Sun and Maximum Power Point Tracking in Solar Array Systems Using Fuzzy Controllers Via FPGA

128 Pages·2011·3.87 MB·English

The Islamic University – Gaza ةزغ – ةیملاسلإا ةعماجلا

Deanery of Graduate Studies ایلعلا تاساردلا ةدامع

Faculty of Engineering ةــــــــــسدنهلا ةيلك

Electrical Engineering ةیئابرهكلا ةسدنهلا

Sun and Maximum Power Point Tracking in Solar Array
Systems Using Fuzzy Controllers Via FPGA

Mohammed S. EL-Moghany

Advisor
Dr. Basil Hamed

This Thesis is submitted in Partial Fulfillment of the Requirements for the Degree of
Master of Science in
Electrical Engineering

م 2011 ــ ھ1432
Dedication

To my parents, big brother, sisters, wife, and
lovely kids

Mohammed Saker Elmoghany

ii
Acknowledgments
At the beginning, I thank ALLAH for giving me the strength and
health to let this work see the light.

I wish to express my deepest gratitude to my advisor, Dr. Basil Hamed, for his
professional assistance, support, advice and guidance throughout my thesis, and
to my discussion committee, Dr. Hatem El Aydi and Dr. Assad Abu Jasser for

their acceptance to discuss my thesis.

I would also like to extend my gratitude to my family for providing all the
preconditions necessary to complete my studies.

iii
Abstract

Sun and Maximum Power Point Tracking in Solar Array
Systems Using Fuzzy Controllers Via FPGA

By
Mohammed S. EL-Moghany

Solar energy is viewed as clean and renewable source of energy for the future. So the use of
Photovoltaic systems has increased in many applications. That need to improve the materials
and methods used to harness this power source. There are two major approaches; sun tracking
and maximum power point tracking. These two methods need efficient controllers. The
controller may be conventional or intelligent such as Fuzzy Logic Controller (FLC). FLCs
have the advantage to be relatively simple to design as they do not require the knowledge of
the exact model and work well for nonlinear system. To implement this controller, Field
Programmable Gate Array (FPGA) can be used. This method has many advantages over
classical microprocessors.

In this research, Two fuzzy logic controllers are fabricated on modern FPGA card (Spartan-
3AN, Xilinx Company, 2009) to increase the energy generation efficiency of solar cells. These
controllers are, sun tracking controller and maximum power point tracking controller.

Sun tracking generating power system is designed and implemented in real time. A tracking
mechanism composed of photovoltaic module, stepper motor, sensors, input/output interface
and expert FLC controller implemented on FPGA, that to track the sun and keep the solar cells
iv
always face the sun in most of the day time. The proposed sun tracking controller is tested
using Matlab/Simulink program, the results show that the controller have a good response.

Maximum power point tracking system is designed and implemented. The system composed
of photovoltaic module, buck converter and the fuzzy logic controller implemented on FPGA
for controlling on/off time of MOSFET switch of a buck converter. The proposed maximum
power point tracking controller for grid-connected photovoltaic system is tested using model
designed by Matlab/Simulink program with graphical user interface (GUI) for entering the
parameters of any array model using information from its datasheet, the results show that the
controller have a response better than conventional controller applied on the same system.

v
ثحبلا صخلم

مادختساب ةيسمشلا ايلاخلا تافوفصم يف ةردقلل ةميق ىصقأ عبتتو سمشلا عبتت
FPGA لا ةينقتب ةيبابض تامكحتم

دادعإ
ينغملا رقص دمحم

لررك رم رروكأ ررضني ل ردرصم ير و ةررلايبلل ارويولت لرقًاو وةددرقتملاو ةررفيلنلا ةرقاالا ردارصم دررحا ةيرسمشلا ةرقاالا رربتعت
رلاتي اذر و .ةيرسمشلا اريلاخلا اورلأ مدختست يتلا تاقيباتلا ددع دايدزا ىلإ ىدأ اذ و .ةفورعملا ىرخًا ةقاالا رداصم
رم ار يلع لرصحتملا ةردرقلا ةداريزل اتيرسيلار ارتقيرا ارن .اذ ةقاالا ردصم ريخستل ةلمعتسملا قرالاو داوملا يسحت
ىرلإ ارتحي يتقيرالا لاكو . كمي ام ىصقأ ةردقلا ا دنع وكت يتلا ةاقنلا عبتتو سمشلا اكم عبتت ي و ةيسمشلا ةملنًا
يبابررضلا مكحتررملل أ أرريح .ةيبابررضلا تاررمكحتملا لرروم يرركذ دوررن ررم وأ درريلقت دوررن ررم ورركي اررمإ مكحتررملا اذرر .مكحتررم
مكحتلا دارملا مالنلا فصت يتلا ةيضايرلا تلداعملا ع ةقيقد ةفرعم اتحي ل و ف ميمصتلا يف ةيبسن ةلو س لوم تازيمم
تارباوبلا ةفوفرصم ةرينقت مادخترسا لرضفي هرنيف مكحترملا اذر يرنبن يركلو .ةرياخلالا ةرملنًا عرم لضفأ لكشب لمعي و و وهب
. ةقيقدلا تاقلاعملا ع تازيمم ةدع ا ل ةقيرالا هذ و . (FPGA) ةيلقحلا ةقمربلل ةلباقلا

