DESIGN OF THERMOELECTRIC ENERGY HARVESTER USING LTC 3108

BOOST CONVERTER

MUHAMMAD ZULHAIZER BIN AB RASHID

This Report Is Submitted In Partial Fulfillment Of Requirements For The Bachelor

Degree of Electronic Engineering (Industrial Electronic)

Fakulti Kejuruteraan Elektronik dan Kejuruteraan Komputer

Universiti Teknikal Malaysia Melaka

June 2013

UNIVERSTI TEKNIKAL MALAYSIA MELAKA FAKULTI KEJURUTERAAN ELEKTRONIK DAN KEJURUTERAAN KOMPUTER

BORANG PENGESAHAN STATUS LAPORAN

PROJEK SARJANA MUDA II

Tajuk Projek :

Design Of Thermoelectric Energy Harvester Using LTC3108

Boost Converter

Sesi

Pengajian : 0 8 / 0 9

Saya MUHAMMAD ZULHAIZER BIN AB RASHID mengaku membenarkan Laporan Projek

Sarjana Muda ini disimpan di Perpustakaan dengan syarat-syarat kegunaan seperti berikut:

1. Laporan adalah hakmilik Universiti Teknikal Malaysia Melaka.

2. Perpustakaan dibenarkan membuat salinan untuk tujuan pengajian sahaja.

3. Perpustakaan dibenarkan membuat salinan laporan ini sebagai bahan pertukaran antara institusi

pengajian tinggi.

4. Sila tandakan ( √ ) :

SULIT*

*(Mengandungi maklumat yang berdarjah keselamatan atau

kepentingan Malaysia seperti yang termaktub di dalam AKTA

RAHSIA RASMI 1972)

TERHAD**

**(Mengandungi maklumat terhad yang telah ditentukan oleh

organisasi/badan di mana penyelidikan dijalankan)

TIDAK TERHAD

Disahkan oleh:

__________________________

___________________________________ (TANDATANGAN PENULIS) (COP DAN TANDATANGAN PENYELIA)

Tarikh: ……………………….. Tarikh: ………………………..

iii

I declare that this thesis entitled “Design of Thermoelectric Energy Harvester Using

LTC3108 Boost Converter” is the result of my own research except as cited in the

references. The thesis has not been accept for any degree and is not concurrently

submitted in candidature for any other degree.

Signature :

Author : MUHAMMAD ZULHAIZER BIN AB RASHID

Date : 10th

JUNE, 2013

iv

I hereby declare that I have read this thesis and in my opinion this thesis is sufficient in

term of scope and quality for the award of the Bachelor of Electronic Engineering

(Electronic Industries) With Honours

Signature :

Supervisor name : ENGR HAZLI RAFIS BIN ABDUL RAHIM

Date : 10th

JUNE, 2013

v

Specially dedicated to my beloved parents, family members and fellows friend

vi

APPRECIATION

First of all, praise to Allah S.W.T., because of His grace, I was able to implement

my final year project till the end without any problems. I want to take this opportunity to

express my appreciation to those who have helped me a lot throughout completing my

PSM whether directly or indirectly. Special thanks to my family especially both of my

parent who non-stop gave me morale supports and financial resources. Thanks also to

my supervisor, Eng. Hazli Rafis Bin Abdul Rahim, for guiding me throughout getting an

analysis and also gave some advice for my project. Lastly for my love, housemate and

fellow friends, thank you so much for helped me out when I need an idea or something

that related with my project. I express my gratitude for everyone that I not mention

above and hope God will repay you well one day.

vii

ABSTRACT

Renewable energy technique is the process of converting available ambient

energy into usable electrical energy through the use of a particular material or

transduction mechanism. Nowadays, the evolution of new technology which involving

renewable energy technique and smart grid system has a huge potential in the energy

market. In line with the current technology interest in the smart grid technology, power

transformer health condition becomes one of the main issue need to be considered. The

way to monitor health condition of the power transformer has started to evolve from

typical monitoring technique to a new development of using energy harvesting

technology to activate sensors network for the monitoring purpose. For this project,

Thermoelectric Power Generator (TEG) is used to convert the heat energy get from the

power transformer into small electrical energy in order to power up electronic devices

that will triggering up the monitoring system. TEG only produces small electrical

energy, so the boost converter is needed in order to increase the electrical energy from

the TEG and get its maximum power point tracking (MPTT). The boost converter is a

type of DC-to-DC converter which has a greater output than the input voltage. So, the

result of this project will show us the small electrical energy, converted from the heat

energy , range between 20 mV to 1.5V that is get from the TEG will be raised up until at

least 5V using a boost converter. 5V is the minimum volts to trigger up the PIC circuit

or any others small electronic appliance that has low power consumption.

