WIRELESS POWER TRANSFER FOR LOW POWER DEVICE USING MAGNETIC RESONANT COIL MUHAMMAD FITRA ZAMBAK UNIVERSITI MALAYSIA PERLIS 2016

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WIRELESS POWER TRANSFER FOR LOW POWER DEVICE USING MAGNETIC

RESONANT COIL

MUHAMMAD FITRA ZAMBAK

UNIVERSITI MALAYSIA PERLIS

2016

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WIRELESS POWER TRANSFER FOR LOW POWER DEVICE USING MAGNETIC

RESONANT COIL

By

Muhammad Fitra Zambak (1440911287)

A thesis submitted

In fulfillment of the requirement for the degree of Doctor of Philosophy

SCHOOL OF ELECTRICAL SYSTEMS ENGINEERING UNIVERSITI MALAYSIA PERLIS

2016

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ACKNOWLEDGMENTS

Alhamdulillah, all praises to Allah, finally I able to complete my Thesis as scheduled time. Somehow it is not possible to complete successfully in time without technical support, teaching and aid from others parties. Here I proudly would like to express my deepest appreciation for the contributions of several people for their support which helped me throughout this thesis.

For the first of all, I would like to extend my sincere gratitude to my supervisor Dr. Syafruddin Hasan, co-supervisor Dr. Muzamir Bin Isa, Dr. Muhammad Irwanto from School of Electrical Systems Engineering and Assoc. Prof. Dr. Mohd Fareq Bin Abd Malek for his patience, advices, extensive knowledge and infinite guidance throughout the completion of this thesis. Thank you for your patience giving assistance, sharing knowledge and experiences. All the knowledge and advice provided is invaluable. A million thanks to your infinity guidance.

A special gratitude I would like to give to my family, laboratories assistance, friends, Centre of Excellent for Renewable Energy (CERE), Pusat Pengajian Kejuruteraan Sistem Elektrik (PPKSE), Research & Development (R&D) and Centre Graduate Study (CGS) UniMAP. I would like to take this opportunity to tremendously acknowledge for their constructive ideas, indirect support, give financial support and helps from the beginning stages of this thesis until it is completed.

Thank you very much.

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TABLE OF CONTENTS

PAGE

DECLARATION OF THESIS i

ACKNOWLEDGMENTS ii

TABLE OF CONTENTS iii

LIST OF TABLE vii

LIST OF FIGURE viii

LIST OF SYMBOLS xii

LIST OF ABBREVIATION xiii

ABSTRAK xv

ABSTRACT xvi

CHAPTER 1 INTRODUCTION 1

1.1 Background 1

1.2 Aims and Objective 3

1.3 Problem Statement 4

1.4 Scope 5

1.5 Project Outline 6

CHAPTER 2 LITERATURE REVIEW 8

2.1 History of Wireless Power Transfer 8

2.2 Inductive Power Transmission 10

2.3 System model and circuit analysis 11

2.4 Wireless charging in inductive mode 13

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2.5 Wireless charging in resonant mode 14

2.6 The tradeoff between resonant and inductive mode 14

2.7 Power Loss 15

2.8 Low Frequency non-Radiative Power Transfer 16

2.9 Em Energy Flow In Near Fields, Far Fields 17

2.9.1 Near Field Consideration 17

2.9.2 Energy Flow Consideration 20

2.10 EM Fields and ‘Evanescent’ Fields in Power Transfer Analysis 21

2.11 Inductor Construction 24

2.11.1 Toroidal Cores 24

2.12 LC-Pair 28

2.12.1 Coil Modeling 29

2.12.2 Electromagnetic waves and health 30

2.12.3 Acoustic and electrical resonance 31

2.13 Compact and Tunable Transmitter and Receiver for Magnetic Resonance

Power Transmission to Mobile Objects 33

2.13.1 Basic model 33

2.13.2 Analysis of transmission efficiency 37

CHAPTER 3 RESEARCH METHODOLOGY 44

3.1 Introduction 44

3.2 Project Flow Process 44

3.3 Block Diagram Wireless Power Transfer 46

3.4 Friis Equations 48

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3.5 Multisim Software Simulation 53

