DESIGN OF MICRO-POWER GENERATOR BASED ON ELECTROMAGNETIC MECHANISM HARVESTING ENERGY FROM DIRECT AIR FLOW TAN JYE GIN

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1 i DESIGN OF MICRO-POWER GENERATOR BASED ON ELECTROMAGNETIC MECHANISM HARVESTING ENERGY FROM DIRECT AIR FLOW TAN JYE GIN A thesis submitted in fulfillment of the requirements for the Bachelor Degree Of Electronic Engineering (Industrial Electronic) Faculty of Electronic Engineering and Computer Engineering UNIVERSITI TEKNIKAL MALAYSIA MELAKA JUNE 2013 i

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3 iii I declare that this thesis entitle DESIGN OF MICRO-POWER GENERATOR BASED ON ELECTROMAGNETIC MECHANISM HARVESTING ENERGY FROM DIRECT AIR FLOW is the result of my own reaesrch except as cited in the references. The thesis has not been accepted for any degree and is not concurrently submitted in candidature of any other degree. Signature :... Name : TAN JYE GIN Date :...

4 iv I declare that I have read this work and in my opinion this work is adequate in terms of scope and quality foe the purpose of awarding a Bachelor s Degree of Electronic Engineering (Industrial Electronics). Signature :... Name : DR. KOK SWEE LEONG Date :...

5 v To my beloved family and friends who, of all that walk the earch, are most precious to me.

6 vi ACKNOWLEGEMENT In preparing this thesis, I was in contact with many people, researchers, academicians and practitioners. They have contributed towards my understanding and thought. In particular, I wish to express my sincere appreciation to my thesis supervisor, Dr. Kok Swee Leong, for encouragement, guidance critics and friendship. Without his continued support and interest, this thesis would not have been same as presented here. I am also indebted to University Techinical Malaysia Malacca (UTeM) in allowing me to use entire facilities available to complete my testing and studies. My fellow friends should also be recognised for their support. My sincere appreciation also extends to others who have provided assistance at various occasions. Their views and tips are useful indeed. Unfortunately, it is not possible to list all of them in this limited space. I am grateful to all my family members.

7 vii ABSTRACT This project is to construct a micro-power generator based on electromagnetic mechanism harvesting energy from direct air flow. The concept is to make a magnet-attached cantilever to oscillate in the presence of direct air flow. The oscillation happens when air travel and provide a force to push the cantilever downward in a repetition manner as a result of vortex generated underneath the cantilever. In order to generate electrical energy, a pair of magnet mounted on the cantilever and with a magnetic coil in between and fixed vertically at the tip of the cantilever is used to pick up the induced current. The E.M.F. voltage produced is directly proportional to the rate of change of magnetic flux. Experiment is carried out to analyze the output voltage produced by the micro-generator. The output power generated is able to activate small electronic device, this is shown by an LED indicator. A prototype for the micro power generator is constructed to demonstrate the capability of the generator in producing a sufficient electrical power by transforming kinetic energy to electrical energy. The direct air-flow is eco-friendly, less cost and renewable.

8 viii ABSTRAK Projek ini dijalankan bertujuan untuk menjana kuasa mikro dengan kehadiran aliran udara terus berdasarkan teori elektro-magnet. Penjanaan juasa dibinakan melalui satu julur yang berayun tegak dengan kemasukan aliran angin terus. Perayunan tersebut berlaku apabila penekanan julur secara berualang-ulang daripada pengaliran angin terus akibat vorteks yang terdapat di bawah julur tersebut. Susunan sepasang magnet dibina pada julur bersama gegelung magnet yang diletakkan di tengah serta berdiri tegak di hujung julur adalah untuk menghasilkan tenaga elektrik. Penghasilan voltan E.M.F. adalah berkadar langsung dengan kadar perubahan fluks magnet. Eksperimen telah dilaksanakan untuk menganalisis penghasilan voltan daripada penjana mikro ini. Kuasa hasilan daripada penjana mikro ini dapat mengaktifkan alat elektronik yang memerlukan kuasa kecil seperti yang ditunjukkan oleh isyarat LED. Satu prototaip penjana mikro kuasa ini dibinakan untuk mengetengahkan keupayaan penjana ini menukarkan tenaga kinetik kepada tenaga elektrik dengan bersumberkan aliran udara terus. Aliran udara terus merupakan satu sumber yang mesra alam, kos rendah dan boleh diperbaharui.

