DESIGN OF A HYBRID CONTROLLER FOR SOLAR AND OCEAN WAVE ENERGY HARVESTER

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DESIGN OF A HYBRID CONTROLLER FOR SOLAR AND OCEAN WAVE ENERGY

HARVESTER

by

AHMAD SHUKRI BIN FAZIL RAHMAN (1240910950)

A thesis submitted

In fulfilment of the requirements for the degree of Doctor of Philosophy in Electrical Systems Engineering

School of Electrical Systems Engineering UNIVERSITI MALAYSIA PERLIS

2017

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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 : AHMAD SHUKRI BIN FAZIL RAHMAN Date of birth : 15 APRIL 1976

Title : DESIGN OF A HYBRID CONTROLLER FOR SOLAR AND OCEAN

WAVE ENERGY HARVESTER

Academic Session : 2016/2017

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

AHMAD SHUKRI BIN FAZIL RAHMAN PROF. DR. SYED IDRIS SYED HASSAN 760415-07-5990

Date : Date :

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ACKNOWLEDGEMENTS

Alhamdulillah, thankful to Allah for giving me the strength and courage to complete this project. The thesis resulted from effort and hard work from myself and caring peoples around me. Therefore, I express my gratitude to Prof. Dr. Syed Idris for his guidance and support in bringing this thesis to completion. Not forgetting to PPKSE’s responsible staff, technicians and colleagues for their valuable effort and contribution, also included Unimap’s administrative staff for giving me the opportunity to pursue my study locally. And lastly, my family for their constant support I have relied throughout my PhD period. Thank you.

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TABLE OF CONTENTS

PAGE

DECLARATION OF THESIS i

ACKNOWLEDGEMENTS ii

TABLE OF CONTENTS iii

LIST OF TABLES vi

LIST OF FIGURES vii

LIST OF ABBREVIATIONS x

LIST OF SYMBOLS xiii

ABSTRAK xv

ABSTRACT xvi

CHAPTER 1 INTRODUCTION 1.1 Overview 1

1.2 Renewable Energy Scenario in Malaysia 2

1.3 Hybrid Renewable Energy 5

1.4 Problem Statement 7

1.5 Research Objectives 8

1.6 Research Scope 9

1.7 Thesis Outline 9

CHAPTER 2 LITERATURE REVIEW 2.1 Introduction 11

2.2 Investigations of Solar and Wave Energy Potentials 11

2.2.1 Global potential of solar 12

2.2.2 Solar potential in Malaysia 15

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2.2.3 Wave energy potential analysis in in Malaysia 17

2.3 Wave Energy Converter (WEC) 18

2.4 Hybrid system overview 23

2.5 Summary 30

CHAPTER 3 METHODOLOGY

3.1 Introduction 35

3.2 Propose system design 36

3.2.1 Hybrid System 39

3.2.2 Communication and Control System 46

3.2.3 Mobility Control 54

3.3 Harvester Module 57

3.4 PV System 61

3.5 Summary 62

CHAPTER 4 RESULTS AND DISCUSSION

4.1 Introduction 63

4.2 Harvester Module System Overview 64

4.2.1 Hybrid control module 65

4.2.2 Communication & Control module 68

4.2.3 Mobility module 72

4.3 Power elements for harvester module 75

4.3.1 Drive unit for mobility module 76

4.3.2 Non-inverting buck and boost module 79

4.4 Automatic control harvester module 86

4.4.1 Generator unit 86

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4.4.2 Energy harvesting mechanism 87

