Design and Implementation of an Isolated Solar Photovoltaic Power Generation System

Design and Implementation of an Isolated Solar Photovoltaic Power Generation System
A Thesis on
Design and Implementation of an Isolated Solar
Photovoltaic Power Generation System
Submitted by
RUPESH PATEL
INDUSTRIAL ELECTRONICS
ROLL NO. – 212EE5399
Department of Electrical Engineering
National Institute of Technology
Rourkela - 769008
June 2014
National Institute of Technology Rourkela
Design and Implementation of an Isolated Solar
Photovoltaic Power Generation System
A Thesis Submitted in Partial Fulfilment
of the Requirements for the Award of the Degree of
Master of Technology
In
Electrical Engineering
(Industrial Electronics)
Submitted by
RUPESH PATEL
ROLL NO. – 212EE5399
Under the guidance of
Dr. MONALISA PATTNAIK
Department of Electrical Engineering
National Institute of Technology
Rourkela - 769008
June 2014
National Institute of Technology Rourkela
Department of Electrical Engineering
National Institute of Technology, Rourkela
Rourkela-769008, Odisha
CERTIFICATE
This is to certify that the project report entitled “Design and
Implementation of an Isolated Solar Photovoltaic Power Generation
System” being submitted by Rupesh Patel (212EE5399), Department of
Electrical Engineering, National Institute of Technology Rourkela, Rourkela on
partial fulfilment of the requirements for the award of the Degree of Master of
Technology in Industrial Electronics specialisation, Department of Electrical
Engineering, National Institute of Technology Rourkela is an authentic work
carried out by him under my supervision and guidance.
To the best of my knowledge, the matters embodied in this Project Report
have not been submitted to any other University or Institute for the Award of any
other Degree or Certificate.
Date
Dr. MONALISA PATTNAIK
Department of Electrical Engineering
National Institute of Technology, Rourkela
National Institute of Technology Rourkela
DEDICATED
TO
MY RESPECTED PARENTS
AND
MY BROTHER MUKESH
National Institute of Technology Rourkela
ACKNOWLEDGEMENTS
With a deep sense of gratitude, I wish to express my sincere thanks to my guide, Dr.
MONALISA
PATTNAIK, Department of Electrical Engineering, National Institute of
Technology, Rourkela for giving me the opportunity to work under her on this project. I truly
appreciate and value her esteemed guidance and encouragement from the beginning of this
project and putting this thesis together. I am extremely grateful to her. Her knowledge and
company at the time of crisis would be remembered lifelong.
I want to thank all my teachers for providing a solid background for my studies and
research thereafter. They have been great sources of inspiration to me and I thank them from the
bottom of my heart.
I will be failing in my duty if I do not mention the laboratory staff and administrative staff
of this department for their timely help.
I also want to thank my parents. I would like to share this moment of happiness with my
parents and brother. They rendered me enormous support during the whole tenure of my stay in
NIT Rourkela.
I would like to thank our department for giving me the opportunity and platform to make
my effort a successful one.
Finally, I would like to thank all whose direct and indirect support helped me to
completing my semester project report in time.
RUPESH PATEL
212EE5399
National Institute of Technology Rourkela
ABSTRACT
Solar photovoltaic power generation system is one of the burning research
fields these days, even governments are also making plans toward increasing the
amount of power generation from renewable energy sources because in future
viability
and
government
crisis
of
liberalisation
conventional
and
energy
technical
sources
developments
will
increase.
encourage
the
Further
use
of
renewable sources for power generation in terms of distributed generation system.
In order to rigging the present energy crisis one renewable method is to develop an
efficient manner in which power extracts from the incoming son light radiation
calling
Solar
implementation
Energy.
This
thesis
deals
of a simple and efficient
with
the
design
and
hardware
solar photovoltaic power generation
system for isolated and small load up to 5 KW. It provides simple basic theoretical
studies of solar cell and its modelling techniques using equivalent electric circuits.
Solar Photovoltaic (PV) power generation system is comprising several elements
like solar panel, DC-DC converter, MPPT circuit, Battery charge controller and
load, these subsystems are designed in Proteus software and DC-DC (Boost)
converter, MPPT circuit using microcontroller and sensors adopting perturbation
and observation method, Battery charge controller and single phase inverter for AC
loads are implemented in hardware in simple manner.
