POWER ELECTRONIC INVERTER CIRCUITS By Wafaa Ahmed Hamed Ahmed INDEX NO. 084089

89 Pages·2013·5.46 MB·English

POWER ELECTRONIC INVERTER CIRCUITS

By
Wafaa Ahmed Hamed Ahmed
INDEX NO. 084089

Supervisor
Dr. Sharif Babikir

THESIS SUBMITTED TO
UNIVERSITY OF KHARTOUM
IN PARTIAL FULFILMENT FOR THE DEGREE OF
B.Sc. (HON)
IN ELECTRICAL AND ELECTRONICS ENGINEERING
(CONTROL ENGINEERING)
FACULTY OF ENGINEERING
DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING
JULY 2013
I
DICLARATION OF ORIGINALITY
I declare that this report entitled “Power electronic Inverter Circuits” is my own work
except as cited in the references. The report has not been accepted for any degree and is not
being submitted concurrently in candidature for any degree or other award.

Signature : _________________________

Name : _________________________

Date : _________________________

II
ABSTRACT
An inverter has the capability to convert the DC power into AC power that is useful for
generating equipment like household items, computers, power tools, etc.
This project aims to design an inverter circuit using PWM technology because of its
advantageous over others technologies.
The project objectives had been met successfully initially by illustrating the concept of
power inversion using a simple inverter circuit, then the PWM technology was clearly
demonstrated and PWM signals were generated using ATmega32 Microcontroller. The designs
of single-phase and three-phase inverters were successfully implemented by means of software
simulation.

III
صلختسملا
يف اهنم ةدافتسلإا متيل بوانتم رايت ةردق ىلا رشابملا رايتلا ةردق ليوحت ىلع ةردقملا ةردقلا سكاعل
.ةردقلا تاودأو ،بيساوحلا ،ةيلزنملا ضارغلأا لثم يئابرهكلا ديلوتلا ضارغأ
نم ةدافتسلال ةضبنلا ضرع ليدعت ةينقت مادختساب ةردق سكاع ةراد ميمصتل عورشملا اذه فدهي
.ىرخلأا تاينقتلا ىلع ةقوفتم اهلعجي امم ةددعتملا اهايازم
ةراد ميمصت ربع ةردقلا ليوحت موهفم حيضوتب قلعتي اميف حاجنب عورشملا اذه فادهأ قيقحت مت
مكحتملا مادختساب ةضبنلا هذه ديلوت مت امك ةضبنلا ضرع ليدعت ةينقت موهفم حيضوت مت .طيسبلا ةردقلا سكاع
."ATmega32" عون نم قيقدلا
ةاكاحملا جمانرب مادختساب روطلا يثلاثو روطلا يداحأ سكاعلا رئاودل حرتقملا ميمصتلا قيبطت مت
."Proteus"

IV
ACKNOWLEDGEMENT
All thanks, praise and glory is due to the Almighty GOD, without His uncountable
blessings I wouldn’t be the person I am.
I would like to express my appreciation to my beloved family, who constantly support me
through my entire life and unconditionally provide me with all the means of success.
I would like to extend my sincere gratitude to my supervisor Dr. Sharief F. Babikir for his
patience, motivation, enthusiasm, for he is a man of immense knowledge. He was there for us as
a helpful teacher and sympathetic friend.
Also, I would like to thank my partner WafaaAlkhair for her support and patience
throughout this tiresome journey, I could not have asked for a better partner. She taught me the
meaning of team work and to strive for success.
Special thanks to the staff of the Department of Electrical and Electronics Engineering
for their appreciated support and I would like to say that I‘m really honoured to be a student in
such a Department.
Moreover, further gratitude to my friends and esteemed colleagues, who motivate and
support me whenever I need them, especially my classmate MowafagIsmat A. Abbashar for his
support and assistance, he taught me perseverance, so for him I am grateful.

