Post on 01-Feb-2017
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BATTERY MANAGEMENT SYSTEM FOR SOLAR APPLICATION
Mohd Fazlan bin Ali
Bachelor in Electrical Engineering
(Control, Instrumentation and Automation)
JUNE 2013
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BATTERY MANAGEMENT SYSTEM WITH SOLAR APPLICATION
MOHD FAZLAN BIN ALI
A report is submitted in partial fulfillment of the requirement for the degree
of Bachelor in Electrical Engineering
(Control, Instrumentation and Automation)
Faculty of Electrical Engineering
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
JUNE 2013
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I declare that this report entitle “Battery Management System for Solar Application” is the result of my
own research except as cited in the references. The report has not been accepted for any degree and is
not concurrently submitted in candidature of any other degree.
Signature : ………………………………
Name : ……………………………....
Date :…………………………….....
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“ I hereby declare that I have read through this report entitle “Battery Management System for Solar
Application ” and found that it has comply the partial fulfillment for awarding the degree of Bachelor
of Electrical Engineering (Control, Instrumentation and Automation)”
Signature : ………………………………
Supervisor's Name : En Norhafiz Bin Salim
Date : ………………………………
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ACKNOWLEDGEMENT
First and foremost, I would like to take this golden opportunity to express my
appreciation to my final year project supervisor, Mr Norhafiz bin Salim for being a dedicated
lecturer guiding me through this project to run smoothly. This project cannot be completed and
perfected if without the valuable suggestion and useful information from my supervisor. His
patience and enthusiastic in guided me through this final year project have gave me a great
courage in completing this project.
Apart from that, I also would like to thanks to my lecturer Dr. Abdul Rahim bin
Abdullah and all my friends for the helped especially, Mohd Hazwan bin Abdullah and Mohd
Shahmir bin Mohmad Selami in giving me their morals support during this project
development and also shared some information with regards to the photovoltaic system and
the software guide.
Last but not least, I would like to express my deepest love and gratitude to my beloved
parents for giving me unlimited encouragement during my studies in University Technical
Malaysia Malacca (UTeM).
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ABSTRACT
Battery Management System for solar application system consists of lead asid battery
serving as its energy storage elements. The most commonly used storage technology for solar
application is the lead acid battery. This system is constructed for the purpose of gathering
data on different charge and discharge current flow through the storage and load. The aim of
this project is to analyze a charging process with battery utilization in a way to optimize load
variation and making the overall system more reliable. The solar charge controller with Pulse
Width Modulation (PWM) technique making the solar panels able to optimize under varying
illumination level. The battery charging from different power of solar panel is the key point
to found the suitable sources to power up these prototype. The new system configuration with
parallel is to create a optimal storage. According to the size of battery characteristic, the
battery management is optimized for longer life time and batter performance. Charge and
discharge of SLA battery at 50% of battery capacity conducted on the static load resistor
through 90 watt laptop adaptor. Voltage and current were recorded during an increment of out
power from 10W to 70W. The experimental result analyzed through this project carry out via
actual measurement and hardware that has been developed. This prototype of portable dc
power supply has been developed and tested under lab experimental . All results were verified
through experiment with the load variation that has been done.
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ABSTRAK
Sistem Pengurusan Bateri untuk aplikasi sistem solar terdiri daripada bateri asid
plumbum berfungsi sebagai elemen storan. Teknologi storan yang biasa digunakan untuk
aplikasi solar ini adalah bateri asid plumbum. Sistem ini dibina untuk tujuan pengumpulan
data ke atas cas dan nyah cas yang berbeza-beza melalui sistem storan dan beban. Tujuan
projek ini adalah untuk menganalisis proses mengecas dengan menggunakan bateri dengan
cara untuk mengoptimumkan kepada perubahan beban dan menjadikan keseluruhan sistem ini
lebih dipercayai. Pengawal cas solar dengan teknik Pulse Width Modulation (PWM) adalah
teknik yang menjadikan panel solar dapat mengoptimumkan di bawah tahap pencahayaan
yang berubah - ubah . Bateri cas daripada sumber kuasa yang berubah - ubah dari panel solar
adalah kunci kepada penemuan sumber yang bersesuaian untuk sistem prototaip ini berfungsi.
Konfigurasi sistem dengan penyambungan selari untuk menghasilkan storan yang optimum.
