WIRELESS POWER TRANSMISSION-EXPLORING
SOURCE TO LOAD INDUCTIVE LINK
PERFORMANCE UNDER RESONANCE AND
VARYING LOAD CONDITIONS
BY
KHANDKER JAMIL AHMED
A dissertation submitted in partial fulfilment of the
requirement for the degree of in Master of Science
(Electronics Engineering)
Kulliyyah of Engineering
International Islamic University Malaysia
MAY 2017
ii
ABSTRACT
Recently, Wireless Power Transmission (WPT) system has been significantly crucial
for the battery charging system since it is hassle free, efficient, user friendly, low cost
as well as ecofriendly. Wireless power transmission (WPT) for charging up of the
electronic gadgets, electric vehicles, and biomedical implants is being researched
heavily these days. Researchers have been proposing the WPT technique with two
categories of non-radiative and radiative. However, it had been investigated that the
inductive coupling of non-radiative technique is much more efficient than the radiative
technique. As wireless power transmission in configurations at many-to-one as well as
one-to-many systems is concerned the selective resonant frequency has got a role to
play. This dissertation explores the one-to-one and one-to-two power transmission
inductive link scenarios. The technique of analysis of both of these links is based on
studying the effect of the magnitude of the reflective impedance to estimate the power
transfer efficiency. To evaluate the performance of both of, the scenarios the MATLAB
and Pspice software analysis and simulation tools are used. The result suggests that the
output efficiency has been improved for 1-to-many and many-to-one application,
scenarios.
iii
خلاصة البحث
لا يمكن تخيل العالم بدون طاقة كهربائية. وعادة يتم نقل الطاقة من خلال الأسلاك. وفي الآونة
الأخيرة، أصبح نقل الطاقة الكهربائية لاسلكيا جزءا مهما من نظام الشحن الكهربائي. العديد من
( لشحن الأدوات الإلكترونية، WPTائية لاسلكيا )الأبحاث في هذه الأيام تناولت نقل الطاقة الكهرب
والسيارات الكهربائية، وفي الزراعة الطبية الحيوية. وقد تم البرهان على أن نظام شحن البطارية
لاسلكيا هو أكثر فائدة، وخال من المتاعب، وأكثر كفاءة، وأسهل في التركيب، وأخيرا فإن تكلفة
( تنقسم إلى فئتين: غير الإشعاعي والإشعاعي. WPTفإن تقنية ) المحافظة عليه أقل. في الأساس،
ومن بين هذه التقنيات غير الإشعاعية تعتبر تقنية الاقتران الحثي هي الأكثر كفاءة من غيرها. كما
لنقل الطاقة الكهربائية في سيناريو العديد إلى واحد، أن تقنية الرنان الانتقائية تلعب دورا حيويا
حد إلى العديد. يستكشف هذا البحث روابط ملف المصدر إلى الحمل من نوع واحد الى وكذلك الوا
كمعامل من أجل تقدير كفاءة (ZRefواحد، وواحد إلى اثنين، باستخدام قيمة المقاومة الانعكاسية )
( كبرامج محاكاة. كما تم Pspice( و )MATLABنقل الطاقة. في هذا البحث، استخدم برنامجا )
التعابير التحليلية ونتائج المحاكاة في هذا التحليل، حيث أظهرت تأثير مطابقة الرنين استكشاف
والحمل.
iv
APPROVAL PAGE
I certify that I have supervised and read this study and that in my opinion, it conforms
to acceptable standards of scholarly presentation and is fully adequate, in scope and
quality, as a dissertation for the degree of Master of Science (Electronics Engineering).
…………………………………..
Sheroz Khan
Supervisor
…………………………………..
Anis Nurashikin Nordin
Co-Supervisor
I certify that I have read this study and that in my opinion it conforms to acceptable
standards of scholarly presentation and is fully adequate, in scope and quality, as a
dissertation for the degree of Master of Science (Electronics Engineering).
…………………………………..
Mohamed Hadi Habaebi
Internal Examiner
…………………………………..
Belal Ahmed Hamida
Internal Examiner
This dissertation was submitted to the Department of Electrical and Computer
Engineering and is accepted as a fulfilment of the requirement for the degree of Master
of Science (Electronics Engineering).