3.5.1 Wireless power transmitter circuit simulation 53 3.5.2 Wireless Power Receiver Circuit Simulation 55

3.6 PCB Layout Design 55

3.7 Design Magnetic Resonant Coil by using CST Studio Suite software 62

3.8 Experimental set up 70

3.8.1 Equipments and Materials 70

3.8.2 Electronic Component 71

3.8.2.1 Power MOSFET 72

3.8.2.2 Torroid 72

3.8.2.3 Ceremic MKV capacitor 72

3.9 Preparing Transmitter and Receiver 73

3.9.1 Transmitter 73

3.9.2 Receiver 74

3.10 Preparation of Magnetic Resonant Coil Holder 74

3.11 Enamel coil For Transmitter and Receiver of Wireless power transfer 77

3.12 Obstacles between Transmitter and Receiver 80

3.12.1 Human hands as obstacle 80

3.12.2 Book as obstacle 81

3.12.3 Plastics as obstacle 82

3.13 Transmitter and Receiver Self Resonators Free Positions 82

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CHAPTER 4 EXPERIMENTAL RESULTS AND DISCUSSION 86 4.1 Simulation Results using Multisim 13 Version Software 86

4.1.1 Transmitter Simulation Result 86

4.1.2 Receiver simulation result 89

4.2 Experimental Results 91

4.2.1 Effect of Transistor and MOSFET types 91

4.2.2 Effect of The Capacitor 96

4.2.3 Effect of the Torroid Inductor value 97

4.2.4 Effect of Type of coil, Number of coil turn and coil size Tx and Rx 98

CHAPTER 5 CONCLUSION AND RECOMMENDATION 109

5.1 Conclussion 109

5.2 Recommendation and Future Work 110

REFERENCES 111

APPENDIX A PUBLICATIONS 117

APPENDIX B AWARDS 119

APPENDIX C DATASHEET COMPONENT of MOSFET & MKV CAP

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LIST OF TABLE

NO. PAGE

3.1 List of component at the proposed wireless power transfer system 71

4.1 WPT performance by using transistor BD139 91

4.2 WPT performance by using transistor BC639PH29 92

4.3 WPT performance by using MOSFET IRFZ44N 93

4.4 WPT performance by using Mosfet IRFP450 94

4.5 Summary WPT performance different type of transistors and MOSFETs 95 4.6 Summary different value of capacitor at Tx and Rx 96

4.7 Summary different of Torroid inductor value 97

4.8 Comparison type coil of Tx and Rx 99

4.9 Comparison number of turn of Tx and Rx 99

4.10 Comparison between 30cm and 15cm of diameter coil Tx & Rx 100 4.11 Comparison between 15cm of diameter coil & 0.5cm coil size of Tx & Rx 101 4.12 Comparison between 30cm and 4, 4.5, 5cm of diameter coil Tx & Rx 102 4.13 Comparison between 15cm and 4, 4.5, 5cm of diameter coil Tx & Rx 103 4.14 Comparison between 4, 4.5, 5cm of diameter coil and 0.01cm of coil size of

Tx & Rx 104

4.15 Comparison between 4,4.5,5cm of diameter coil and 0.5cm of coil size of

Tx & Rx 105

4.16 Summary of experiment wireless power transfer by using magnetic resonant

coil for mobile phone charger 108

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LIST OF FIGURE

NO. PAGE

2.1 Typical arrangement of an inductively coupled power transfer system. 11

2.2 Model of wireless power transfer system. 12

2.3 Wireless power charging in inductive mode. 13

2.4 Wireless power charging in resonant mode. 14

2.5 Lowest system loss factor as a function of the FOM (Figure of Merit) Qk

(Stielau, O. H et al., 2000) 16

2.6 Typical fields for EM sources showing region differentiation by wavelengths

(Yates, D. C et al., 2004) 18

2.7 (a), (b), (c), Practical winding hints (C. Bowick, 1982). 28

2.8 The LC-pair in series resonance frequency. 28

2.9 Modeling of a single magnetic coil (Kundert K, 2006). 30 2.10 Three types of concept figures of the basic wireless power transmission system

model (a) Image of the basic system, (b) Equivalent circuit model, (c) Two- port network unit model (Takashi Komaru, et al., 2015) 35 2.11 Three dimensional plot and contour of the transmission efficiency in ω − r

domain with k = 0.01 and QS = QD = 1000 (Takashi Komaru et al, 2015). 38 2.12 Maximum transmission efficiency plotted along figure of merit (Takashi