V
DEDICATION

To my Family

To my Friends

VI
TABLE OF CONTENTS
TITLE ........................................................................................................................................................ I
DICLARATION OF ORIGINALITY ...................................................................................................... II
ABSTRACT ............................................................................................................................................. III
صلختسملا ................................................................................................................................................... IV
ACKNOWLEDGEMENT ........................................................................................................................ V
DEDICATION ........................................................................................................................................ VI
TABLE OF CONTENTS ....................................................................................................................... VII
LIST OF FIGURES .................................................................................................................................. X
LIST OF TABLES ................................................................................................................................. XII
LIST OF ABBREVIATIONS AND TERMINOLOGIES .................................................................... XIII
CHAPTER 1 .............................................................................................................................................. 1
INTRODUCTION ..................................................................................................................................... 1
1.1 Introduction ................................................................................................................................. 1
1.2 Project Background ..................................................................................................................... 1
1.3 Problem Statement ...................................................................................................................... 2
1.4 Motivation ................................................................................................................................... 2
1.5 Project Objectives ....................................................................................................................... 3
1.6 Thesis Layout .............................................................................................................................. 3
CHAPTER 2 .............................................................................................................................................. 4
LITERATURE REVIEW .......................................................................................................................... 4
2.1 Introduction: ................................................................................................................................ 4
Bipolar Junction Transistor ................................................................................................................ 4
2.2 Power MOSFET .......................................................................................................................... 5
2.2.1 The N-channel MOSFET ........................................................................................................... 6
2.2.2 The P-channel MOSFET ........................................................................................................... 6
2.3 Inverters:...................................................................................................................................... 7
2.3.1 Classification of Inverters .......................................................................................................... 8
2.4 Pulse Width Modulation.............................................................................................................. 9
2.4.1 Duty Cycle Definition ............................................................................................................... 9
2.4.2 Pulse Width Modulation (PWM) Definition ........................................................................... 10
2.4.3 Sinusoidal Pulse Width Modulation ........................................................................................ 10
VII
2.4.4 Filtering PWM Signals ............................................................................................................ 11
2.4.5 Advantages of using PWM: ..................................................................................................... 13
2.4.6 Single – Phase PWM Inverter ................................................................................................. 13
2.4.7 Three-Phase PWM Inverter: .................................................................................................... 14
2.5 Applications of Inverters: .......................................................................................................... 15
CHAPTER 3 ............................................................................................................................................ 16
METHODOLOGY .................................................................................................................................. 16
3.1 Introduction ............................................................................................................................... 16
3.2 The Simple Inverter Circuit ...................................................................................................... 16
3.2.1 How MOSFETs Work ............................................................................................................. 16
3.3 Single Phase Inverter using PWM Technique........................................................................... 18
3.3.1 Generating a Sinusoidal PWM Signal using the Microcontroller ........................................... 18
3.4 Three Phase Inverter using PWM Technique: .......................................................................... 30
CHAPTER 4 ............................................................................................................................................ 32
IMPLEMENTATION AND RESULTS .................................................................................................. 32
4.1 Introduction .................................................................................................................................... 32
4.2 System Components .................................................................................................................. 32
4.2.1 Hardware Components ............................................................................................................ 32
4.2.2 Software Components.............................................................................................................. 35
4.3 Implementation of the Simple Inverter ..................................................................................... 35
4.3.1 Software Implementation ........................................................................................................ 36
4.3.2 Hardware Implementation ....................................................................................................... 36
4.4 Implementation of Single-Phase PWM Inverter ....................................................................... 37
4.4.1 Generation of 50Hz PWM Signal ............................................................................................ 37
4.4.2 Generation of Variable Frequency PWM Signal ..................................................................... 39
4.5 Implementation of Three-Phase PWM Inverter ........................................................................ 41
4.6 The Results ................................................................................................................................ 42
4.6.1 The Simple Inverter Results .................................................................................................... 42
4.6.2 The Single-Phase PWM Inverter Results ................................................................................ 43
4.6.3 The Three-Phase PWM Inverter Results ................................................................................. 50
4.7 Discussion ................................................................................................................................. 52
CHAPTER 5 ............................................................................................................................................ 53
VIII
CONCLUSION AND FUTURE WORK ................................................................................................ 53
5.1 Completion Status: ......................................................................................................................... 53
5.2 Future Work: .................................................................................................................................. 55
REFERENCES ........................................................................................................................................ 56
APPENDIX A ....................................................................................................................................... A-1
APPENDIX B ........................................................................................................................................ B-1
APPENDIX C ........................................................................................................................................ C-1