…………………………………..
Anis Nurashikin Nordin
Head, Department of Electrical
and Computer Engineering
This dissertation was submitted to the Kulliyyah of Engineering and is accepted as a
fulfilment of the requirement for the degree of Master of Science (Electronics
Engineering).
…………………………………..
Erry Yulian Triblas Adesta
Dean, Kulliyyah of Engineering
v
DECLARATION
I hereby declare that this dissertation is the result of my own investigations, except
where otherwise stated. I also declare that it has not been previously or concurrently
submitted as a whole for any other degrees at IIUM or other institutions.
Khandker Jamil Ahmed
Signature ........................................................... Date .........................................
vi
INTERNATIONAL ISLAMIC UNIVERSITY MALAYSIA
DECLARATION OF COPYRIGHT AND AFFIRMATION OF
FAIR USE OF UNPUBLISHED RESEARCH
WIRELESS POWER TRANSMISSION-EXPLORING SOURCE
TO LOAD INDUCTIVE LINK PERFORMANCE UNDER
RESONANCE AND VARYING LOAD CONDITIONS
I declare that the copyright holders of this dissertation are jointly owned by the
student and IIUM.
Copyright © 2017 Khandker Jamil Ahmed and International Islamic University Malaysia. All rights
reserved.
No part of this unpublished research may be reproduced, stored in a retrieval system,
or transmitted, in any form or by any means, electronic, mechanical, photocopying,
recording or otherwise without prior written permission of the copyright holder
except as provided below
1. Any material contained in or derived from this unpublished research
may be used by others in their writing with due acknowledgement.
2. IIUM or its library will have the right to make and transmit copies (print
or electronic) for institutional and academic purposes.
3. The IIUM library will have the right to make, store in a retrieved system
and supply copies of this unpublished research if requested by other
universities and research libraries.
By signing this form, I acknowledged that I have read and understand the IIUM
Intellectual Property Right and Commercialization policy.
Affirmed by Khandker Jamil Ahmed
……..…………………….. ………………………..
Signature Date
vii
ACKNOWLEDGEMENTS
Firstly, it is my utmost pleasure to dedicate this work to my dear parents and my family,
who granted me the gift of their unwavering belief in my ability to accomplish this goal:
thank you for your support and patience.
I would like to express my appreciation to Dr. Mohammad Kamrul Hasan for his
insightful advice and comments on my research work. I would like to extent my
appreciation, respect and thanks to all of my lecturers in the department of Electrical
and Computer Engineering, Kulliyyah of Engineering.
Finally, a special thanks to Professor Dr. Sheroz Khan for his continuous
support, encouragement and leadership, and for that, I will be forever grateful.
My appreciation and thanks to Md Mizanur Rahman for his valuable support. It
is a great pleasure to thank to my parents through whom Allah has endowed
me through unshakeable support since the very beginning of my life.
viii
TABLE OF CONTENTS
Abstract….. .............................................................................................................. ii
Abstract in Arabic .................................................................................................... iii
Approval Page .......................................................................................................... iv
Declaration .............................................................................................................. v
Copyright page ......................................................................................................... vi
Acknowledgement ................................................................................................... vii
List of Tables ........................................................................................................... x
List of Figures .......................................................................................................... xi
List of Abbreviations ............................................................................................... xiii
List of Symbols ........................................................................................................ xiv
CHAPTER ONE: INTRODUCTION ................................................................. 1
1.1 Background of Study .............................................................................. 1 1.2 Research Problem Statement and Its Significamts ................................. 9
1.2.1 Problem Identification and Motivation ......................................... 9
1.3 Research Objectives ................................................................................ 9
1.4 Methodology: .......................................................................................... 10
