MODELING OF HYBRID RENEWABLE ENERGY GENERATION...
Transcript of MODELING OF HYBRID RENEWABLE ENERGY GENERATION...
MODELING OF HYBRID RENEWABLE ENERGY GENERATION CONSISTING
OF WIND, FUEL CELL AND ULTRA CAPACITOR
MOHAMMAD FATHI
A project report submitted in partial fulfilment of the requirements for the award of the degree of Master of Engineering (Electrical - Power)
Faculty of Electrical Engineering Universiti Teknologi Malaysia
MAY 2011
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To God the Almighty, without whom knowledge without faith is fruitless and to my
lovely parents and my sisters and brother, who do not let me sense me alone.
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ACKNOWLEDGEMENT
First of all, I am greatly indebted to ALLAH SWT to make this project
successful. I would like to acknowledge my supervisor Professor Ir. Dr. Abdullah
Asuhaimi bin Mohd Zin who has given me support and guidance throughout the
period of this research. His patience and perseverance towards the outcome of this
study is of the highest standard. Without him this project could not become a reality.
Last but not least, I would like to thank other Faculty of Electrical Engineering
(FKE) staffs and my family for their motivation and moral supports.
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ABSTRACT
Consider to the finish of fossil fuel and the growth of population, the need of
creating and utilizing new sources of energy is increased. During the past few
decades, scientists have discovered new resources to generate electricity. These kinds
of energy are called renewable energies. Alongside all the benefits of new resources
they have some disadvantages that cannot use them widely. For example, one of the
issues in generating electricity from wind is the variation of wind speed. In the case
of having an ideal generation of electricity, the use of stable and power quality curve
is necessary. But this variation of wind speed sometimes makes a problem in
drawing this curve. In order to solve this problem, this study offered the utilizing of
the wind and fuel cells as renewable energy in a hybrid configuration. This
configuration can solve problems of renewable energy. In this project, the generating
of electricity is hydride from wind turbines and fuel cell. If the speed of wind is not
enough to generate the electricity, the fuel cell would start to generate it. However,
the fuel cell needs the time to arrive nominal value which ultra capacitor start to
generate the electricity in this gap. All the system consists of grid, wind turbine, fuel
cell and ultra capacitor was simulated in MATLAB software. The output of system
should be a stable carve. It means this hybrid system’s generation as a reliable
production is used in all wind speed condition. By using this, the disadvantage of
using wind is reduced and also the power quality of distribution’s grid and electricity
production be improved.
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ABSTRAK
Kekurangan bahan api sejak kebelakangan ini memberi motivasi untuk
mencari sumber tenaga yang baru. Beberapa dekad yang lalu, para ahli saintis telah
mempelajari bagaimana penggunaan sumber tenaga dalam penghasilan elektrik.
Tenaga yang dimaksudkan ialah tenaga yang boleh di perbaharui. Walaupun tenaga
yang boleh diperbaharui mempunyai banyak kebaikan tetapi keburukan yang ada
padanya telah menghalang penggunaan sumber tersebut secara berleluasa.
Contohnya, kepelbagaian kelajuan angin merupakan isu yang besar dalam tenaga
angin. Bagi menghasilkan penjanaan yang sempurna, penghasilan elektrik perlu
dilakukan dalam lengkungan yang tepat. Bagi menyelesaikan masalah tersebut,
penggunaan sumber tenaga secara hibrid telah diperkenalkan dalam projek ini. Dua
sumber tenaga boleh diperbaharui telah digunakan iaitu fuel cell and tenaga angin.
Dalam keadaan tenaga angin tidak mencukupi, tenaga akan dihasilkan daripada fuel
cell. Dengan kata lain, apabila pengeluaran angin berkurangan, tenaga akan mula
dihasilkan daripada fuel cell. Walaubagaimanapun, fuel cell memerlukan masa untuk
mencapai nilai yang nominal yang mana masalah ini dapat diatasi dengan
menggunakan kapasitor sebagai penyimpan tenaga. Sistem yang terdiri daripada
penjana angin, fuel cell dan kapasitor telah di analisis dalam perisian MATLAB.
Keluaran sistem tersebut perlu dalam lengkungan yang tepat. Ini bermakna, dalam
sistem hibrid ini, penjanaan tenaga boleh dalam semua keadaan angin. Oleh yang
demikian, sumber tenaga boleh diperbaharui dapat digunakan secara meluas. Akhir
sekali, jumlah kos penghasilan tenaga elektrik akan semakin berkurangan.
