SIMULATION OF A HYBRID PHOTOVOLTAIC/FUEL CELL

ENERGY SYSTEM

AZIM SHUKRI BIN A SHUKOR

A project report submitted in partial fulfillment of the

requirements for the award of a degree of

Master of Engineering (Electrical – Power)

Faculty of Electrical Engineering

Universiti Teknologi Malaysia

JANUARY 2013

iii

DEDICATION

This thesis is dedicated to my beloved wife, my dearest parents, sister, and friends

who have given me continuous support and

encouragement to pursue my dreams.

iv

ACKNOWLEGMENT

Firstly, I would like to express my sincere gratitude to my dedicated supervisor,

Dr. Tan Chee Wei for his guidance, enlightening instruction, and support in my research

and project work. .

I would like to thank my colleagues and friends for their constant support and

encouragement. Special thanks to Mr. Chandran and Mr N.Vikneswaran for their help in

contributing valuable information for me.

Last but not least, I am grateful towards my family for their continuous support

and encouragement throughout my master program

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ABSTRACT

Basically, Malaysia energy production has been always generated from crude oil

and natural gas. Currently, Malaysia has 13GW of electrical generation capacity.

According to Malaysia Suruhanjaya Tenaga, as of July 2007, a total of 19,023 MW

power generation capacity connected to the Malaysian National Grid, with a maximum

demand(MD) of 13,340 MW. Total electricity generation for 2007 is 108,539 GW·h with

a total consumption of 97,113 GW·h or 3,570 kW·h per capita. In 2007 also, the

Malaysia consumes about 514 thousand barrels (23.6 million tonnes) of oil daily against a

production of 755 thousand barrels (34.2 million tonnes) per day. Research shows that

Malaysia only has 33 years of natural gas reserves, and 19 years of oil reserves. As

Malaysia are moving towards further growth and development, the demand for energy is

increasing every day and then. With that kind of scenario, Malaysian government is

looking for other alternative measures as to mitigate the matter and hereby this renewable

energy sources surface out and comes into the big picture. For the time being, 16% of

Malaysian electricity generation is hydroelectric, the remaining 84% being thermal. The

solar generating system is soon to follow and catch up with the latest technology in

hands.

vi

ABSTRAK

Secara dasarnya, pengeluaran tenaga Malaysia telah sentiasa dihasilkan daripada

minyak mentah dan gas asli. Pada masa ini, Malaysia mempunyai 13GW kapasiti

penjanaan elektrik. Menurut Suruhanjaya Tenaga Malaysia, Julai 2007, sejumlah 19.023

MW kapasiti penjanaan kuasa yang disambungkan ke Grid Kebangsaan Malaysia,

dengan permintaan maksimum (MD) 13.340 MW. Jumlah penjanaan elektrik bagi tahun

2007 adalah 108.539 GW • h dengan penggunaan sejumlah 97.113 GW • h atau 3.570

kW • h per kapita. Pada tahun 2007 juga, Malaysia menggunakan kira-kira 514,000 tong

(23.6 juta tan metrik) minyak setiap hari terhadap pengeluaran sebanyak 755,000 tong

(34200000 tan) setiap hari. Kajian menunjukkan bahawa Malaysia hanya mempunyai 33

tahun rizab gas asli dan 19 tahun rizab minyak. Memandangkan Malaysia sedang

bergerak ke arah pertumbuhan dan pembangunan seterusnya, permintaan untuk tenaga

semakin meningkat setiap hari dan kemudian. Dengan jenis yang senario, kerajaan

Malaysia sedang mencari langkah-langkah alternatif lain untuk mengurangkan perkara ini

dan dengan ini sumber tenaga boleh diperbaharui permukaan keluar dan datang ke dalam

gambaran yang lebih besar. Buat masa ini, 16% daripada penjanaan tenaga elektrik di

Malaysia adalah hidroelektrik, baki 84% menjadi haba. Sistem penjanaan solar tidak

lama lagi untuk mengikuti dan mengejar dengan teknologi terkini di tangan.

1

CHAPTER 1

INTRODUCTION

1.1 General Introduction

Today, the energy we use is mainly from fossil fuels such as oil, gas and coal. They are

non-renewable and soon it will be completely depleted. Malaysia domestic oil reserves

are expected to dry up by the end of this decade and gas reserves by 2040. However,

with the rapid growth of population and industrialization throughout the world,

somehow it has trigger a drastic increment trending towards electrical energy demand.

