DESIGN OF DC-DC BUCK-BOOST NON- INVERTING CONVERTER USING PIC

(1)

DESIGN OF DC-DC BUCK-BOOST NON- INVERTING CONVERTER USING PIC

MICROCONTROLLER

AHMED KHUDHAIR ABBAS

SCHOOL OF ELECTRICAL SYSTEM ENGINEERING UNIVERSITI MALAYSIA PERLIS

2015

item is protecte

d by

original

copyr

ight

(2)

DESIGN OF DC-DC BUCK-BOOST NON- INVERTING CONVERTER USING PIC

MICROCONTROLLER

By

AHMED KHUDHAIR ABBAS (1432221154)

A dissertation submitted in partial fulfillment of the requirements for the degree of Master of Science (Electrical Power Engineering)

School of Electrical System Engineering UNIVERSITI MALAYSIA PERLIS

2015

item is protecte

d by

original

copyr

ight

(3)

i

UNIVERSITI MALAYSIA PERLIS

NOTES : * If the thesis is CONFIDENTIAL or RESTRICTED, please attach with the letter from the organization with period and reasons for confidentially or restriction.

DECLARATION OF THESIS

Author’s full name : AHMED KHUDHAIR ABBAS Date of birth : 14 NOVERMBER 1989

Title : Design of DC-DC Buck-Boost Non-Inverting

Converter using PIC Microcontroller

Academic Session : 2014 - 2015

I hereby declare that the thesis becomes the property of Universiti Malaysia Perlis (UniMAP) and to be placed at the library of UniMAP. This thesis is classified as :

CONFIDENTIAL (Contains confidential information under the Official Secret Act 1972)*

RESTRICTED (Contains restricted information as specified by the organization where research was done)*

OPEN ACCESS I agree that my thesis is to be made immediately available as hard copy or on-line open access (full text)

I, the author, give permission to the UniMAP to reproduce this thesis in whole or in part for the purpose of research or academic exchange only (except during a period of _____ years, if so requested above).

Certified by:

_________________________ _________________________________

SIGNATURE SIGNATURE OF SUPERVISOR

A1867012 DR. ABADAL-SALAM TAHA HUSSAIN

___________________________________ ____________________________________________

(NEW IC NO. / PASSPORT NO.) NAME OF SUPERVISOR

Date :_________________ Date : _________________

/

item is protecte

d by

original

copyr

ight

(4)

ii

ACKNOWLEDGMENT

First and foremost, I am most thankful to Allah S.W.T for giving me the strength, health and time to complete my thesis dissertation. I would like to express my special acknowledgement and deepest appreciation to my supervisor, Dr. Abadal-Salam Taha Hussain for his kindness, encouragement and support towards the completion of this Masters project.

Special thanks to School of Electrical System Engineering. I also want to thank to all lecturers in, School of Electrical System Engineering, Universiti Malaysia Perlis for all the knowledge they shared, gave to me, the guidance and the friendly attitude to me when I need them.

I am extremely grateful to my parents for their love, prayers, caring and sacrifices for educating and preparing me for my future. Also I express my thanks to my sisters, brother, sister in law and brother in laws for their support and valuable prayers. My Special thanks goes to my friends those who were directly or indirectly supported me throughout the whole duration of my Project dissertation.

Last but not least, with deepest love, I dedicate my appreciation to my Parents, who has always been there with love, support, understanding and encouragement for all my endeavours. Although far away from them, they always concentrate on my life here and gave me great support and encouragement. I can feel their selfless love all the time. Your love and encouragement has been the most valuable thing in my life!

Thanks a lot.

item is protecte

d by

original

copyr

ight

(5)

iii

TABLE OF CONTENTS

PAGE

DECLARATION OF THESIS i

ACKNOWLEDGEMENT ii

TABLE OF CONTENTS iii

LIST OF TABLES viii

LIST OF FIGURES ix

LIST OF ABBREVIATIONS xi

LIST OF SYMBOLS xii

ABSTRAK xiii

ABSTRACT xiv

CHAPTER 1 INTRODUCTION 1.1 Introduction 1

1.2 Background 2

1.3 Problem Statement 2

1.4 Objectives 3

1.5 Scope of Project 3

1.6 Thesis Outline 4

item is protecte

d by

original

copyr

ight

(6)

