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SMART BOOST CONVERTER FOR DC ENERGY SOURCE APPLICATION
MUNIRAH BT AYUB
A report is submitted in partial fulfillment of the requirements for the award of the degree of Bachelor of Electrical Engineering(Power System)
Faculty of Electrical & Electronic
Universiti Malaysia Pahang
OCTOBER 2009
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“I hereby acknowledge that the scope and quality of this thesis is qualified for the award of the Bachelro Degree of Eletrical Engineering (Power System)”
Signature :
Name : MUHAMAD ZAHIM BIN SUJOD
Date : 23 NOVEMBER 2009
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“All the trademark and the copyrights use here in are property of their
respective owner References of information from other sources are quoted
accordingly; otherwise the information presented in this report is solely
work of the author”.
Signature :
Name : MUNIRAH BT AYUB
Date : 23 NOVEMBER 2009
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ACKNOWLEDGEMENT
First of all I am so thankful to Allah the Almighty for it is His blessing and mercy that I may complete this project.
I fell so grateful and thankful to all lecturers and teaching staff at Faculty of Electric and Electronic of University Malaysia Pahang for their help, guide and support throughout my degree course here.
I am also indebted to all those who made contribute critics, as well as those who shared their thoughts and concerns on the project; especially my supervisor, Mr. Muhamad Zahim Bin Sujod and my class peers.
Furthermore I am so thankful to Mr Shahbuddin who share his thoughts, help and teach me how to work on my project and also provide equipments and concerns on the project.
Lastly, I am forever grateful and indebted to my parents, Mr Ayub Bin Abd Gani and Madam Norhidah Binti Mohamed Shukor for their never ending support and encouragement to me.
May Allah reward His peace and blessings to all of you, and may this work brings benefits to mankind.
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ABSTRACT
Basically this project is about the operation of step-up dc-dc boost converter for DC
energy source application. The objective of this project is to practice the application of boost
converter and DC source energy. It also have it’s purpose in producing a simple control
method for maximum power protection by employing a step-up dc-dc boost converter voltage
to a certain value and set the limit voltage for the overvoltage protection system application
and load protection. The DC source energy application can be obtain from voltage multiplier
as power supply circuit. By using the basic principle, we will build the model and get the
simulation for the circuit. In other way to generally explain the operation is the boost converter
has functioning switch which had to produce the step-up voltage according to the correct
design, the voltage will be the input for the overvoltage protection circuit which is used to
protect the load. This circuit has variable voltage setting which can be set as the cut-off
voltage to stop the excess voltage from damaging the load or equipment. LED power saving
are implement as the load for the DC source energy and also have economical purposes in
saving power consumption.
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ABSTRAK
Projek ini merangkumi operasi penaikan voltan terus dalam aplikasi sumber
tenaga voltan terus.Tujuan projek ini adalah pengaplikasian penukar arus terus dan
punca tenaga arus terus. Ia juga merupakan salah satu cara menghasilkan satu kawalan
ringkas untuk melindungi litar dari kesan operasi kuasa maksimum dengan
menetapkan voltan ‘boost converter’ pada nilai voltan tertentu dan voltan tersebut
ditetapkan pada satu nilai supaya dapat dikesan oleh aplikasi alat perlindungan voltan
tinggi untuk melindungi beban elektrik tertentu.Secara ringkasnya, litar penaikkan
voltan yg akan menaikkan voltan pada suatu nilai yg telah ditetapkan dengan
menggunakan litar rekaan yg betul.Voltan keluar dari litar tadi akan menjadi punca
kepada litar perlindungan voltan tinggi dan akan memastikan operasi pengeluaran
voltan tidak melebihi voltan yang sepatutnya.