9 ix TABLE OF CONTENT Title page Declaration Dedication Acknowledgement Abstract Abstrak Table of content List of Tables List of Figures PAGE i iii v vi vii viii ix xi xii 1. INTRODUCTION 1.1 General Background Project Overview Problem Statement Objectives Scope of work Report Structure 6 2. LITERATURE REVIEW 2.1 Introduction Ambient Energy Souces Ambient Energy System Comparison of Power Density of Energy Harvesting Methods VibrationEnergy-Harvesting Techiques Basic Principles of Electromagnetic Energy-Harvesting Working Principles Faraday s Law Voltage Multipliers Previous research related to current study METHODOLOGY 3.1 Experimental Flow Chart Simulation Software Multisim Software Proteus Software Hardware Protype RESULT AND DISCUSSIONS 4.1 Theoretical Hypothesis Number of Turns of Coil 31

10 x Experimental Result Stages of Multipliers Simulation Result Experimental Result Discussion of Result Stages of Multipliers Comparision of Design Fabrication Citcuit CONCLUSION & SUGGESTION 5.1 Conclusion Suggestion for Future Development 54 REFERENCES 56 APPENDIX 59

11 xi LIST OF TABLES TABLE TITLE PAGE 2.1 Ambient Energy Sources Comparison Power Density of Energy Harvesting Methods Comparison of Vibration Energy-Harvesting Techniques Comparison of electromagnetic vibration transducer prototypes Common magnetic material properties Specification of Energy Harvester Result of Output Voltage Simulation Output Voltage for Input Voltage = 0.1V Result of Simulation Power for Input Voltage = 0.1V Simulation Output Voltage for Input Voltage = 0.5V Result of Simulation Power for Input Voltage = 0.5V Experimental Output Voltage for Input Voltage=0.1V Result of Experimental Power for Input Voltage = 0.1V Experimental Output Voltage for Input Voltage=0.5V Result of Experimental Power for Input Voltage = 0.5V Comparison of Results for Input=0.5V 47

12 xii LIST OF FIGURES FIGURE TITLE PAGE 1.1 Power consumption of various wireless standards Projected Annual Battery Change Labor Cost Scavengable Energies from Non-Biological Converted To 8 Electrical Energy for Use by Small Electric Unmanned Systems 2.2 Ambient Energy Systems Comparisons of Battery and Energy Harvesting Karman vortex street Cantilever-Based Electromagnetic Micro-Generator Relative Displacement in Electromagnetic Micro-Generator Energy Harvester from Airflow Principles Of Energy Harvester Principles of Airflow Energy Harvester Output Power of Airflow Energy Harvester Project Flow Chart Constructed Energy Harvester Fabricated Tunnel Turning Fan Different numbers of turns of coil 28

13 xiii 3.6 Acrylic Graph of Mean Output Voltage vs Number of Turns of Coil Designed Circuit Simulation of Input and Output Waveform for Input Voltage 33 = 0.1V 4.4 Result of Measuring Voltage for Input Voltage = 0.1V Comparison of Theoretical Capacity and Energy Stored Simulation Power Generated for Input Voltage = 0.1V Simulation of Input and Output Waveform for Input 38 Voltage=0.5V 4.8 Result of Measuring Voltage for Input Voltage = 0.5V Comparison of Theoretical Capacity and Energy Stored Simulation Power Generated for Input Voltage = 0.5V Experimental circuit Comparison of Theoretical Capacity and Energy Stored Experimental Power Generated for Input Voltage = 0.1V Comparison of Theoretical Capacity and Energy Stored Experimental Power Generated for Input Voltage = 0.5V Comparison of Voltage Output Experimental Results with Standard Deviation LTC 3535 in DFN Package Circuit Layout of LTC Performance of LTC Snapshots from Proteus Snapshots from ARES Successful Fabricated Circuit (Front) Successful Fabricated Circuit (Back) 52

14 1 CHAPTER 1 INTRODUCTION In this chapter, the discussion is mainly about the introduction and motivation of this project. The investigation is included the background of project, project overview, problem statement that inspired, objectives to carry out and the scope for the project. The overall report structure is concluded at the end of this chapter. 1.1 General Background Energy has become an essential element in human life which integrals with the almost every civilian application in the developing modern societies such as domestic, transport, industrial, medical, etc. Hence, there is a need for a secure and accessible supply of energy for sustainability of the growing world population. The term of renewable energy has been defined as the only solution to the growing energy challenge [11]. Renewable energy is believed comes from the sources that are easily replenished, likewise solar, wind, geothermal, wave, and tidal power [2].