4.4.3 PV System Assessment 90

4.5 Overall System Assessment 92

4.6 Summary 95

CHAPTER 5 CONCLUSION AND FUTURE WORK 5.1 Conclusions 96

5.2 Future work 98

REFERENCES 100

APPENDIXES APPENDIX A PROGRAM CODE 107

APPENDIX B MECHANICAL SYSTEM DESIGN 113

APPENDIX C INSTRUMENT SPECIFICATION S 140

APPENDIX D LIST OF PUBLICATIONS 148

APPENDIX E AWARDS AND MEDALS 149

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LIST OF TABLES

NO. PAGE

2.1 Hybrid system achievements on global scale. 30

2.2 Study of ocean related technologies potential. 31

2.3 Hybrid components general overview. 31

2.4 Hybrid resources prospect in Malaysia. 33

2.5 Summary of hybrid related technology. 34

3.1 Parameter setting for buck and boost converter design. 41

3.2 Switching pattern for PIC18F4550. 42

4.1 Efficiency comparison table. 94

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LIST OF FIGURES

NO. PAGE

1.1 Primary energy supply. 3

1.2 Final energy consumption by sectors. 4

2.1 Wave formation mechanism. 19

2.2 Oscillating Water Column layout. 20

2.3 Overtopping Wave Energy Converter principal operation. 21 2.4 Schematic representation of a typical point absorber device. 22

2.5 Attenuators device operation principle. 22

2.6 Series hybrid block diagram. 25

2.7 Parallel hybrid block diagram. 25

3.1 Methodology process flow layout. 36

3.2 SOWEH system block diagram. 38

3.3 Buck and boost schematic. 39

3.4 PWM pulse generation sequence. 40

3.5 The proposed non-inverting buck and boost converter. 41 3.6 Initialization code for PWM waveform at f=50 kHz. 43

3.7 Flowchart for PWM generation. 44

3.8 (a) Microcontroller implementation with mosfet driving circuit. (b) P-mosfet

driver. (c) N-mosfet driver. 45

3.9 Physical sensors location on the designed system. 46

3.10 Voltage sensor circuit. 47

3.11 ACS712 based current sensor module. 48

3.12 Tilt sensor. 48

3.13 System initialization and data transmission code. 49 3.14 Program flowchart for Communication and Control. 50

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3.15 Ultrasonic distance sensor operating signals. 51 3.16 Schematic setup for Communication and Control System. 52 3.17 Graphical user interface (GUI) enables data manipulation from hardware

system. 53

3.18 Direct current (dc) motor responsible for providing motion to the system. 54

3.19 Program flowchart for Mobility Control. 55

3.20 (a) Microcontroller setup for Mobility Control. (b) Oscillator circuit.

(c) Driver circuit. 56

3.21 A modified motor using ceiling fan motor. 58

3.22 Proposed energy harvesting mechanism. 59

3.23 Flywheel design stage. 60

3.24 Flywheel bracket. 61

4.1 Simulation result during boost action. 66

4.2 Actual result during boost action. 66

4.3 Simulation result for buck action. 67

4.4 Actual result for buck action. 68

4.5 UART signal data transmission before and after wireless transmission. 69 4.6 Simulation waveform captured when tilt sensor deactivate. 70 4.7 Actual result displaying tilt sensor transition from high to low state. 70

4.8 Ultrasonic triggering event in channel B. 71

4.9 Actual case ultrasonic triggering event shown in channel 2. 72

4.10 Signal pair depicted via channel B and D. 73

4.11 Actual case for tilt sensor activating port RD1 and RD3. 73 4.12 Ultrasonic triggering event invoking port RD1 and RD3. 74 4.13 Actual case for ultrasonic triggering event invoking port RD1 and RD3. 75

4.14 Actual case implementation circuit. 77

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4.15 Actual case ultrasonic triggering event invoking negative output. 78 4.16 Actual case Tilt2 triggering event invoking negative output. 78 4.17 Simulation response for buck mode at 62.5% duty cycle. 80 4.18 Actual case buck mode output operating at 62.5% duty cycle. 80 4.19 Simulation response for boost mode at 62.5% duty cycle. 81 4.20 Hybrid implementation output for two simulated sources (buck mode). 82 4.21 Simulated buck mode operation with similar hybrid setting. 83 4.22 Hybrid implementation output for two simulated sources (boost mode). 84 4.23 Simulated boost mode operation with similar hybrid setting. 85 4.24 Experimentation setup for generator testing. 86 4.25 Generator curve for open circuit voltage (Vgen) versus speed (rpm). 87 4.26 Experimentation layout for wave energy harvesting mechanism. 88 4.27 Conceptual layout for electrical attainment. 88 4.28 Generator no load response when prime mover at 99.3rpm. 89 4.29 Generator on load response when prime mover at 99.3rpm. 90