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TABLE OF CONTENTS
CHAPTER TITLE PAGE
TITLE PAGE i
DECLARATION ii
DEDICATION iv
ACKNOWLEDGEMENT v
ABSTRACT vi
ABSTRAK vii
TABLE OF CONTENT viii
LIST OF FIGURES xi
LIST OF TABLES xiv
LIST OF APPENDICIES xv
1. INTRODUCTION
1.1 Background 1
1.2 Voltage multiplier 5
1.3 LED Power Saving 6
1.4 Objective of Project 8
1.5 Scope Of Project 8
1.6 Summary of The Project 9
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2. THEORY AND LITERATURE REVIEW
2.1 Introduction 16
2.2 Boost Converter 16
2.3 Boost Converter Pitfall 19
2.4 Boost Converter Improvement 21
2.5 Overvoltage Protection Circuit 23
2.6 LED Power Saving 24
2.7 Voltage Multipliers 27
3. METHODOLOGY
3.1 Introduction 29
3.2 Research for Boost Converter 29
3.2.1 Books 30
3.2.2 Internet 31
3.3 Hardware Implementation 32
3.3.1 Boost Converter hardware 32
3.3.2 Boost Converter Circuit 37
3.3.3 Boost Converter Calculation 39
3.3.4 Voltage Multipliers 42
3.3.5 Voltage Regulator 46
3.3.6 Overvoltage Protection Circuit 47
4. RESULT AND ANALYSIS
4.1 Introduction 49
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4.2 Voltage Regulator Result 50
4.3 LED Power Saving Results 52
4.4 PSPICE Simulation Result 53
4.5 LED Power Savings Curent Results 57
4.6 Result Comparison 59
5. CONCLUSION AND RECOMMENDATION
5.1 Conclusion 62
5.2 Problems 63
5.3 Recommendation 64
5.4 Costing And Commercialization 65
REFERRENCES 68
APPENDICIES 70
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LIST OF FIGURES
FIGURES TITLE PAGE
1.0 The boost converter circuit when the switch is close 2
1.1 The boost converter circuit when the switch is open 2
1.2 The schematic of current and voltage for boost converter 3
1.3 The two configurations of a boost converter 4
1.4 Example Cockcroft-Walton Voltage Multiplier Circuit 6
1.5 Green Electroluminescence 7
1.6 The block diagram 9
1.7 Gantt chart of the Project Schedule for Semester 1 13
1.8 Gantt chart of the Project Schedule for Semester 2 13
1.9 Flow chart of Development 14
2.0 Boost converter Evaluation Board 19
2.1 Example of overvoltage protection circuit 24
2.2 LED Power Saving 27
2.3 Half-wave voltage doubler. 28
2.4 Half-wave voltage Tripler 28
3.0 Methodology block diagram 29
3.1 Capacitors 32
3.2 Diode 1N4148 32
3.3 Resistors 33
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3.4 Crystal 20Mhz 33
3.5 Voltage regulator LM7809 33
3.6 MOSFET IRF740 34
3.7 Voltage regulator LM7815 34
3.8 Inductor 60uH 34
3.9 Regulator LM 317 35
3.10 Voltage binder 35
3.11 LED lamp 36
3.12 LED bulb 36
3.13 Meter reading 37
3.14 Boost converter circuit 38
3.15 Basic circuit of boost converter 38
3.16 Voltage multiplier circuit 42
3.17 A Full-Wave Voltage Doubler 43
3.18 A Full-Wave Voltage Tripler 44
3.19 The combination of voltage doubler and voltage tripler 45
3.20 Voltage regulator circuit 46
3.21 Overvoltage protection circuit 47
3.22 The combination flow of the overall circuit 48
4.0 Boost converter circuit 50
4.1 Result from oscilloscope for voltage regulator LM7815 51
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4.2 Result from oscilloscope for voltage regulator LM7805 51
4.3 LED lamp is in ON state 52
4.4 LED bulb is in ON state 52
4.5 Overvoltage protection PSPICE circuit 53
4.6 Simulation result 54
4.7 Timer and IC flip-flop circuit 54
4.8 Output voltage for timer 55
4.9 Trigger voltage for timer 55
4.10 Simulation result for the LM 7815of voltage multiplier 56
4.11 Simulation result for the LM 7805 of voltage multiplier 56
4.12 Simulation result for the LM 7809 of voltage multiplier 57
4.14 LED bulb current reading 58
4.15 LED lamp current reading 60
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LIST OF TABLES
TABLE TITLE PAGE
4.15 Result Compare for Voltage Multiplier 59
4.16 Result Compare for Boost Converter of
Voltage Regulator 59
4.17 Result Compare for Input and Output of
boost converter 60
4.19 Result Compare for Voltage Multiplier
Voltage Value 61
4.20 Overall cost for one set of Boost Converter ,
Voltage Multiplier and Overvoltage Protection
Circuit 65
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LIST OF APPENDICIES
APPENDIX TITLE PAGE
A Voltage Multiplier Sketch 70
B Voltage Multiplier Circuit 71
C Overvoltage Protection Circuit 72
D Project Pictures 73
E Result pictures 75
F Datasheets 79
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CHAPTER 1
INTRODUCTION
1.1 Background
A boost converter (step-up converter) is a power converter with an
output DC voltage greater than its input DC voltage. It is a class of switching-
mode power supply (SMPS) containing at least two semiconductor switches, a
diode and a transistor and at least one energy storage element. Filters made of
capacitors (sometimes in combination with inductors) are normally added to the
output of the converter to reduce output voltage ripple. Power can also come from
DC sources such as batteries, solar panels, rectifiers, and DC generators. A
process that changes one DC voltage to a different DC voltage is called DC to DC
conversion.
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Figure 1.0: The boost converter circuit when the switch is close
Figure 1.1: The boost converter circuit when the switch is open
The main part that drives the boost converter is the tendency of an inductor to
resist changes in current. When being charged it acts as a load and absorbs energy
somewhat like a resistor, when being discharged, it acts as an energy source like a
battery. The voltage it produces during the discharge phase is related to the rate of
change of current, and not to the original charging voltage, thus allowing different
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input and output voltages. The basic principle of a Boost converter consists in 2
distinct states (see figure 1.4):
In the On-state, the switch S (see figure 1.3) is closed, resulting in an increase
in the inductor current;
In the Off-state, the switch is open and the only path offered to inductor
current is through the flyback diode D, the capacitor C and the load R. This result
in transferring the energy accumulated during the On-state into the capacitor.