Komaru et al, 2015). 39

2.13 Three dimensional plot (a, b,c) and contour of transmission efficiencies in ω − r domain with various coupling coefficients k and quality factors QS = QD =

1000. (Takashi Komaru et al., 2015) 43

2.14 Transmission efficiency with the three types of impedance matching control

schemes (Takashi Komaru et al., 2015). 43

3.1 Project flow chart for research work. 45

3.2 Block diagram of wireless power transfer. 47

3.3 Design Transmitter circuit using single transistor. 54 3.4 Design Transmitter circuit using parallel MOSFET. 55

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3.5 Design Receiver circuit. 56

3.6 PCB layout ultiboard using transistor. 57

3.7 PCB layout ultiboard 3D top layer view. 57

3.8 PCB layout ultiboard 3D bottom layer view. 58

3.9 PCB layout ultiboard using MOSFET. 59

3.10 Transmitter PCB layout ultiboard 3D top layer view. 59 3.11 Transmitter PCB layout ultiboard 3D bottom layer view. 60

3.12 Receiver PCB layout ultiboard. 61

3.13 Receiver PCB layout ultiboard 3D top layer view. 61 3.14 Receiver PCB layout ultiboard 3D bottom layer view. 62 3.15 CST studio suite displays create new project. 63

3.16 Application Area CST Studio Suite. 64

3.17 Workflow for the antenna. 65

3.18 Time domain for the antenna. 65

3.19 Unit of the antenna. 66

3.20 Summary of the setting parameters. 67

3.21 Small antenna. 67

3.22 Magnetic resonant coil right side view. 68

3.23 Magnetic resonant coil front view. 69

3.24 Magnetic resonant coil side view. 69

3.25 Magnetic resonant coil left side view. 70

3.26 Equipments and materials used in this study. 71

3.27 Transmitter circuit test on training board. 73

3.28 Wireless power transfer receiver circuit test on mobile phone charger. 74 3.29 Preparation pvc holder of antenna wireless power transfer. 75

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3.30 Mounting pvc pipe to the magnetic resonant coil wireless power transfer. 75 3.31 Copper tube and enamel wire of magnetic resonant coil. 76 3.32 Experimental WPT by using magnetic resonant coil. 77 3.33 Magnetic resonant coil different of diameter use of wireless power transfer. 78 3.34 Magnetic resonant coil with diameter 30cm, 15cm and 5cm. 78 3.35 Coil Size measure using Electronic Digital Caliper. 79

3.36 Experiment Setup and collect data. 80

3.37 The experimental setup for WPT using hands as an obstacle. 81 3.38 The experimental setup for WPT using books as an obstacle. 81 3.39 The experimental setup for WPT using plastic types products as an obstacle. 82

3.40 Tx and Rx experiment with vertical position. 83

3.41 Tx and Rx experiment with tilted 900. 83

3.42 Tx and Rx experiment with horizontal position. 84 4.1 Simulation circuit of transmitter with transistor BD139 and BC639. 87 4.2 Output waveforms are observed from simulation transmitter with transistor. 87

4.3 Circuit simulation transmitter with MOSFET. 88

4.4 Output waveforms are observed from simulation transmitter with MOSFET. 88

4.5 Rectifier simulation. 90

4.6 Rectifier simulation waveforms. 90

4.7 Graphic WPT performance by using transistor BD139. 92 4.8 Graphic WPT performance by using transistor BC639. 93 4.9 Graphic WPT performance by using MOSFET IRFZ44N. 94 4.10 Graphic WPT performance by using MOSFET IRP450. 95 4.11 Graphic comparison WPT performance different type of transistor and

MOSFET. 96

4.12 Summary different value of capacitor at Tx and Rx. 97

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4.13 Graphic Summary different of Torroid inductor value. 98