4.30 Output profile during open circuit test. 91

4.31 Output profile for load test. 91

4.32 PV data distribution from 8:00am to 5:00pm. 92 4.33 Overall system experimental setup block diagram. 92

4.34 Overall system result. 93

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LIST OF ABBREVIATIONS

4FDP81 Four Fuel Diversification Policy in 1981 5FP2000 Fifth Fuel Policy in 2000

ac alternating current

ADC Analogue to Digital Converter ANN artificial neural networks

CAD/CAM Computer Aided Design/Computer Aided Manufacturing CAES Compressed Air Energy Storage

CCP Capture/Compare/PWM

CNC computer numerical control

dc direct current

FiT Feed-in-Tariff

GTFS Green Technology Financial Scheme GUI Graphical User Interface

HRES Hybrid Renewable Energy System

Hs Height significant

Hz Hertz

ITA Investment Tax Allowance

km² kilometer square

knot one nautical mile

LCD Liquid Crystal Display

Mosfet Metal oxide semiconductor field effect transistor

MP Malaysia Plant

NDP80 National Depletion Policy in 1980 NEP79 National Energy Policy in 1979

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NGTP National Green Technology Policy

ORE Ocean Renewable Energy

OTEC Ocean Thermal Energy Conversion

OPT Ocean Power Technologies

OWC Oscillating Water Column

OWEC Overtopping Wave Energy Converter PID Proportional–Integral–Derivative

PS Pioneer Status

PV Photovoltaic

PWM Pulse Width Modulation

RBH Rawdhat Bin Habbas

RE Renewable Energy

REBF Renewable Energy Business Fund

RF Radio Frequency

SEA South East Asia

SEAREV Système électrique autonome de récupération de l'énergie des vagues

SMES Superconducting Magnetic Energy Storage SOWEH Solar and Ocean Wave Energy Harvester

SPICE Simulation Program with Integrated Circuit Emphasis SREP Small Renewable Energy Programme

SREP Small Renewable Energy Power Program SSG Seawave Slot-Cone Generator

SWAN Simulating Waves Nearshore

UART Universal Asynchronous Receiver/Transmitter

V Volt

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xii VSM Virtual System Modelling

WET Wave Energy Turbine

Wh/m² Watt Hour per meter square

WW3 WaveWatch III

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LIST OF SYMBOLS

% Percentage

 Ohm

Iout Ripple current

V_out Ripple voltage

A Ampere

AH Ampere Hour

C Capacitor

D Duty cycle

F Farad

f Frequency

H Henry

H2 Hydrogen

Hs Wave Height

I_bnb Buck and boost current

I_out Output current

kWh/m² kilowatt-hours per square meter

km kilometer

kn knot

kW kilo Watt

kW/m kilo Watt per meter

L Inductor

m meter

mA mili Ampere

ms mili second

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m/s meter per second

MW Mega Watt

MWp Mega Watt peak

Pout Output power

psu practical salinity unit

RL Load Resistor

rpm revolutions per minute

Te wave energy period

Vbnb Buck and boost voltage

Vgen Generator voltage

Vin Input voltage

Vld Load voltage

V_out Output voltage

Vref Reference voltage

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Reka Bentuk Pengawal Hibrid Solar dan Gelombang Lautan Penuai Tenaga

ABSTRAK

Tesis ini membentangkan pendekatan pelaksanaan sistem hibrid antara Photovoltaik dan gelombang lautan. Sumber-sumber tenaga yang boleh diperbaharui ini sangat banyak, bersih dan bermanfaat berbanding bahan api fosil yang sedia ada. Kaedah biasa mengekstrak tenaga daripada sumber-sumber ini biasanya digunakan untuk menjana sumber tenaga secara tunggal untuk pengeluaran tenaga. Melalui sistem hibrid, integrasi dua atau lebih sumber boleh dilakukan. Penggabungan sumber gandaan tenaga ini akan melengkapkan dan menyokong mana-mana kekurangan mengiringi sumber-sumber ini.