Not forgetting the restrains that exist towards the development of electric power

transmission line, which leads to high load density and contributing power quality

concerns. Hence, as been attracted to the attention of power system, many researchers

and designers had come with a reliable solution, especially for rural and remote areas

which then renewable energy becomes the hot topic to talk about.

1.2 Problem Statement

Renewable Energy Sources (RES) such as wind and solar power systems which

previously still under research and study, have now gained famous in the last decade as

one of future prospects of energy resources. However, this wind and solar power system

2

have their own problems and limitations related to the inconsistency and uncertainty of

the power that they produce. The inevitable weather conditions will definitely be a

problem and need to be overcome in some design criteria, which later as to justify,

overdesign and oversize of the system parameter is performed to meet much reliable

load demand. The other approach is moving towards integration of renewable resources

together, as to enhance the reliability performance of the system, whereby using the

advantage of one source to compensate for the drawback of another. With this, evolved

the hybrid systems, which in this project will look into the simulation of hybrid

photovoltaic and fuel cell system and to conclude and justify the propose effective

controller which can gain Maximum Power Point Tracking (MPPT) and taking the grid-

connection into account.

1.3 Objective of Project

The objective of this project is to investigate and review the various control techniques

which supposed to be used together with Power Conditioning Unit in this Hybrid

Photovoltaic and Fuel Cell System as to obtain Maximum Power Point Tracking in grid-

connection line. This control techniques found, and the hybrid model will be later be

simulated using MATLAB/Simulink simulation package and the results will later be

analyzed for further future improvement. In order to accomplish this objective, it is vital

to understand the fundamental knowledge of the hybrid Photovoltaic-Proton Exchange

Membrane Fuel Cell Energy System based on the literature review done.

3

1.4 Scope of Project

Firstly, the Fuel Cells System itself is a wide area as there many type of Fuel Cells. This

project scope and focused on Proton Exchange Membrane Fuel Cell, or also known as

PEM Fuel Cell only. Secondly, most of the project is related to MATLAB/Simulink

Design &Simulation. Hence, in order to complete the project, one must have strong

knowledge in MATLAB/Simulink. On top of that, as to develop the hybrid model, a lot

of research and literature review need to be done. Some papers already describe the

topologies used to develop this hybrid model. And some papers shares the problems

arise in obtaining the output result. Finally, for this paper, the scope of project is up until

the simulation results only. Hopefully, it will be useful as for reference to other students

and researchers.

1.5 Project methodology

In order to accomplish the PROJECT OBJECTIVE, initially some study should be made

throughout the literature review done from previous related Thesis, International IEEE

Journals, Case studies, Technical Research & Reviews and some Text books. Later from

the deduced sets of mathematical equations formula obtained from each photovoltaic

and fuel cell system case studies, a comprehensive design module should be made and

simulated through the Matlab/Simulink package. It will further on develop a hybrid

system as integration of photovoltaic and fuel cell system which require a complete

review on various control techniques used. This project require a lot of simulation as to

obtain the best result, and hence the mastering of Matlab/Simulink package is vital and a

must.

4

1.6 Thesis organization

Chapter 1: This chapter describes the introduction to the hybrid Photovoltaic/Fuel Cell

energy system as the sources of alternative energy with their basic historical

background. In addition to that it provides introductory explanations about problem

statement, project objectives, scope and methodology.

Chapter 2: This chapter will cover the literature review done for the hybrid

Photovoltaic /Fuel Cell Energy System. There are many methods and topologies as seen

from the published Technical Papers which can be used for reference.

Chapter 3: This chapter emphasizes more on the modeling process of each subsystem

of hybrid Photovoltaic/Fuel Cell Energy System and development of the Simulink block

diagrams in MATLAB/Simulink.

Chapter 4: This chapter will look into the the results obtained from MATLAB

Simulation for each stage in the Hybrid Photovoltaic/Fuel Cell Energy System.

Chapter 5: This chapter elaborate further case study on Fit-In Tariff which already

being implemented in Malaysia and also on the real-time development of Photovoltaic

System which emerge as potential resources for residential area.

Chapter 6: This chapter gives the conclusion of the entire work, and some additional

works have been suggested for future development.

62

REFERENCES

[1] Saifur Rahman, Kwa Sur Tam “A feasibility study of photovoltaic-fuel cell hybrid

energy system”, IEEE Transactions on Energy Conversion, Vol. 3, No. 1, March 1988

[2] Antonio Luque, Steven Hegedus “Handbook of photovoltaic science and

engineering”

[3] Gil Knier “ How do photovoltaic work”, Science@NASA Headline News

[4] Emil A. Jimenez-Brea, “Control of Alternative Energy Hybrid System for

Residential and Low Power Applications”, A thesis submitted in partial fulfillment for

the degree of Master of science in Electrical Engineering, University of Puerto Rico,

2009.