iv CHAPTER 2 LITERATURE REVIEW

2.1 Introduction 6

2.2 Continuous Conduction Mode (CCM) 6

2.3 Discontinuous Conduction Mode (DCM) 7

2.4 Pulse-Width Modulation (PWM) 8

2.5 DC-DC Converters 9

2.6 Single Ended Primary Inductor Converter (SEPIC) 10

2.7 Combination Converters 12

2.7.1 Boost-Buck Non-Inverting Converter 13

2.7.2 Buck-Boost Non-Inverting Converter 15

2.7.2.1 Buck Converter 15

2.7.2.2 Boost Converter 16

2.8 Conclusion 17

CHAPTER 3 RESEARCH METHODOLOGY 3.1 Introduction 19

3.2 Software Description 22

3.2.1 Micro C PRO Software Application 22

3.2.2 Simulation Proteus Software 22

3.2.3 PIC2Kit Software 23

3.2.4 SK40c Kit 23

3.3 Circuit Designing And Operation 24

3.3.1 Buck-Boost Non-Inverting Converter 25

3.3.2 Buck Converter 26

3.3.3 Boost Converter 28

item is protecte

d by

original

copyr

ight

(7)

v

3.4 Calculation Theory 30

3.5 Construction Buck-Boost Non-Inverting Converterusing Proteus Software 32

3.6 Voltmeter Measurement 34

3.7 Voltage Divider 35

3.8 Regulator Circuit 36

3.9 Hardware Descriptions 36

3.9.1 PIC Microcontroller 16F877A 37

3.9.2 Power Mosfet 38

3.9.3 Toroidal Ferrite Inductor 38

3.9.4 Capacitor 39

3.9.5 Schottky Diode 39

3.10 Gate Drivers 39

3.10.1 High-Side Switches Control 40

3.10.2 High Side Connection Of Gate Driver 41

3.10.3 Low Side Switches Control 43

3.10.4 Low Side Connection Of Gate Driver 40

3.11 Schematic Designs Layout And Printed Out Circuit PCB Board Development 46 3.12 Development Buck-Boost Non-Inverting Converter Circuit For High Power 47

Application. 3.13 Relay Voltage Protection 49

3.14 Discussion 52

3.15 Summaries 52

item is protecte

d by

original

copyr

ight

(8)

vi

CHAPTER 4 RESULT AND DISCUSSION

4.1 Introduction 53

4.2 Proteus Simulation Software Results 53

4.2.1 PWM Waveform Result 54

4.2.2 Voltage Output 55

4.2.3 Result of Buck Converter on Simulation Software 56

4.2.4 Result of Boost Converter on Simulation Software 57

4.3 Circuit Connected To A Varies Load 58

4.4 Hardware Implementation 59

4.4.1 Gate Driver With PWM Output 59

4.4.2 Result of Buck Converter On Experimental 60

4.4.3 Result of Boost Converter On Experimental 62

4.5 Summary 65

CHAPTER 5 CONCLUSION AND FUTURE WORKS 5.1 Conclusion 66

5.2 Future Work 68

REFERENCES 69

APPENDICES 74

APPENDIX A 74

APPENDIX B 93

item is protecte

d by

original

copyr

ight

(9)

vii

LIST OF PUBLICATIONS 99

LIST OF AWARDS 100

item is protecte

d by

original

copyr

ight

(10)

viii

LIST OF TABLES

NO. PAGE

3.1 Operating Of Buck-Boot Non-Inventing Converter 25

3.2 Parameters Of Buck-Boost Non-Inverting Convertter Proteus 31

Simulation 3.3 Parameters Have Used For Hardware Implementation 36

3.4 Component For Gate Driver 42

4.1 Output Voltage During Buck Converter On Simulation 57

4.2 Output Voltage During Boost Converter On Simulation 57

4.3 Output Voltage During The Input Voltage & Output Load A Variable 58 4.4 Output Voltages During Buck Converter 61

4.5 Output Voltages During Boost Converter 62

item is protecte

d by

original

copyr

ight

(11)