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ABSTRAK

Teknik tenaga boleh diperbaharui adalah proses menukarkan tenaga ambien yang

sedia ada kepada tenaga elektrik yang boleh digunakan melalui penggunaan bahan

tertentu atau mekanisme transduksi. Kini, perkembangan teknologi baru yang

melibatkan teknik tenaga boleh diperbaharui dan sistem grid pintar mempunyai potensi

yang besar dalam pasaran tenaga. Selaras dengan kepentingan teknologi semasa dalam

teknologi grid pintar, keadaan transformer kuasa menjadi salah satu isu utama yang

perlu dipertimbangkan. Cara untuk memantau keadaan transformer kuasa telah berubah

mengikut peredaran masa sehinggalah penghasilan teknologi baru melalui penuaian

tenaga untuk menghidupkan rangkaian sensor sebagai tujuan pemantauan.Untuk projek

ini, penjana thermoelectric (TEG) digunakan untuk menukarkan tenaga haba yang

diperolehi daripada transformer kuasa kepada tenaga elektrik kecil yang mampu

menghidupkan alat-alat elektronik yang akan mencetuskan satu sistem pemantauan.

TEG akan menghasilkan tenaga elektrik kecil, jadi penukar tingkat diperlukan dalam

usaha untuk meningkatkan tenaga elektrik daripada TEG dan mendapatkan pengesanan

titik kuasa maksimum (MPTT). Penukar tingkat adalah sejenis penukar DC ke DC yang

mempunyai keluaran yang lebih besar daripada voltan masukan. Jadi, hasil daripada

projek ini akan menunjukkan kepada kita tenaga elektrik kecil, ditukar daripada tenaga

haba, julat antara 20 mV sehingga 1.5V yang didapati daripada TEG akan ditingkatkan

sehingga sekurang-kurangnya 5V menggunakan penukar tingkat. 5V adalah volt

minimum untuk menghidupkan litar PIC atau mana-mana perkakas elektronik lain yang

mempunyai penggunaan kuasa yang rendah.

ix

TABLE OF CONTENTS

CHAPTER CONTENT PAGES

PROJECT TITLE i

DECLARATION iii

DEDICATION v

APPRECIATION vi

ABSTRACT vii

ABSTRAK viii

TABLE OF CONTENTS ix

LIST OF TABLES xiii

LIST OF FIGURES xiv

LIST OF ABBREVIATIONS xvi

LIST OF APPENDICES xvii

x

I INTRODUCTION

1.1 Project Introduction 1

1.2 Project Objective 5

1.3 Problem Statement 5

1.4 Scope of Work 6

1.5 Brief Description of Methodology 6

1.6 Report Overview 6

II BACKGROUND STUDY / LITERATURE REVIEW

2.1 Basic Understanding of Boost Converter (Ideal Circuit) 8

2.1.1 Mathematical Model of Boost Converter 11

2.2 Literature Review From Related Journal 12

2.3 Basic Introduction Based On Literature Review 17

2.3.1 List of Hardware Involved 17

2.3.1.1 TEG 17

2.3.1.2 LTC3108 IC 21

2.3.1.2.1 Pin Configuration of LTC3108 22

2.3.1.2.2 Operation of LTC3108 26

2.3.1.3 SMT Component 33

2.3.1.3.1 History of SMT 35

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2.3.1.3.2 Advantage and Disadvantage of SMT 36

2.3.1.3.3 Type and Size of SMT Component 38

2.3.1.4 Custom Made Double Layer PCB 39

2.3.2 List of Software Involved 40

III RESEARCH METHODOLOGY

3.1 Project Background 41

3.2 Project Methodology 43

3.2.1 Phase of Method and Approach

3.2.1.1 First Phase (Literature Review) 45

3.2.1.2 Second Phase (Design, Simulation and Analysis) 45

3.2.1.3 Third Phase (Implementation) 49

3.2.1.4 Fourth Phase (Thesis Writing) 49

IV RESULT AND DISCUSSION

4.1 Introduction 50

4.2 Structure of the System 51

4.3 Final Design 52

4.3.1 Circuit Diagram (Schematic) 52

4.3.2 Circuit Diagram (PCB Layout) 53

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4.3.2.1 Pin Name and Function 54