[5] Dachuan Yu, Engine Research-Advance Power Sources, Caterpillar Inc. ,

S.Yuvarajan, Elect Eng Dept. North Dakota State University “Load Sharing In Hybrid

Power System with a PV Panel and a PEM Fuel Cell” IEEE Applied Power Electronics

Conference, March 2006. pg 1245 – 1249

[6] Zhenhua Jiang, Department of Electrical Engineering, University of New Orleans

“Power Management of Hybrid Photovoltaic -Fuel Cell Power Systems”, IEEE 2006

[7] Loc Nguyen Khanh, Jae-Jin Seo, Yun-Seong Kim, and Dong-Jun Won, “Power-

Management Strategies for a Grid-Connected PV-FC Hybrid System”, IEEE

TRANSACTIONS ON POWER DELIVERY, VOL. 25, NO. 3, JULY 2010, pg 1874 –

pg 1882

[8] Kyoungsoo Ro, Saifur Rahman, Center for Energy and the Global Environment

Virginia Polytechnic Institute and State University ”Two-loop controller for maximizing

performance of a grid-connected PV-Fuel Cell Hybrid Power Plant” IEEE Transactions

on Energy Conversion, Vol. 13, No. 3, September 1998, pg 276 – 281

[9] Akrem Mohamed Elrajoubis, “Simulation of a hybrid photovoltaic/wind energy

system”,

A Thesis submitted in partial fulfillment for the degree of Master of Electrical Power,

Universiti Teknologi Malaysia, 2010.

[10] Huan-Liang Tsai, Ci-Siang Tu, and Yi-Jie Su, Member, IAENG, “Development of

Generalized Photovoltaic Model Using MATLAB/SIMULINK”, San Francisco, USA,

WCECS 2008, October 22 - 24, 2008.

63

[11] Sonal Panwar, Dr. R.P. Saini, “Development and Simulation of Solar Photovoltaic

model using Matlab/simulink and its parameter extraction”, International Conference on

Computing and Control Engineering (ICCCE 2012), 12 & 13 April, 2012

[12] Matthew Martin, “Performance Optimization of Small Scale Photovoltaics”, A

thesis submitted in partial fulfilment for the requirement of degree in Master of Science

in Renewable Energy Systems and the Environment, University of Strathclyde, 2010

[13] Yuncong Jiang, Jaber A. Abu Qahouq, and Mohamed Orabi, “Matlab/Pspice

Hybrid Simulation Modeling of Solar PV Cell/Module”, IEEE 2011, pg 1244 –pg 1250

[14] Fuel Cell Handbook (Seventh Edition), EG&GServices, Parsons Inc., DEO of

Fossil Energy, National Energy Technology Lab, Nov 2004

[15] Chong Kiat Shiu, “Dynamic Modeling and Simulation of a Stand–Alone Solid

Oxide Fuel Cell Energy System” A Thesis submitted in partial fulfillment for the degree

of Master of Electrical Power, Universiti Teknologi Malaysia, 2010.

[16] J. Larminie and A. Dicks, Fuel Cell Systems Explained. New York:Wiley, 2001.

[17] Fuel Cell Handbook (Fifth Edition),EG&GServices, Parsons Inc., DEO of Fossil

Energy, National Energy Technology Lab, Oct. 2000.

[18] Sandip Pasricha, Student Member, IEEE, and Steven R. Shaw, Senior Member, IEEE, “A

Dynamic PEM Fuel Cell Model”, IEEE Transactions on energy conversion, VOL. 21,

NO. 2, JUNE 2006

[19] J. A. Smith, M. H. Nehrir, V. Gerez, and S. R. Shaw, “A broad look at the

workings, types, and applications of fuel cells,” in Proc. IEEE Power Eng. Soc. Summer

Meeting, vol. 1, Chicago, IL, Jul. 2002, pp. 70–75.

[20] Caisheng Wang, Nehrir, M.H., Shaw S.R., “Dynamic Models and Model Validation

for PEM Fuel Cells Using Electrical Circuits”, IEEE Transactions on Energy

Conversion, Vol.20, Issue 2, June 2005

[21]. Emil A. Jimenez-Brea, “Control of Alternative Energy Hybrid System for

Residential and Low Power Applications”, A thesis submitted in partial fulfillment for

the degree of Master of science in Electrical Engineering, University of Puerto Rico,

2009.