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CONTENTS
Abstract
i
Contents
ii
List of Figures
v
List of Tables
vii
Abbreviated Word
viii
Chapter 1 Introduction
1
1.1
Overview on Need of Solar Power Generation
2
1.2
Motivation
3
1.3
Objective
4
1.4
Thesis Organization
4
Chapter 2 Solar Panel Design in Proteus
2.1 Solar Cell Overview
6
7
2.1.1 Basic Theory of Solar Cell
7
2.1.2 Solar Cell Connections
9
2.1.3 Solar Cell Technologies
10
2.1.4 Solar Cell, Solar Module or Panel and Solar PV Array
10
2.1.4.1 PV Module
11
2.1.4.2 PV Array
11
2.1.5 Solar Cell Modelling
11
2.1.6 I-V Characteristic Curve of a Solar Panel
12
2.1.7 Impact of Solar Irradiation on I-V Characteristic of a Solar Panel
13
2.1.8 Impact of Temperature on I-V Characteristic of a Solar Panel
14
2.2 Modelling of Solar Panel in Proteus
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ii
Chapter 3 Boost Converter for Proposed System
18
3.1 Overview on DC/DC converter
19
3.2 Need of DC/DC converter
20
3.3 Boost Converter
20
3.4 Design of Boost Converter on Proteus
22
3.5 Hardware Implementation of Boost Converter
23
Chapter 4 MPPT Implementation for Proposed System
26
4.1 Introduction to MPPT
27
4.2 MPPT Requirements
28
4.2.1 Sensors
28
4.2.1.1 Voltage Sensor
28
4.2.1.2 Current Sensor
29
4.2.2 Analog to Digital converter
30
4.2.3 Microcontroller
31
4.2.4 MPPT Algorithms to run the microcontroller
31
4.2.5 PWM Output Generator
34
4.2.6 DC/DC Converter
34
4.3 Design of MPPT Circuit on Proteus
35
4.4 MPPT Hardware Implementation
36
4.5 Summary of Chapter
38
Chapter 5 Proposed Battery Charge Controller
5.1 Introduction of Battery Charge Controller
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40
iii
5.2 Proposed Battery Charge controller design on
43
5.3 Hardware implementation of Battery Charge Controller
45
5.4 Difference between Battery charge controller and Solar
Charge Controller
Chapter 6 1Φ Inverter for Proposed system
46
48
6.1 Overview on 1Φ Inverter
49
6.2 Proteus Design of Proposed 1Φ Inverter
50
6.3 Hardware Implementation of 1Φ Inverter
52
Chapter 7 Conclusion and Scope for Further Work
54
7.1 Conclusion
55
7.2 Scope for Further Work
56
References
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iv
LIST OF FIGURES
Figure 2.1 : Solar Cell
7
Figure 2.2 : P-N junction illustration of PV cell
8
Figure 2.3 : Flow of current
8
Figure 2.4 : Series connection of solar cell
9
Figure 2.5 : Parallel connection of solar cell
9
Figure 2.6 : Formation of solar Module and solar PV Array
10
Figure 2.7 : Equivalent circuits of solar cell
11
Figure 2.8 : Equivalent circuits with dual diode of solar cell
12
Figure 2.9 : Standard I-V Characteristic of a Solar Panel
13
Figure 2.10 : Effect of solar irradiation
14
Figure 2.11 : I-V curve for Different Temperatures
15
Figure 2.12 : Solar Panel Design on Proteus
16
Figure 2.13 : Open circuit voltage
17
Figure 2.14 : Short circuit current
17
Figure 3.1 : Boost Converter
20
Figure 3.2 : Equivalent Circuit for Mode 1
21
Figure 3.3 : Equivalent Circuit for Mode 2
22
Figure 3.4 : Boost Design on Proteus
23
Figure 3.5 : Boost circuit Hardware
23
Figure 3.6 : Boost O/P at 42.2 % Duty Cycle
24
Figure 3.7 : Boost O/P at 45.9 % Duty Cycle
24
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Figure 3.8 : Boost O/P at 50.7 % Duty Cycle
24
Figure 3.9 : Boost O/P at 70.7 % Duty Cycle
24
Figure 4.1 : Voltage Sensor
29
Figure 4.2 : ACS712 Current Sensor
30
Figure 4.3 : Pin Diagram
30
Figure 4.4 : Arduino Development Board
31
Figure 4.5 : Power vs. Voltage Curve of Panel
33
Figure 4.6 : P & O Flow Chart
34
Figure 4.7 : MPPT Circuit Design on Proteus
35
Figure 4.8 : Generated PWM Signal From MPPT Circuit
36
Figure 4.9 : MPPT hardware circuit with sensors
37
Figure 4.10 : Panel O/P Voltage and Current with MPPT Circuit
37
Figure 5.1 : To 5.4 Batteries Connection
40-41
Figure 5.5 : Position of the Battery Charge Controller
42
Figure 5.6 : Proteus Design of Battery Charge Controller
44
Figure 5.7 : Battery Charge Controller (charging condition)
45
Figure 5.8 : Connection block diagram of solar charge controller
46
Figure 6.1 : Inverter Position and importance
49
Figure 6.2 : Propose design of Solar Inverter
51
Figure 6.3 : AC Output Voltage wave form of inverter
51
Figure 6.4 : Square Wave Single Phase Inverter
52
Figure 6.5 : Output Voltage Wave form of 1φ Inverter
52
Figure 6.6 : Output Voltage Wave form of 1φ Inverter with RC filter
53
