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UNIVERSITI MALAYSIA SABAH
SCHOOL OF ENGINEERING AND INFORMATION TECHNOLOGY
Design Project
KE 30602
Final Report
Lecturer name : Yoong Hou Pin
Team member : Albert Ling Hoe Ying (BK09110140)
Norrahmah Binti Salleh (BK08110327)
Kong Mei Chie (BK09110029)
Azahar B. Ali (BK09160210)
Nur Fakhriah Binti Mohd Yusuf (BK08160432)
Siti Hajar Binti Basuni(BK09110030)
Date of Submission : 4 June 2012
Final Report
Maximum Power Point Tracking
(MPPT)
Client : Mr. Yoong
Project Manager : Mr. Yoong Hou Pin
Project Leader : Albert Ling Hoe Ying
Abstract
The project works with maximum power point tracking (MPPT) using the Perturb and Observe (P&O)
algorithm. The P&O algorithm is implemented using the controller make up of logic components such as
voltage follower, voltage inverter, differentiators, comparators, and X-OR gates. The solar energy
harvested from solar panel is fed into the MPPT system to acquire maximum power output at the load.
Typical solar panel works with low efficiency such < 15% thus, maximizing from the solar panel energy
is a necessity to achieve optimum performance of solar energy. A simple MPPT system is built to
maximize the power of solar panel (80W).
TABLE OF CONTENT
CHAPTER TITLE PAGE
ABSTRACT i
LIST OF TABLE ii
LIST OF FIGURE iii-iv
LIST OF ABBREVIATION v
1 Introduction
1.1 Overview 1
1.2 Power Supply Research 2
1.3 MPPT Research 2
1.4 Objective 3
1.4.1 Problem statement 3
1.4.2 Requirements 3
1.4.3 Safety Feature 4
1.4.4 Tolerance/Accuracy 4
1.4.5 Input/output Definition 4
1.4.6 Operation Environment 4
1.4.8 Hazardous Level 4
1.4.9 Overshoot Protection 4
1.5 Scope of work 5
1.5.1 Academic Review 5
1.5.2 Mathematical Modeling 5
1.5.3 Simulation 5
1.5.4 Hardware Realization 5
1.5.5 Testing 5
1.5.6 Calibration 6
1.6 METHODOLOGY 6
1.6.1 Academic Review 6
1.6.2 Mathematical Modeling 6
1.6.3 Simulation 7
1.6.4 Hardware Realization 7
1.6.5 Testing 7
1.6.6 Calibration 8
2 LITERATURE REVIEW
2.1 Solar energy 9
2.2 The concepts behind solar panel 10
2.3 The Characteristic of Solar Panel 11
2.4 Side Effect to the Solar Panel 12
2.4.1 Panel Arrangement/ Orientation 12
2.4.2 Roof and Panel Pitch 12
2.4.3 Temperature 12
2.4.4 Partial Shading 13
2.5 Perturb and Observe (P&O) Algorithm 13
2.6 Buck Converter 15
2.6.1 Continuous mode 16
2.7 Impedance matching 18
3 LIST OF COMPONENT
3.1 Resistor 20
3.2 Capacitor 21
3.3 PIC (Programmable Interface Controllers) 22
3.4 D flip-flop 23
3.5 Operational Amplifier ( Op Amp ) 24
4 OPERATION OF ELECTRONIC PARTS
4.1 Introduction 25
4.2 Solar Array 26
4.3 Controller 27
4.3.1 Voltage Follower 27
4.3.2 Voltage Inverter 28
4.3.3 Analog Multiplier 29
4.3.4 Differentiators 29
4.3.5 Comparators 30
4.3.6 XOR gate 31
4.3.7 D Flip-Flop 32
5 SYSTEM MODELING
5.1 Input and output definition 34
5.2 Detail design and drawing 34
5.3 Operation of MPPT system using P&O algorithm 34
5.4 Buck converter operation 36
5.5 Buck converter detail design 38
5.6 ADC scaling in PIC 39
6 FABRICATION
6.1 Prototype picture 41
6.2 Comments 41
7 KEY PERFORMANCE INDEX
7.1 Time performance index 42
7.2 Gantt Chart 43
7.3 Comments on TPI and Gantt Chart 44
7.4 Cost performance index 45
8 CONCLUSION AND FUTURE WORK
8.1 Conclusion 47
8.2 Future work 47
REFERENCE 48
APPENDIX 49
ii
LIST OF TABLE
TABLE
NUMBER
TITLE PAGE
1 Level of efficiency of different type of material solar panel 10
2 PRE and CLR function table 31
3 Circuit operation of MPPT by P&O algorithm 35
4 Week number in dates 42
5 Weekly TPI for MPPT project 42
6 Simplified schedule of project 44
iii
LIST OF FIGURE
FIGURE
NUMBER
TITLE PAGE
1 I-V Curve of typical solar 3
2 p-n junction of solar panel 10
3 I-V curve of different Solar Panel power 11
4 I-V Photovoltaic Characteristics for four different irradiation levels 14
5 P-V photovoltaic characteristics for four different irradiation levels 15
5.1 Thevenin Equivalent circuit 19
6 Resistor Color Code 21
7(a) Electrolytic Capacitors (Electrochemical type capacitors) 22
7(b) Ceramic Capacitors 22
8 PIC (Peripheral Integrated Circuit) 22
9 D flip-flop Diagram 23
10 D flip–flop: (a) Truth Table and (b)Timing Diagram 23
11 Operational Amplifier ( Op Amp ) 24
12 MPPT Charge Controller Circuit 25
13 Specifications of solar panel (Sharp NE-80E2EA) 26
14 Voltage follower connection 27
15 Inverting Op-amp connection 28
16 Connection of analog multiplier AD633 29
17 Voltage and Power Differentiator Connection 30
iv
18 Power and voltage comparators 31
19
(a) Connection diagram of IC7486, (b) XOR truth table, (c) Connection of
XOR gate in the circuit
32
20 74HC74 D-Flip-flop connection 32
21 Simple block diagram for overall system. 34
22 Full schematic diagram for MPPT system and Buck Converter 35
23 Flow chart for MPP tracking 35
24 The Circuit operation chart. 36
25 Circuit diagram of Buck Converter 38
26 Voltage Divider Using Resistor 40
v
LIST OF ABBREVIATION
CPI Cost Performance Index
KPI Key Performance Index
MPP Maximum Power Point
MPPT Maximum Power Point Tracking
P&O Perturb and Observe
PV Photovoltaic
TPI Time Performance Index
VMPP Maximum power point voltage
Voc Open circuit voltage
X-OR Excusive OR
1
CHAPTER 1
INTRODUCTION
1.1 Overview
The development of renewable energy has been an increasingly critical topic in the 21st century with the
growing problem of global warming and other environmental issues. With greater research, alternative
renewable sources such as wind, water, geothermal and solar energy have become increasingly important
for electric power generation. Although photovoltaic cells are certainly nothing new, their use has become
more common, practical, and useful for people worldwide.