Walau bagaimanapun, kerumitan sistem akan meningkat berkadaran dengan jumlah sumber lantas menyebabkan sistem menjadi rumit. Maka, kaedah kawalan yang betul diperlukan bagi pengurusan sumber yang berkesan. Oleh itu, kajian ini dijalankan untuk membangunkan satu pengawal bagi dua modul sistem penuai, Photovoltaik dan penukar tenaga gelombang untuk sistem kuasa hibrid. Pengawal ini perlu sepenuhnya mengeksploitasi ciri-ciri potensi tenaga dengan memanfaatkan ia ke tahap maksimum.

Kajian ini menyediakan kaedah yang berkesan untuk menuai Photovoltaik dan ombak lautan. Sumber Photovoltaik bergantung pada keamatan cahaya matahari manakala turun naik tenaga ombak lautan tidak sesuai melalui kaedah penuaian konvensional.

Pengawal yang dibangunkan akan mengintegrasikan Photovoltaik dan gelombang lautan serta mengimbangi turun naik kuasa. Integrasi yang betul telah berjaya dilaksanakan melalui modul penukar ronta dan galak. Modul penukar tenaga gelombang yang dibangunkan menggunakan mekanisme roda bergigi searah manakala unit penjana telah diekstrak daripada motor kipas siling mini. Sistem pemantauan tambahan telah ditambah dengan merelisasikan penghantaran tanpa wayar kepada pengendali.

Pembangunan Photovoltaik dan penukar gelombang ombak mencapai kemajuan pesat dengan kuasa purata yang dihasilkan masing-masing adalah 76.91mW dan 82.237W.

Pengawal yang dicadangkan cemerlang dalam prestasi dan menghasilkan pengurusan tenaga hibrid berkesan dengan pengukuran kecekapan pengekstrakan kuasa pada 58%.

Sistem hibrid ini telah berjaya dilaksanakan dalam sempadan skop yang telah ditetapkan.

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Design of a Hybrid Controller for Solar and Ocean Wave Energy Harvester

ABSTRACT

This thesis presents an approach of hybrid system implementation between Photovoltaic and ocean waves. These renewable energy sources are abundant, clean and beneficial compared to existing fossil fuel. Common method of extracting energy from these sources normally utilized a single energy source for energy production. Through hybrid system, two or more sources integration is possible. Merging of multiples energy sources will complement and support any inadequacy attribute accompanying these sources. However, system complexity will increase as source increases resulting in complicated system. Thus a proper controlling method is required for effective source management. Therefore, this research was initiated to develop a controller for two system harvester modules, Photovoltaic and wave energy converter for hybrid power system. The controller should fully exploit energy potential characteristic by harnessing it to the maximum. This research provides an effective method of harvesting Photovoltaic and ocean waves. Photovoltaic source is dependable toward sun intensity while the ocean waves’ intermittent energy is unsuitable through conventional harvesting method. The established controller will integrate Photovoltaic and ocean waves and compensate power fluctuations. Proper integration was successfully executed through buck and boost converter module. The wave energy converter module was developed using ratchet mechanism and the generator unit was extracted from mini ceiling fan motor. An additional monitoring system was added and performs wireless transmission to operator. The developed Photovoltaic and Wave Energy Converter (WEC) sources progress rapidly with average power produced are 76.91mW and 82.237W respectively. The proposed controller excels in performance and produce effective hybrid energy management with measured with power extraction efficiency at 58%. The hybrid system was successfully executed within the prescribe scope boundaries.

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1 CHAPTER 1

INTRODUCTION

This chapter initiates the research work reported in this thesis. First, the fundamentals of the research background and its significant effect is presented first and concluded by an overview pertaining to the research topic. Then, brief descriptions on the study system and research objectives are outlined. The system limitations and thesis outline are given at the end of this chapter.

1.1 Overview

Gradual depletion of natural resources and its effect towards the environment are on the rise. Rapid energy demand from developing country also worsens the problem.