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LIST OF TABLES
Table 2.1 Vikram Solar ELDORA 40-P Data
15
Table 3.1 Boost Elements
23
Table 3.2 Boost Operating points
24
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ABBREVIATED WORDS
Iph
Photon generated current
Id
Current through Diode
P
Power
KW
Killo Watt
mW
milli Watt
η
Efficiency
PV
Photovoltaic
PWM
Pulse Width Modulation
MPPT
Maximum Power Point Tracking
P&O
Perturb and Observe
ADC
Analog to Digital Conversion
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Chapter 1
Introduction
1.1 Overview on Need of Solar Power Generation
1.2 Motivation
1.3 Objective
1.4 Thesis Organization
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1.1 Overview on Need of Solar Power Generation
In the field of power sector in these days one of the major concerns is dayby-day increasing more power demand but the quantity and availability of
conventional energy sources are not enough resources to meet up the current
day’s power demand. While thinking about future availability of conventional
sources of power generation, it is become very important that the renewable
energy sources must be utilized along with source of conventional energy
generation systems to full fill the requirement of the energy demand.
In order to rigging the current day’s energy crisis one renewable method
is the method in which power extracts from the incoming son radiation calling
Solar Energy, which is globally free for everyone.
Solar energy is lavishly available on the earth surface as well as on space
so that we can harvest its energy and convert that energy into our suitability form
of energy and properly utilize it with efficiently. Power generation from solar
energy can be grid connected or it can be an isolated or standalone power
generating system that depends on the utility, location of load area, availability of
power grid nearby it. Thus where the availability of grids connection is very
difficult or costly the solar can be used to supply the power to those areas. The
most important two advantages of solar power are that its fuel cost is absolutely
zero and solar power generation during its operation do not emanate any
greenhouse gases. Another advantage of using solar power for small power
generation is its portability; we can carry that whenever wherever small power
generation is required.
In the last few years the power conversion mechanisms for solar energy
has been significantly comes in compact size. The advance research in the field of
power electronics and material science have greatly helpful for engineers to
develop such a system that very small but effective and powerful systems that
have capability to withstand for supplying the high electric power demand.
For every country day by day power density demand is increasing. Solar
power generation have also the capability to handle the voltage fluctuation very
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effectively by setting the system for the use of multiple input converter units. But
in solar power generation system due to its high installation cost and the low
efficiency of the solar cells, this power generating systems can hardly participate
in the competitive power markets as a main renewable source of power
generation.
Scientists are constantly trying to improve in the field of development of
the solar cells manufacturing technology for increasing efficiency. That will
definitely help to make the solar generation as in habit for use in daily life as
prime renewable source of electrical power on a wider range basis than present
day conditions. In solar power generation system the latest power control
mechanisms is using now these days calling the Maximum Power Point Tracking
frequently referred as MPPT, it has guide to the increase in the efficiency of
operation of power generation from the solar cells. Thus MPPT is most important
in the field of consumption of renewable sources of energy [1].
1.2 Motivation
The key motivation is fascinating the scientists more to research in this
field. Now this field is become burning research fields these days. A key point for
encouraging to the use of solar PV power generation system across the whole
world wide many of the Governments giving centre of attention to their
investments in renewable and clean energy sources for developing their power
sector areas because every country have limited sources of conventional energy.