4.4 Final Product 55

4.5 Analysis of TEG and LTC3108 Boost Converter 58

4.5.1 Voltage Output Versus Current (TEG) 58

4.5.2 Temperature Versus V out (TEG) 59

4.5.3 Vin Versus Vout (LTC3108 Boost Converter) 60

4.6 Final Output of LTC3108 Boost Converter 62

4.7 Final Discussion 62

V CONCLUSION AND RECOMMENDATION

5.1 Conclusion 63

5.2 Potential of Commercialization 64

5.3 Recommendation 64

REFERENCES 65

APPENDICES 67

xiii

LIST OF TABLES

NO. DESCRIPTION PAGES

2.1 Pin Function of LTC3108 23

2.2 Regulated Voltage Using Pins VS1 and VS2 25

2.3 Operation of LTC3108 27

4.1 Pins Name and Its Function 54

xiv

LIST OF FIGURES

NO. DESCRIPTION PAGES

1.1 Power Transformer in Distribution System 2

1.2 Hot Spot Measurement of High Voltage Transformer 3

2.1 Basic Circuit of Boost Converter 10

2.2 ON and OFF State of Basic Boost Converter 11

2.3 Example of TEG Device 18

2.4 The Seebeck Effect Due To Temperature Gradient 19

2.5 Basic Structure of Thermoelectric Couple 20

2.6 Equivalent Thermoelectric Model 21

2.7 Pin Configuration of LTC3108 23

2.8 Block Diagram of LTC3108 27

2.9 Output Voltage Sequencing with Vout Programmed

for 3.3V (Time Not to Scale) 33

xv

2.10 Comparison between SMT Component (left) with

Through-hole Component (right) 34

2.11 Surface-mount Capacitor 34

2.12 Size of SMT Component 38

3.1 Flow of Project 43

3.2 Methodology Flowchart 44

4.1 Structure of the System 52

4.2 Schematic Diagram of the Project 53

4.3 PCB Layout Diagram of the Project 54

4.4 Final Product Using LTC3108 IC And Surface

Mount Component 56

4.5 Real Size of the Product Which Is Compact 57

4.6 Final Product Inside the Packaging 57

4.7 Vout, V VS Current,I 59

4.8 Temperature, °C VS Vout, V 60

4.9 Vin, V VS Vout, V 61

4.10 Final Output 62

xvi

LIST OF ABBREVIATIONS

TNB – Tenaga Nasional Berhad

TEG – Thermoelectric Generator

V - Voltage

PIC – Programmable Integrated Circuit

IC – Integrated Circuit

DC – Direct Current

PWM – Pulse Width Modulator

SMD – Surface Mount Device

SMT – Surface Mount Technology

PMC – Power Management Circuit

PCB – Printed Circuit Board

I – Current

C - Celcius

xvii

LIST OF APPENDICES

(noted that the appendix section is start at page 67)

NO. DESCRIPTION PAGES

A ELECTRICAL AND TYPICAL PERFORMANCE

CHARACTERISTIC OF LTC3108 APPENDIX A-1

B TYPE OF SMT PACKAGE APPENDIX B-1

C GAANT CHART APPENDIX C-1

D COMPONENT SELECTION APPENDIX D-1

1

CHAPTER I

INTRODUCTION

1.1 Project Introduction

Renewable energy technique is the process of converting available ambient

energy into usable electrical energy through the use of a particular material or

transduction mechanism. Nowadays, the evolution of new technology which involving

renewable energy technique and smart grid system has a huge potential in the energy

market. Although the application of new technology in the smart grid system has

evolved rapidly, devices such as power transformer is still be a major component in the

power distribution system. Thus, in line with the current technology interest in the smart

grid technology, power transformer health condition becomes one of the main issues

considered.

2

Figure 1.1: Power Transformer In Distribution System

In this situation, the health condition of power transformer is about how much

the heat generate during the transformer operated. Heat is generated due to the high

voltages that need to be step-up or step-down by the transformer. Overheat may cause

minor or major damage to the transformer and this will affect the performance of the

transformer and this also will lead to failure of the transformer. So to reduce and

overcome this problem, we must have a device that could monitor the heat generate by

the power transformer. This monitoring system will be used to inform the relevant

authority, for example Tenaga Nasional Bhd. (TNB) or other electric supply company,

whether the temperature of the transformer is in control or not. This will allowed them to

make any maintenance before the transformer malfunction or get any another major

damage.

3

Figure 1.2: Hot Spot Measurement of High Voltage Transformer

The way to monitor power transformer has started to evolve from typical

monitoring technique to a new development of using energy harvesting technology to

activate sensors network for the monitoring purpose. The ambient heat energy obtained

from the power transformer will be harvested to turn on power electronic compensator

and driven the sensors.