15 2 The argument of environmental damage from wind energy has been debated. The wind energy system impacts on noise pollution and visual pollution. The large-scale wind generation systems are built in more remote area and create noise pollution which harshly harmful to native animal species as well as the nearby residents. Visual pollution changes the image of the landscape. Climatological impacts from wind generation system are also come across discussion. In the early stage of implementation, avian mortality was an issue. The birds flying in close proximity were likely to be dragged into the flow and killed [8]. Energy harvesting technologies are ideas of alternative energies by converting non-electric environmental ambient energy into electrical energy. Obtaining an energy autonomous and maintenance-free sensor system with long-availability life time is the priority achievement [9]. Figure 1.1 shows the power acquired by special purpose low-data rate network protocols such as Zigbee for transmission [6]. Figure 1.1: Power consumption of various wireless standards [6]

16 3 1.2 Project Overview Ambient energy harvester is known as power scavenging method. In this context, airflow is presented naturally and regarded as an environment-friendly power source. The airflow energy harvester is proposed to have a geometry made of a wing that attached to a cantilever spring, permanent magnet, coil, ferromagnetic circuit with air gap and a conversation circuitry. Alternating current (AC) is induced in a conductive coil when magnetic flux changes. This can be done by either moving the coil or the permanent magnet. In this project, air flow is used as the ambient source to oscillate a magnet which is attached to a cantilever. When the direct airflow is entering the energy harvester, it is blocked by the bluff body constructed. A vortex is circulated under the cantilever. Current is generated when the cantilever moving along with the magnetic and cut the magnetic flux through the moving coil. Power is harvested from this system is capable to power up some small electronic devices such as wireless sensor node. 1.3 Problem Statement A battery which is also known as a DC voltage source has finite amount of current over time. The battery cannot supply a fixed amount of current at a constant voltage indefinitely for any length of time. As the battery ages and becomes discharged, its capacity to generate current is diminishing as the time goes by. Since some of the batteries are not rechargeable, it may cause hazard to the users. The leakage of chemical from the battery after long-used is also will lead to the hazardous of environment and health [4].

17 4 Thus, energy storage technologies have been greatly developed in the recent past. However, the progress has not been mature to keep up with microprocessors, memory storage, and wireless technology applications. The battery life time is limited which unable to last for a longer period of time. Figure 1.2 illustrates the annual battery change labor cost[5]. Maintenance of a large-scale network is difficult to carry out for hundreds or thousands of sensor nodes [14]. Figure 1.2: Projected Annual Battery Change Labor Cost [5] According to Zhu [16], the smart buildings in technology-driven generation are equipped with intelligent systems which acquired numerous sensors. Wired sensors have some drawbacks on high wiring and maintenance costs and time consuming. Hence, wireless self-powered sensors are desirable in applications of systems. However, batteries as a conventional power supply have a finite amount of energy, difficulties to deploy in large scale or inaccessible locations and required high maintenance. Furthermore, the operating temperature of batteries which is ranging from -55 to +85 is insufficient to apply in some application [9].

18 5 1.4 Objectives Three specific objectives have been defined for this study; 1. To design an energy harvester based on electromagnetic mechanism harvesting ambient energy from airflow. 2. To construct a prototype of the energy harvester using available materials. 3. To analysis the workability of the air flow energy harvester on a daily application. 1.5 Scope of the Project Scope is designed so that the project is within the area of concern. The scopes of the project are as follows: 1. The experiment is conducted in a fabricated tunnel which has length of 1-2metres and height of 25cm. 2. Size of energy harvester is small (12cm x 8cm x 6cm). 3. The airflow source is within closed environment. 4. The power harvested is in the range of mw and the voltage induced is lesser than 2V. 5. The mechanical design of the cantilever is referred.