Even in the India government also aims to achieving generating capability of
20GW from solar energy by year 2020 and 40% of it will generate by solar PV
power generation system according to draft report of JNNSM (Jawaharlal Nehru
National Solar Mission) MNRE, India.
Power generation method from solar photovoltaic module is a foremost
effective technique of using the solar energy. In this method solar panel directly
convert sunlight irradiation into electricity by the photovoltaic effect, and it has
spacious scenario for improvement with a number of advantages like clean and
pollution-free due to solar power generation do not releases any greenhouse gases
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in its operation, easy in structure and free from noise pollution due to it does not
contain any moving parts, no fuel cost required because it uses son light as a
input that is globally free, little maintenance and renewable [1]. Solar power
generation have low conversion efficiency and high installation cost therefore our
target should be increases the efficiency for power generation from the system.
Researchers are continuously searching to develop better and efficient solar cell
materials and give service to minimise the cost for power consumers of solar
systems.
While thinking of designing part of this project we need designing
software like Matlab, Labview, Multisim, PSpice and Proteus etc. Proteus is
especially attracted me because while executing condition of program or circuit
functions, we can switching the circuit or changing the operating mode of
designing and also one lab class on Proteus is taught in first year of M-tech.
These days microcontrollers are coming with its development board kit,
on that board many supporting connection circuit with the microcontroller are
there, one of the advanced development board is Arduino complete development
board kit. It has many advantages and ACS712 current sensor Hall Effect based
[22] have good resolution and available in different ranges of current in lowest
cost which are very efficient and easy for hardware implementation.
1.3 Objective
The mainline objective of this project work is to – “Design and hardware
implementation of an isolated Solar PV power generation system for small load
rating Up to 5 KW”.
And this objective is further divided into following parts for
simplicity of implementation.
 To Design of Solar panel in Proteus software.
 To design and implementation of a DC-DC (Boost) converter
using Proteus software.
 To design of a battery charge controller in Proteus and its
implementation.
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 To design MPPT circuit using microcontroller and sensors in
Proteus and its implementation.
 To develop C code for P&O MPPT algorithm using Keil
software for Proteus software execution.
 To design and hardware implementation of a single phase solar
inverter.
1.4 Thesis Organization
This thesis is organized in chapter wise as follows:
Chapter 1 An overview on why we have to increase power generation
from renewable energy sources. Glance over advantages of solar PV power
generation system. Motivation for this project with mainline objective is divided
into subparts.
Chapter 2 An overview on solar cell, its basic theory, connections,
technologies and modelling. Design of a solar panel in Proteus is described.
Chapter 3 About DC/DC converter especially Boost converter and its
need in solar power generation are described. A design of Boost converter in
Proteus software is shown with its hardware implementation.
Chapter 4 Small introduction on MPPT and its importance in solar PV
power generation is given. What are the MPPT’s requirements described. Its
circuit design on Proteus and hardware implementation is shown.
Chapter 5 About Battery charge controller, its reason for need and its
functions are described. A proposed battery charge controller is designed in
Proteus and its hardware is implemented.
Chapter 6 A proposed single phase non sinusoidal inverter for isolated
system is designed on Proteus and its hardware is implemented.
Chapter 7 Conclusion and scope of further to work is presented.
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Chapter 2
Solar Panel Design in Proteus
2.1
Solar Cell Overview.
2.2
Modeling of Solar Panel in Proteus.
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2.1 Solar Cell Overview
A solar cell is an electronic device that converts the light energy directly
into electric energy without any form of moving parts by using photovoltaic
effect.
 A Solar cell is also calling Photovoltaic (PV) Cell.
 It is a static device, no moving part.
 “Photo” means Light and “voltaic” means producing electricity.
 It is a solid state electronic device made of semiconductor materials like
silicon.
 Solar cell converts energy of light directly into Direct Current (DC).
 Solar cell does not use heat of light to produce electrical energy.
 In 1839 the photovoltaic effect was discovered, in 1883 first thin film solar
cells fabricated and the first practical photovoltaic cell was developed in
1954.
 Efficiency of solar cell depends on many factors like shading on cells,
irradiance, temperature etc.
