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.