Menurut saiz serta ciri bateri, pengurusan bateri dapat dioptimumkan untuk masa jangka hayat
lebih panjang dan serta dengan prestasi lebih baik. Cas dan nyahcas bateri SLA pada 50%
kapasiti nya dijalankan pada perintang beban melalui 90 watt adaptor komputer riba. Voltan
dan arus telah direkodkan semasa kenaikan kuasa dari 10W sehingga 70W. Hasil experiment
di analisa dalam projek ini dijalankan melalui ukuran sebenar serta perkakasan yang telah
dibangunkan. Prototaip bekalan kuasa dc mudah alih ini dibangunkan dan diuji dalam makmal
eksperimen .Semua keputusan telah disahkan melalui eksperimen dengan perubahan beban
yang telah dilakukan.
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TABLE OF CONTENTS
CHAPTER TITLE PAGE
ACKNOWLEDGEMENT ii
ABSTRACT iii-iv
TABLE OF CONTENTS v-vii
LIST OF TABLES viii
LIST OF FIGURES ix-x
LIST OF APPENDICES xi
1 INTRODUCTION
1.1 Background 1
1.2 Problem statement 2
1.3 Objective 2
1.4 Project Scope 3
2 LITERATURE REVIEW
2.1 Introduction 4
2.2 Solar Panel 5-8
2.3 Solar Charge Controller Operation 8
2.3.1 Stage 1 (Bulk Charge) 9
2.3.2 Stage 2 (Boost Charge / absorption charge) 9
2.3.3 Stage 3 (Float Charge) 9-10
2.4 Storage system 10-11
2.4.1 Lead - Acid Batteries 11
2.4.2 Liquid Vented 11
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2.4.3 Sealed Lead - Acid Batteries (VRLA) 12
CHAPTER TITLE PAGE
2.4.4 Alkaline Batteries 12
2.4.5 Battery Capacity 12-13
2.5 Battery Management System (BMS) 13-14
3 METHODOLOGY
3.1 Project development process steps 15-18
3.2 System Overview 19
3.2.1 Overall layout of circuit development 19-20
3.3 Mechanical Construction 21
3.3.1 Mechanical Development 21-26
3.4 Hardware Development 27
3.4.1 Battery configuration 27
3.4.1.1 Series connection 28
3.4.1.2 Parallel connection 29
3.4.1.3 Combined in parallel and serial 30
3.5 Experiment steps 30
3.5.1 Experiment 1 30-32
3.5.2 Experiment 2 33-34
3.5.3 Experiment 3 35-36
4 RESULT
4.1 Definition Process 37
4.2 Experiment 1 37-39
4.3 Experiment 2 40-41
4.4 Experiment 3 42
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CHAPTER TITLE PAGE
5 ANALYSIS AND DISCUSSION OF RESULT
5.1 Definition Process 43
5.2 Experiment 1 43
5.2.1 Analysis and discussion on result 43-46
5.3 Experiment 2 46
5.3.1 Analysis and Discussion on Result 46-48
5.4 Experiment 3 49
5.4.1 Analysis and Discussion on Result 49-50
5.5 Discussion 51-52
6 CONCLUSION AND RECOMMENDATION
6.1 Conclusion 53-54
6.2 Recommendation 54
REFERENCE 55
APPENDICES 56-57
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LIST OF TABLES
TABLE TITLE PAGE
2.1 Different type of Solar Panel 6
2.2 Advantages of Crystalline PV Cells 8
2.3 Disadvantages of Crystalline PV Cells 8
3.1 Hardware development flow 25-26
3.2 Specification of Seal Lead Acid Battery (SLA) 28
3.3 General specification of the 30 watt of solar panel 31
3.4 General specification of the 75 watt of solar panel 33
3.5 The approximate battery and cell voltages for various
states of charge 34
4.1 Average analysis data of solar panel in 5 days from
7 March 2013 - 12 March 2013 38
4.2 Calculation power efficiencies of solar panel 39
4.3 Data during charging battery of
Solar Charge Controller 40
4.4 The data 90 W laptop adapter 42
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LIST OF FIGURES
LIST TITLE PAGE
2.1 a Monocrystalline cells 6
2.2 b Polycrystalline cells 6
2.2 c Amorphous cells 7
2.2 Solar Charge Controller (Battery Charging) 8
3.1 a Top view of battery layout 17
3.1 b Isometric view of frame with battery layout 17
3.2 Flowchart of Project Flow 18
3.3 Overall system of Battery Management System
with Solar Application 19
3.4 Design mechanical frame by using Solid Work software
3.4 a Shaded With Edge View 21
3.4 b Hidden Line Visible View 21
3.5 Material used (L Angle steel bar) 22
3.6 Frame of portable dc power supply 22
3.7 Frame with acrylic casing front view 23
3.8 Frame with acrylic casing rear view 23
3.9 Parallel connection of SLA battery 27
3.10 90 Watt Universal Laptop Adaptor 28
3.11 Series connection 28
3.12 Parallel connection 29
3.13 Combined series and parallel connection 30
3.14 Diagram of solar connection 31
3.15 30 Watt of Solar 31
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3.16 Meter measurement 32