1.5 Dissertation Organization: ...................................................................... 12
CHAPTER TWO: LITERATURE REVIEW .................................................... 13 2.1 Introduction............................................................................................. 13 2.2 Non-Contact Powering Means ................................................................ 13
2.3 Inductive Coupling Analysis .................................................................. 18 2.4 Resonant Inductive Power Transfer Link ............................................... 35
2.5 Two and Four Coils WPT System .......................................................... 36 2.6 Slectective Power Transfer Technique ................................................... 41
2.7 Chapter Summary ................................................................................... 42
CHAPTER THREE: ANALYTICAL AND MATHEMATICAL
MODELING OF WIRELESS POWER TRANSMISSION SYSTEM ............. 44 3.1 Introduction............................................................................................. 44 3.2 Development of Wireless Power Transmission System ......................... 45
3.2.1 Inductive Coupling ....................................................................... 45 3.2.2 Effect of Air Co-efficient (k) ........................................................ 45 3.3 Inductive Power Transferring (IPT) System........................................... 47
3.4 Inductive Charging for Electric Vehicles ............................................... 48
3.4.1 Series Resonant (SLC) Topology ................................................. 48 3.4.2 Parallel Resonant (PLC) Topology ............................................... 50 3.5 One to One Tencnique in WPT System .................................................. 51
3.6 One to Two Technique in WPT System ................................................. 54 3.7 Two to One Technique in WPT System ................................................. 56
3.8 Performance Metrics ............................................................................... 58 3.8.1 Reflective Impedance ................................................................... 59 3.8.2 Output Power ................................................................................ 60
ix
3.9 Simulation Setup and Parameters ........................................................... 60
3.10 Chapter Summary ................................................................................. 63
CHAPTER FOUR: RESULT ANALYSIS AND DISCUSSION ...................... 64 4.1 Introduction............................................................................................. 64 4.2 Performance Evaluation Technique ........................................................ 64
4.2.1 Analytical Approach ......................................................................... 64
4.2.1 Simulation Approach ........................................................................ 65 4.3 Result Analysis ....................................................................................... 65
4.3.1 Result Discussion for Analytical Evaluation ................................. 66 4.3.2 Result Discussion for Simulation Evaluation ............................... 69 4.4 Chapter Summery ................................................................................... 77
CHAPTER FIVE: CONCLUSION AND FUTURE RECOMENDATION .... 79 5.1 Conclusion .............................................................................................. 79
5.2 Thesis Contribution ................................................................................ 80
5.3 Recommendation .................................................................................... 80
REFERENCES ....................................................................................................... 81
LIST OF PUBLICATIONS .................................................................................. 87
APPENDIX A ......................................................................................................... 88
x
LIST OF TABLES
Table No. Page No.
2.1 Summary of the Related Works 43
3.1 Impedance of SRLC WPT system and PRLC WPT system 52
3.2 Simulation Parameters 60
xi
LIST OF FIGURES
Figure No. Page No.
1.1 Block Diagram of Typical WTP System (in EV) 5
1.2 Different Types of Wireless Power Transmission Systems 5
1.3 Flow Chart of Research Methodology 11
2.1 A Diagram of a Wireless Power Transfer System 15
2.2 Leakage Flux and Mutual Flux in IPT Transformer 20
2.3 IPT Transformer Coupling Model 21
2.4 Typical Wireless EV Charging System 22
2.5 General Two-Coil WPT System 23
2.6 A User Plugs the Charging Cable Into an Electric Powered Vehicle 26
2.7 Small Paddle Inductive Station(Left), and The Paddle (Right) 25
2.8 Inductive Interface (Paddle) Equivalent Circuit 26