In producing an auto monitoring system for the power transformer, the

Thermoelectric Power Generator (TEG) can be used as a device which will generate a

small electrical energy. Normally TEG will generate an electrical voltage between 20

mV to 1.5 V, depend from the heat generated. When the temperature increases, the

voltage generated also increases. The output of TEG is normally very small and varies.

This is because the output is depend on the temperature different between 2 different

plate inside the TEG, so this small electrical energy need to be boost up to a higher level

which can be used to triggering up the PIC circuit. Normally PIC usually need around

5V to 5.5V to be operated. Therefore, the input get from the TEG must be boost up at

least 5V to let the PIC switch ON. There are two function of this PIC circuit in this

situation. First, PIC circuit is used to triggering up the communication device such as

Zigbee or Xbee to the user. Secondly, this PIC circuit reads the surrounding heat

temperature using a heat sensor so that this temperature reading can be sent through the

4

communication device and be used by the user whether the temperature of power

transformer is still in control or not.

This project only covered up until the operation of TEG and the design a boost

converter which used LTC3108 IC and also Surface Mount Device (SMD). This design

of boost converter must be compact and able to step-up the voltage produce by the TEG

which in range between 0.7V to 1.5V into a minimum output level which is at least 5V.

The LTC3108 is a highly integrated DC-DC converter ideal for harvesting and

managing surplus energy from extremely low input voltage sources such as TEGs

thermopiles and small solar cells. The step-up topology operates from input voltages as

low as 20mV.

Using a small step-up transformer, the LTC3108 provides a complete power

management solution for wireless sensing and data acquisition. The 2.2V LDO powers

an external microprocessor, while the main output is programmed to one of four fixed

voltages to power a wireless transmitter or sensors. The power good indicator signals

that the main output voltage is within regulation. A second output can be enabled by the

host. A storage capacitor provides power when the input voltage source is unavailable.

Extremely low quiescent current and high efficiency design ensure the fastest possible

charge times of the output reservoir capacitor.

The LTC3108 is available in a small, thermally enhanced 12-lead (3mm × 4mm)

DFN package and a 16-lead SSOP package.

5

1.2 Project Objective

i. To design a compact DC-DC boost converter using LTC3108 IC and SMD in

order to increase and stabilize the output voltage generated from the TEG.

ii. To demonstrate experimentally DC/DC boost converter using LTC3108.

iii. To analyze and evaluate the characteristic of TEG and output range produced

from the boost converter whether it capable to supply a sufficient voltage and

activated at least small electronic devices.

1.3 Problem Statement

i. TEG generated power which is varies, intermittent and limited, so the power

management circuit (PMC) using DC-DC boost converter which use an

LTC3108 and SMD component can be used to stabilize the power to the load and

also extract maximum power.

ii. The needs of alternative power supply to power the sensor system to grant the

effectiveness of the sensor system.

iii. The maintenance cost to change the battery is a big issue as batteries is known to

have short lifetime

iv. A renewable energy is an energy that have a large potential in the market

nowadays, so we need to design a new source of energy using a renewable

energy to power up small or low voltage device by manipulating an energy

harvesting technique

6

1.4 Scope of Work

i. Determine the output voltage that can be harvested from the TEG circuit based

on temperature different from surrounding. This output voltage will be used as an

input to the boost converter circuit.

ii. Developed circuit which is used to power up the PIC circuit that involving the

TEG and boost converter using LTC3108 IC, SMD component and fabricated

circuit . Where SMD component consists of resistor, capacitor and small

transformer.

1.5 Report Overview

„Design of Thermoelectric Energy Harvester using LTC3108 boost converter’ is

the title of this report where it contains a combination of five chapters from the

introduction of this project to the outcome, expected result and conclusion of this

project. The report is written in detail on each of every step to take under consideration

on the progression of the project.

Chapter 1 elaborate briefly what the project is all matter. Here clearly stated the

background of the project, the objective, the scope of work of this project, brief

description of methodology and the overview of each of the chapter contains.

Chapter 2 is some of the literature review from an article, paper work, book,

website and all the written text that are related to the project topic. Where in this thesis,

it is included a literature review on TEG, Boost converter, SMD component and

LTC3108 as all of the materials is used in this project.

7

Chapter 3 is on the methodology of overall project. It will discuss about the

project background and also project methodology. At project methodology we will

discuss further the way how this project will going on. It is not limited to the hardware

choose, it also discuss on the software implementation choose.

Chapter 4 will discuss about the result that had been obtain from the project such

as the structure of the system, finished product and analysis taken. This chapter also we

will discuss about the overall data that have been collected.

Chapter 5 will concludes the overall view of the project. This chapter will

summarize the findings of the project, analysis achievement, potential of

commercialization and suggest further research for the future.