LIST TITLE PAGE
3.17 100 ohm (10watt) ceramic resistor 32
3.18 Experiment layout 33
3.19 The 90 watt laptop adaptor 35
3.20 TERCO current meter 35
3.21 TERCO Watt meter 36
3.22 TERCO Load Resistor MV110 36
5.1 The voltage of solar panel 43
5.2 The current of solar panel 44
5.3 The power (watt) of solar panel 45
5.4 The radiation from sun 45
5.5 The average battery voltage and solar voltage 46
5.6 The PV current and battery current 47
5.7 The battery capacity - State of charge (SOC) 48
5.8 Input and output power of laptop adaptor 49
5.9 Input and output current of laptop adapter 50
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LIST OF APPENDICES
APPENDIX TITLE PAGE
A Sealed Lead Acid Battery Specification Chart
(AGM and GEL) 56
B Gantt Chart 57
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CHAPTER 1
INTRODUCTION
1.1 Background
The electrical energy has become of the most important aspect for human, because the
equipment and the future of many portable electrical devices such as cellular telephones,
notebook computer, personal digital assistant, and etcetera need electricity to get it operated.
Continuous use of electronic devices will lead to reduction of the power source. Additional
electrical energy are required to continue the without disrupting the work operations.
Limitation of power sources are an issue if the laptop or hand phone when there is shortage of
battery. So, the portable dc power supply base on Battery Management system (BMS) to be
supplied to some of load (laptop or cell phone ) at a time is an alternative way. With the
availability of solar power as a source of renewable energy, it is easy to handle and easy to
recharge solar energy plays an important role in the generate of electric power. Solar
photovoltaic modules produce electrical energy in the solar arrays. The nonlinear output power
of Photovoltaic (PV) source mainly depends upon the environmental condition such as level of
light intensity. For stand-alone solar systems, storage device are required to store energy that
are not connected to the grid supply. The selection of the suitable battery type is important to
emphasis on deep of discharged to ensure an optimization charge/discharge cycle also to
prolong the battery life. The (BMS) with solar charge controller in solar system to improve
the efficiency of the array and charge safely to the storage system. The BMS overcome the
charge/discharge by implanting system with more reliable and efficiently.
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1.2 Problem statement
The usage of outlet socket are very important for us to get electric supply for electronic
devices. Usually, user must be close with the outlet socket when using the electronic device
due to battery weakness. Limitation of power sources is an issue when the electronic device is
having a lack of battery supply. With the availability portable dc supply base on Battery
Management System (BMS), the user is able to use the electronic devices at anywhere.
BMS is a process to ensure that a battery cell string receives an optimum charge without
conducting damage to the battery string. Battery is regular depth of discharged (DOD)
because of no ideal dc source from solar energy and this may not to ensure charge/discharge
cycle optimally. The poor charge/discharge cycle may results in sulfation, stratification or
gassing resulting in the end of battery life. In addition, erratic temperature range during
operation interfere optimal storage level. The battery management system is required to
overcome these problems by making the system more reliable and efficient. Thus, a proper
charging/discharging will prevent the battery becoming repeatedly overcharged or
undercharged [3][4].
1.3 Objective
i. To investigate Battery Management and Solar system.
ii. To develop a BMS and Solar network for load variation.
iii. To verify between theoretical and experimental result.
iv. To analyze the entire battery management and solar system.
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1.4 Project Scope
In order to achieve this objective, several scopes had been outlined which to
implemented of the portable dc power supply base on Battery Management System (BMS).