ix

LIST OF FIGURES

NO. PAGE

2.1 Continuous Conduction Mode (CCM) waveforms. 7

2.2 Discontinuous Conduction Mode (DCM) waveforms. 8

2.3 SEPIC Circuit Diagram 10

2.4 Circuit Of SEPIC When Switch Q Is Closed 11

2.5 Circuit Of SEPIC When Switch Q Is Open 12

2.6 Circuit Of Boost-Buck Non-Inverting Converter 13

2.7 Boost Buck Circuit During Boost Converter Operate 14

2.8 Circuit During Buck Converter Operate 14

2.9 Circuit Of Buck Boost Non-Inverting Converter 16

3.1 Block Diagram Of The Circuit 20

3.2 Flow Chart For Methodology Process 21

3.3 Circuit Diagram Of Buck-Boost Non-Inverting Converter 24

3.4 First Case Of Operating In Buck Converter 27

3.5 Second Case Of Operating In Buck Converter 27

3.6 First Case Of Operating In Boost Converter 29

3.7 Operation Of Boost Converter During Second Case 29

3.8 Design Circuit Connection Of Buck Boost Non-Inverting Converter 33

3.9 Circuit Of Voltage Divider 35

3.10 High Side MOSFET Control 40

3.11 Circuit Connection Of Gate Driver On High Side Switch 42

3.12 Low Side MOSFET Control 43

item is protecte

d by

original

copyr

ight

(12)

x

3.13 Circuit Connection Of Gate Driver Hef4093b 44

3.14 Flow Chart Of Operation Circuit 45

3.15 Layout Schematic For The Circuit 46

3.16 Hardware Implementation Buck Boost Non-Inverting Converter 47

3.17 Circuit Connection Of Buck-Boost Non-Inverting Converter With 49

Multi-Modular. 3.18 Multi-Modular Buck-Boost Non-Inverting Converter With Couple 51

of Relay Protection 4.1 PWM On Simulation Software At 80% Of Duty Cycle 54

4.2 PWM On Simulation Software At 50% Of Duty Cycle 55

4.3 Output Voltage During Buck Converter At 66% Of Duty Cycle 55

4.4 Output Voltage During Boost Converter At 50% Of Duty Cycle 56

4.5 Output Waveform For Switching On Experimental At 80% Of Duty 60

Cycle 4.6 Output Waveform For Switching On Experimental At 50% Of Duty 60

Cycle 4.7 Input and Output Voltage of Buck Converter Shown By Voltmeter 61

& Oscilloscope at 66% of duty cycle. 4.8 Input and Output Voltage of Buck Converter Shown By Oscilloscope. 62 4.9 Input and Output Voltage of Boost Converter Shown By Voltmeter 63

& Oscilloscope at 50% of duty cycle.

4.10 Input and Output Voltage of Boost Converter Shown By Oscilloscope 64

item is protecte

d by

original

copyr

ight

(13)

xi

LIST OF ABBREVIATIONS

DC Direct Current

FSW Switching Frequency PWM Pulse Width Modulation

V Voltage

I Current

R Resistance

L Inductor

C Capasitance

E.M.F Electro Magnetic Field PCB Printed Circuit Board

PIC Programmable Intelligent Compute IDE Integrated Development Environment MCU Microcontroller Unit

CCM Continuous Current Mode ESR Equivalent Series Resistance BJT Bipolar Junction Transistor IGBT Insulated-Gate Bipolar Transistor

MOSFET Metal Oxide Semiconductor Field Effect Transistor ISIS Intelligent Schematic Input System professional

Ω Ohm

% Percentage

item is protecte

d by

original

copyr

ight

(14)

xii

LIST OF SYMBOLS

d Duty Cycle

d1 Duty Cycle Of Buck Converter d2 Duty Cycle Of Boot Converter D1 Diode Of Buck Converter D2 Diode Of Boost Converter S1 Switch Of Buck Converter S2 Switch Of Boost Converter

RL Resistive Load

item is protecte

d by

original

copyr

ight

(15)

xiii

Rekabentukkan Penukar DC- DC Buck-Boost Tidak-Songsang Menggunakan PIC Pengawal Mikro

ABSTRAK

Suis penukar MOSFET DC-DC telah digunakan secara meluas dalam pelbagai jenis peranti mudah alih dan bukan mudah alih elektronik. Tujuan utama kajian ini adalah voltan masukan, yang terhasil dari sumber yang dinamik. Ia diperlukan untuk mengawal model Buck-Boost bukan penyongsang penukar pengawal oleh kitaran penuh isyarat dalam PWM. Objektif kajian ini adalah untuk mereka bentuk, simulasi dan menganalisis litar penukar untuk mengawal voltan keluaran dengan menggunakan PIC Microcontroller (16F877A). Dalam merekabentuk litar, kekutuban voltan keluaran harus tidak berubah.