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TABLE OF CONTENTS
CHAPTER TITLE PAGE
DECLARATION ii
DEDICATION iii
ACKNOWLEDGMENT iv
ABSTRACT v
ABSTRAK vi
TABLE OF CONTENTS vii
LIST OF FIGURES x
LIST OF ABBREVIATIONS
LIST OF SYMBOLS
LIST OF APPENDICES
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1 INTRODUCTION 1
1.1 Background of the Study 1
1.2 Significance of Study 3
1.3 Problem statements 4
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1.4 Objective of Study 5
1.5 Scope of Study 5
1.6 Organization of the Report 5
2 LITERATURE REVIEW 7
2.1 Introduction 7
2.2 System description 10
2.2.1 Wind Energy Conversion System 11
2.2.1.1 Advantages 12
2.2.1.2 Disadvantages 13
2.2.1.3 Description of wind turbine characteristics
2.2.2 Fuel Cell (FC)
2.2.2.1 Technology Basics
2.2.2.2 Types of fuel cells
2.2.2.3 Advantages
2.2.2.4 Disadvantages
2.2.2.5 Model Assumptions
2.2.2.6 Model Limitations
2.2.2.7 Applications
2.2.2.8 Stationary power
2.2.2.9 Hydrogen Generation
2.2.3 Storage and Ultra Capacitor
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2.2.3.1 Ultra Capacitor
2.3 Design of the Hybrid System
2.4 Summary
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3 METHODOLOGY 32
3.1 Introduction 32
3.2 Data Collection
3.2.1 Load demand, PD
3.2.2 Generation limit, P max and P min
3.2.3 Wind speed
3.2.4 Wind generator capacity
3.2.5 Maximum allowed delay for generation
3.2.6 FC capacity of generation and H2 storage tank
3.3 System Elements
3.3.1 Wind turbine compound with generator (doubly-fed
induction generation or DFIG)
3.3.2 Fuel Cell (FC)
3.3.3 Ultra Capacitor (UC)
3.4 Assumptions
3.5 Limitations
3.6 Design hybrid system
3.7 The economical assessment of hybrid system by HOMER
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3.8 Summary 49
4 RESULTS 50
4.1 Introduction 50
4.2 Wind Energy Conversion System 51
4.3 Fuel Cell 53
4.4 Ultra capacitor
4.5 Design of the Hybrid System
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4.5.1 FC and wind generate (both start t=0s) 57
4.5.2 FC and wind generate with UC (all start t=0s) 58
4.5.3 FC (start t=0s) and wind generate with delay
4.5.4 FC and UC (start t=0) and wind generate with
delay
4.6 Summary
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5 CONCLUSIONS 61
5.1 Introduction 61
5.2 Conclusions 61
5.3 Suggestions for Future Works 62
REFERENCES 64
APPENDX A 66
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LIST OF FIGURES
FIGURE NO. TITLE PAGE
2.1 Wind-Fuel Cell hybrid energy system 9
2.2 Two different of wind turbine model 12
2.3 Wind speed, scaled data daily profile 14
2.4 The Wind Turbine and the Doubly-Fed Induction Generator System15
2.5 Fuel Cell 17
2.6 Basic fuel cell components 17
2.7 The exhaust of fuel cell after generating electricity is water 20
2.8 PEM fuel cell system block diagram 22 2.9 Classical equivalent model for the UC unit 29
3.1 Flow Chart for Project’s Methodology 33
3.2 The Block diagrams of wind turbine and drive train 37
3.3 The Simulink model of the wind turbine 38
3.4 The Simulink model of the drive train connect to wind turbine 38
3.5 Block diagram of doubly fed induction generator 39
3.6 Block diagram of Fuel Cell 42
3.7 Dynamic model of solid oxide Fuel cell (SOFC) 43
3.8 Block diagram of FC and its inverter before connect to grid 44
3.9 Simulink equivalent model for the UC unit 45
3.10 Block diagram of UC and its inverter before connect to grid 45
3.11 Schematic picture of Hybrid generation consist of
wind turbine, FC and UC 47
3.12 Connections of three elements of system 48
4.1 The result of wind turbine and generator if the wind
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at the time t=0 be 1pu 51
4.2 The voltage and current output of wind turbine in volt
and ampere unit 52
4.3 The RMS value of voltage and current output of wind
turbine in volt and ampere unit 52
4.4 The value of generation from FC 53
