| 78<\/td>\n | Figure E.16 \u2013 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 \u2013 Peak of 10 g average SAR movedin (a) horizontal direction, (b) vertical direction <\/td>\n<\/tr>\n | ||||||
| 79<\/td>\n | Figure E.18 \u2013 Peaks of 10 g average SAR <\/td>\n<\/tr>\n | ||||||
| 80<\/td>\n | Figure E.19 \u2013 Wireless power transfer system configurations Figure E.20 \u2013 Electric field and magnetic field distributionsaround the coil when an input power is 1 W Figure E.21 \u2013 Exposure conditions for WPT system <\/td>\n<\/tr>\n | ||||||
| 81<\/td>\n | E.3 Coupling factor E.3.1 WPT system for EV Table E.3 \u2013 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) <\/td>\n<\/tr>\n | ||||||
| 83<\/td>\n | Figure E.22 \u2013 Top and bird\u2019s-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 \u2013 Dimensions of WPT systems for electric vehiclesconsidered by different groups [13] <\/td>\n<\/tr>\n | ||||||
| 84<\/td>\n | E.3.2 WPT system for mobile device Table E.5 \u2013 Coupling factor for internal electric field of WPT systems for EV [13] <\/td>\n<\/tr>\n | ||||||
| 85<\/td>\n | E.3.3 Evaluation example of CF and GGSM using a cylinder model Figure E.23 \u2013 A numerical model of dielectric cylinder used in the calculation Table E.6 \u2013 Coupling factor for peak 10 g SAR for WPT systemsat 6,78 MHz (implemented on the desk) [13] Table E.7 \u2013 Coupling factor for internal electric field for WPT systemsat 6,78 MHz (implemented on the desk) [13] <\/td>\n<\/tr>\n | ||||||
| 87<\/td>\n | Figure E.24 \u2013 Distribution of induced electric field strength insidethe cylinder in the vicinity of a one-turn loop with 1 A current Figure E.25 \u2013 A two-line current model <\/td>\n<\/tr>\n | ||||||
| 88<\/td>\n | Figure E.26 \u2013 Decay profile of incident magnetic field for each component Figure E.27 \u2013 Profile of incident magnetic field for Gn = 13 (left) and 80 (right) Figure E.28 \u2013 Distribution of induced electric field for x-, y-, and z-componentsof the incident magnetic field profiles generated by GGSM <\/td>\n<\/tr>\n | ||||||
| 89<\/td>\n | E.4 SAR measurement Table E.8 \u2013 NICT and IT\u2019IS results of induced electric field and local peak 10 gaverage SAR in the dielectric cylinder using GGSM <\/td>\n<\/tr>\n | ||||||
| 90<\/td>\n | Figure E.29 \u2013 Solenoid-type WPT system (left) and flat-spiral-type WPTsystem (right) used for SAR measurement Figure E.30 \u2013 SAR distribution in a liquid phantom, calculated by MoM (above) and measured by the developed measurement system (below) Table E.9 \u2013 Experimental and numerical results of spatial peak 10 g average SAR (input power = 10 W) <\/td>\n<\/tr>\n | ||||||
| 91<\/td>\n | E.5 Contact current E.5.1 WPT system for EV Figure E.31 \u2013 Two conditions of contact current measurement <\/td>\n<\/tr>\n | ||||||
| 92<\/td>\n | E.5.2 WPT systems for mobile (MHz) Figure E.32 \u2013 Contact currents with ungrounded condition Figure E.33 \u2013 Contact currents with grounded condition <\/td>\n<\/tr>\n | ||||||
| 93<\/td>\n | Figure E.34 \u2013 Contact current with ungrounded metal Figure E.35 \u2013 Contact current with grounded metal <\/td>\n<\/tr>\n | ||||||
| 94<\/td>\n | Annex F (informative)Medical implants F.1 Background F.2 Medical implant enhancement factor <\/td>\n<\/tr>\n | ||||||
| 95<\/td>\n | Table F.1 \u2013 Preliminary medical implant enhancement factorsfor nerve stimulation up to 10 MHz Table F.2 \u2013 Preliminary medical implant enhancement factorsfor tissue heating up to 10 MHz (\u2206T) <\/td>\n<\/tr>\n | ||||||
| 96<\/td>\n | Figure F.1 \u2013 Model of the insulated perfectly conducting wire with non-insulated bare tips used as generic implantable medical device Table F.3 \u2013 Dielectric and thermal properties assignedto the muscle tissue and to the generic implants <\/td>\n<\/tr>\n | ||||||
| 97<\/td>\n | Table F.4 \u2013 Induced E-field in the homogeneous tissuewithout the implant to reach J-BR of ICNIRP 1998 Table F.5 \u2013 Induced E-field in the homogeneous tissue without the implantto reach SAR-BR of ICNIRP 1998 and IEEE 2005 for f \u2265 100 kHz <\/td>\n<\/tr>\n | ||||||
| 98<\/td>\n | Figure F.2 \u2013 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) <\/td>\n<\/tr>\n | ||||||
| 99<\/td>\n | F.3 Numerical evaluation of medical implant enhancement factor F.3.1 General F.3.2 Numerical setup Figure F.3 \u2013 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 <\/td>\n<\/tr>\n | ||||||
| 101<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Exposure assessment methods for wireless power transfer systems<\/b><\/p>\n |