 In 2014 the highest 44.7% efficiency has achieved by using the multiple
junction cells.
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2.1.1 Basic Theory of Solar Cell
Solar cells are made by two types of semiconductor materials one is Ntype semiconductor and other is P-type semiconductor material for generation of
electricity [2].
 When light strikes on semiconductor, it generates electrons (-) and holes
(+) pairs.
 when electron and hole pair reaches between two different type of
semiconductor's joint surface then electron and hole are separated, electron
is attached by N-type semiconductor and hole is attached by P-type
semiconductor after that they are not rejoin due to joint surface do not
allow both way traffic.
Fig 2.2 P-N junction illustration of PV cell
 Now electrons are contained by N-type semiconductor and holes are
contained by P-type semiconductor, an electro motive force (emf) is
generated in electrodes.
 When these electrodes are connected together by a conductor electrons run
toward O-type semiconductor and holes run toward N-type semiconductor.
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Fig. 2.3 Flow of current
2.1.2 Solar Cell Connections
Solar cell
connection
is
just
like battery connection. When
positive
terminal of one solar cell is connected to negative terminal of another solar cell
then they form series connection. In series connection current is same for all cells
and voltage is added by each cell shown in figure 2.4.
And when all positive terminals of solar cells connected to one terminal
and all negative positive terminals of solar cells connected to another one
terminal then forms parallel connection. As shown in figure 2.5 here current is
added and voltage is same for all cells.
Fig 2.4 Series connection of solar cell
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Fig. 2.5 Parallel connection of solar cell
2.1.3 Solar Cell Technologies
Solar
cell
is
manufacturing
by
different
materials.
The
two
major
technologies are wafer-based silicon and thin-film [3].
Crystalline silicon solar cell is more efficient than thin-film solar cell but
that is more expensive to produce. They are most commonly uses in large to
medium electric applications like grid connected PV power generation.
Mono-crystalline
solar
cell
is
manufactured
by
pure
semi-conducting
materials so it has higher efficiency (above 17% in industrial production and 24%
in research laboratories [4]. Poly-crystalline solar cell is slightly less efficient
than Mono-crystalline but less in cost.
In thin-film solar cell very thin layers of semiconducting materials are
uses so they can be produces in large quantity at lower cost but it efficiency is
less. This technology is uses in calculators, watches and toys etc.
There are too many other PV technologies available like Organic cells,
Hybrid PV cells combination of both mono crystalline and thin film silicon etc.
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2.1.4 Solar Cell, Solar Module or Panel and Solar PV Array
In solar power generation system number of solar cells is required to
produce high power so they are connected in form of Solar Module or Solar panel
and for higher capability form Array as shown in figure 2.6
Fig. 2.6 Formation of solar Module and solar PV Array
2.1.4.1 PV Module
A solar panel or module is a group of connected solar photovoltaic cells
electrically and mounted on a sustaining structure. A photovoltaic module is a
systematical arranged series connection of solar cells.
2.1.4.2 PV Array
A solar array is a group of solar photovoltaic panels or modules connected
electrically together and mounted on a sustainable structure to produce higher
amount of power. For this project the main task is to design a stand-alone power
generation system for a small load like a house situated on hilly area or for any
small load that is not connected to grid network. For this kind of loads design
such a system that uses the power generated from PV Array and convert it into
AC for AC loads or stores it in storage element with efficiently and paralleling
supplies the load. In this project Vikram solar panel is used so not need to bother
about solar PV Array implementation.
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2.1.5 Solar Cell Modeling
From the physical heavier and mechanism of a solar cell an equivalent
electrical circuit is derived [5], worldwide two different circuit are accepted as
equivalent electrical circuit of solar cell [6, 7], the first one is a simplified model
of a single solar cell that exhibits an approximate characteristic of a solar cell and
second one having two diodes combination one for reflecting diffusion and other
for carrier. The equivalent circuits are shown in figure 2.7 and 2.8 below.
Fig. 2.7 Equivalent circuits of solar cell
Fig. 2.8 Equivalent circuits with dual diode of solar cell
Applying node equation in figure 2.7(a), where
, diodes,
and
are meeting together.