2.9 Two Basic Structure of RWPT Systems: (a) Two Coil Structures and
(b) Four Coil Structure 30
2.10 Conventional Double Load-transfer RWPTS systems: (a) Two Coil
Structures and (b) Four Coil Structure 31
2.11 Employing Double Load-Transfer RWPT Systems Structure 32
2.12 Simplified Typical Schematic of a Resonant Inductive Charger 36
2.13 Two Coils Series to Series WPT System 38
2.14 Four Coils Series to Parallel WPT System 40
3.1 Two Coaxial Coils With Radiuses a and b 47
3.2 Block Diagram of WPT System 48
3.3 Block Diagram of Resonant Circuit in WPT System 50
3.4 Block diagram of parallel resonant circuit in WPT System 51
3.5 One-One WPT System 54
xii
3.6 Equivalent Circuit Model of One to One WPT 54
3.7 Circuit Model Under Resonance of One to One WPT 53
3.8 One-to-two WPT System 56
3.9 Tencnique in WPT System 58
3.10 The One-to-Two Configuration for WPT System 59
3.11 The Two-to-One Configuration for WPT System 60
4.3 Magnitude of the Reflective Impedance versus Frequency of One-to-
One Coil Inductive Link 66
4.4 Magnitude of the Reflective Impedance versus Frequency of One-to-
Many Coil Inductive Link 66
4.5 Comparison and Benchmark of the Eficciency Verus Frequency 68
4.6 Output Power versus Frequency of One-to-One Coil Inductive Link 69
4.7 Output Power versus Frequencies of One-to-Two Coil Inductive Link
67
4.8 Efficiency versus Frequency for One-to-One Inductive Link 70
4.9 Efficiency versus Frequency for One-to-Two Inductive Link 71
4.10 Output Power versus Frequency for One-to-Two Inductive Links 71
4.11 Output Power versus Frequency when R is 10 and 11 for One-to-Two
Inductive Links 72
4.12 Efficiency versus Frequency when R4, R6 is 10, 20, 30, 50, 80, 80,
100 and 140 for One-to-Two Inductive Links 73
4.13 Efficiency versus Frequency when R4, R6 is 10, 20, 30, 50, 80, 100
and 140 for Two-to-One Inductive Links 74
4.14 Output Power versus Frequency when R6 is 0.5, 1, and 1.5 for Two to
One Inductive Links 75
4.15 Output Power versus Frequency Two to One Inductive Links 75
xiii
LIST OF ABBEREVIATIONS
WPT Wireless Power Transmission
Txs Transmission Side
Rxs Receiving Side
Q-factor Quality Factor
Zref Magnitude of The Reflective Impedance
NY New York
IPT Inductive Power Transmission
AGV Automated Guided Vehicle
BEV Battering Powered Electric Vehicle
PEV Plugged-In Electric Vehicle
AMI Advanced Metering Infrastructure
EV Electric Vehicle
RPEV Roadway-powered Electric Vehicle
PHEV Plugged-In Hybrid Electric Vehicle
MPT Microwave Power Transmission
SPS Solar Power Satellites
EMI Electro-magnetic Interference
ZVS Zero-Voltage Transmitting
LCL Less container load
G2G Vehicle to lattice Applications
G2V Matrix to Vehicle Applications
GM General Motors
ESR Equivalent Series Resistance
RWPT Resonant Wireless Power Transmission
MRC-WPT Magnetic-Coupled Wireless Power Transmission
PTE Power Transmission Efficiency
SLC Series Resonant Topology
PLC Parallel Resonant Topology
xiv
LIST OF SYMBOLS
C Capacitance
D Diode
k Coupling Co-efficient
L Inductance
M Mutual Inductance
R Resistance
η Efficiency
f 0 Frequency
1
CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF STUDY
Nowadays, wireless power transmission has become a significant part of daily life.
Moreover, this technology is now becoming more and more popular day by day because
of the user-friendly nature and hustle free charging system. In contrast, traditional
cables or wires for charging create limitation on the mobility of any electronic or
electrical appliance (Hatanaka et al., 2002; Murakami et al.,1996). By considering
overall advantages, power transmitting by the transmitters (Txs) and receivers (Rxs) or
vice versa is coming up in new shapes finding applications of these days. Such power
transfer is the transmission of electrical energy from a power source to an electrical load
without the use of human-made conductors, that is, through non-contact means. Such
non-contact transfer of power could be one source to multiple loads or multiple source
to single load. Coupling among the multiple Txs or Rxs coils is being explored. In order
to transmit more power transmission with maximum efficiency, an important issue is
resonant frequency. By fixing exact resonant frequency much efficiency can be
achieved (Jang et al.,2003). However, there are some other issues, for example number
of coil turns in primary and secondary side, air gap between sources and loads, Q-factor
etc. Many-to-one as well in one-to-many power transfer selective resonant technique
plays a vital role (Choi et al.,2004; Hirai et al.,A. 2000) So, in this research we explores
the one-to-one and one-to-two source-to-load-coil links using the magnitude of the
reflective impedance as a parameter for estimating the power transfer efficiency. The
2
analytic expressions and simulation results have been explored in this analysis, showing
the effect of resonant and load matching.