The most important aspect of a solar cell is that it generates solar energy directly to electrical
energy through the solar photovoltaic module, made up of silicon cells. Although each cell outputs a
relatively low voltage, if many are connected in series, a solar photovoltaic module is formed.
A photovoltaic module is used efficiently only when it operates at its optimum operating point.
Unfortunately, the performance of any given solar cell depends on several variables. At any moment the
operating point of a photovoltaic module depends on varying insolation levels, sun direction, irradiance,
temperature, as well as the load of the system. The amount of power that can be extracted from a
photovoltaic array also depends on the operating voltage of that array. As we will observe, a maximum
power point (MPP) will be specified by its voltage-current (V-I) and voltage-power (V-P) characteristic
curves. Solar cells have relatively low efficiency ratings.
Thus, operating at the MPP is desired because it is at this point that the array will operate at the
highest efficiency. With constantly changing atmospheric conditions and load variables, it is very difficult
2
to utilize all of the solar energy available without a controlled system. For the best performance, it
becomes necessary to force the system to operate at its optimum power point. The solution for such a
problem is a Maximum Peak Power Tracking system (MPPT).
1.2 Power Supply Research
A battery is a source portable electric power. A storage battery is a reservoir, which may be used
repeatedly for storing energy. Energy is charged and drained from the reservoir in the form of electricity,
but it is stored as chemical energy. But, for our design we use capacitor for storing the energy.
In a way, a capacitor is a little like a battery. Although they work in completely different ways,
capacitors and batteries both store electrical energy. Inside the battery, chemical reactions produce
electrons on one terminal and absorb electrons on the other terminal. A capacitor is much simpler than a
battery, as it can't produce new electrons -- it only stores them.
Inside the capacitor, the terminals connect to two metal plates separated by a non-conducting
substance, or dielectric. It won't be a particularly good capacitor in terms of its storage capacity, but it will
work. In theory, the dielectric can be any non-conductive substance. However, for practical applications,
specific materials are used that best suit the capacitor's function. Mica, ceramic, cellulose, porcelain,
Mylar, Teflon and even air are some of the non-conductive materials used. The dielectric dictates what
kind of capacitor it is and for what it is best suited. Depending on the size and type of dielectric, some
capacitors are better for high frequency uses, while some are better for high voltage applications.
1.3 MPPT Research
The Maximum Power Point Tracker (MPPT) is needed to optimize the amount of power obtained from
the photovoltaic array to the power supply. The output of a solar module is characterized by a
performance curve of voltage versus current, called the I-V curve. See Figure 1. The maximum power
point of a solar module is the point along the I-V curve that corresponds to the maximum output power
3
possible for the module. This value can be determined by finding the maximum area under the current
versus voltage curve.
1.4 Objective
The objective of the project is to design a Maximum Power Point Tracking (MPPT) charge collecter
which operate with photovoltaic module and produce maximum power to solar power collector. This
component optimized the amount of power obtained from the photovoltaic array and charged the power
supply.
1.4.1 Problem statement
To fight against the global warming and any other problem that related with fossil fuels, most countries
are switching to renewable energy source like sunlight, biomass, hydro and wind. Eventhough some
countries already use renewable energy source, the renewable energy technologies are not appropriate in
some application and location. However, among several renewable energy source, photovoltaic array are
used in many application such as water pumping, battery charging and street lighting. In this application
the load can be demand more power than photovoltaic (PV) system can deliver. Therefore to achieve the
power required, power conversion system is used to maximize the power from PV system.
1.4.2 Requirements
Figure 1: I-V Curve of typical solar
panel
4
MPPT is able to maximize power up to 80W. It also can used to operate up to 20 panel in parallel. The
load used is water pumping. The system has display to show the power.
1.4.3 Safety Feature
All electronic part only consumes 5V. To prevent damage on the solar electronic devices, a regulator is
used to regulate the dc supply to 5V.
1.4.4 Tolerance/Accuracy
The MPPT systems have temperature tolerance of +/-2⁰C.
1.4.5 Input/Output Definition
Input is solar power. Output is load.
1.4.6 Operation Environment
This device operate in outdoor when there have sufficient sun light during day time.
1.4.7 Hazardous Level
MPPT system operate outdoor in order to collect the solar power which is all the device expose to
disturbance like temperature, environment and else. The overheated wire connection is possible to cause
the system fail to operate.
1.4.8 Overshoot Protection
The IP56 is used to hold the electronic device of the MPPT system. The wire need casting to protect the
wire from overheating.
5
1.5 Scope of work
1.5.1 Academic Review
Before the MPPT project taken out, the background research for the MPPT was collected. MPPT and
photovoltaic cell research need to consider since the MPPT was design according to the solar panel
system. Information and data from the analysis will combine to get the idea how to design and how the
MPPT system will work.
1.5.2 Mathematical Modeling
The maximum power of MPPT system will calculated based on the maximum power from Solar Panel. It
includes the calculation for the system loading effect where the internal resistance can be obtained. The
MPPT circuits also need to calculate the power, voltage and current for the input and output of the load.
1.5.3 Simulation
Circuit will simulate using the Proteus or Pspice Software to ensure whether the installation of the circuit
can be running or not. The circuit will be tested using different sorts of input to get the desired output.
The most important device in this system is Peripheral Interface Controller (PIC). It will control the
whole system and display the load output.
1.5.4 Hardware Realization
After the simulation done, circuit will be construct. The collected power from solar panel will and the
maximum power that can archive will record to ensure it ready to be connected to the circuit. The final
stage to complete this circuit is combined the circuit with the final structure. The IP56 casing will be use
for the safety future.
1.5.5 Testing
6
The Solar Panel will be connected as input to the MPPT system and the motor pump will be used as the
output. The flow of testing process is:
i. Monitoring system test
ii. Temperature control test
iii. Power absorbed test
iv. Electrical safety test
1.5.6 Calibration
Calibration will be done according to an error of the system, which is help to improve the system
accuracy. The device with the known or assigned correctness is called the standard. Then the conceptual
design of MPPT should be achieved.
1.6 METHODOLOGY
1.6.1 Academic Review
Firstly, research about the meaning of the Maximum Power Point Tracking (MPPT) device and its
function with photovoltaic cell will be done. Via internet and other resources, circuit of the MPPT device
will be learned as well as method of how the MPPT device controls the power which will supply directly
to the load. In addition, some useful equations will be reviewed as well so that the modeling can be done
easily.
1.6.2 Mathematical Modeling
The modeling part will divided into three parts. The first part is the photovoltaic cell (also known as solar
cell). Photovoltaic has a method for generating power using solar cells to convert energy from the sun
into the flows of electrons. Solar cells have a complex relationship between solar irradiation,
temperature and total resistance that will produces non-linear output efficiency. Secondly, MPPT system
is used to sample the output of the cells and apply the proper resistance (load) to obtain maximum power
7
for any given environmental conditions. MPPT system will be build according to the desired output and
supply to the desired load.
