Fuzzy Logic Control for Stand-alone Photovoltaic Energy Conversion System, and Innovation in ...

151 Pages·2016·2.82 MB·English

by  Md. Aminul Islam

Fuzzy Logic Control for Stand-alone Photovoltaic Energy Conversion
System, and Innovation in Renewable Energy

By
Zainab Almukhtar

A Thesis Submitted to Saint Mary’s University, Halifax, Nova Scotia in Partial
Fulfillment of the Requirements for the Degree of Master of Technology
Entrepreneurship and Innovation

June 29, 2016, Halifax, Nova Scotia
Copyright Zainab Almukhtar, 2016

Approved: Dr. Adel Merabet
Supervisor
Division of Engineering

Approved: Dr. Claudia De Fuentes
Supervisory Committee Member
Management Department, Sobey
School of Business

Approved: Dr. Rasheed Beguenane
External Examiner
ECE, Royal Military College

Date: June 29th, 2016
Fuzzy Logic Control for Stand-alone Photovoltaic Energy Conversion System, and
Innovation in Renewable Energy.
by Zainab Almukhtar
Abstract

In this dissertation, simulation and hardware emulation was implemented to experiment
the operation of a power regulation system for stand-alone PV system with DC loads using
Fuzzy Logic Control (FLC). The system encompasses the functions of Maximum Power
Point Tracking (MPPT) to bring the power to the maximum value, load power regulation
and control of battery operation.
An algorithm that tracks the maximum power, and the corresponding fuzzy logic
controller were developed. An improved method for the battery operation regulation
including a fuzzy logic controller was applied. Load voltage regulation was achieved by a
modified cascaded PI controller.
The power regulation system managed to stabilize the load power, proved fast MPPT
tracking and regulation of the battery operation in the presence of fluctuations and fast
input variations.
The work included a study of the importance of university-industry collaboration to
innovation in renewable energy. The current collaboration channels and the contribution
of the current work was analysed through a questionnaire directed to the supervisor.
.

June 29th, 2016
Acknowledgement

I would like to start by thanking my parents and brother. Without them, I wouldn’t have
been able to achieve many of my goals. Many thanks to my husband and my wonderful
daughter and son for their encouragement and patience throughout the research work.
I would like to express my appreciation to my supervisor Dr. Adel Merabet for his
continuous directions, useful comments, and guidance in all the stages of this thesis.
Many thanks to Dr. Claudia De Fuentes for the very beneficial directions and for taking
the time to read the work and give me very useful feedback.
I sincerely thank Saint Mary’s University and the Master of Technology
Entrepreneurship and Innovation department for their support. Special thanks to the
Faculty of Graduate Studies and Research for their help and readiness to answer my
questions and inquiries.
Last but not least I thank all the people and friends that helped, and supported me during
this work.