Wireless Power Transfer (WPT) refers to the process of transmission of
electrical energy through non-contact means, and has been known since the middle of
the 19th century. It was first introduced by Nikola Tesla (Landt, J. et al 2005), who
ambitiously thought of larger amount of power transfer to aircrafts and ships. Before
that in 1868 James Clerk Maxwell proposed the classical electromagnetic theory. Later
in the year of 1888, Henrich Rudolf Hertz demonstrated practically setting up the first
radio transmitter. Once James Clerk Maxwell built up the traditional electromagnetic
hypothesis, the start of wireless power transmission can be traced back to 1868.
Maxwell's conditions bind together past random perceptions of power, attraction and
optics into one predictable hypothesis. Later in 1888, Heinrich Rudolf Hertz checked
the presence of electromagnetic radiation through building the main radio transmitter
(Covic, G. A. & Boys, J. T. et al 2013). The main noteworthy leap forward in wireless
power transmission innovation happened in 1897 when Nikola Tesla documented his
first licensed Wardenclyffe Tower, which is otherwise called Tesla Tower in Colorado
Springs please support this by source as Tesla Tower is in NY Tesla reverberated a 3
feet distance across copper ball on top of the 200 feet control with 300 kW of force from
the Colorado Springs Electric Company.
To make conceivable probably the most noteworthy accomplishments of our
time, the drive to utilize electrical power in novel ways has formed practically every
part of innovative progression during the last two hundred years. This now omnipresent
piece of innovative society has as of not long ago has basically reminded depended on
the vehicle of charge transporters crosswise over separation through copper conveyors.
Wireless inductive power transmission (IPT) likewise referred to even for the most part
3
as wireless power transmissions (WPT) is a developing innovation that utilizations time
changing attractive ends to securely and dependably transmit control over expansive air
gaps to invigorate or charge at least one electrical load with high efficiency.
This novel innovation not only has been unnoticeable developing in research
labs while recent decades but also is currently ready to reduce the way electrical power
is demolished by society on the loose. To date, IPT has been effectively embraced in
clean rooms and mechanical assembling tools for driving robotized guided vehicles
(AGVs) that are obliged to go over a track and can require multi-kilowatt levels of
energy to work (Green et al.,J. T. 1994; Covic et al.,2000; Stielau et al.,2000; Hu et
al.,2008). It has additionally been utilized to exchange little measures of control over
little air crevices for charging of convenient customer hardware, for example, PDAs,
tablets, and electric tooth brushes (Hui et al.,2005; Kim et al.,2001; Sample et al.,2011;
Cannon et al.,2009). More as of late however, the use of this innovation for static and
in-movement charging of elasticized transportation, for example, electric vehicles,
transports, and prepare frameworks over bigger air holes and misalignment has seen a
blast in innovative work in the scholarly community and private industry.
With an interoperability industry standard (SAEJ2954) well in advance towards
fulfilment by 2015, remote charging of EVs has gone from being only a dark and
fascinating innovation to a substantial and engaging reality.
Using induction, Nikola thought, it was possible to transmit and receive high
current signals over a considerable distance. However, to transmit significant power
through that way, the two inductors must be placed in fairly proximity. On the other
hand, to cover more area through contactless power transmission system a more
efficient technique achieved which is electrodynamics induction also known as resonant
inductive coupling. By adding only one capacitor in parallel with the receiving end coil
4
creates a circuit which resonates at the frequency of the voltage source at the
transmitting end coils (Kurs et al.,2007). As a result, generating resonance between the
primary and secondary coils, radiative losses are impressively reduced and power
transmission efficiency can reach up to 40%-50% (Jonah et al.,2012; Karalis et
al.,2008).
Due to recent advancement of wireless technology, application of the wireless
charging of electronic devices, powering radio frequency identification and biomedical
implants and many other such sectors get innovative impetus (Kiani et al.,2012).
Batteries usually power such as electronic devices. For devices quick charging,
conventional batteries have lack from re-charging or replacement provisions (. Lisi et
al.,2016). Therefore, the independence of continuous power supply is one important
achievable objective in this work. Instead of charging battery from traditional sources
an attractive and alternative of charging source is the wireless power transmission
technique through inducting coupling technique. In addition, the magnetic resonance in
WPT technique generates a more regulated DC power to electronic components
(Choudhary et al.,2011). .It is clear that, almost 90% of all car trips are less than 10km,
meaning that almost all average day-to-day travelling can be easily accomplished with
a Bettering powered Electric Vehicle (BEV) or Plugged-in Electric Vehicle (PEV).