1.6.3 Simulation
After modeling the desired part of the system, all of the system will be simulated using proper software
(Pspice or Proteus) to ensure that the desired output will be obtained. The software we will use allows for
the division of a stimulated system into numbers of subsystems. This subsystems can be model and test
individually and then interconnected later. This makes it possible to build the physical subsystems such
as the solar panel, MPPT and other system as independent units and verify their proper functionality.
Display blocks and graphs can be attached to any interconnecting line to monitor the corresponding
signal's behavior. The monitored signal can also be written to a workspace variable for further evaluation
and analysis.
1.6.4 Hardware Realization
After all the stimulation, all of the circuit will be constructing according to the designed. In this part, we
are more focusing on the MPPT system, controller and the load. For the solar system, the solar panel
used in our system will provided by School of Engineering and Information Technology. PIC
microcontroller is use in the MPPT system to control the output which will be the supply of the load.
Software for the controller can be developed, deployed, and tested by using C/C++ assembler. For the
circuit side, Printed Circuit Board (PCB) will be used and the circuit drawn as per designed. After all the
circuit is being done, the circuit will place into the appropriate housing or casing which we will use IP56
case and for the cable, we use cable trunking so that our design look need and tidy.
1.6.5 Testing
After all the circuit and hardware have been successfully attached, the device will be tested to know the
performance of each device. First of all, the solar panel will be connected to the MPPT device and
8
monitoring the output of the system which display by the LCD display board. The control system will
control and set the desire output and supply to the load.
1.6.6 Calibration
All the testing and troubleshooting will be doing it in the same time when there is failure and problem
occurs while doing testing. Some calibration will be carry out in order to get the desire output.
9
CHAPTER 2
LITERATURE REVIEW
2.1 Solar energy
Solar energy is imperative to support critical energy sources on earth. Basically, it work to grow our food,
light our days, manipulate weather patterns, provide heat, and can be used to generate solar electricity.
Solar electricity relies upon man-made devices such as solar panels or solar cells in order to provide a
source of clean, or we can speak as a low cost renewable energy. The fully system of solar electricity are
involved from the critical part called solar panel. It‟s should be the main part that absorbed the sun energy
then convert it into another energy to ensure the voltage and power are produced. As solar energy
technologies become more advanced, we are able to develop the energy we receive from the sun to
provide a greater, significant amount of our electricity. Being implicit in several characteristic of how
solar panel works make our ability to produce the maximum power are closed.
2.2 The concepts behind solar panel
Solar cells are usually made from silicon, the same material used for transistors and integrated circuits.
The silicon is treated or "doped" so that when light strikes it electrons are released, so generating an
electric current. There are three basic types of solar cell which is Monocrystalline, Polycrystalline and
Amorphous. Monocrystalline cells are cut from a silicon ingot (bar) grown from a single large crystal of
silicon whilst polycrystalline cells are cut from an ingot made up of many smaller crystals. The third type
is the amorphous or thin-film solar cell.
10
Table 1: Level of efficiency of different type of material solar panel
Material Level of efficiency %
Monocrystalline silicon 14 to 17
Polycrystalline silicon 13 to 15
Amorphous silicon 5 to 7
We should be familiar with concepts of "Doping", it‟s the intended introduction of chemical
elements, with which one can obtain a surplus of either positive charge carriers (p-conducting
semiconductor layer) or negative charge carriers (n-conducting semiconductor layer) from the
semiconductor material. If two differently contaminated semiconductor layers are combined, then a so-
called p-n-junction results on the boundary of the layers.
Figure 2: p-n junction of solar panel
At this junction, an interior electric field is built up which leads to the separation of the charge
carriers that are released by light. Through metal contacts, an electric charge can be tapped. If the outer
circuit is closed, meaning a consumer is connected, and then direct current flows. Finally, metal contacts
on the cell allow connection of the generated current to a load. A transparent anti-reflection film protects
the cell and decreases reflective loss on the cell surface.
11
2.3 The Characteristic of Solar Panel
The characteristic is usually different based on the types of solar panel material. For analysis through
characteristic, we always refer to the voltage-current V-I characteristic.
Figure 3: I-V curve of different Solar Panel power
Every model of solar panel has unique performance characteristics which can be graphically represented
in a chart. The graph in Figure 3 is called an “I-V curve”, and it refers to the module‟s output relationship
between current (I) and voltage (V) under existing conditions of sunlight and temperature. Theoretically,
every solar panel has multiple I-V curves (several of which are shown above for one particular module)
one each for all the different combinations of conditions that would affect the STC rating parameters
above: temperature, air mass, irradiance and so on. Because of Ohm‟s Law (and the equation Power =
Voltage x Current), the result of reduced voltage is reduced power output. The ideal position on any I-V
curve, the sweet spot where we can collect the most power from the module is at the “knee”. That‟s the
maximum power point (MPP), and we can see that its position changes with temperature and irradiance.
The objective for a system to constantly track the P-V curve to keep the operating point as close to the
maxima while energy is extracted from the PV array.
12
2.4 Side Effect to the Solar Panel
Basically, we need to construct an experiment while „playing‟ with solar panel as our source energy from
sun ray. The general concept or theory according to the parameters like current-voltage behavior,
maximum power produced from opened-circuit and closed-circuit or the efficiency normally different to
the real world while testing.
2.4.1 Panel Arrangement/ Orientation
Solar panels are installed differently based on our geographic locations throughout the world. The idea
behind this is simple; the sun is in a different place in the sky, so panels need to be directed according to
this positioning. The ideal situation is when the sun is hitting the panels at a perfectly perpendicular angle
(90°). This maximizes the amount of energy striking the panels and being produced. The two factors that
such an angle is controlled by are the orientation (North/South/East/West) and the angle of the panels
from the surface of the Earth.
2.4.2 Roof and Panel Pitch
The most application using the solar panel is placed at the highest part of building. The “pitch” or tilt of
our roof can affect the number of hours of sunlight we receive in an average day throughout the year.
Large commercial systems have solar tracking systems that automatically follow the sun‟s tilt through the
day. These are expensive and not necessary to the normal type of application such as 12 Volt output
devices.
2.4.3 Temperature
This is the huge problem always facing to the small component devices. Some panels like it hot but most
don‟t. So, panels typically need to be installed a few inches above the roof with enough air flow to cool
them down. As a result the power output will be reduced by between 0.25% (amorphous cells) and 0.5%
13
(most crystalline cells) for each degree C of temperature rise. This reduction in efficiency may be
important to us if we have a high electricity demand to the devices.
2.4.4 Partial Shading
Basically, shade is the enemy of solar power. With poor solar design, even a little shade on one panel can
shut down energy production on all of your other panels. Before we design a system for our devices, we‟ll
conduct a detailed shading analysis of our roof to reveal its patterns of shade and sunlight throughout the
year. There may be situations where this cannot be avoided, and the effects of partial shading should be
considered as part of energy absorption.