Selain itu, litar ini harus boleh bertindak secara automatik untuk mengubah dari satu mod ke mod yang lain untuk penukar Buck-Boost. Sebelum ini, dua penukar digabungkan bersama-sama telah digunakan, iaitu di dalam keluaraga Buck dan Boost. Litar ini akan melaksanakan operasi dua langkah, mod menaik dan mod menurun, yang bergantung kepada keadaan input masukan. Perisian simulasi dan perkakasan pelaksanaan model telah siap dibina. Proteus Software telah digunakan sebagai alat perisian simulasi. PIC Microcontroller telah digunakan dalam litar ini untuk menjana PWM. Litar ini telah mencapai voltan keluaran 12VDC walaupun voltan masukan berubah-ubah dengan pelbagai tahap voltan masukan di antara (6-18) VDC. Litar ini telah dipilih dalam projek disertasi ini kerana ia mempunyai spesifikasi terbaik seperti induktor dan kapasitor tunggal untuk kedua-dua penukar, jumlah komponen elektrik yang kurang, tekanan yang lebih rendah, dan membawa kepada mengurangkan jumlah kos kerugian, kos dan juga meningkatkan kecekapan litar . Lebih-lebih lagi, ia telah mencapai voltan keluaran bekalan dengan kutub positif. Daripada keputusan ujian, kecekapan purata penukar yang dicadangkan itu mencapai pada 82%. Satu alternatif yang baru boleh digunakan untuk meningkatkan prestasi bukan menyongsang penukar Buck-Boost pada simulasi untuk aplikasi yang berkuasa tinggi dan telah dicadangkan berkaitan dengan penukar konvensional DC-DC ini telah dibahagikan dengan modaliti selari dalam penukar Multi- Modular. Oleh itu, tekanan yang tinggi semasa suis semikonduktor adalah dapat diatasi.

Ia adalah satu penyelesaian yang optimum untuk keperluan semasa bagi beban tinggi dalam penukar DC.

item is protecte

d by

original

copyr

ight

(16)

xiv

Design of DC-DC Buck-Boost Non-Inverting Converter using PIC Microcontroller

ABSTRACT

Switching MOSFET of DC-DC converters were widely used in different types of portable and non-portable electronic devices. The main aim of this research is the input voltage, which comes from a varaible sources. It is required to control model of Buck- Boost non-inverting converter controller by a duty cycle of PWM signal. The objective of the research is to design, simulate and analyze circuit converter to regulate the output voltage by using PIC Microcontroller (16F877A). In the circuit design, the polarity of the output voltage should be not changed. Moreover, the circuit is required to act automatically from one mode to the other mode of Buck-Boost converter.

Conventionally, two converters combined together were utilized, a Buck and Boost family of converters. The circuit were perform the dual operations of step-down and step- up modes, which relies on input conditions. The simulation software and the implementation hardware were completed. Proteus Software has been adopted as a simulation tool. The PIC Microcontroller was used in this circuit to generate PWM. The circuit was achieved the output voltage at 12VDC even the input voltage a variable with a range of input voltages was between (6-18) VDC. This circuit was selected in this dissertation project because it has the best specifications such as single inductor and capacitor for both of converters, less number of electrical components, lower stresses, which leads to reduce the total losses, cost and increase the efficiency of the circuit.

Moreover, it was achieved supply output voltage with positive polarity. From the collected data, the average efficiency of the proposed converter was reached at 82%. A new alternative for improving the performance of Buck-Boost non-inverting converter on simulation for high power application was proposed with respect to conventional DC-DC converter, current was divided by parallel modality in Multi-Modular converters.