4.5 The voltage and current of FC in volt and ampere unit 54
4.6 Power generated by UC in t=0s 55
4.7 The voltage and current of FC in volt and ampere unit 55
4.8 The RMS value of voltage and current of UC in volt and ampere unit 56
4.9 Generating result of wind and FC when all start from t=0s 57
4.10 Generating result of wind, FC and UC when all start from t=0s 58
4.11 Generating result of wind and FC when FC start at t=0s and
wind start at t=0.4s 59
4.12 Generating result of wind, FC and UC when FC and UC
start at t=0s and wind start at t=0.4s 59
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LIST OF ABBREVIATIONS
FC - Fuel Cell
UC - Ultra Capacitor
NREL - National Renewable Energy Laboratory’s
WT - Wind Turbine
PEM - Proton exchange membrane or Polymer Exchange Membrane
DFIG - Doubly fed induction generation
IG - Induction Generator
MCFC - Molten Carbonate
SOFC - Solid Oxide Fuel Cell
AFC - Alkaline Fuel Cell
PAFC - Phosphoric acid Fuel Cell
DMFC - Direct Methanol Fuel Cell
ESR - Equivalent series resistance
EPR - Equivalent parallel resistance
PF - Power Factor
VSC - Voltage-sourced converters
IEEE - The Institute of Electrical and Electronics Engineers
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LIST OF SYMBOLS
푃 - Mechanical output power of turbine
퐶 - Performance coefficient of the wind turbine
휆 - Tip speed ratio of the rotor blade tip speed to wind
훽 - Blade pitch angle ( )
휌 - Air density (kg/푚 )
A - Turbine swept area (m )
푣 - Wind speed ( )
푛 - Hydrogen produced (moles/sec)
휂퐹 - Faraday efficiency=96.5푒(. . )
휂푐 - Number of electrolyzer cells in series
푖 - Electrolyzer current
F - Faraday constant (CK/mol)
T - Temperature of operation
z - Number of moving electrons
i0 - Exchange current
En - Nernst voltage
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α - Charge transfer coefficient C - Capacitance [F]
CUC-total - The total UC system capacitance [F]
EPR - Equivalent parallel resistance [Ω]
ESR, R - Equivalent series internal resistance [Ω]
EUC - The amount of energy released or captured by the UC bank [Ws]
ns - The number of capacitors connected in series
np - The number of series strings in parallel
R UC-total - The total UC system resistance [Ω]
푉 - The initial voltage before discharging starts [V]
푉 - The final voltage after discharging ends [V]
Tm - Shaft mechanical torque
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LIST OF APPENDICES
APPENDIX TITLE PAGE
A Feasibility of hybrid renewable energy
types consist of Wind, Fuel Cell with
CHP, Diesel Generator and Battery under
Alaska condition
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CHAPTER 1
INTRODUCTION
1.1 Background of Study
With the developed of world, it seemed the energy was the main part for
improving economic and social development and also it drives a good living standard.
Due to increased access to electricity, it will improve opportunities for industrial
development and enhances health and education. Renewable Energy (RE) has a great
potential to contribute to development of national sustainable energy infrastructures in
many countries in the world. Hybrid Renewable Energy is a combination of more than
one type of energy in one system. For instance, Fuel cell and wind can become one
hybrid type of Renewable energy generation. A hybrid energy system based on such
alternative technologies has been proven to be a feasible solution for stand-alone
power generation at remote locations, where the cost of grid extension is prohibitive
and the price of fossil fuels increase drastically. Moreover, the hybrid systems such as
wind/diesel are now proven technologies and are an option to supply small electrical
loads at remote locations as reported by Zhang Hongyi et al. , Lundsager and Bindner
[1].
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A wind system alone cannot satisfy the load requirement for 24 hours.