[22]. Muhammad H.Rashid. “Power electronics circuits, devices, and applications”, (3th

Edition).University of West Florida.: Tom Robbins, 2004.

[23] N. Mohan, T. M. Undeland and W. P. Robbins, Power Electronics – Converters,

Applications, and Design, John Wiley & Sons , Inc., 2003.

64

[24] Gyu-Yeong Choe*, Jong-Soo Kim*, Byoung-Kuk Lee*, Chung-Yuen

Won*,”Comparative Study of Power Sharing Algorithm for Fuel Cell and Photovoltaic

Hybrid Generation System” The 2010 International Power Electronics Conference

[25] Li Wei, “Modeling, Control and Simulation of A Small Photovoltaic Fuel Cell

Hybrid Generation System”, Power System Technology (POWERCON), 2010

International Conference

[26] Ying Liu “Advanced control of photovoltaic converters” , Thesis submitted to the

Department of Engineering, University of Leicester for the degree of Doctor of

Philosophy, April 2009.

[27] C. Liu, B. Wu and R. Cheung, Department of Electrical & Computer Engineering,

Ryerson University, Toronto, Ontario, “ADVANCED ALGORITHM FOR MPPT

CONTROL OF

PHOTOVOLTAIC SYSTEMS” Canadian Solar Buildings Conference Montreal, August

20-24, 2004 Refereed Paper

[28] http://ecee.colorado.edu/ecen2060/matlab.html.

[29] www.mathworks.com/products/matlab/ [31] Handbook on the Malaysian Feed-in tariff for the promotion of renewable energy

vii

TABLE OF CONTENTS

CHAPTER TITLE PAGE

DECLARATION ii

DEDICATION iii

ACKNOWLEDGEMENT iv

ABSTRACT v

ABSTRAK vi

TABLE OF CONTENTS vii

LIST OF TABLES x

LIST OF FIGURES xii

LIST OF ABBREVIATIONS xvi

LIST OF SYMBOLS xvii

1 INTRODUCTION

1.1. General Introduction 1

1.2. Problem Statement 1

1.3. Objective 2

1.4. Scope of Project 2

1.5. Project Methodology 2

1.6. Thesis Organization 3

2. LITERATURE REVIEW

2.1. Introduction 4

2.2. Photovoltaic System 4

2.2.1. Background 4

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2.2.2. Photovoltaic Model 5

2.2.3. Photovoltaic Array 7

2.2.4. Photovoltaic Characteristic 8

2.2.5. Case Study No. 1 9

2.2.6. Case Study No. 2 12

2.2.7. Conclusion 15

2.3. Fuel Cell System 16

2.3.1. Background 16

2.3.2. Fuel Cell Model 17

2.3.3. Fuel Cell Characteristic 20

2.3.4. Case Study No. 1 21

2.4. Power Electronic Interfacing Circuit 23

2.4.1. Introduction 23

2.4.2. DC DC Boost Converter 23

2.4.3. AC DC Converter (Rectifier) 24

3. MODELLING OF THE SYSTEM AND SIMULATION SETUP

3.1. Introduction 27

3.2. The Overall System 27

3.3. System Schematic Diagram 30

3.3.1. Modeling and Simulation of PV Sub-system 23

3.3.2. Modeling of PV MPPT Controller 32

3.3.3. Modeling of DC DC Boost Converter 35

3.3.4. Modeling of Single Phase Inverter 36

3.3.5. Proton Exchange Membrane (PEM) Fuel Cell

Simulation 37

3.3.6. Modeling The Photovoltaic System as Connected

To Grid-Line 38

3.3.7. Modeling The PEM Fuel Cell System as Connected

To Grid-Line 39

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4. RESULT, DISCUSSION AND ANALYSIS 40