June 29th, 2016
Table of Contents

Chapter 1 ........................................................................................................................... 1
1 Introduction ............................................................................................................... 1
1.1 Problem Definition ............................................................................................... 6
1.2 Objective .............................................................................................................. 7
Chapter 2 ........................................................................................................................... 8
2 Stand- alone PV systems with Battery Storage ...................................................... 8
2.1 Introduction ............................................................................................................... 8
2.2 PV Module ................................................................................................................ 8
2.2.1 PV systems ......................................................................................................... 8
2.2.2 PV Modelling ................................................................................................... 11
2.3 Energy Storage System ........................................................................................... 17
2.3.1 MPPT Techniques ............................................................................................ 17
2.3.2 DC-DC Converters ........................................................................................... 26
2.3.3 Storage Devices ................................................................................................ 28
2.3.4 Power Regulation System ................................................................................ 30
2.4 Applications ............................................................................................................ 33
2.4.1 Solar Cell Technologies ................................................................................... 33
2.4.2 Development of Solar Systems ........................................................................ 35
2.4.3 Obstacles and Potentials in the use of Solar Energy ........................................ 37
2.5 Conclusion ............................................................................................................... 42
Chapter 3 ......................................................................................................................... 44
3 Fuzzy Control System ............................................................................................. 44
3.1 Introduction ............................................................................................................. 44
3.2 Fuzzy Control Theory ............................................................................................. 45
3.2.1 Fuzzy Logic ...................................................................................................... 45
3.2.2 The Structure of the Fuzzy Controller .............................................................. 53
3.2.3 Applications of Fuzzy Control Systems ........................................................... 55
3.3 MPPT Control (Based on FLC) .............................................................................. 58
3.4 Battery Regulator (Based on FLC).......................................................................... 66
3.5 Load Side Control .............................................................................................. 73
3.6 Conclusion ............................................................................................................... 75
Chapter 4 ......................................................................................................................... 76
4 Experimentation and Results ................................................................................. 76
4.1 Introduction ............................................................................................................. 76
4.2 Real Time Control Hardware .................................................................................. 76
4.3 Real Control Software (RT-Lab)............................................................................. 80
4.4 Experimental PV System with Battery Storage. ................................................ 82
4.5 Experimental Results............................................................................................... 85
4.6 Conclusion ............................................................................................................... 98
Chapter 5 ......................................................................................................................... 99
5 Innovation and Technology Transfer .................................................................... 99
5.1 Introduction ............................................................................................................. 99
5. 2 The Classical Understanding of Research ............................................................ 100
5.3 The New Understanding of Basic and Applied Research ..................................... 102
5.4 University-Industry Interaction ............................................................................. 105
5.5 Potential in University-Industry Collaboration. .................................................... 110
5.6 Conclusion ............................................................................................................. 115
Chapter 6 ....................................................................................................................... 116
6 Conclusion .................................................................................................................. 116
6.1 Suggestions for Future Work ................................................................................ 118
References ...................................................................................................................... 120
Appendix A .................................................................................................................... 139
Acronyms and Abbreviations ...................................................................................... 139
Appendix B .................................................................................................................... 141
Specifications of the Hardware Parts .......................................................................... 141
List of Figures
Figure 1 2014 Energy consumption percentages [4]. .........................................................2
Figure 2. 2013 Energy use for electricity generation [4]. ....................................................3
Figure 3 Solar cell, module and array [15] . ......................................................................10
Figure 4 Equivalent circuit of a PV panel [16] ..................................................................11
Figure 5 Current- voltage curve of a PV panel [18] .........................................................12
Figure 6 Voltage-current characteristics of a PV panel in different light intensities [18]. 13
Figure 7 Voltage Current characteristics of a PV panel in different temperatures [18] ....13
Figure 8 The Effect of incident angle on the PV power [22].............................................15
Figure 9. The Cosine Effect [23]. ......................................................................................16
Figure 10 Variation of solar power with sun intensity [20]. ..............................................17
Figure 11 Power voltage-current characteristics of a PV Panel [24]. ...............................17
Figure 12 Power -voltage characteristics of PV at different light intensities [24] .............18
Figure 13 Perturb and Observe method ............................................................................21
Figure 14 The fill factor .....................................................................................................25
Figure 15 Boost converter .................................................................................................27
Figure 16. Buck-boost converter configuration. ...............................................................28
Figure 17 Power Regulation in PV systems. .....................................................................32
Figure 18 Basic structure of a solar cell [15]. ...................................................................33
Figure 19 Main parts of home solar system from Alternative Energy Tutorials [84] ......39
Figure 20 The distribution and the capacity of solar resources in Canada [77]. ...............41
Figure 21. Fuzzy membership functions. ...........................................................................47
Figure 22. The structure of a fuzzy control system [7]. .....................................................53
Figure 23 The centre of area defuzzification method [129] ..............................................54
Figure 24. The configuration of a Neural network ............................................................57
Figure 25 MPPT controller configuration ..........................................................................60
Figure 26.Flow chart of control algorithm .........................................................................61
Figure 27. FLC functions for MPPT .................................................................................63
Figure 28 Fuzzy output membership function for MPPT. ................................................64
Figure 29. Units of the battery control. ..............................................................................68
Figure 30 Flow chart of the battery operation ...................................................................69
Figure 31 FLC PID Controller ...........................................................................................70
Figure 32 Fuzzy input membership functions for the battery operation control. .............71
Figure 33 Fuzzy output membership function for the battery operation control. ..............72
Figure 34 Load voltage control .........................................................................................74
Figure 35. Real time system for the HIL stand-alone photovoltaic energy conversion
system. .......................................................................................................................77
Figure 36 Opal RT interface panel.....................................................................................78
Figure 37 OPAL-RT Signal Conditioning Module Interface (OP8660). ..........................79
Figure 38. subsystem for OPAL RT LAB .........................................................................82
Figure 39 Hardware configuration of the power control system. ......................................83
Figure 40 Schematic of the power control system .............................................................84
Figure 41 Voltage response in the PV energy system. (a) PV module voltage; (b) Load
voltage; (c) Battery voltage; (d) MPPT Voltage, reading1 .......................................89
Figure 42 Current response in the PV energy system. (a) PV module current; (b) Battery
current; (c) Load current, reading 1 ...........................................................................90
Figure 43 Power at different locations in the PV energy system, reading 1 ......................91
Figure 44 Current at different locations in the PV energy system, reading 1 ....................91
Figure 45 Voltage response in the PV energy system. (a) PV module voltage; (b) Load
voltage; (c) Battery voltage; (d) MPPT Voltage, reading 2. ......................................92
Figure 46 Current response in the PV energy system. (a) PV module current; (b) Battery
current; (c) Load current, reading 2 ...........................................................................93
Figure 47 Power at different locations in the PV energy system, reading 2. .....................94
Figure 48 Power at different locations in the PV energy system, reading 2 ......................94
Figure 49 Voltage response in the PV energy system. (a) PV module voltage; (b) Load
voltage; (c) Battery voltage; (d) MPPT Voltage, reading 3 ......................................95
Figure 50 Current response in the PV energy system. (a) PV module current; (b) Battery
current; (c) Load current, reading 3 ...........................................................................96
Figure 51 current at different locations in the PV energy system, reading 3 .....................97
Figure 52 Power at different locations in the PV energy system, reading 3 ......................97
Figure 53. Pasteur’s Quadrant [173] ................................................................................104
List of Tables
Table 1. MPPT FLC rules ................................................................................................. 65
Table 2 Fuzzy rule base for the battery control ............................................................... 72
Nomenclature

Solar Photovoltaic Cell

A Diode ideality factor
I Load current
I Current at maximum power point
mp
In Light intensity
IPH Photocurrent
I Diode reverse saturation current
RS
Is Diode saturation current
I Short circuit current
c
S
K Boltzmann’s constant
h Rate of switching
n Number of cells in parallel
p
n Number of cells in series
s
P Cell generated power in neutral temperature
0
P Cell generated power
Pmax Maximum PB power
PV Photovoltaic
q Electron charge
R Series resistance
S
T Cell temperature
i
T Reference temperature
r
V Cell terminal voltage
V Voltage at maxim power point
mp
V Open circuit voltage
OC

ii