The input current is the same as the inductor current as can be seen in figure 2.
So it is not discontinuous as in the buck converter and the requirements on the
input filter are relaxed compared to a buck converter.
Figure 1.2: The schematic of current and voltage for boost converter
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Figure 1.3: The two configurations of a boost converter, depending on the state
of the switch S.
Boost converter already been used widely either in electronic for small
component with small scale of step-up voltage or mechanical and automotive
engineering for its‟ specialty of converting the voltage to a larger voltage, for
example, the Toyota Prius HEV contains a motor which utilizes voltages of
approximately 500 V. Without a boost converter, the Prius would need nearly 417
cells to power the motor. However, a Prius actually uses only 168 cells and
boosts the battery voltage from 202 V to 500 V.
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1.2 Voltage multiplier
A voltage multiplier is an electrical circuit that converts AC electrical power from
a lower voltage to a higher DC voltage by means of capacitors and diodes
combined into a network.
Voltage multipliers can be used to generate bias voltages of a few volts or
tens of volts or millions of volts for purposes such as high-energy physics
experiments and lightning safety testing. The most common type of voltage
multiplier is the half-wave and full wave series multiplier, also called the Villard
cascade (but actually invented by Heinrich Greinacher). Such a circuit is shown
opposite.
Voltage multipliers may be classified as voltage doublers, triplers, or
quadruplers. The classification depends on the ratio of the output voltage to the
input voltage. For example, a voltage multiplier that increases the peak input
voltage twice is called a voltage doubler. Voltage multipliers increase voltages
through the use of series-aiding voltage sources. This can be compared to the
connection of dry cells (batteries) in series. The input could be directly from the
power source or line voltage. This, of course, does not isolate the equipment from
the line and creates a potentially hazardous condition. Most military equipments
use transformers to minimize this hazard.
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Figure 1.4: Example Cockcroft-walton voltage multiplier circuit
1.3 LED Power Saving
LEDs are based on the semiconductor diode. When the diode is forward
biased in switched on state, electrons are able to recombine with holes and energy
is released in the form of light. This effect is called electroluminescence and the
color of the light is determined by the energy gap of the semiconductor. The LED
is usually small in area (less than 1 mm2) with integrated optical components to
shape its radiation pattern and assist in reflection.
LEDs present many advantages over traditional light sources including lower
energy consumption, longer lifetime, improved robustness, smaller size and faster
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switching. However, they are relatively expensive and require more precise
current and heat management than traditional light sources.
Applications of LEDs are diverse. They are used as low-energy indicators but
also for replacements for traditional light sources in general lighting, automotive
lighting and traffic signals. The compact size of LEDs has allowed new text and
video displays and sensors to be developed, while their high switching rates are
useful in communications technology.
Figure 1.5 : Green electroluminescence from a point contact on a crystal of SiC
recreates H. J. Round's original experiment from 1907.
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1.4 Objective of Project
The objective of this project is to:
i. Build a voltage multiplier that capable to step-up DC-DC input voltage into
multiple range of output that supply by the DC power supply
ii. Apply the LED power saving at boost converter output to prove economical
power consumption
iii. Compare the complexity of voltage multiplier and boost converter as the
source of LED power saving
1.5 Scope of Project
In this project, I want to build a boost converter which will interface with the PIC
controller that controls the driver circuit that generate the pulse for the boost
converter. There are specifications that need to consider for the boost converter
such as:
Voltage multiplier Input : 240 VAC
Voltage multiplier Output : 9VDC, 15VDC, 24VDC, 105VDC
Boost converter input voltage : 15V
Boost converter output voltage : 28VDC-30VDC
LED power supply source : 12VDC
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1.6 Summary of the Project
The flow of the project can be summarized by the block diagram and
flow chart respectively from figure 1.41 and figure 1.42. Both of the diagram and
chart can summarize all the work progress that has been implemented in first and
second semester.
Figure 1.6: The block diagram
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Description:
Boost converter circuit was sketched based on the basic boost
converter circuit. Boost converter part and component has been studied and
identified. At first the boost converter specification are listed to ensure the
required calculation for the component such as inductor, capacitor and resistor
value. It is important especially for the inductor since the value for inductor
cannot be found in the market; it has to be made by using conventional way.
The circuit has been designed in the PSPICE to ensure that the result of the boost
converter certified with the output voltage specification. It is important to know
whether the boost converter successfully step-up the voltage to the calculation
value of output voltage.
The voltage regulator are needed to get desired voltage regulated from the
source voltage for the boost converter while the capacitor are needed as the filters
to get clean Vdc output for any lamp or other applications.
Description:
The voltage multipliers are use in this project as the source for the boost
converter and other application even for the LED power saving and motor. The