4.1. Introduction 40

4.2. Simulation Results and Discussion 40

5. CASE STUDY ON FiT

5.1. Introduction 49

5.2. The Concept of Feed-In Tariff 50

5.3. Implementation Feed-In Tariff by Photovoltaic

Installation 51

6. CONCLUSION AND FUTURE WORKS

6.1. Summary and Conclusion 55

6.2. Recommendation for Future Works 56

REFERENCES

x

LIST OF TABLES

TABLE NO. TITLE PAGE

2.1 The Factor A according to PV Technology 7

5.1 Quotation sample for Home Solar PV System Installation 51

5.2 Return of Investment for Home Solar PV System Installation 51

xi

LIST OF FIGURES

FIGURE NO. TITLE PAGE

1.0 The circuit diagram of the PV Cell 5

2.0 Equivalent Circuit of PV Array 7

3.0 Photovoltaic I-V Characteristic Curve 9

4.0 Generalized PV Module 9

5.0 Subsystem implementation of generalized PV model 10

6.0(a) I-V output characteristics with different Tc 11

6.0(b) P-V output characteristics with different Tc 11

7.0(a) I-V output characteristics with different λ 11

7.0(b) P-V output characteristics with different λ 11

8.0 Photo current Matlab®/Simulink® calculation block 12

9.0 Pspice® Schematic of PV cell 13

10.0 Proposed simulation model of Photovoltaic cell 13

11.0 Characteristic curves of PV Cell under USC 15

12.0 Characteristic curves of PV Module under USC 15

13.0 Conceptual diagram of PEM Fuel Cell 17

14.0 Second conceptual diagram of PEM Fuel Cell 18

15.0 Schematic diagram of a PEM fuel cell and voltage drops across it 19

16.0 Ideal and Actual Fuel Cell Voltage/Current Characteristic 21

17.0 Simulation results are validated with published results of

Avista Labs SR-12 PEM Fuel Cell 22

18.0 P-I Characteristic & simulation results are validated with

published results of Avista Labs SR-12 PEM Fuel Cell 22

19.0 DC-DC Boost Converter circuit 23

20.0 Three-phase full diode bridge rectifier 24

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21.0 Single-phase full-bridge inverter 26

22.0 Fuel Cell and Photovoltaic hybrid generation system types. 28

23.0 Hybrid generation system for Photovoltaic and PEM Fuel Cell 29

24.0 Initial stage of Matlab/Simulink of Photovoltaic system 30

25.0 The completion stage of Matlab/Simulink of Photovoltaic system 31

26.0 Generalized PV Arrays Model 31

27.0 The Photovoltaic Panel Characteristic which shows

the intersection of MPPT 32

28.0 Photovoltaic generation which equipped with MPPT Controller 34

29.0 MPPT Controller by using Block Diagram in Matlab /Simulink 34

30.0 Boost DC DC Switch Controller Example 35

31.0 IGBT used as switch in this Boost DC DC Controller circuit 35

32.0 Modelling of Switched-Mode DC-AC Inverter (averaged model) 36

33.0 Single-phase DC-AC inverter for grid-connected systems

(as look under mask) 37

34.0 Modeling Proton Exchange Membrane (PEM) Fuel Cell 37

35.0 Modelling of PV Generator connected to Grid System 38

36.0 Modeling 6kW 45VDC Fuel Cell Stack as connected to grid line 39

37.0 I-V Characteristic of Photovoltaic Model system 41

38.0 P-V Characteristic of Photovoltaic Model system 41

39.0 V-I Characteristic of PEM Fuel Cell system 42

40.0 P-V Characteristic of PEM Fuel Cell system 43

41.0 (a) Maximum Power Point Tracking (MPPT) output trend

(b) Time response of PV Power 44

42.0 (a) Time response of PV current

(b) Time response of PV Voltage 44

43.0 Comparison between voltage measurement before and after

DC DC Boost Converter (a) Voltage before DC DC Converter

(b) Voltage after DC DC Boost Converter 45

44.0 Three-phase V-I Measurement after Power Converter (a) Voltage

Measurement (b) Current measurement 46

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45.0 Simulation result on 6kW 4VDC Fuel Cell Stack (a) Fuel Flow

(b) Utilization of Oxygen and Hydrogen (c) Stack Consumption (lpm)

for Air and Fuel (d) Stack Efficiency in % 47

46.0 Time response of PEM FC (a) Voltage measurement

(b) Current Measurement (c) DC Bus Voltage (d) DC Bus Current 47

47.0 Three-phase V-I Measurement for PEMFC after Power Converter

as connected to Grid-line (a) Voltage Measurement

(b) Current Measurement 48

48.0 Home Solar Photovoltaic System Control Circuit 52

49.0 Home Solar Photovoltaic Metering 52

50.0 Home Solar Photovoltaic Metering Installation 53

51.0 Home Solar Photovoltaic Metering Installation by TNB 54

xiv

LIST OF ABBREVIATIONS

PEM - Proton Exchange Membrane

PV - Photovoltaic

MPPT - Maximum Power Point Tracking

DC - Direct Current

HVDC - High Voltage Direct Current

AC - Alternating Current

GT - Gas Turbine

BUS - Busbar

xv

LIST OF SYMBOLS

k - Kilo

V - Volt

P - Real Power

Q - Reactive Power

M - Mega

W - Watt

VAr - Volt-ampere-reactive

s - second

t - time

Hz - Hertz

f - Frequency

% - Percentage