Electric charging systems, one is as shown in Figure 1.1, could be residential (3kW),
public place (22kW) or the ones with extra short charging times access points (50kW).
AC utility
power
Charge
controller
Rectifier
Charge
controller
BatteryVehicle
inletConnectorPower
conversionComm
FluxCharging side Vehicle side
Control Status
Figure 1.1: Block diagram of typical WTP system (EV).
5
Many different mechanisms such as electric induction, electromagnetic radiation
and magnetic induction are in wireless power transmission system (Khan et al., 2012).
Among these the magnetic resonance technique has got higher power transmission and
higher area coverage compared to the other methods. Hence, there has been significant
progress in wireless power transmission (WTP) system. Figure 1.2: shows different
types of WPT system.
Wireless Power
Transmission
ResonantInductiveLaser Microwave
Magnetic inductionElectric inductionElectromagnetic
radiation
Figure 1.2: Different Types of Wireless Power Transmission Systems
In such cases, the power transfer is maximized if coils engaged in the power transfer
are tuned up at a common resonating frequency. This is done through resonating the
coupled coils, that is, the coupled inductors are tuned up at a common resonant
frequency for power transfer over distances in the meters’ range (Boby et al.,2014).
Another form of wireless energy transfer is electromagnetic radiation, such as in radio
waves or Microwave. With the wireless power transmission method, household devices
and gadgets need to be charged up through induction mechanism, which can only
6
happen if the coils are close together (Kim et al.,2014). Some research works have
focused on developing three dimensional mathematical models of the magnetic field of
spiral and solenoid coils to investigate the effect of lateral misalignment on the mutual
inductance of the coils. They worked on Finite Element Method (FEM) simulations of
the spiral and solenoid transmit coils, which were carried out to validate the developed
models. Coil circuit parameters such as inductance, resistance and quality factor are also
given (Liu et al.,2009). Again, another unfolding idea is based on coupled circuits, and
used to transfer power by magnetic inductive resonance or wireless inductive power
transfer method where the individual nodes are battery-less for making them
maintenance free Besides that, existing parts such as the tank and rectifier circuits are
optimized to increase efficiency and improve inerrability (Pannier et al.,2009).
Magnetic inductive resonance mainly works on Electromagnetic field induced between
two coils that are tuned to resonate at the same frequency. Some researcher developed
a methodology for a resonant reactive shield for the reduction of magnetic field leakage
from a wireless power transfer (WPT) systems. By using LC resonance, the reactive
shield can generate a cancelling magnetic field to reduce the incident magnetic field
from WPT coils and effectively reduce the total magnetic field without consuming
additional power (Bosshard, R., Mühlethaler, 2013). There are some issues need to
studied to develop practical wireless charging system: magnetic coupler design
techniques, control methods, compensation topologies, foreign object detection
algorithms, and the radiation (Choi et al.,2015) . Among them, magnetic couple design
is the crucial and basic part. A larger stronger field could induce current from farther
away, but the process would be extremely inefficient. Since a magnetic field spreads in
all directions, making a larger one would waste a lot of energy. In another paper the
research introduced the most efficiency depend on Power circuit, receiver quality and
7
position of receiver (Zhang et al.,2015). Researcher also found that while researching
on the applications with biomedical implants and radio-frequency identification
systems some new efficient coil design can charge the batteries of consumer electronic
devices for the hybrid electric vehicles with minimum loss of power (Mecke et al.,
2004). Some focused on the electricity distribution layer using wireless power and data
communication, ranging from Advanced Metering Infrastructure (AMI) gateways at the
house-hold to the distribution point where a multi-hop mesh network is built for large
coverage to transmit power and data (Shabani et al.,2013). Where some concept
showed that, Roadway-powered electric vehicles (RPEVs) are attractive candidates for
future transportation because they do not rely on large and heavy batteries but directly
and efficiently get power while moving along a road (Kim et al.,2014). The interest for
the use of electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) has been
growing because of the growth in greenhouse-gas emissions which affect the
environment and the fossil-fuel price fluctuations in the past decade. The electric
vehicle powered by the high power and large capacity battery pack. However, the