The extensive used of coal, petroleum, and other fossil fuels, through combustion process lead to the emission of harmful substances to the atmosphere. These limited sources are affecting the earth supply storage. According to Bose (2013), the world coal reserves will last for about 200 years, oil reserve is expected to be exhausted in 100 years and gas is expected to last for about 150 years. These challenges have raised awareness and prompted immediate action (Darmani, Arvidsson, Hidalgo et al., 2014).

Thus, the requirement of an alternative energy production promoted the efforts to utilize renewable energy sources as the preferable energy source.

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The phrase renewable energy is acquired from a large scope of resources, in which all are based from self-renewing energy sources such as sunlight, wind, waves, the earth’s internal heat and biomass. Renewable energy is more beneficial than the conventional energy sources; it is clean, minimizes environmental impacts, produces minimum secondary wastes and is sustainable based on current and future economic and social needs (Manzano-Agugliaro, Alcayde, Montoya et al., 2013). Its resources are abundant worldwide with 1000 times more energy reaches the surface of the earth from the sun than is released today by all fossil fuels consumed (Bull, 2001).

1.2 Renewable Energy Scenario in Malaysia

Malaysia’s rising population growth and economic development increases energy demand. Malaysia is currently dependent on fossil fuels such as coal, oil and natural gas to generate electricity. The global trend of extreme energy consumption is quite reflective towards Malaysia as it progress towards achieving an industrialized country.

Typical situation in Malaysia’s energy mix (oil, gas, coal and hydroelectric) is depicted in Fig. 1.1(Energy_Commission/SuruhanjayaTenaga(ST)Malaysia, 2014). The graph provides an overview of Malaysia’s energy supply for more than a decade.

Significant downwards trend is visible with oil losing 1.5% of its share to 32.5% in 2012. Hydropower contributes the lowest share in energy supply even though Malaysia is surrounded with substantial hydroelectric resources. Consequently, primary energy mix are formed on fossil fuel resources (coal, oil and gas), forcing tremendous pressure on the depleting natural resources.

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Figure 1.1: Primary energy supply.

These depleting sources are the byproduct of growing demand and consumption interaction occurs globally. The degree of energy consumption scenario in Malaysia for

more than a decade could be viewed in Fig. 1.2

(Commission/SuruhanjayaTenaga(ST)Malaysia, 2014). Progressive approach towards industrialized nation is highly reflected by the strong dominance of industry and transport sector throughout the period. Consequently, these dominant sectors imposed a heavy load on Malaysia’s energy sustainability, efficient resource utilization and environmental safeguarding.

0%

50%

100%

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

Share(%)

Year

Primary energy supply

Hydropower Coal and Coke

Natural Gas (Sales Gas)

Crude Oil and Petroleum Products & Other

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Figure 1.2: Final energy consumption by sectors.

Nevertheless, the large scale exploration of renewable energy source during the last decade is proven to be advantageous. Today, renewable energy source supply 14%

of the total world energy demand, and is expected to increase significantly from 30% to 80% by 2100 (Manzano-Agugliaro, Alcayde, Montoya et al., 2013). Figures from Hitam (1999) estimated solar power to be four times the world fossil fuel resources in Malaysia. On average, the annual solar irradiations in Malaysia is from 4.21 kWh/m²to 5.56 kWh/m², with Northern region and some places in East Malaysia receives highest solar radiation (Azhari, Sopian, Zaharim et al., 2008). The transition period between monsoons presents the lowest solar radiation at 0.61 kWh/m² in December.

The convenience of being surrounded by large coastline could contribute to Malaysia energy sustainability (Chong & Lam, 2013). Having 4675 km long coastline, longest straits in the world, constant flow rate up to 4 m/s and average current speed of 2 m/s are sufficient for exploring potential ocean renewable energies prospect. Tidal current energy, tidal barrage, ocean thermal energy conversion (OTEC), power wave energy and salinity gradient power are extensively accepted as an effective technique

0 10,000 20,000 30,000 40,000 50,000

Energy Consumption in ktoe

Year

Final Energy Consumption by Sectors

Industry Transport

Residential and Commercial Non-Energy Use Agriculture

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for harnessing ocean energy. Carefully examined and executed, these renewable energy prospects could be utilized to their maximum potential for better efficiency in energy conversion.