2.5 Perturb and Observe (P&O) Algorithm
Solar cells produce energy by performing two basic tasks: (1) absorption of light energy to create free
charge carriers within a material and (2) the separation of the negative and positive charge carriers in
order to produce electric current that flows in one direction across terminals that have a voltage
difference. Solar cells perform these tasks with their semiconducting materials. The separation function is
typically achieved through a p-n junction. Solar cell regions are made up of materials that have been
“doped” with different impurities. This creates an excess of free electrons (n-type) on one side of the
junction, and a lack of free electrons (p-type) on the other. This behavior creates an electrostatic field with
moving electrons and a solar cell is essentially, a large-area diode (Richard, 2006). Researches on
renewable energies have received much attention due to their capability of reducing the fossil fuels usage
and mitigating the environmental issues such as the green house effect and air pollution (Liu and Huang,
2011). Among the renewable energies, the photovoltaic (PV) generation system has become increasingly
important as a renewable source due to its advantages such as absence of fuel costs, low maintenance
requirement and environmental friendliness. However, in PV generation system, the conversion efficiency
is very low, especially under low irradiation, and the amount of the electric power generated by solar cells
varies with weather conditions. Therefore, a maximum power point tracking (MPPT) method is used to
14
maximize the harvested solar energy from the solar panel. In the MPPT system, the system works to find
the maximum power point (MPP) via powerful microcontroller. There are many ways of distinguishing
and grouping methods that seek the MPP from a photovoltaic (PV) generator (Salas et al, 2006). All the
different algorithms has its own pro and cons. In addition, each PV has its own voltage-current (V-I)
characteristics. Figure 4 shows the V-I characteristics of a PV under different irradiance. Figure 5 shows
the P-V photovoltaic characteristics for four different irradiation levels.
Figure 4: I-V Photovoltaic Characteristics for four different irradiation levels.
15
Figure 5: P-V photovoltaic characteristics for four different irradiation levels
From Figure 4 and Figure 5, the MPP can be determined. It is used widely in seeking it using different
algorithms. There are many algorithms in tracking the MPP, for instances, Perturb and observe algorithm,
incremental conductance algorithm, parasitic capacitances, constant voltage control, constant current
control, pilot cell, artificial intelligent method (Algazar et al, 2012).
2.6 Buck Converter
A buck converter is a step-down DC to DC converter. Its design is similar to the step-up boost converter,
and like the boost converter it is a switched-mode power supply that uses two switches (a transistor and
a diode), an inductor and a capacitor. The operation of the buck converter is fairly simple, with
an inductor and two switches (usually a transistor and a diode) that control the inductor. It alternates
between connecting the inductor to source voltage to store energy in the inductor and discharging the
16
inductor into the load. For the purposes of analysis it is useful to consider an idealised buck converter. In
the idealised converter all the components are considered to be perfect. Specifically the switch and the
diode have zero voltage drop when on and zero current flow when off and the inductor has zero series
resistance. Further it is assumed that the input and output voltages do not change over the course of a
cycle (this would imply the output capacitance being infinitely large).
2.6.1 Continuous mode
A buck converter operates in continuous mode if the current through the inductor (IL) never falls to zero
during the commutation cycle. In this mode, the operating principle is described by the plots in figure 4:
When the switch pictured above is closed (On-state, top of figure 2), the voltage across the inductor
is . The current through the inductor rises linearly. As the diode is reverse-biased
by the voltage source V, no current flows through it;
When the switch is opened (off state, bottom of figure 2), the diode is forward biased. The voltage
across the inductor is (neglecting diode drop). Current IL decreases.
The energy stored in inductor L is
Therefore, it can be seen that the energy stored in L increases during On-time (as IL increases) and then
decreases during the Off-state. L is used to transfer energy from the input to the output of the converter.
The rate of change of IL can be calculated from:
With VL equal to during the On-state and to during the Off-state. Therefore, the increase
in current during the On-state is given by:
, t{on} = DT
17
Identically, the decrease in current during the Off-state is given by:
, t{off} = (1-D)T
If we assume that the converter operates in steady state, the energy stored in each component at the end of
a commutation cycle T is equal to that at the beginning of the cycle. That means that the current IL is the
same at t=0 and at t=T (see figure 4).
So we can write from the above equations:
It is worth noting that the above integrations can be done graphically: In figure 4, is proportional
to the area of the yellow surface, and to the area of the orange surface, as these surfaces are
defined by the inductor voltage (red) curve. As these surfaces are simple rectangles, their areas can be
found easily: for the yellow rectangle and for the orange one. For steady
state operation, these areas must be equal.
As can be seen on figure 4, and . D is a scalar called the duty cycle with a value
between 0 and 1. This yields:
From this equation, it can be seen that the output voltage of the converter varies linearly with the duty
cycle for a given input voltage. As the duty cycle D is equal to the ratio between tOn and the period T, it
cannot be more than 1. Therefore, . This is why this converter is referred to as step-down
converter.
18
2.7 Impedance Matching
Maximum power transfer occur when the impedance of the source equals to the load. The maximum
possible power is delivered to the load when the impedance of the load (load impedance or input
impedance) is equal to the complex conjugate of the impedance of the source (its internal or output
impedance). For two impedance to be complex conjugate conjugate their resistance must be equal, and
their reactances must be equal in magnitude but of opposite signs.
Suppose we have a two terminal circuit and we want to connect a load resistance RL such that the
maximum possible power is delivered to the load. To analyze this problem, we go through Thevenin
equivalent circuit as shown in Figure 2.10. The current flowing through the load resistance is given by
𝑖𝐿 =𝑉𝑠
𝑅𝑆+𝑅𝐿 (2.4)
The power delivered to the load is
𝑃𝐿 = 𝑖𝐿2𝑅𝐿 (2.5)
Substituting for the current, we have
𝑃𝐿 =𝑉𝑠
2𝑅𝐿
𝑅𝑆+𝑅𝐿 2 (2.6)
To find the value of the load resistance that maximizes the power delivered to the load, we set the
derivative of 𝑃𝐿with respect to 𝑅𝐿 equal zero:
𝑑𝑃𝐿
𝑑𝑅𝐿=
𝑉𝑠2 𝑅𝑆+𝑅𝐿
2−2𝑉𝑠2𝑅𝐿 𝑅𝑆+𝑅𝐿
𝑅𝑆+𝑅𝐿 4 = 0 (2.7)
Solving for the load resistance, we have
𝑅𝑆 = 𝑅𝐿 (2.8)
Thus, the load resistance that absorbs the maximum power from a two-terminal circuit is equal to the
thevenin resistance. The maximum power is found by substituting 𝑅𝑆 = 𝑅𝐿 into
𝑃𝐿 =𝑉𝑠
2
4𝑅𝑆 (2.9)
19
Figure 5.1 : Thevenin Equivalent circuit
20
CHAPTER 3
LIST OF COMPONENTS
3.1 Resistor
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit
element. The current through a resistor is in direct proportion to the voltage across the resistor's terminals.