driving range, cost and inconvenience charging are the main barrier to fulfill the
customer satisfaction. By the development of research, researcher also found that the
driving frequency greatly influences the efficiency of a load know as resonance
frequency and they designed that hardware for multiple-load system with different
resonant frequencies for efficiency expression (Arshad et al.,2014). While other
research proposed the concept and design methodology for a resonant reactive shield
for the reduction of magnetic field leakage from a wireless power transfer (WPT)
systems. Their concept was to use LC resonance for the reactive shield, which can
generate a cancelling magnetic field to reduce the incident magnetic field from WPT
coils and effectively reduce the total magnetic field without consuming additional
8
power (Chen, et al 2014). Measuring precise values of passive elements such as
resistors, inductors as well as capacitors through non-contact through inductive
coupling for series and parallel. Resonant circuit is used for selective identification of
high frequency components. However, if one of the circuit components such as the
inductance, capacitance or resistance is made to vary, it will cause a change in the
impedance output. In an eye-catching research, some researcher proposed the
QUADRUPLE, where they found four emitting coils configuration not only increase
the transmission distance but also weaken the sensitivity of the angle change (Choi et
al., 2016). Recently reported is the work by authors in which we find quadruple coils at
the sending end of the WPT link (used as transmitter coils) and using a single coil as
receiver of wireless power. EMF noise is significantly reduced with negligible change
in induced voltage. 3D simulations and the field distributions are shown and the pros
and cons are of the quadruple coil designs are discussed (Jegadeesan et al., 2012).
The efficiency of load vehicles is greatly influenced by the circuits driving these
transfer links at a known resonant frequency while in applications of multiple-loads
scenario using different resonant frequencies. Measuring precise values of passive
elements of resistors, inductors, and capacitors for application in this non-contact
inductive coupling approach, resonant circuit is used to maximize for selective power
transfer (Eason et al., 1955). However, if one of the circuit components such as the
inductance, capacitance or resistance is made to vary, it will cause a change in the
impedance output. To improve the convenient charging system to the end user, the
wireless power technology (WPT) has been considered as a potential solution.
Throughout all static effective research and experiments, we focus here in this work on
a work that can be considered as an evolved work of the research conducted in our
research Wireless Communication and Signal Processing research group here at IIUM.
9
The Quadruple components involved such as Quadruple antennas based on magnetic
resonance for electronic circuits ideally speaking coil-design shapes has proven better
than the original one when it comes down to transfer efficiency
1.2 RESEARCH PROBLEM STATEMENT AND ITS SIGNIFICANCE:
1.2.1 Problem Identification and Motivation
The application of Wireless Power Transfer is increasing widely around for applications
and research because of safe power transferring, reducing the risk of corrosion,
environment friendly. There are many WPT systems available: Inductive coupling, Air
ionization, LASER power transmission, Resonant Inductive coupling, Microwave
Power Transmission (MPT). Parameter such as especially distance, diameters,
frequency, and impedance, coupling co-efficient and sending-receiving points are the
major issues to achieve high efficiency in Inductive coupling and resonant inductive
coupling.
In addition, the resonant inductive coupling method depends on one-to-many
coils and vice versa configuration for selective power transfer. Furthermore, reflective
impedance on resonant frequency is an important issue. In this research, mainly our
focus is to explore the output power efficiency varying load conditions for one-to-many
and many-to-one scenario under the resonance frequency.
1.3 RESEARCH OBJECTIVES
The focus in this work is to explore the output power transfer efficiency under resonant
frequency condition for reactively coupled WPT system. The following issues need to
be addressed to achieve the main objectives:
10
1. To study analytical and simulation concept of one-to-one, one-to-many and
many-to-one wireless power transmission system.
2. To develop and analyze the series resonance circuit for one-to-one, one-to-
many and many-to-one wireless power transmission system
3. To evaluate the output power, efficiency under varying load conditions for one-
to-many and many-to-one configuration under the resonance frequency
condition.
1.4 METHODOLOGY:
The methodology of this study is given in Figure 1.3.