Wireless Power Transfer (WPT) enables power to be transferred from a grid or storage unit to a device without the need for cable connections. This can be performed by inductive coupling of magnetic fields as well as by direct radiative transfer via beams of electromagnetic waves, commonly radiowaves, microwaves or lasers. Inductive coupling is the most widely used wireless technology with applications including charging handheld devices, RFID tags, chargers for implantable medical devices, and proposed systems for charging electric vehicles. Applications of radiative power transfer include solar power satellites and wireless powered drone aircraft.
This book covers the very latest in theory and technology of both coupling and radiative wireless power transfer. Topics covered include the basic theory of inductive coupling and resonance coupling WPT; multi-hop WPT; circuit theory for wireless couplers; inverter/ rectifier technologies for WPT systems; basic theory of WPT via radio waves; technologies of antenna and phased array for WPT via radio waves; transmitter/rectifier technologies for WPT via radio waves; applications of coupling WPT for electric vehicle charging; applications of long-distance WPT; and biological interactions of electromagnetic fields and waves.
Author(s): Naoki Shinohara
Publisher: The Institution of Engineering and Technology
Year: 2018
Language: English
Pages: 294
Cover
Contents
About the editor
1
Introduction
References
2
Basic theory of inductive coupling
2.1 Introduction
2.2 WPT system
2.2.1 Basic theory of WPT system
2.2.2 Microwave method
2.2.3 Magnetic resonance method
2.2.4 Electrical resonance method
2.2.5 Electromagnetic induction method
2.3 Magnetic induction
2.3.1 Power transformer
2.3.2 Magnetic induction (LC mode)
2.4 Medical applications
References
3
Basic theory of resonance coupling WPT
3.1 Classification of WPT systems
3.1.1 Classification of near-field and far-field WPT
3.1.2 Classification of resonant WPT
3.1.3 Relationship among WPT types
3.2 Unified model of resonance coupling WPT
3.2.1 Concept of the "coupler"
3.2.2 Unified model based on resonance and coupling
3.2.3 Application for LC resonator
3.2.4 Application for electric field coupling WPT
3.2.5 Application for self-resonator
3.3 Generalized model of WPT
3.3.1 Energy flow in WPT system
3.3.2 Generalized model
3.3.3 Understanding of coupled-resonator WPT system through generalized model
3.3.4 Understanding of coupler-and-matching-circuit WPT system through generalized model
Acknowledgment
References
4
Multi-hop wireless power transmission
4.1 Transfer distance extension using relay effect
4.2 Multi-hop routing
4.3 Equivalent circuit and transfer efficiency
4.4 Design theory based on BPF theory
4.5 Design theory for arbitrary hop power transmission
4.6 Power efficiency estimation
References
5
Circuit theory on wireless couplers
5.1 Introduction
5.2 Inductive coupler
5.2.1 Equivalent circuit
5.2.2 Coupling coefficient
5.2.3 Q factor
5.2.4 Coupling Q factor
5.2.5 Optimum impedance
5.2.6 Maximum efficiency
5.3 Capacitive coupler
5.3.1 Equivalent circuit
5.3.2 Coupling coefficient
5.3.3 Q factor
5.3.4 Coupling Q factor
5.3.5 Optimum admittance
5.3.6 Maximum efficiency
5.4 Generalized formulas
5.4.1 Two-port black box
5.4.2 Impedance matrix
5.4.3 Generalized kQ
5.4.4 Optimum load and input impedance
5.4.5 Maximum efficiency
5.5 Conclusion
Appendix A
A. 1 Measurement of kQin practice
Acknowledgments
References
6 Inverter/rectifier technologies on WPT systems
6.1 Introduction
6.2 WPT system construction
6.3 General theory of optimal WPT system designs
6.3.1 Coupling coils
6.3.1.1 Self-inductance of air-core solenoid
6.3.1.2 Mutual inductance
6.3.1.3 Equivalent series resistance
6.3.2 Optimal design of coupling part
6.3.2.1 Impedance transformation of rectifier and transformer
6.3.2.2 Efficiency of coupling part
6.3.2.3 Optimal coupling part design and secondary resonance