Therefore, the high current stress on the semiconductor switches were overcame. It was an optimal solution for high load current requirements in a DC converter.

item is protecte

d by

original

copyr

ight

(17)

1 CHAPTER 1

INTRODUCTION

1.1 Introduction

This research presents the technique that used for controlling Buck-Boost non- inverting converter. It is a beneficial application in the domain of renewable energy, a topic that covers subjects such as energy acquired from wind turbine and sun-light energy (Kjaer, et al., 2005). Another application when a battery voltage dropped and we need to maintain the constant voltage load (Liou., 2008), (Zhou., 2006). Therefore, for any practical reasons, these kinds of resources are always dynamic resources of energy.

The hybrid energy such as solar energy and wind energy are categorized as varied voltage due to the fact that solar power is dependent on sunlight and the wind energy depends on the wind. For that reason, DC-DC converter is used to regulate output voltage to be steady. That is utilized for supplying the electrical appliances.

Buck-Boost non-inverting converter is a circuit that convert a variable input voltage into a fixed output voltage. The output voltage of this circuit is controlled by using a duty cycle (Syed., 2004). Which is able to be the output voltage (greater, less or equal) to the input voltage.

item is protecte

d by

original

copyr

ight

(18)

2 1.2 Background

There are many typologies were used for converting the DC-DC voltage. They have been commonly used in the power supply appliances for the majority of electronic systems. Such as Buck converter, Boost converter and Buck-Boost converter. (Yao., &

Lee., 2002), (Chakraborty, 2006). The basic principle of DC-DC Buck-Boost non- inverting converter is to convert DC input voltages to DC output voltages. The output voltage can be less than input, which is during Buck converter (step down), higher than the input during Boost converter (step-up) converter. It also could be same as the input.

In recent years, DC-DC converters have been grown to be a popular subject matter, which has a lot of requirements for best specification such as less costly, smaller size, lighter in weight and less power loses towards a high efficient power conversion. Moreover, pulse width modulation (PWM) have been growth of DC electronic devices.

1.3 Problem Statement

The major focus of this thesis are:

i. The dynamic input voltage, which is come from a renewable energy source. It is order to step up or step down the output voltage to supplied steady levels.

ii. In high power applications the problem with high current of DC-DC power converter.

iii. The power semiconductor is always stressed by high current so the high current will be affected on the efficiency.

item is protecte

d by

original

copyr

ight

(19)

3

iv. Buck-Boost non-inverting converter can be improved to control a DC voltage, which is controlled by duty cycle of PWM signal which that generated by using PIC Microcontroller.

1.4 Objectives

The major objectives of this research program are:

i. To design, simulate, analyze and implement circuit of Buck-Boost non-inverting converter to regulate the output voltage which drives by Pulse Width Modulation (PWM) that generated by using PIC microcontroller (16F877A).

ii. Construct the circuit without changing the polarity of the output voltage related to the input voltage.

iii. To simulate a reliable design circuit of Buck-Boost non-inverting converter with Multi-Modular converter of high power application with two relays protection.

1.5 Scopes of Project

There are plenty ranges of electrical power switches. During this project, the metal- oxide-semiconductor field-effect transistor (MOSFET) power switching is chosen while it has many positive aspects over the insulated-gate bipolar transistor (IGBT) and thyristors, which is generally, faster and has better gate turn off capability (Jack., 2000).

As well as the MOSFETs are easier to drive and to utilize.

item is protecte

d by

original

copyr

ight

(20)

4

With an improvement, DC-DC converter requires PWM signals with a higher switching frequency to quickly response to compensate the required level of DC output voltage. Buck-Boost non-inverting converter circuit can improve the control of DC voltage, which is controlled by duty cycle of PWM. The PIC Microcontroller is selected to generate PWM pulses because the characteristic of this IC is good for producing optimal DC-DC converter. The PIC enables to re-programmable flash-memory, high efficient, low price, and small size. The PIC Microcontroller can do more than one operations at the same time. Proteus software is used throughout for this project to simulate the circuit of Buck-Boost non-inverting converter. Additionally to development the work to use on electric power management, utilizing this topology hybrid automobile, electric grid and diversified renewable power resources.

1.6 Thesis Outline

This thesis report consists five chapters’ introduction, literature review, methodology, results and finally conclusion. In chapter one, the overview of the idea and the whole system especially in Buck-Boost non-inverting converter is presented.

Including the problem statements, objectives, and research scope.