The solar panel will be used to harvest solar energy and the ratings is 30Watt at 18Volt and
75Watt at 17Volt. In this (BMS) , solar charge controller is use in order to optimize the entire
system . The Seal Lead Acid Battery (SLA) si selected as a storage elements energy system.
The load test will be conducted on laptop and mobile phone as a load. The charge/discharge
process and output power of the (BMS) will be analyzed throughout the experimental result
that will be taken.
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CHAPTER 2
LITERATURE REVIEW AND PROJECT BACKGROUND
2.1 Introduction.
Literature review in terms of definition is a review of the research that has been made
about a particular problem that has been identified and needs to be answered. It is done in
order to enquire an understanding of the project and to identify what the key issues are. This
review should describe, summarize, evaluate and clarify the project. It also goes beyond the
search for information and includes the identification and articulation of relationships between
the literature and the field of research.
The research can be done through books, journals, web pages, reports and others. From
these sources, a literature review has to be organized around and related to the thesis and the
result has to be synthesized into a summary so that the areas that are important can be
identified. Other than that, questions that need further research are also formulated here. The
term ‘green system’ that has been getting more attention lately making the solar-powered
device to be more popular. Thus, come an idea of having a portable solar charger in order to
charge up small devices. A solar charger comes with an internal battery where the sun’s
energy gets stored in the device itself so that devices can be charge even without the presents
of lights. The downside of having a charger without battery is that if there is no sun equals no
phone or music. Therefore, this paper works out on what is really needed in a solar charger.
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2.2 Solar Panel
Solar power is one of the first things that come to people’s minds when the topic of
renewable energy is discussed. Implementation of solar panels for multipurpose has bring a lot
of benefits in many industries such as transportations, agricultural and residential. There are a
few advantages of having solar as the renewable source of electricity such as it can provide
needed source of electrical to all the household or office consumptions. Other than that, any
other additional solar modules that have to be added according to the demand can be done
easily as solar modules are only in the form of panels, without moving parts and can be
installed in windows, walls or roof tiles form. The electricity is also provided without emitting
any greenhouse gases.
There are quite a number of journals that were published regarding to solar and one of
it is title “Modeling and Simulation of Maximum Power Point Tracker for Photovoltaic
System”. It is mentioned in this paper where the utilization of the solar energy can be divided
into two ways which are the solar heating and cooling and these energies needed, can be
converted into electrical energy through photovoltaic cells. Unfortunately, the disadvantage of
the PV system is due to its nonlinear, insolation level and temperature dependent current and
voltage. However, in these fast evolving world, the solutions are already found such as the
manufacturing process of solar arrays need to be improved, and also by controlling the
insulation input to PV array which is shown in this project too [1] .
A paper that was published which is entitle “Effect of Dc to Dc Converters on Organic
Solar Cell Arrays for Powering Dc Loads”, that discuss about solar cells that are divided into
two main classes which are organic and inorganic. Inorganic solar cells are made from
crystalline silicon and the organic solar cells that differ from inorganic by their carbon-based
semiconducting materials such as Buckminsterfulleine. Organic cells have more advantages
than inorganic solar whereby they are lighter in their weight, more flexible and also less
costly. The only bad side that organic cell has is that the poor power-conversion efficiency [2].
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Table 2.1 : Different type of Solar Panel
TYPE OS SOLAR PANEL EXPLAINATION
Figure 2.1 a : Monocrystalline cells
Monocrystalline cells are cut from a single
crystal of silicon, which means that they are
basically a slice from a crystal.
In appearance, these cells have a smooth texture
and the thickness of the slice will be able to be
seen clearly.
These cells have to be mounted in a rigid frame
are the most efficient and the most expensive to
produce.
Figure 2.2 b : Polycrystalline cells
Polycrystalline cells are a slice cut from a whole
block of silicon, which means that these cells
consist of a large number of crystals.
They have a speckled reflective appearance and
the thickness of the slice can be seen.
These cells are slightly less efficient and slightly
less expensive than Monocrystalline cells but
they also need to be mounted in a rigid frame.
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Figure 2.2 c : Amorphous cells
Amorphous cells are manufactured by
placing a thin film of amorphous (non
crystalline) silicon onto a wide choice of
surfaces.
These are the least efficient and least
expensive to produce of the three types.