(2.1)
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(2.2)
(2.3)
When both diodes are combined together then equation is become
(2.4)
Where A is ideality factor and takes the value between 1one and 2. [5, 6, 7]
2.1.6 I-V Characteristic Curve of a Solar Panel
A PV module produces maximum current when it’s positive and
negative terminal is shorted, this maximum current is named as
short circuit
current of PV panel. When panel is short circuited, it’s voltage across terminal is
zero.
Fig. 2.9 Standard I-V Characteristic of a Solar Panel
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When panel terminal is kept open circuited then the voltage across its
terminal is maximum called open circuit voltage
of that panel. This time
panel fells infinite resistance since the current is zero this time. Between these
two extremes point under different load resistance condition different pair of
points of current and voltage are achieved, by connecting points a curve is find
called I-V curve. This curve is called I-V characteristics of that particular panel.
Figure 2.9 showing the I-V curve with the output power curve.
As showing in figure 2.9
is occurred when current is zero and
is
occurred when voltage is zero on that curve and power of that panel at any point
in Watt is calculated by multiplying both the current and voltage of that point.
2.1.7 Impact of Solar Irradiation on I-V Characteristic of a
Solar Panel
Highest solar irradiance on the earth ground level is 1000 W/
. If the
solar irradiance is decreases due to cloud, the earth movement or any other reason
will reduce the output current of the solar panel because of the
proportional to the sun irradiance while the variation on voltage
is directly
is much smaller
as shown in Figure 2.10 [8].
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2.1.8 Impact of Temperature on I-V Characteristic of a Solar
Panel
Temperature affects the saturation current of solar cell and small affect on
so
has negative (-) temperature coefficient (for silicon –2.3mV/°C),
figure 2.11showing the I-V curve for different temperature variation.
Fig. 2.11 I-V curve for Different Temperatures
2.2 Modeling of Solar Panel in Proteus
In this project “Vikram Solar ELDORA 40-P” solar panel is used as a DC
source. From the help of its datasheet its characteristic is achieved by designing
on Proteus software as shown in figure 2.12 some data of that panel from its
datasheet is given in table 2.1
Pmax
37W
No. of Solar Cells
36
Vmax (V)
18.1V
Impp (A)
2.1A
Open Circuit Voltage
21.77V
Short Circuit Current
2.26A
Table 2.1 Vikram Solar ELDORA 40-P Data
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Fig. 2.12 Solar Panel Design on Proteus
In figure 2.12 36 solar cells are connected in series to achieve the ELDORA 40-P
panel characteristic. Proteus design solar panel open circuit voltage (21.667V) and short
circuit current (2.26A) values are shown in figure 12.13 and 12.14.
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Fig. 12.13 Open circuit voltage
Fig. 12.14 Short circuit current
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Chapter 3
Boost Converter for Proposed System
3.1 Overview on DC/DC converter
3.2 Need of DC/DC converter
3.3 Boost Converter
3.4 Design of Boost Converter on Proteus
3.5 Hardware Implementation of Boost Converter.
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3.1 Overview on DC/DC converter
The basic DC/DC converter comprises a switch, a filter circuit and load.
The DC/DC converter may classify by various methods, one of the basic methods
is isolation, according to that it is classified into two types.
1) Isolated DC/DC converter.
2) Non-Isolated DC/DC converter.
In isolated DC/DC converter type the output and input are electrically
isolated by the use of a transformer. It is bulky, requires more space and costly
while comparing with the non-isolated type DC/DC converter.
The
non-isolated
DC/DC
converters
can
be
further
differentiated
by
element connections like Buck converter, Boost converter, Buck-Boost converter,
Cuk converter and Sepic converter.
DC/DC
converter
is
widely
used
for
the
purpose
of
converting
unregulated DC input into a regulated DC output [8]. A DC-DC converter is a
hart of MPPT hardware implementation. MPPT uses the one of the above
converter for regulating the solar input voltage to the MPP and providing
impedance matching for the maximum power transfer to the load.
Buck and Boost converter are the basic and simple, easy circuit and less
components requires. In this project Boost converter is selected due to [10] –
 It is a step up DC/DC converter, it boosting the input voltage and gives
that voltage to the output.
 Boost converter operates by temporarily storing the input energy and
then releasing that energy to the output at a higher level of voltage.
 In case if switching device is fail then load is still connected to the
source.
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3.2 Need of DC/DC converter
A dc/dc converter is an integral part of any MPPT circuit system. Without
dc/dc converter no any MPPT circuit can be designed.