Thus, the ratio of the voltage applied across a resistor's terminals to the intensity of current through the
circuit is called resistance. This relation is represented by Ohm's law, where I is the current through the
conductor in units of amperes, V is the potential difference measured across the conductor in units of volts,
and R is the resistance of the conductor in units of ohms.
The electrical resistance is equal to the voltage drop across the resistor divided by the current
through the resistor. Resistors are used as part of electrical networks and electronic circuits. Resistor has
their own color code, where the color code is is determine the value and tolerance of the resistor. Figure 6
shows the table on how to read the value and tolerance of resistor using the color code.
21
Figure 6: Resistor Color Code
3.2 Capacitor
The capacitor's function is to store electricity, or electrical energy. The capacitor also functions as a filter,
passing alternating current (AC), and blocking direct current (DC). The capacitor is constructed with two
electrode plates facing each other, but separated by an insulator. When DC voltage is applied to the
capacitor, an electric charge is stored on each electrode. While the capacitor is charging up, current flows.
The current will stop flowing when the capacitor has fully charged. The capacitance of a capacitor is
generally very small, so units such as the microfarad (10-6
F ), nanofarad ( 10-9
F ), and picofarad (10-12
F )
are used. Recently, an new capacitor with very high capacitance has been developed. The Electric Double
Layer capacitor has capacitance designated in Farad units.
Figure 7(a): Electrolytic Capacitors (Electrochemical type capacitors)
Aluminum is used for the electrodes by using a thin oxidization membrane. Large values of
capacitance can be obtained in comparison with the size of the capacitor, because the dielectric used is
22
very thin. The most important characteristic of electrolytic capacitors is that they have polarity. They have
a positive and a negative electrode.
Figure 7(b): Ceramic Capacitors
Ceramic capacitors are constructed with materials such as titanium acid barium used as the
dielectric. Internally, these capacitors are not constructed as a coil, so they can be used in high frequency
applications. Typically, they are used in circuits which bypass high frequency signals to ground. These
capacitors have the shape of a disk. Their capacitance is comparatively small.
3.3 PIC (Programmable Interface Controllers)
A PIC microcontroller is a processor with built in memory and RAM and you can use it to control your
projects (or build projects around it). It has been already mentioned that microcontrollers differs from
other integrated circuits. Most of them are ready for installation into the target device just as they are, this
is not the case with the microcontrollers. In order that the microcontroller may operate, it needs precise
instructions on what to do. In other words, a program that the microcontroller should execute must be
written and loaded into the microcontroller.
Figure 8: PIC (Peripheral Integrated Circuit)
They can be programmed to be timers or to control a production line and much more. They are
found in most electronic devices such as alarm systems, computer control systems, phones, in fact almost
23
any electronic device.PIC Microcontrollers are relatively cheap and can be bought as pre-built circuits or
as kits that can be assembled by the user.
3.4 D flip-flop
The D flip-flop tracks the input, making transitions with match those of the input D. The D stands for data.
This flip-flop stores the value that is on the data line. It can be thought of as a basic memory cell. A D
flip-flop can be made from a set/reset flip-flop by tying the set to the reset through an inverter. The result
may be clocked.
Figure 9: D flip-flop Diagram
The D (Data) flip-flop has an input D, and the output Q will take on the value of D at every triggering
edge of the clock pulse and hold it until the next triggering pulse. The D flip-flop is usually positive edge
triggered.
(a) (b)
Figure 10: D flip–flop: (a) Truth Table and (b)Timing Diagram
CLK D Q Condition
0 1 0 Start
Raising edge 1 1 Store 1
0 0 Q No Charge
Raising edge 0 0 Store 0
24
3.5 Operational Amplifier ( Op Amp )
The Operational Amplifier (Op Amp ) can be used in many different ways. The Op-amp has two inputs
an inverting input ( - ) and a non-inverting input ( + ) and one output. A signal applied to the inverting
input will have its polarity reversed on the output. A signal applied to the non-inverting input will retain
its polarity on the output. The gain or amplification of the signal is determined by a feedback resistor that
feeds some of the output signal back to the inverting input. The smaller the resistor, the lower the gain.
Figure 11: Operational Amplifier (Op Amp )
The name operational amplifier was originally adopted for a series of high performance DC amplifiers
used in analog computers. These amplifiers were used to perform mathematical operations applicable to
analog computation such as summation, scaling, subtraction, integrating and essentially any feedback
operation.
25
CHAPTER 4
OPERATION OF ELECTRONIC PART
4.1 Introduction
This part will cover all components used in the MPPT charge controller circuit and its operation. There
will be details of the function of each components used and its operations. The circuit was divided into 3
parts which are solar array, control circuit and lastly the power stage. The MPPT charge controller
referred is shows below.
Figure 12: MPPT Charge Controller Circuit
26
4.2 Solar Array
For the solar array, the model of the solar panel we used is Sharp NE-80E2EA. This solar
module is able to output a maximum power of 80 Watt. The specifications of the solar module are
supplied by the manufacturer‟s datasheet as shown in figure 13 below.
Figure 13: Specifications of solar panel (Sharp NE-80E2EA).
4.3 Controller
The controller circuit consists of voltage follower, an analog inverter, a multiplier, two differentiators,
two comparators, a XOR-gate and a D Flip-Flop.
4.3.1 Voltage Follower
Voltage follower achieved using op-amp. Op-amp is a DC coupled high gain electronic voltages
amplifier with a differential inputs and single-ended output. The function of op-amp is to amplify the
input voltages and produce larger output.
27
Figure 14: Voltage follower connection
In the referred circuit, the array was connected to a voltage divider before fed into the voltage
follower. LM318 op-amp was used as voltage follower. The used of 51k ohm and 200k ohm voltage
divider is to have high impedances input at multiplier as the voltage follower is then connected as the
input of the multiplier. The supply voltage of the op-amp were set to V+ = 5V and V– = -5V. The output
voltage of the voltage follower is
V+=R3
R2 + R3Varray
=200k
200k + 51KVarray
= 0.7968 𝑉𝑎𝑟𝑟𝑎𝑦
𝑉𝑜𝑢𝑡 = 𝑉 −
= 𝑉 +
= 0.7968 𝑉𝑎𝑟𝑟𝑎𝑦
Varray
28
4.3.2 Voltage Inverter
Another application of op-amp was inverting the voltage and fed into the op-amp. The current
array was measured in term of voltage connecting the array with small value of resistor. The input into
the voltage inverter is negative of array current multiply, -IARRAY with the value sensing resistor, Rs. The
output voltage, VOUT of will be to positive value multiplying with resistance R4 and R6 connecting the
op-amp. Then output voltage waveform of the will be the same as the input waveform shape but the value
is invert from negative to positive and also based on value of R4 and R6. The op-amp being used in the
circuit is LM318.