4.14 Graphic Comparison type coil of Tx and Rx. 99

4.15 Comparison coil size and number of turn of Tx and Rx. 100 4.16 Graphic comparison between 30cm and 15cm of diameter coil Tx & Rx. 101 4.17 Graphic comparison between 15cm of diameter coil and 0.5cm of coil size

of Tx & Rx. 102

4.18 Graphic comparison between 30cm and 4, 4.5, 5cm of diameter coil

Tx & Rx. 103

4.19 Graphic comparison between 15cm and 4, 4.5, 5cm of diameter coil

Tx & Rx. 104

4.20 Graphic comparison between 4,4.5,5cm of diameter coil and 0.01cm of

coil size of Tx & Rx. 105

4.21 Graphic comparison between 4,4.5,5cm of diameter coil and 0.05cm of

coil size of Tx & Rx. 106

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LIST OF SYMBOLS

#N Number of turns

% Percent

o Degree

η Efficiency

μr Relative Permittivity

Ω Ohm

λ Wavelength

π Pi

ω Omega

a_r Radially Directed Unit Vector Ae Defined as the area

B Electromagnetic field

c The speed of light

E Electric Field Vector

G Gain

H* The complex conjugate of the magnetic field I_o Dipole current amplitude

K Coefficient

Ploss Power loss

P_rad Radial Direction Pt Magnetic resonant coil

Q Quality

rS Impedance ratio

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xiii Rr Radiation resistance RL Loss resistance

S Poynting vector

W_r Radialcomponents of complex power density

W Average power density

W_θ Azimuthal components complex power density

Wi Power density

Γ Decay constant

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LIST OF ABBREVIATION

1D One Dimension

2D Two Dimension

3D Three Dimension

A Ampere

AC Alternated current

B Magnetic field

C Capacitor

cm Centimetre

CST Computer Simulation Technology

DC Direct current

D Diameter

E-field Electric Field

F Frequency

Fr Resonant frequency

H-field Magnetic Field Strength

Hz Hertz

IC Integrated Circuit

IEEE Institute of Electrical and Electronic Engineers ITx Current of Transmitter

I_Rx Current of Receiver

LCR Inductor, Capacitor, Resistor

LED Light Emitting Diode

L Inductor

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MKV Metal Layer Vapor (Deposited on Two Sides of Paper) MOSFET Metal Oxide Semiconductor Field Effect Transistor

P Power

PCB Printed Circuit Board PTx Power of Transmitter

PRx Power of Receiver

PQ Power quality

R Resistor

Rx Receiver

Tx Transmitter

V Volt

VTx Volt of Transmitter

VRx Volt of Receiver

WPT Wireless Power Transfer

μH Micro Henry

𝑉𝑑𝑐 Direct current voltage

𝑉𝑜𝑢𝑡 Output voltage

𝑉𝑟𝑚𝑠 RMS voltage

𝑋C Capacitance impedance

𝑋𝐿 Inductance impedance

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Pengiriman Kuasa Tanpa Wayar untuk Peralatan Kuasa Rendah menggunakan Gegelung Salunan Magnetik