19 6 1.6 Report Structure In this report, there are three chapters are written. Each chapter has dedicated different focus and discussions. As in Chapter One, the project is introduced. Brief general background, inspired problem statement, objectives, limits of the report is outlined. Literature review is the main concern in Chapter Two. The literature review evaluates the previous research that has been proposed. The review is described and summarized. Chapter Three is reporting on the methodology. The purpose of this chapter is to explain and document the research approaches and testing strategy carried out in the project. Chapter Four is discussing the results and observations obtained.throughout the research. Analysis on the output is presented for theoretical, simulation and experimental findings. In Chapter Five, the overall summary of the research based on the objectives and achievements will be performed.

20 7 CHAPTER 2 LITERATURE REVIEW In this chapter, existing knowledge is outlined. The relevant information on previous technologies is identified and justified. 2.1 Introduction Energy harvesters have been discussed intensely for the potential to be applied in wireless sensor node applications. The term of ambient energy harvesting is applied. The harvested power is dependable on the energy source being harvested. A survey has proved that the greatest effectiveness can be obtained by devices within the range of Hz [7]

21 Ambient Energy Sources Several of scavenging energy sources is categorized into five majors which are photonic, kinetic, thermal, electromagnetic, autophagous (self-consuming) structure-power. A suggestion [10] of scavengable energies from non-biological is illustrated in Figure 2.1. Figure 2.1: Scavengable Energies from Non-Biological Converted To Electrical Energy for Use by Small Electric Unmanned Systems Whereas Yildiz [14] claimed that no single power source is enough for all applications and the energy source must be selected by considering the application characteristics. Hence, the ambient energy sources are summarized with their characteristics in Table 2.1 below.

22 9 Table 2.1: Ambient Energy Sources Energy Sources Human Body Natural Energy Mechanical Energy Thermal Energy Light Energy Electromagnetic Energy Characteristics Mechanical and thermal energy is generated by human or animal body by actions. Wind, water flow, ocean waves, and solar energy are limitless readily available from environment. Ambient mechanical energy sources are captured from vibrations of machines, mechanical stress, strains of high-pressure motors, manufacturing machines, and waste rotations. Waster heat energy from furnaces, heaters, and friction sources. The energy is captured through photo sensors, photo diodes, and solar photovoltaic (PV) panels regardless from indoor or outdoor. Inductors, coils, and transformers are the considered ambient energy sources dependable on application requirement Ambient Energy Systems A general overview of ambient energy-harvesting systems is illustrated as Figure 2.2 [14]. In Figure 2.2, there are three rows of division. The first row indicates the energy sources; the second row shows the actual implementation and employed tools and the third row illustrates the techniques of energy-harvesting from each source.

23 10 Figure 2.2: Ambient Energy Systems Energy harvesting has different charging rate across time and physical domains. The energy harvesting has shorter duty cycle and the average charging rate is lower than the rate of energy consumption. Figure 2.3 shows the comparison of battery and energy harvesting. Figure 2.3: Comparisons of Battery and Energy Harvesting

24 Comparison of Power Density of Energy Harvesting Methods Kazmierski [3] reported that power densities acquired from machine vibration application and human-powered application are 800μW/cm 3 and 140μW/cm 3 respectively. The power output for vibration-harvesting inertial generators is highly stimulated by frequency and amplitude of the vibration source. In the study of Yildiz [14], the comparison of power density of energy harvesting methods is highlighted in Table 2.2. The values are summarized from published studies, experiments conducted and the information captured by reading materials. From the Table 2.2, a wide range of potential scavenging energy from various ambient energy sources is provided. Table 2.2: Comparison Power Density of Energy Harvesting Methods Energy Source Acoustic noise Ambient light Vibration (micro-generator) Power Density & Performance 0.003μW/cm 75Db 0.96μW/cm 100Db 100mW/cm 2 (direct sun) 100μW/cm 2 (illuminated office) 4μW/cm 3 (human motion-hz) 800μW/cm 3 (machines-hz) Vibrations (Piezoelectric) 200μW/cm 3 Airflow 1μW/cm 2 Temperature variation 10μW/cm 3 Ambient radio frequency 1μW/cm 2