Figure 15: Inverting Op-amp connection
The output voltage of LM318 voltage inverter is;
−𝐼𝑎𝑟𝑟𝑎𝑦 𝑅𝑠 − 𝑉−
𝑅4=
𝑉− − 𝑉𝑜𝑢𝑡𝑅6
𝑉− = 0𝑉
𝑉𝑜𝑢𝑡 =𝑅6𝐼𝑎𝑟𝑟𝑎𝑦 𝑅𝑠
𝑅4
=36𝑘 × 0.47 × 𝐼𝑎𝑟𝑟𝑎𝑦
1𝑘
= 16.92𝐼𝑎𝑟𝑟𝑎𝑦
29
The output voltage of inverting op-amp is then fed into the multiplier. The current of the op-amp
was inverted due to have positive value of power at the multiplier.
4.3.3 Analog Multiplier
Analog multiplier is an electronic device that evaluated the product of two analog signals which it
is output. Analog multiplier is use to calculate power of the array by multiplying the array voltage and
the array current. AD633 is an analog multiplier, four quadrants. It includes high impedance, differential
X and Y inputs and high impedance summing input, Z. This analog multiplier was built using differential
op-amps, multiplier and a voltage follower.
Figure 16: Connection of analog multiplier AD633
4.3.4 Differentiators
Another application of op-amp is to differentiate the voltage fed into the op-amp. This application
was achieve connect a capacitor in series with the op-amp and a resistor at the feedback. In the MPPT
circuit referred, the measured power and voltage of the array is approximately differentiated using high
pass filter. The op-amp used as in differentiator circuit is LM318. The connection for power and voltage
differentiator is shown below. It can be seen that the parameter of capacitors, and resistors used in the
differentiator circuit is same. The differentiated value power and voltage of array is measured as the value
is needed to evaluate to track the MPP.
30
Figure 17: Voltage and Power Differentiator Connection
4.3.5 Comparators
The comparators also using op-amp which compares two voltages or currents and switches its
output to indicate which one is larger. From the referred circuit, the outputs of differentiators‟ dV/dt and
dP/dt were fed into the comparator. At the comparators both the differentiated voltage and array was
compared to ground. The op-amp being used as the comparators were LM311. Although an ordinary op-
amp can be used as comparator, there is special integrated circuit intended for use as comparators. LM311
chips are designed for very fast response and aren‟t in the same league as other op-amp.
31
Figure 18: Power and voltage comparators
The comparators will produce output 1 if the input value is greater than zero while it produce zero
if the input value is lower than zero.
4.3.6 XOR gate
In the referred MPPT charge controller circuit, both output of comparators to the XOR gate.
There is pull-out resistors connected parallel in between the comparators and XOR gates. This connection
is to provide additional power to drive the XOR gate. In the pull-out resistor, 4.7k ohm resistor connected
in series with 5V voltage source and shunted in between comparators and XOR gate. The XOR being
used in the circuit was IC7486. Since there were two inputs to the XOR gate, then there will be 4
conditions. The truth table of the XOR gate showing the output of each condition is shown as well as its
connection in the circuit.
Xv Xp output
0 0 0
0 1 1
1 0 1
1 1 0
(b)
(a)
32
(c)
Figure 19: (a) Connection diagram of IC7486, (b) XOR truth table, (c) Connection of XOR gate in
the circuit
4.3.7 D Flip-Flop
Flip-flop is an electronic circuit that has two stable states and thereby is capable of serving one bit of
memory. It usually controlled by one or two signals and/or a gate or clock signal. The output of D-flip-
flop, Q looks a delay of input D. In the referred circuit, the D flip flop that being used is 74HC74 D flip-
flop. The connection to flip-flop is shown below.
Figure 20: 74HC74 D-Flip-flop connection
33
𝑃𝑅𝐸 and 𝐶𝐿𝑅 must be connected high logic (1) to enable the flip-flop to operate where output
was determined by input, D. According to table 2 below, flip-flop will operate if 𝑃𝑅𝐸 and 𝐶𝐿𝑅 are set to
HIGH logic.
Table 2: PRE and CLR function table
The output of XOR is connected to flip-flop before fed to switch because to prevent high
frequency switching chattering and to minimize the unavoidable interference generate by the buck
converter‟s switching action [David and Yan, 2000]. This interference occurs immediately after the clock
transition and is over before the next, so latch never samples it.
34
CHAPTER 5
SYSTEM MODELING
5.1 Input and output definition
The input of our design MPPT system is the DC power supply from the solar panel. The output of this
system is the output voltage to the load supplying 80 W to the DC motor. The power that is harvested
from solar panel is maximized using the MPPT system by using P&O algorithm. Basically, to have the
maximum power transfer to the load, an impedance matching circuit design is required. Hence, our
overall design can be divided into four simple stages as in figure 21. Figure 21 shows the input solar
panel is fed into the MPPT system and impedance matching to have the desired output at the load.
Figure 21: Simple block diagram for overall system.
5.2 Detail design and drawing
The overall design of MPPT is built based on logic components such as, voltage follower, voltage
inverter, analog multiplier, differentiators, voltage comparators, X-OR gate, and D-flip flop. These
components are used to track the MPP by using the P&O algorithm. The DC-DC buck converter is used
to step down to 12V for the load use. The overall design schematic is as follows,
Solar Panel MPPT Impedance
matching Load- DC
motor
35
Figure 22: Full schematic diagram for MPPT system and Buck Converter
5.3 Operation of MPPT system using P&O algorithm
MPPT system tracks the maximum power point of the solar panel and supplies it to the buck converter.
The overall operation of the operation is simplified as in flow chart in Figure 23. Figure 23 shows the
flow of tracking the MPP of solar panel.
Figure 23: Flow chart for MPP tracking
Voltage
follower Differentiators
Differentiators
Comparator
Comparator Inverting
Amplifiers Multiplier X-OR
D-flip flop Switch
Varray dV/dt
dP/dt Parray
36
Figure 24: The Circuit operation chart.
The solar panel will exhibit the PV curve as in Figure 24. Refer to the P-V curve in Figure 24, the P&O
algorithm is implemented using the MPPT controller circuit. By referring to the Maximum Power Point
(MPP), the voltage array is increased or decreased by charging or discharging of capacitors.
At point A, V<VMPP, the 𝑑𝑉
𝑑𝑡 is negative as well for as the
𝑑𝑃
𝑑𝑡 while retreating from MPP. The switch is
opened to let the capacitor charging to increase V towards VMPP. V now increases towards VMPP, 𝑑𝑉
𝑑𝑡 and
𝑑𝑃
𝑑𝑡 are now positive while increasing towards MPP. The switch opens and capacitors charging to increase
V towards VMPP.
At point B, V<VMPP, the 𝑑𝑉
𝑑𝑡 is positive but
𝑑𝑃
𝑑𝑡 is negative while retreating from VMPP. The switch is closed
and the capacitor start discharging resulting V decreases towards VMPP. V now is decreased towards VMPP,
Vmax
MPP
Power, W
Voltage, V
Pmax
A B
37
𝑑𝑉
𝑑𝑡 now is negative and
𝑑𝑃
𝑑𝑡 is positive while P is increasing toward MPP. The switch is closed and
capacitor discharged resulting in V decreasing toward VMPP.