ABSTRAK

Kuasa dipindahkan tanpa wayar melalui gegelung salunan magnetik, yang mana salunan magnetik adalah secara antena untuk menghantar dan menerima kuasa. Kaedah ini, tidak lagi rumit dengan berlalunya kabel di sekeliling, dengan bekalan elektrik tanpa wayar ia boleh digunakan sebagai sumber kuasa kepada peralatan elektronik seperti telefon bimbit, pemain MP3, semua peralatan yang menggunakan sumber bateri atau pendawaian elektrik. Komponen yang digunakan untuk membina pemindahan kuasa secara tanpa wayar boleh dibahagikan kepada 4 komponen; seksyen pemancar akan menukarkan voltan arus terus (DC) kepada bentuk arus ulang alik (AC) maka penerima akan menukarkan AC kepada DC yang serasi dengan peranti kuasa rendah. Manakala, di bahagian penerima yang mengandungi dengan gegelung penerima planar, penerima litar penerus, pengatur voltan litar terkamil (IC) dan bateri telefon bimbit. Sumber DC yang bersambung dengan pemancar disediakan dari sumber DC yang voltan dan arus boleh laras. Fungsi gegelung pemancar untuk menukarkan kuasa DC dari pengayun kepada isyarat kuasa AC berfrekuensi tinggi. Arus frekuensi tinggi yang dikaitkan dengan tanpa wayar gegelung kuasa pemancar akan mewujudkan medan magnet dalam gegelung kerana kuasa salunan magnetik digunakan untuk menghantar kuasa. Dalam pengecas kuasa seksyen penerima tanpa wayar, gegelung penerima menerima tenaga sebagai voltan ulang alik yang disebabkan oleh gegelung salunan dalam gegelung dan penerus dalam seksyen kuasa penerima tanpa wayar menukarkan voltan AC kepada voltan DC. Voltan DC akan memberi arus searah kepada beban melalui seksyen pengawal voltan. Fungsi utama pengecas bateri penerima mudah alih seksyen tanpa wayar adalah untuk mengenakan kuasa bateri mudah alih melalui gegelung salunan magnetik. Dari eksperimen keseluruhan dilaksanakan, pelbagai rekabentuk litar penerus dan penerima menggunakan transistor dan mosfet, diameter gegelung, saiz gegelung dan jenis bahan gegelung salunan magnetik. Faktor-faktor ini adalah kaedah dan aspek yang diperlukan untuk pemindahan kuasa tanpa wayar untuk pengecas telefon mudah alih. Dari ujian transistor dan mosfet untuk pemindahan kuasa tanpa wayar dengan menggunakan gegelung salunan magnetik, ia menunjukkan bahawa IRFP450 mosfet mempunyai kecekapan yang paling tinggi berbanding dengan mosfet IRFZ44N, transistor BC639 dan transistor BD139. Mosfet IRFP450 juga ditambah dengan 50μH daripada torroidal dan 61.2nF kapasitor dengan kadar galangan yang terbaik berbanding 100, 150, 200, 250, 300μH dan 6.8 ke 54.4nF yang tidak meningkatkan kecekapan pemindahan kuasa. Eksperimen penggunaan gegelung magnetik antara tiub tembaga dan dawai enamel di mana hanya mosfet IRFP450 dengan 50μH daripada torroidal dan juga 61.2nF dari nilai pemuat. Hasil kajian menunjukkan bahawa kecekapan tertinggi diperolehi dengan wayar enamel daripada copper tubing yang merupakan 25.41%

dengan saiz gegelung 0.05cm. Keputusan ini menunjukkan bahawa kecekapan pemindahan kuasa tanpa wayar boleh mencapai sehingga jarak 50cm, hasil penyelidikan ini dicadangkan supaya menggunakan enamel gegelung alternatif saiz kecil gegelung dan diameter untuk pengecas telefon bimbit. Penyelidkan juga menunjukkan tenaga tanpa wayar dengan menggunakan gegelung salunan magnetik tidak banyak dipengaruhi oleh tangan, buku dan berbagai jenis plastik.

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Wireless Power Transfer for Low Power Device using Magnetic Resonant Coil