زارا م ةويدح (FPGA) ةقااب ىلع ييبابض يمَ كحتم ءانب ي و لاقملا اذ يف ةروام ةركف ارتقا مت أحبلا اذ يف
وسمرشلا عربتتي ةيرسمشلا اريلاخلا ول لعقل يمَ كحتملا دحأ . م 9002 ماع سكنليز ةكرش اتنإ م (Spartan-3AN(
.ةقاالا ديلوت يف ةيسمشلا ايلاخلا ةءافك ةدايزل لذو . كمي ام ىصقأ ةردقلا ا دنع وكت يتلا ةاقنلا عبتتيل رخًا مكحتملاو

vi
لخادملل تلاصوم وةواخلا روتوم وتاسقم وةيسمشلا ايلاخلا م ول : م وكتي ذلاو سمشلا عبتتم قيباتو ميمصت مت
.رار نلا لغأ سمشلا هقاوت ةيسمشلا ايلاخلا ول ءاقبلإ لذو (FPGA) ةقااب ىلع هلمع مت يبابض مكحتم و و راخملاو
. سح لكشب مكحتملا ةباقتسا أ ةقيتنلا تناكو لاتاملا جمانربل عباتلا نيلويميسلا جمانرب مادختساب مكحتملا رابتخا متو

مكحترم و (Buck) دورن رم لورحم وةيرسمش اريلاخ ورل رم وركملاو وةردرقلل ةراقن ىرصقأ عبتت مالن قيباتو ميمصت مت
.لورحملا لرخاد دورقوملا (MOSFET) لا ارتفم قلارغإ و ترف يف مكحتلل لذو (FPGA) ةقااب ىلع هلمع مت يبابض
ةيرسمش اريلاخ ةفوفرصم أ ولرس يكاحيل هميمصت مت لدوم قيرا ع و نيلويميسلا جمانرب مادختساب مكحتملا رابتخا متو
و ةفوفصملل تاريغتملا ميق لاخدلإ لذو لاتاملا جمانربل عباتلا (GUI) جمانرب مادختساب يمدختسملل ةموسرم ة قاو وذ
رحف ةرقيتن ترناكو .هريلع مكحترملا ريولرتو ةفوفرصملا هذر ولرس راربتخلإ وجتَرنملا تافصاوم ليلد يف جتِنملا ا عضي يتلا
.مالنلا سفن ىلع هقيبات مت ديلقت رخأ مكحتم م ا يلع لصحتملا ةقيتنلا م لضفأ يبابضلا مكحتملا