Guided by future demands, Malaysia has initiated step towards alternative energy specifically renewable energy to alleviate Malaysia’s dependency over fossil fuels and managing its growing demand for energy. Initial steps taken appear from the 7th Malaysia Plan (7MP) to 10th Malaysia Plan (10MP) aimed to promote utilization of renewable energy resources and efficient use of energy (Hashim & Ho, 2011).

Concerted effort, such as Small Renewable Energy Programme (SREP) (May 2001) contributed 56.7MW (energy mix) from 286MW of its actual potential (Mustapa, Leong Yow, & Hashim, 2010) and Malaysia aimed to raise it to 2,000MW by 2020.

Renewable energy capacity in Malaysia is less than 1% of total electricity generation in Malaysia. By utilizing only 5% of renewable energy in the energy mix will save the country RM 5 billion (US$ 1.32 billion) for a period of 5 years (Hashim & Ho, 2011).

1.3 Hybrid Renewable Energy

Limitations of conventional power production method such as power fluctuations, intermittent renewable sources such as solar and wind requires support with other utility generation resources. Current method of harnessing single energy generation systems such as solar, wind, biomass, geothermal, hydropower and diesel are not realistic in terms of cost, reliability and efficiency. Since, different renewable energy resources can complement each other; taken together they can optimize effective and efficient energy production. Thus, a single source energy production may evolve to

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a variety of energy production systems comprising a renewable energy based hybrid system that offers a better option than a single source based system.

A hybrid power system refers to a system having two or more components combined for the purpose of efficient utilization of resources. For example, wind energy source integration to an existing solar system will provide support during peak power load and perform system matching. Through proper technology selection, the system could also perform energy storage for future usage.

A controller is an integral part of a hybrid power system. Primarily, it involved power electronics based DC-DC converter to extract maximum energy from sources (Nema, Nema, & Rangnekar, 2009). A controller will determine and assign active and reactive output power dispatch from each energy source while maintaining its output voltage at the desired level. Normally, each source is equipped with a local controller to provide improvement that corresponds to the current information. The operating features may consist of on-grid or off-grid operation mode and changes in combination of energy sources supplying the load.

Hybrid energy systems are becoming an essential part of the energy planning process to supply remote areas such as India, Thailand, Spain, South Africa and Australia. Growing research focused on the performance analysis and the development of efficient power converters resulting in the development of reliable and cost-effective system.

This thesis research was planned to tackle drawbacks arise from hybrid power system implementation. Through common Photovoltaic (PV)/wind based controller, improvements are made for possible PV/wave hybrid configuration. This thesis also presents a manageable solution in providing data monitoring package for PV/wave hybrid configuration.

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7 1.4 Problem Statement

Conventional hybrid configuration may consist of wind/PV, thermal/solar, PV/hydro/biomass etc. The PV condition is heavily affected by weather conditions which require integration of supporting energy source such as wind, biomass, thermal etc. These hybrid systems normally operated from a fixed location to maximize energy capture from the prevailing surrounding conditions. Constructing these hybrid systems require supporting structures such as extracting plant for thermal, hydro and biomass;

tall towers for wind turbines hence incurred additional cost on the existing system.

While stable large and rigid structures is affecting the surrounding ecosystem thus, hampered the growth of hybrid power system.

Current hybrid controller normally focused on wind/PV configuration and its variation making the feature impractical for non-PV/wind hybrid power system configuration. Control strategy for power management may consists of voltage regulation, state-based strategy by evaluating sensed conditions to set an operating mode, state machine, and the use of a programmed algorithm. To achieve effective working conditions, the control strategy is usually being integrated as a part of hybrid system controller along with source controller, storage management and system monitoring.

However, conventional control schemes employed do not provide an easier approach in term of implementation. System configuration requires intricate design to accomplish optimal result prompting an increase in complexity level which will incur additional cost and time. It is therefore desirable that the proposed controller is capable of attaining effective and optimal performance with minimal impacts toward implementation, operation and its environment.

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