ABSTRACT

The power is transferred wirelessly through a magnetic resonant coil as an antenna to transmit and receive the energy. This method no longer need complicated with the cable passing around us, with wireless electricity we can charge and make wireless electricity as an input source for electronic equipment such as Handphone, MP3 Player, everything works as a battery source or electrical wiring. The components used to build wireless power transfer can be divided into 4 parts components, transmitter section will convert Direct Current (DC) voltage to Alternating Current (AC) form then receiver will convert AC to DC form that compatible for low power device. Whereas, at receiver section containing with receiver planar coil, receiver rectifier circuit, voltage regulator Integrated Circuit (IC) and mobile phone battery. The DC source that connected to transmitter was provided by the DC source regulator which voltage and current can be adjusted separately. The transmitter coil is function to converts the DC power from an oscillator to a high frequency AC power signal. This high frequency alternating current, which is linked with the wireless power transmitting coil, would create an alternating magnetic field in the coil due to magnetic resonant to transmit energy. In the wireless power charger receiver section, the receiver coils receives that energy as an induced alternating voltage due to resonant coil in its coil and a rectifier in the wireless power receiver section converts that AC voltage to a DC voltage. Rectified DC voltage would be feed to the load through a voltage controller section. That is, the wireless mobile battery charger receiver section main function is to charge a power mobile battery through magnetic resonant coil. From the overall experiment conducted from various design transmitter and receiver circuit using transistor and mosfet, diameter, size and type of materials of magnetic resonant coil. These factors are the norms and necessary aspect of wireless power transfer for mobile phone charger. From the transmitter circuit design using transistor and mosfet test for wireless power transfer by using magnetic resonant coil, it shows that the mosfet IRFP450 has the highest efficiency comparing to mosfet IRFZ44N, transistors BC639 and BD139. The receiver circuit design using full bridge rectifier has the better output DC comparing to half bridge rectifier. Mosfet IRFP450 are also added with 50μH of torroidal and 61.2nF of capacitor has the best impedance rate compared to 100, 150, 200, 250, 300μH and 6.8 to 54.4nF which did not increase the power transfer efficiency. The results show that the highest efficiency is obtained by enamel wire rather than copper tubing which is 25.41% with coil size 0.05cm. The investigation for mobile phone application with small diameter (4, 4.5 and 5cm) and coil size 0.05cm of enamel wire, the distance of power transfer can be up to 50cm. The investigation also showed that the wireless power transfer by using magnetic resonant coil is not much influenced by the presence of hands, books and types of plastics.

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CHAPTER 1

INTRODUCTION

1.1 Background

Wireless power transfer (WPT) has been a dream of human beings. Many scientists have researched it uninterruptedly, but little progress has been made.

Recently, the wireless power transfer has become interesting topic of research in electrification of the transportation system. Researchers are studying the ways to change electric or plug in hybrid electric to charge mobile phone using wireless power transfer while the mobile phone are charged by wireless power and wireless power while they are in motion.

Wireless power transfer is possible because of resonant circuits. When a transmitter circuit is tuned to resonate at the same frequency as a receiver circuit, power is transmitted wirelessly through the magnetic coil of the inductive coils found in the circuits. Because the power is transferred by magnetic coils, there is a little electric contact danger to any biological entity. Electronics within the charging area are also unaffected unless they are resonant at the same frequency.

Scientists have researched the wireless power transfer since the classical work dates back from Hertz (1888), who first demonstrated the electromagnetic wave propagation in free space. Thereafter there was keen research interest and experimental

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tests were carried over by (Nicola Tesla, 1899). He inculcated the idea of power transfer through RF-signals. A classical breakthrough is the transmission of signals by (Marconi, 1901) over the Atlantic Ocean. This paved the way and turned the attention of scientist towards the RF-signals.

One of the earliest research papers about submeter, high power, and efficient wireless power transfer was published by (Karalis, A. Joannopoulos, J.D. & Soljacic, M, 2008). In that paper, the authors presented a non-radiative scheme based on magnetic resonance coupling. They analyzed the strong coupling regime of two resonating dielectric disks, capacitively-loaded conducting-wire loops with Coupled Mode Theory (CMT). Since they used CMT, the characteristic equations of the two resonating objects were decoupled, the analysis of the system was very simple and quality factor and power transfer efficiency of the coupled objects could be easily calculated. However, the paper did not provide a design-oriented model for such wireless power transfer systems, suitable for designing or validating a design.

In 2009, Waffenschmidt and Staring published a paper about the limitations of the inductive power link system in consumer electronics. They derived optimal system parameters for efficient power transfer and investigated the effects of distance and size of coil on power transfer efficiency. However, their analysis only used a resonant circuit of the receiver coil, not on the transmitter, and as a result, they concluded that inductive power transfer is only effective over short distances. They did not explore how power transfer capacity of a wireless power transfer system can be improved significantly if both the transmitter and the receiver are tuned LC resonant circuits as demonstrated in.

(Yang, T.Y. Li, X.H. Zhang, H.R. Peng, F. Li, Y. Wang & B. Fang, D.M., 2012)

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published a paper about inductor modeling in wireless links for implantable devices design. However, in general, the rated power of these applications was a few milliwatts and the distance between two coils was just a few centimeters. As a result, the models in these papers are not applicable to far distances and higher power systems.