6.3.3 Design strategies of rectifier and inverter
6.4 High-efficiency rectifier
6.4.1 Class D rectifier
6.4.2 Effects of diode parasitic capacitance
6.4.3 Class E rectifier
6.4.4 Class E/F rectifier
6.5 High-efficiency inverters
6.5.1 Class D inverter
6.5.2 Class E inverter
6.5.3 Class DE inverter
6.5.4 Class E/F inverter
6.5.5 Class Φ inverter
6.6 Design example of optimal WPT system
6.6.1 Optimal design for fixed coil parameters
6.6.1.1 Receiver part design
6.6.1.2 Class E inverter design
6.6.2 Optimal WPT system design
6.7 Conclusion
References
7
Basic theory of wireless power transfer via radio waves
7.1 Introduction
7.2 Propagation of radio waves
7.2.1 Radio waves in a far field
7.2.2 Radio waves in the radiative near field
7.2.3 Radio waves in the reactive near field
7.2.4 Radio waves from a dipole antenna
7.3 Directivity control and beam formation using phased-array antenna
7.4 Receiving antenna efficiency
References
8
Technologies of antenna and phased array for wireless power transfer via radio waves
Abstract
8.1 Introduction and rationale
8.2 Design of antenna and phased arrays for WPT: problem formulation
8.2.1 The end-to-end WPT efficiency
8.2.2 The WPT antenna design problem
8.3 WPT phased array synthesis techniques
8.3.1 Uniform excitations in WPT
8.3.2 Heuristic tapering methods
8.3.3 Designs based on optimization strategies
8.3.4 Optimal WPT phased array synthesis
8.3.5 Unconventional architectures for WPT phased arrays
8.3.5.1 Clustered WPT layouts via CPM synthesis
8.3.5.2 CS-designed sparse WPT arrangements
8.4 Final remarks, current trends, and future perspectives
Acknowledgments
References
9
Transmitter/rectifier technologies in WPT via radio waves
9.1 Introduction
9.2 RF transmitter
9.2.1 RF amplifier with semiconductor
9.2.2 Vacuum tube type microwave generator/amplifier
9.3 RF rectifier
9.3.1 RF rectifier with semiconductor
9.3.2 Vacuum tube-type microwave rectifier
9.4 RF amplifier/rectifier with semiconductor
References
10
Applications of coupling WPT for electric vehicle
10.1 Introduction
10.2 EV and charging
10.3 Conductive charging
10.4 Wireless charging
10.4.1 Field evaluation in Europe
10.4.2 Filed evaluation in Japan
10.4.3 Filed evaluation in Korea
10.4.4 Filed evaluation in China
10.5 Regulation and standardization for WPT
10.5.1 Japan
10.5.2 European standards for electricity supply
10.5.3 China
10.5.4 IEC/ISO and SAE
10.6 ITU activity on WPT; frequency allocation
10.6.1 2014: Approval of non-beam WPT report
10.7 Coexisting with other wireless service (CISPR)
10.8 Human safety; IEC TC106 and ICNIRP
10.9 WPT application for the future: dynamic charging for EV
References
11
Applications of long-distance wireless power transfer
11.1 Introduction
11.2 Long-distance WPT in far field
11.2.1 Energy harvesting and scavenging
11.2.2 Ubiquitous WPT
11.3 Long-distance WPT in the radiative near field
11.4 Long-distance WPT in fielded field
11.5 Near-field WPT in a cavity resonator
References
12
Biological issue of electromagnetic fields and waves
12.1 Introduction
12.2 Epidemiological studies
12.3 Animal studies
12.4 Cellular studies
12.4.1 Genotoxic effects
12.4.1.1 Chromosomal or chromatid aberration
12.4.1.2 DNA strand breaks
12.4.1.3 Micronucleus formation
12.4.1.4 Mutation
12.4.2 Nongenotoxic effects
12.4.2.1 Cell proliferation and differentiation
12.4.2.2 Gene and protein expression
12.4.2.3 Immune response
12.4.2.4 Apoptosis
12.5 Conclusions on IF and RF studies
References
13 Impact of electromagnetic interference arising from wireless power transfer upon implantable medical device
13.1 EMI studies on active implantable medical devices
13.1.1 In vitro EMI measurement system for WPTSs
13.1.1.1 Measurement system configuration
13.1.1.2 Torso phantom
13.1.1.3 Electronic devices
13.1.2 Operation conditions of the AIMD
13.1.3 Fundamental test procedure
13.1.4 Measurement results for WPTS examples [45]
13.2 RF-induced heating of metal implants
Acknowledgment
References
Index
Back Cover