Stand-alone diesel generator sets are generally expensive to operate and maintain
especially at low load levels. In simple system, the diesel runs continuously to
cover the difference between the load demand and the wind energy, as a result
the diesel generator runs sometimes under light-load conditions. Due to low
efficiency of the generator at light load, the fuel saving potential is limited. Wind and
diesel have complementary characteristics namely, capital cost of diesel is lower
compared with wind turbine system, maintenance requirements of wind are less
compared to diesel, and diesel energy is available all the time where as the availability
of wind energy is dependent on the wind. Battery technology has reached a very
suppurate stage; size, cost and disposal are the constraining factors for its use in remote
stand-alone applications. Recent advancements in Fuel Cell (FC) and electrolyzer
technology have opened up the option for using hydrogen as an energy storage
medium [2] .
Some studies are reported about design, optimum combination and analysis
of hybrid renewable energy power generations with energy storage. The overall
goal is to identify the current availability of commercial hybrid renewable energy
systems and its components by using Homer software. Inputs to HOMER will
perform an hourly simulation of every possible combination of components
entered and rank the systems according to user-specified criteria, such as cost of
energy (COE, US$/kWh) or capital costs. Furthermore, HOMER can perform
“sensitivity analyses” in which the values of certain parameters (e.g., solar
radiation or wind speed) are varied to determine their impact on the system
configuration [3]
Standalone diesel generating system utilized in remote islands has long been
practiced in Alaska. Because of high fluctuation diesel price, such a system is seemed to
be uneconomical, particularly in the long run if the supply of electricity for rural areas
only depends on such diesel generating system. Here the potential use of hybrid
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Wind/Fuel cell (FC)/Battery /diesel energy system was analyzed in remote areas.
National Renewable Energy Laboratory’s (NREL) HOMER software was used to
present the techno economic feasibility of hybrid Wind/Fuel cell (FC) /Battery/diesel
energy system. The investigation verified the impact of wind/ FC penetration and battery
storage on energy production, cost of energy and number of operational hours of diesel
generators for the given hybrid configuration. Emphasis has also been placed on
percentage fuel savings and reduction in carbon emissions of different hybrid systems.
At the end, suitability of utilizing hybrid Wind/Fuel cell (FC)/Battery /diesel energy
system over standalone diesel system would be discussed mainly based on different load
demand, wind speed, FC and diesel prices . In order to determine the economic and
technical feasibility of a wind/fuel cell/diesel system, computer modeling of the different
power system options have to be done [4].
1.2 Significance of Study
This project needs to be solved. Notice to this case that it should feed all demand
loads with different types of generation with enough power, reliable voltage and
frequency in our grid. Thus for having a reliable power system, it needs to assess our
system in two status. First of all before start to design each system it is necessary to have
an economical assessment. It is mean that, if it was assumed to make a power plant for
generating electricity. In this case it’s so important the low cost of production. In the
other word, the electricity generation in new power plant should not be more expensive
in compare to normal generation on that place. Second of all, the new planned system
should be able to work in normal and abnormal condition. It means this new system
capable to work in practical state. Thus this system has to assess from technical
viewpoints. Each parts has own characteristics for having a best work points.
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The disadvantages of these renewable types are:
In wind turbine: the wind speed is variable and sometimes it stops to blow.
Fuel cell: cannot supply load in long duration and takes time to start to generate
power.
For having a good quality of electricity, should not have any interruption or
blackout for delivering electricity to consumers.
1.3 Problem statements
The problem statements of this project are:
a) The disadvantages of these renewable types.
In wind turbine: the wind speed is variable and sometimes it stops to blow
Fuel cell: cannot supply load in long duration and takes time to start to generate
power
b) For having a good quality of electricity, should not have any interruption or
blackout for delivering electricity to consumers
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1.4 Objective of Study
The objectives of this study are:
1) To generate a system consisting of wind, FC and UC.
2) This system should generate power demand (active power) by the best output
(sustain generation and fast starting) and deliver this power to grid.
1.5 Scope of Study
The scope and limitation of the study are as follow:
1) Handling of the modeling of wind turbine (WT), Fuel Cell (FC) and Ultra
Capacitor (UC) to generate a good quality and quantity of power for deliver to
grid.
2) Integrated these three different types to get better results.
3) The simulation by using MATLAB 7.0 Simulink for technical part and using
HOMER software to do economical assessment.
1.6 Organization of the Report
This thesis is divided into five chapters. The first chapter is the significance of
the study, followed by chapter 2, which discuss about the literature review and previous
study. Chapter 3 describes about the methodology of the system. The results and
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discussions will be discussed in Chapter 4. The last chapter provides the conclusion of
the study.
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REFERENCES
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