Chapter two covers the literature review of previous cases of analysis based on Buck-Boost non-inverting converter background and development. Furthermore, general information about DC-DC converter control method and power switching design. In addition, some other techniques has been completed based on this research.

item is protecte

d by

original

copyr

ight

(21)

5

Chapter three presents the methodology utilized to design Buck-Boost converter with PIC Microcontroller. All the components that have been used are explained well in this chapter. Methodology can be divided into several parts that consist of schematics simulation software, hardware implementation, component selection etc.

Chapter four, explain and discuss about all the results and evaluations of performance of the circuit. A result analysis is given. The results are display the comparison of output voltage between software and hardware results with helps of set of Figures and Tables.

Lastly, chapter five is the conclusion of overall all chapters. In addition, the results have been discussed, analyzed and been used for comparison between simulation software and implemented hardware. At the end, a discussion about future works and new trends in the field of DC-DC converters.

item is protecte

d by

original

copyr

ight

(22)

6 CHAPTER 2

LITERATURE REVIEW

2.1 Introduction

This chapter presents the overview of Buck-Boost converter with a positive output voltage reviewed and analyzed by other researchers. In these days, the applications of DC-DC converters have been improved and increased dramatically since they commonly used in renewable energy systems such as fuel cells, hybrid electric vehicles, battery chargers, and solar systems etc. (Restrepo., 2011), (Erickson., 1997).

There are two modes of operation in DC-DC converters based on inductor current.

i) Continuous Conduction Mode (CCM).

ii) Discontinuous Conduction Mode (DCM).

2.2 Continuous Conduction Mode (CCM)

The difference between the CCM and DCM is that in CCM the current in the inductor does not fall to zero. A converter operates in continuous mode if the current through the inductor never falls to zero during the commutation cycle. Basically for high power application, Conduction Continues Made (CCM) has lower conduction losses an smaller current stress on the semiconductor device. The current flows continuously in the

item is protecte

d by

original

copyr

ight

(23)

7

inductor during the entirely switching cycle (Lynch, B. T., 2008). During CCM is ON state, the switch is closed, which makes the input voltage appear across the inductor and cause a change in current flowing through the inductor. In addition, the current in inductor increased at the end of ON state. As shown in Figure 2.1.

Figure 2.1: Continuous Conduction Mode (CCM) waveform (Lynch, B. T., 2008).

2.3 Discontinuous Conduction Mode (DCM)

In discontinuous mode operation, the duty cycle is a nonlinear function of the output current, in the load, and it cannot secure the maximum power output. Because of the converters operating in this mode have lower power efficiency compared to the continuous mode conduction. The converter is operate in CCM in exactly the same way as a synchronous converter (Lynch, B. T., 2008). The diode will prevent the inductor current from reversing its polarity. The inductor will charge energy through the high-side switch. When the high-side switch is off, the inductor will discharge the stored energy to the capacitor until the current drops to zero. Figure 2.2 shows the inductor current on DCM made. The current will be held at zero until the end of the cycle. This discontinuity in the inductor current defines the discontinuous conduction mode (DCM).

item is protecte

d by

original

copyr

ight

(24)

8

Figure 2.2: Discontinuous Conduction Mode (DCM) waveform (Lynch, B. T., 2008).

2.4 Pulse Width Modulation (PWM)

Pulse-Width Modulation (PWM) are used for controlling analog circuits with a processors digital output. PWM uses a square wave whose duty cycle is modulated resulting in the variation of the average value of the waveform. PWM can be used to reduce the total amount of power delivered to a load without losses normally incurred when a power source is limited. The average power delivered is proportional to the modulation duty cycle. With a sufficiently high modulation of duty cycle (d). With a sufficiently high modulation rate, passive electronic filters can be used to smooth the pulse.

High frequency PWM power control systems are easily realizable with semiconductor switch. The discrete on or off states of the modulation are used to control the state of the switch, which correspondingly controls the voltage across or current through the load. The product of the current and the voltage at any given time defines the power dissipated by the switch, thus no power is dissipated by the switch. Realistically, semiconductor switches such as MOSFETs or BJTs are non-ideal switches, but high efficiency controllers can still be build (Prodic, A., 2001).

item is protecte

d by

original

copyr

ight