Due to the amorphous nature of the thin
layer, it is flexible, and if manufactured on a
flexible surface, the whole solar panel can be
flexible.
One characteristic of amorphous solar cells
is that their power output reduces over time,
particularly during the first few months, after
which time they are basically stable.
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Table 2.2 : Advantages of Crystalline PV Cells
Crystalline PV Cells Amorphous PV Cells
High efficiency level Cheap and affordable
A single element production Si It comes in a wide variety
It has a great accuracy in terms of production Flexible, can adapt different positions
Easy to recycle all environmental impacts Produced more quickly and efficiently.
Table 2.3 : Disadvantages of Crystalline PV Cells
Crystalline PV Cells Amorphous PV Cells
Very Expensive Low efficiency level
Hard to produce in different models Restricted by many constraints
Rigid and hard to adapt visible light beams A wide array is needed
Large arrays required to achieve sufficient
energy
Different elements many undermine the
quality
2.3 Solar Charge Controller Operation
Figure 2.2 : Solar Charge Controller (Battery Charging)
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2.3.1 Stage 1 (Bulk Charge)
Current is sent to the batteries of the maximum safe rate they will accept until their
voltage rises to about 80 to 90% of their fully charged value. The bulk charging voltage is
typically about 14.8V but may be as high as 15.5V for a 12V system, this may vary so that the
maximum possible current in maintained. Gel batteries often have lower recommended
voltages in the region of 13.8 to 14.1V.
2.3.2 Stage 2 (Boost Charge / absorption charge)
When the battery has recharged to the Boost voltage set point, constant-current
regulation is used to prevent heating and excessive battery gassing. The boost stage remains
120minute and then goes to Float Charge. The voltage remains constant, typically about 14.2V
for a 12V system(depending on temperature) and the current tapers off as the battery reaches
100% charge.
2.3.3 Stage 3 (Float Charge)
For a 12V battery bank a voltage of about of about 12.8 to 13.2V is maintained across
the batteries to keep them in good condition. After the battery is fully charged in Boost voltage
stage, the controller reduces the battery voltage to Float voltage set point. When the battery is
fully recharged, there will be no more chemical reactions and all the charge current transmits
into heat and gas at this time. Then the controller reduces the voltage to the floating stage,
charging with a smaller voltage and current. It will reduce the temperature of battery and
prevent the gassing, also charging the battery slightly at the same time. The purpose of Float
stage is to offset the power consumption caused by self consumption and small loads in the
whole system, while maintaining full battery storage capacity. In the Float stage, loads can
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continue to draw power from the battery. In the event that the system loads exceed the solar
charge current, the controller will no longer be able to maintain the battery at the Float set
point. Should the battery voltage remains below boost reconnect charging voltage, the
controller will exit Float stage and return to Bulk charge.
2.4 Storage system
In photovoltaic system , the energy is stored in batteries during the day so as to be used
at night. Also ,as photovoltaic system's power output varies throughout any day, a battery
storage system can provide a relatively constant source of power. Batteries are not hundred
percent efficient. Some energy is lost as heat and in chemical reactions. Therefore, additional
photovoltaic modules are needed to compensate for the loss. Utility grid -connected
photovoltaic system do not require batteries, though they can be used as an emergency backup
power source. The following types of batteries are commonly used in PV system : Lead Acid
Batteries which are either liquid vented or sealed VRLA - ( Valve Regulated Lead Acid) and
Alkaline batteries which are also of two types, Nickel Cadmium and Nickel -Iron.
Batteries are electrochemical device and can be classified as a storage in battery
management system. Solar batteries wider used in renewable energy system is flooded lead
acid battery and low maintenance types such as gel and Absorbed Glass Matte (AGM) lead
acid batteries. For both of low maintenance are considerably more expensive and not as
currently available [3]. It can be operate at high temperature range compared with flooded
lead acid battery. Not only using battery method as a storage device, combining with ultra
capacitor can yield the higher density of capacity storage and also improve on
charge/discharge cycle. So, at the mean time it can achieve better cycle life of storage system
[4]. Otherwise from [5] state that the Li-lon battery is the most higher density capacity storage,
and compactable for all situation for Electric Vehicle (EV) system. Various paper discuss of
different type of battery. The AGM lead acid battery been identify following suitable
characteristic with the propose Battery Management System (BMS). The AGM lead acid
battery are found to be attractive for BMS with solar application. This battery is low