vii
Table of Contents
CHAPTER 1 Introduction ........................................................................................................ 1
1.1 Introduction ................................................................................................................. 2
1.2 Motivation .................................................................................................................... 4
1.3 Objectives .................................................................................................................... 4
1.4 Literature Review ....................................................................................................... 4
1.5 Contribution ................................................................................................................ 6
1.6 Outline Of The Thesis ................................................................................................. 6
Introduction to Solar Energy.................................................................................................... 7
2.1 Background ................................................................................................................. 8
2.1.1 Renewable Energy ................................................................................................. 8
2.1.2 Solar Energy ........................................................................................................... 9
2.2 Photovoltaic Background: .......................................................................................... 9
2.3 Principle of Solar Cells ............................................................................................. 10
2.4 Types of Solar Panels ................................................................................................ 11
2.5 Equivalent Circuit of a Solar Cell ........................................................................... 12
2.6 Balance Of System (BOS): ....................................................................................... 14
2.7 Sun Tracker ............................................................................................................... 15
2.8 Maximum Power Point Tracking ............................................................................ 15
2.9 Pulse Width Modulation (PWM) ............................................................................. 18
2.10 Buck Converter .................................................................................................... 19
CHAPTER 3 ............................................................................................................................. 20
Fuzzy Logic Control ................................................................................................................ 20
3.1 Introduction ............................................................................................................... 21
3.2 Fuzzy Sets .................................................................................................................. 21
3.2.1 Basic Concepts ..................................................................................................... 21
3.2.2 Basic Operations on Fuzzy Sets .......................................................................... 23
3.3 Fuzzy Logic : ............................................................................................................. 26
3.4 Fuzzy Logic Controller Structure ........................................................................... 27
3.4.1 Fuzzification ......................................................................................................... 27
3.4.2 Knowledge Base: .................................................................................................. 28
3.4.3 Fuzzy Inference Engine ....................................................................................... 30
3.4.3.1 Mamdani Fuzzy Model .............................................................................. 31
3.4.3.2 Sugeno Method ........................................................................................... 36
3.4.4 Defuzzification ..................................................................................................... 39
CHAPTER 4 ............................................................................................................................. 42
Field Programmable Gate Arrays (FPGAs) ......................................................................... 42
4.1 Introduction ............................................................................................................... 43
4.2 FPGAs Architecture ................................................................................................. 47
4.3 FPGA Programming Technologies: ........................................................................ 49
4.4 Fuzzy Controller Design using FPGA ..................................................................... 51
4.5 Xilinx Spartan-3AN FPGA Starter Kit: ................................................................. 52
CHAPTER 5 ............................................................................................................................. 54
Designing Sun Tracker System Using FLC on FPGA ......................................................... 54
viii
5.1 Overall System Design and Implementation .......................................................... 55
5.2 Sun Tracker ............................................................................................................... 55
5.3 Sensors: ...................................................................................................................... 56
5.3.1 Photo Sensor: ....................................................................................................... 56
5.3.2 Tracking Sensor Design ...................................................................................... 56
5.3.3 LDR Connection: ................................................................................................. 58
5.3.4 Position Sensor: ................................................................................................... 58
5.3.5 Analog to Digital Converter (ADC) ................................................................... 60
5.4 Fuzzy Logic Controller: ........................................................................................... 61
5.4.1 FLC design ........................................................................................................... 61
5.4.2 Fuzzy Logic Controller Simulation on Matlab/Simulink: ............................... 64
5.5 Stepper Motor Driver: .............................................................................................. 66
5.6 Implementing Fuzzy Logic Controller on an FPGA: ............................................ 69
5.7 Mechanical Construction and Components: .......................................................... 72
5.8 Experimental Results: .............................................................................................. 74
CHAPTER 6 ............................................................................................................................. 77
Designing MPPT System Using FLC on FPGA .................................................................... 77
6.1 MPPT of PV Using Fuzzy Controller: .................................................................... 78
6.2 MPPT Fuzzy Logic Controller: ............................................................................... 78
6.3 MPPT Fuzzy Logic Controller Simulation on Matlab/Simulink: ........................ 82
6.3.1 PV modeling for Simulation ............................................................................... 82
6.3.2 GUI Interface for PV Model: ............................................................................. 83
6.3.3 Control Signal Generation in Simulation .......................................................... 84
6.3.4 Fuzzy Logic Controller Simulation: .................................................................. 84
6.4 Comparison Between FLC and Conventional Controller: ................................... 86
6.5 Implementing the Maximum Power Point Tracker: ............................................. 87
6.5.1 Implementing the FLC of MPPT on FPGA: ..................................................... 87
6.5.2 Implementing the DC-to-DC Converter: .......................................................... 89
6.5.3 Experimental Results: ......................................................................................... 91
CHAPTER 7 Conclusion and Scope for Future Work ....................................................... 96
7.1 Conclusion ................................................................................................................. 97
7.2 Scope for Future Work ............................................................................................. 98
References: ............................................................................................................................... 99
Appendices ............................................................................................................................. 105
1.1 Appendix A .............................................................................................................. 105
1.2 Appendix B: ............................................................................................................. 106
1.3 Appendix C: ............................................................................................................. 107
1.4 Appendix D: ............................................................................................................. 109
1.5 Appendix E: ............................................................................................................. 110
1.6 Appendix F: ............................................................................................................. 111
1.7 Appendix G: ............................................................................................................ 112

ix
List of Tables

Table ‎5-1: Control rule base for fuzzy controller…………………………………… 63
Table ‎5-2: Full-step phase sequence …………………………………………….…… 66
Table ‎5-3: Experimental results of fixed angle type and tracking system…………... 74
Table ‎6-1: Control rule base for MPPT fuzzy controller. …………………………… 81
Table ‎06-2: Comparison of the experimental results obtained with and without
92
using MPPT & sun tracker (ST) controller………………………………………….

x