Currently, long life lithium ion batteries and methanol fuel cells have been persuaded as ways to make the electrical components more mobile, consumers' expectations are still far from being met due to the added weight and expenses for battery replacement. In this thesis, a wireless power transfer system is developed. The discovery of witricity, as a new option, is revolutionizing the wireless industry, and holds great promise to leave the oversized battery as a thing of the past. Without using any expensive equipment. The use of wireless power transfer is one of the most promising approaches to obtain both high performance.

1.2 Aims and Objectives

The aim of this research is to analyze the newly reported where one or more tune resonators are added to the two resonator systems to extend the wireless power transfer distance, increasing wireless power transfer efficiency, and allow for a curved wireless transmission path in space. This thesis also presents a novel spectral analysis approach to facilitate system optimization and evaluation based on energy exchange in both the time and spectral domains. Theoretical analysis has been presented to enhance the understanding of the wireless power transfer by using magnetic resonant coil. Our analytical results in good agreement with the experimental results.

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4 The objectives of this research are :

a) To design wireless power transfer in terms of the transmitter and receiver for mobile phone charger.

b) To analyze the effect of Diameter, Size, Type of Material magnetic resonant coil on wireless power transfer performance.

c) To evaluate the performance of the wireless power transfer towards voltage, current, power, and efficiency.

1.3 Problem Statement

Live in advanced technological, nowadays increase our desired to make life simpler. From year to year, portable electronic devices are very popular. But the case of charging a device for decades, still use an old traditional style of wired system.

This existed system is build from / having snake look a like wires. The expected to eliminated all snake looked wired with the solution is to go with wireless power transfer using mutual inductance principle.

Furthermore the existing charger on the world now a day, commonly have different type of “plug”. For example the “SONY” mobile phone user cannot use charger of “I phone” or “Apple” mobile phone user cannot use charger of

“NOKIA” mobile phone. This is because the different types of universal charger exist.

Moreover, it make life become inconvenience to charge mobile phone when goes to some areas with limited power outlet. The existing mobile charger need plug or

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socket to charge. The problem become worse if the power outlet or socket is unreachable. So this project is an approach that can be effective used in areas where wire system is unreachable.

Conversion performance of WPT significantly depends on the frequency and distance of WPT (Qu, Mei Ling, Xin Zhi Shi, Chang Qi, and Gao Feng Wang, 2012), hence in this study, appropriate distance of wireless power transfer studied.

1.4 Scope

The scope of this thesis revolves around the understanding of wireless power transfer system. It is important to know the effect of distance on wireless power transfer performance, and also to know the efficiency wireless power transfer by using magnetic resonant coil.

This project of WPT is to construct and develop a prototype of wireless power transfer in application of wireless mobile battery charger. To achieve the aim of this project, the analysis are divided into two major parts which are through simulation using software and hardware implementation. In order to make it success, simulation using MULTISIM Version 13.0 are used. The method using MULTISIM is aimed to construct the circuits (transmitter and receiver) because MULTISIM easy to use, simple and many part of component needed. As the result, this software show the oscillating frequency appear at output of transmitter and waveform of input and output of transmitter and receiver circuits. So MULTISIM Version 13.0 to construct circuit foot-

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print into PCB layout from final circuit. In this research, technical skill is needed to create the suitable size of circuit on PCB. All working procedures are discussed in next chapter.

The prototype of wireless mobile battery charger is developed. Procedure from printing PCB layout until testing circuit is discussed in methodology chapter. An accurate component and materials used is important in hardware making. This is because practically testing of circuit is high dangerous rather than simulation.

1.5 Project Outline

This thesis mainly containing 5 chapters. All the activities, project working principle and output are presented in this thesis according to the chapter. The chapter is briefly arranged as ;

Chapter 2 presents the research and studies of others who published into thesis, article, journals and books on information about WPT.

Chapter 3 presents the methodology conducted in this research. The methodology introduces flow process in theoretical, simulation, hardware, experimental equipment set up, and the functions of all material needed to built wireless power transfer.

Chapter 4 presents the results achieved from this project. All the result are compiled then presented into table and graph. The result are also analyzed and discussed.

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