In conclusion, the circuit operation is tabulated in Table 3. Table 3 shows the simplified circuit operation
of tracking MPP by P&O algorithm.
Table 3: Circuit operation of MPPT by P&O algorithm.
Condition 𝑑𝑉
𝑑𝑡
𝑑𝑃
𝑑𝑡
Comparator output X-OR
output
Switch Voltage
XV XP
V<VMPP
Negative Negative 0 0 0 Open Increases
Positive Positive 1 1 0 Open Increases
V>VMPP
Positive Negative 1 0 1 Close Decreases
Negative Positive 0 1 1 Close Decreases
5.4 Buck converter operation
The buck converter circuit is shown in Figure 25, basically it is built up of three main components,
namely diode, inductor and capacitor. The diode is blocking diode which is connected in series with the
solar array to prevent the reverse terminal current. In the circuit, the diode is assumed to be ideal. The
capacitor, C is used to control the voltage of the array. When the operating voltage is smaller than the
voltage at the maximum power point, VMPP, the capacitor will charge to increase the voltage and vice
versa.
Buck converter is a step-down DC-DC converter. The DC input voltage or the current can be
regulated to desired DC output. The output of buck converter is smaller than the input voltage. By
controlling the switch, the output voltage can be controlled.
38
Figure 25: Circuit diagram of Buck Converter
5.5 Buck converter detail design
Assumed input is 20V.
𝐷 =𝑉𝑜𝑉𝑆
𝑉𝑂 = 12𝑣
𝐷 =12
20
= 0.6
Minimum Inductor value;
𝐿𝑚𝑖𝑛 = 1 −𝐷 𝑅
2𝑓
Let switching frequency, f=40Khz
𝐿𝑚𝑖𝑛 = 1 − 0.6 𝑅
2 40𝐾
Where 𝑃 =𝑉𝑜
2
𝑅= 80𝑊
𝑅 =122
80
= 1.8Ω
39
𝐿𝑚𝑖𝑛 =0.4 1.8
80𝐾
= 9𝜇𝐻
To be continuous current, 𝑳𝒎𝒊𝒏 ≥ 𝟗𝝁𝑯
So, we choose 1mH to be used in the circuit.
Capacitor value;
𝐶 ≥1 − 𝐷
8𝐿 Δ𝑉𝑜𝑉𝑜 𝑓2
Assumed 1% of voltages ripple,
𝐶 ≥0.4
8 1𝑚 0.01 (40𝐾)2
≥ 3.125𝜇𝐹
So, we choose 𝟒𝟕𝟎𝝁𝑭.
5.6 ADC scaling in PIC
ADC scaling can be done by determined the supply voltage and input voltage of the component.
If the voltage input value was high, the current voltage level on the supply should estimate the storage
energy left. The charge level should be alert, because it will indicate user weather the device should be
cut off beyond the threshold or drops below a certain level.
For the ADC scaling with PIC, the maximum input voltage should be noted, to ensure the voltage
will be measure is higher or lower than the input voltage for PIC. In this case, easiest way is to use
voltage divider using resistor.
Assuming you want to measure the automotive battery voltage. Typically, the battery voltage will
be 20 V. For safety reason, let's assume we design for 25V maximum input voltage (25% safety factor).
To accomplish this, we'll use 5 resistors of 4.7k each a potentiometer can also be used to set it correctly.
40
Figure 26: Voltage Divider Using Resistor
The input to the ADC will be 5v when voltage input is present 20v, thus the input voltage has been scaled
by factor of 1/5. The ratio is obtained from the voltage divider.
PIC input voltage = (v)R1
(R1+R2+R3+R4+R5)
= (25v)4.7k
(4.7k + 4.7k + 4.7k + 4.7k + 4.7k)
= 5v
By using VDD(5V) as the ADC reference, the ADC reading will be 1023 when the ADC input is 5V. To
obtain the actual reading, the following equation is used,
𝐴𝑐𝑡𝑢𝑎𝑙 𝑟𝑒𝑎𝑑𝑖𝑛𝑔 = 𝐴𝐷𝐶 𝑟𝑒𝑎𝑑𝑖𝑛𝑔 ∗20(𝑑𝑒𝑠𝑖𝑔𝑛𝑒𝑑 𝑚𝑎𝑥𝑖𝑚𝑢𝑚 𝑣𝑜𝑙𝑡𝑎𝑔𝑒)
1024
0
R3
4.7k
R2
4.7k
Actual_Input
R4
4.7kPIC_ADC
R1
4.7k
R5
4.7k
41
CHAPTER 6
FABRICATION
6.1 Prototype picture
6.2 Comments
The product is produced incompletely. There are parts that we could not acquire, such as the LCD display
and the analog multiplier. The failure in obtaining these two components make the overall system could
not perform the MPPT tasks as planned.
42
CHAPTER 7
KEY PERFORMANCE INDEX
7.1 Time performance index
Key performance index (KPI) is used to evaluate the activity‟s success or failure. KPI includes the time
performance index (TPI) and the cost performance index (CPI). A unity for both TPI and CPI indicates a
perfect or optimum performance done by the team. However, TPI which exceeding 1 means the delay in
the project, for the same case, CPI exceeding 1 simply indicates that the expense is over-budgeted. Table
4 shows the weekly TPI by Greentech Engineering in conducting the MPPT project.
Table 4: Weekly TPI for MPPT project
Week W1 W2 W3 W4 W5 W6 W7 W8 W9 W10 W11 W12 W13
TPI 1.00 1.08 1.34 1.53 1.39 1.54 1.69 1.64 1.46 1.59 1.70 1.80 1.43
Table 5: Week number in dates
WEEK DATE
W1 5MAR-9MAR
W2 12MAR-16MAR
W3 19MAR-23MAR
W4 26MAR-30MAR
W5 2APR-6APR
W6 9APR-13APR
W7 16APR-20APR
W8 23APR-27APR
W9 30APR-4MAY
W10 7MAY-11MAY
W11 14MAY-18MAY
W12 21MAY-25MAY
W13 28MAY-1JUN
W14 4JUN-8JUN
43
7.2 Gantt Chart
44
7.3 Comments on TPI and Gantt Chart
Referring to TPI in Table 4, the TPI is greater than 1 which means there is a delay in the project
conducted. For example, taking Week 7 as an example, Week 7 has a TPI of 1.69 which means there is a
69% delay in our project. At the same time, by referring to the Gantt chart in section 7.2, Week 7 shows
the task of system modeling. For the task system modeling, the planned time is 7 days but our group spent
16 days in doing it. The failure in completing the task on time leads our group to incomplete design at the
final time.