IX
LIST OF FIGURES
Figure 2- 1 ................................................................................................................................................................ 5
Figure 2- 2 ................................................................................................................................................................ 6
Figure 2- 3 ................................................................................................................................................................ 6
Figure 2- 4 High Side P-Channel MOSFET ................................................................................................................ 7
Figure 2- 5 Low Side N-Channel MOSFET ................................................................................................................. 7
Figure 2- 6 Duty Cycle Definition ............................................................................................................................. 9
Figure 2- 7 .............................................................................................................................................................. 10
Figure 2- 8 Generation of SPWM signal ................................................................................................................. 10
Figure 2- 9 Generation of SPWM signal using Saw-tooth carrier .......................................................................... 11
Figure 2- 10 Low Pass Filter ................................................................................................................................... 12
Figure 2- 11 Schematic of inverter system ............................................................................................................ 13
Figure 2- 12 Three-Phase Inverter Circuit .............................................................................................................. 14
Figure 3- 1 H-bridge using N-Channel and P-Channel MOSFETs............................................................................ 17
Figure 3- 2 Forward and Reverse paths for current flow ....................................................................................... 18
Figure 3- 3 Timing diagram of Fast PWM mode .................................................................................................... 20
Figure 3- 4 A Flow Chart of counter initialization process ..................................................................................... 22
Figure 3- 5 Flow Chart of Duty Cycle Modification ................................................................................................ 24
Figure 3- 6 Block Diagram of Single-phase Inverter Circuit ................................................................................... 27
Figure 3- 7 Frequency Control Process .................................................................................................................. 29
Figure 3- 8 Block Diagram of Three-Phase Inverter ............................................................................................... 31
Figure 4- 1 ATmega32 Microcontroller .................................................................................................................. 32
Figure 4- 2 IRF640 N-Channel MOSFET .................................................................................................................. 33
Figure4- 3 IRF9540N P-Channel MOSFET ............................................................................................................... 33
Figure 4- 4 NPN BJT BC107 ..................................................................................................................................... 33
Figure 4- 5 Keypad ................................................................................................................................................. 34
Figure 4- 6 LCD ....................................................................................................................................................... 34
Figure 4- 7 DC Power Supply .................................................................................................................................. 35
Figure 4- 8 The Proteus simulation of the simple inverter .................................................................................... 36
Figure 4- 9 Hardware Design of the simple inverter circuit ................................................................................... 36
Figure 4- 10 Hardware design of the simple inverter circuit showing the output. ............................................... 37
Figure 4- 11 Proteus Simulation of single-phase PWM inverter ............................................................................ 38
Figure 4- 12 Hardware circuit for generating PWM signal .................................................................................... 39
Figure 4- 13 Simulation of variable frequency single-phase PWM inverter .......................................................... 40
Figure 4- 14 Three-phase inverter circuit .............................................................................................................. 41
Figure 4- 15 The simple inverter simulation result ................................................................................................ 42
Figure 4- 16 Input signal to the simple inverter ..................................................................................................... 42
Figure 4- 17 Actual output signal across the load .................................................................................................. 43
Figure 4- 18 PWM signal corresponding to 50Hz half sine wave ........................................................................... 43
Figure 4- 19 50 Hz half sine wave .......................................................................................................................... 44
Figure 4- 20 PWM signal across the load ............................................................................................................... 44
Figure 4- 21 PWM signal corresponding to full sine wave ..................................................................................... 45
Figure 4- 22 50 Hz full sine wave ........................................................................................................................... 45
X