Table 6: Simplified schedule of project
Tasks Duration Start date End date
1.1 Project Requirement 1 5/3/2012 5/3/2012
1.2 Background search 7 5/3/2012 15/3/2012
1.3 Conceptual design 7 8/3/2012 13/3/2012
1.4 Proposal preparation 10 5/3/2012 20/3/2012
1.5 Proposal presentation 1 20/3/2012 4/4/2012
2.1 System Modeling 7 4/4/2012 24/4/2012
2.2 Simulation 3 24/4/2012 27/4/2012
2.3 Analysis 3 24/4/2013 27/4/2013
2.4 Detail design and drawing 8 30/4/2012 25/5/2012
3.1 PCB 5 28/5/2012 30/5/2012
3.2 Mechanical fabricatin 7 30/5/2012 30/5/2013
3.3 Assembly 4 30/5/2012 1/6/2012
5.2 User Manual 2 1/6/2012 1/6/2012
5.3 Final Product 5 1/6/2012 1/6/2012
45
7.4 Cost performance index
No. Description Supplier Receipt
No. Date Qty. Unit Price Total
1 IRFZ44N MOS-N-FET-e Genius Electronic Co. 71934 28.05.12 1 4.00 4.00
2 PIC16F877A MPU 1 28.00 28.00
3 36K 1/4W CARBON FILM RESISTOR 1 0.20 0.20
4 0.47R(R47)2W METAL OXIDE FILM RESISTOR 1 1.20 1.20
5 40 PINS CONTACT-STRIPS 1 3.60 3.60
6 8 PINS IC SOCKET 4 0.60 2.40
7 56uF 25Vdc ELECTROLYTIC CAPS 1 1.20 1.20
8 100uF 25Vdc ELECTROLYTIC CAPS 1 0.50 0.50
9 100uF 16Vdc ELECTROLYTIC CAPS 1 0.40 0.40
10 VERO BOARD 64X146MM (2 1/2"X3 1/2")-OT-PCB-2LN RADIOTRONIC SDN. BHD. 01054510 28.05.12 3 1.30 3.90
11 CERAMIC CAPACITOR 104P 50V 2 0.30 0.60
12 DIODE 1 0.30 0.30
13 12.288M CRYSTAL 1 2.00 2.00
14 RESISTOR 1/4W 16 0.20 3.20
15 I.C SN74LS86 2 2.50 5.00
16 I.C 4 4.50 18.00
17 I.C.7805 / MC78M05C/ANT78M05 1 1.50 1.50
18 IC LM311N 2 2.00 4.00
19 3800uH INDUCTOR Genius Electronic Co. 71958 29.05.12 1 7.00 7.00
20 22pF CERAMIC CAPS 2 0.40 0.80
21 CAPACITOR 100uF 16V RADIOTRONIC SDN. BHD. 2049772 01.06.12 2 0.30 0.60
22 CAPACITOR 100uF 25V 2 0.30 0.60
23 I.C 7812 1 1.50 1.50
24 I.C 7805 / MC73M05C/ANT78MOS 1 1.50 1.50
25 DC12 ROCKER SWICTH MS-1366BND12 1 2.40 2.40
46
26 MSR-5-2X 3P ROCKER SW 1 3.00 3.00
27 42/0.15X2C CABLE 1 1.90 1.90
28 9V BATTERY SNAP NH-553/T 1 0.50 0.50
29 44X50X14MM HEAT SINK Genius Electronic Co. 71975 01.06.12 1 4.50 4.50
30 25X30X13MM (TQ220) HEAT SINK 1 1.50 1.50
31 BANANA (SOLDER TYPE) PLUG Genius Electronic Co. 71974 01.06.12 4 1.00 4.00
32 BINDING POST (S) TERMINAL 4 2.00 8.00
TOTAL 117.80
𝑪𝑷𝑰 =𝟏𝟏𝟕.𝟖𝟎
𝟒𝟔𝟒
= 𝟎.𝟐𝟓
The overall CPI is low due to incomplete of project, such that the LCD and casing IP56 is not bought.
47
CHAPTER 8
CONCLUSION AND FUTURE WORK
8.1 Conclusion
The final product is completed but it is not working as expected. The lacks of components lead to the
incomplete design of our product. Although our product does not run successfully, we obtain a lot of new
knowledge from this project. Despite of gaining theoretical knowledge, we as well as acquire soft skills
such as co-operation among team members, communications skills and so on. We gain experiences that
will be useful in our future time and we apply the theoretical world to the practical life. The main reason
the work could not complete is the inappropriate time planning for each tasks. The critical path is not
done properly and punctually. Secondly, the incomplete and insufficient of background research has
interrupted our group in detail designing of MPPT system. And lastly the most critical problem in
completing the project is the self-discipline among the group members.
8.2 Future work
The non-renewable energy is running out nowadays, such as fossil fuels are depleting on earth. Therefore,
changing to renewable energy source is a necessity. Solar energy will be the choice and it is easily
acquired. However, most solar panel has low efficiency, so the MPPT system will help maximizing the
power absorbed from the solar panel.
48
REFERENCE
Adedamola O., 2006. Thesis of Analysis, Modeling and Simulation of Optimal Power Tracking of
Multiple-Modules of Paralleled Solar Cell Systems. The Florida State University.
Algazar M. M., AL-monier H., EL-halim H., Salem M. (2012). Maximum Power Point Tracking Using
Fuzzy Logic Control. Electric Power and Engery Systems, 19, 21-28.
Chaitanya T., Saibabu C., and Kumari J.S., 2011. Modeling and Simulation of PV Array and its
Performance Enhancement Using MPPT (P&O) Technique. International Journal of Computer
Science & Communication Networks, Vol.1(1).
Chia S.L., Ahmad M.H., Ossen D.R. (2004). Impact of solar radiation on high-rise built form in tropical
climate. Department Of Architecture, Faculty Of Built Environment, University Of Technology
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APPENDIX
Company Logo
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Schematic Drawing of MPPT
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CCS C compiler
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Proteus
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Flow chart of P&O algorithm
There are several algorithms used to build MPPT system, it varies from cost and efficiency. The one we
are using here is Perturb and Observe Method (P&O) and Incremental Conductance. The reason we using
a combined algorithm is that P&O alone may not be so accurate of determining the Maximum Power
Point. There are some drawbacks in P&O, such as, the rapidly varying of irradiance.
Basically, P&O algorithm states that when the operating voltage of the PV panel is perturbed by a
small increment, the resulting change in power ΔP is positive, then we are going in the direction of MPP
and we keep on perturbing in the same direction. If the ΔP is negative, we are going away from the
direction of MPP and the sign of perturbation supplied has to be changed.
Figure shows the plot of module output power versus module voltage for a solar panel at a given
irradiation. The point marked as MPP is the Maximum Power Point, the theoretical maximum output
obtainable from the PV panel. By considering A and B as two operating points, we can move towards the
MPP by providing a positive perturbation to the voltage. On the other hand, we can move toward MPP
via point B when there is a negative change in power.
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