When a direct connection is carried out between the source and the load,
the output of the PV module is irregularly shifted away from the maximum power
point.
It is necessary to overcome this problem by adding an adaptation circuit
between the source and the load. [11]. A MPPT controller circuit with a DC-DC
converter circuit is used as an adaptive circuit.
For maximum power transfer from source to load an extra circuit is
required to support the load to match the impedance with source impedance.
3.3 Boost Converter
In a boost converter or regulator output voltage of the converter is greater
than input voltage of the converter circuit that means it boosting the input voltage
that’s way its name is “BOOST” regulator.
The boost circuit consist a energy storing element inductor, a capacitor, a
diode, a load and a switching device like Mosfet BJT etc. Circuit diagram of
boost converter is shown in figure 3.1 below.
Fig. 3.1 Boost Converter
The control strategy is based on manipulation the duty cycle of the Mosfet
causes the voltage change in Boost converter.
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Boost Converter Operating Modes
Boost converter have two operating modes based on "ON" and "OFF"
condition of switching device (Mosfet) [9]
Mode 1 when mosfet is "ON"
Mode 2 when mosfet is "OFF"
Mode 1
This mode is also known as charging mode. In this mode when mosfet is
on inductor is energized and start storing the energy from source during on time
(
) of mosfet. This time period diode restricts the current flow through it from
the source to the load and capacitor is discharging by the load R.
Fig. 3.2 Equivalent Circuit for Mode 1
Assuming the inductor current is linearly rises between
to
then
(3.1)
(3.2)
Mode 2
This mode is known as discharging mode. In this mode mosfet is “OFF”
and diode is forward bias due to nature of inductor opposing its causing in this
mode inductor support source voltage. So the circuit become
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Fig. 3.3 mode 2 equivalent circuit
–
(3.3)
–
(3.4)
(3.5)
From equation 3.5 and 3.2
(3.6)
(3.7)
From equation 3.6 and 3.7
(3.8)
Where, D =
3.4 Design of Boost Converter on Proteus
Proteus design of Boost converter is shown in figure 3.4 and also
corresponding component values are also showing.
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Fig. 3.4 Boost Design on Proteus.
3.5 Hardware Implementation of Boost Converter
According to Boost design on Proteus, Boost converter is implemented by
taking corresponding values of its elements. Figure 3.5 shows the photo of
hardware of boost converter.
Fig. 3.5 Boost circuit
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Table 3.1 contents of the Boost converter circuit inductor and capacitor
with a load elements values.
L
2.5 mH
C
470 µF
RLoad
150 Ω
Table 3.1 Boost Elements
The different
output
voltages
at
different
duty cycle
of that
Boost
converter hardware circuit are shown below
Fig 3.6 Boost O/P at 42.2 % Duty Cycle
Fig 3.7 Boost O/P at 45.9 %
Duty Cycle
Fig 3.8 Boost O/P at 50.7 % Duty Cycle
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Fig 3.9 Boost O/P at 70.7 % Duty Cycle
Page 24
In figure 3.6 to 3.9 all boost converter results are summarise in a table
form shown in table 3.2
Figure No.
Vi (Volt)
D (%)
Vo (Volt)
Fig. 3.3
15.6
42.2
24
Fig. 3.4
15.6
45.9
25
Fig. 3.5
15.6
50.7
30
Fig. 3.6
15.6
7.7
36
Table 3.2 Boost Converter Operating points
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Chapter 4
MPPT Implementation for Proposed System
4.1
Introduction to MPPT
4.2
MPPT Requirements
4.3
Design of MPPT Circuit on Proteus
4.4
MPPT Hardware Implementation
4.5
Summary of Chapter
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4.1 Introduction to MPPT
The efficiency of a solar cell is very low and also when solar cells are
connected together to form a panel then its efficiency is still not increased [8]. In
order to increase the efficiency (𝜂) of solar cell or solar panel we have to use
maximum power transfer theorem. The maximum power transfer theorem says
that the maximum power is transfer when the output resistance of source matches
with the load resistance [12] i.e. solar cell or solar panel impedance. So all MPPT
technique’s principles are based on maximum power transfer theorem that always
trying to matching the impedance of load to source.
The effectiveness of MPPT is given by following equation. [17]
t
𝜂𝑀𝑃𝑃𝑇 =
∫0 Pmeasured (t)dt
𝑡
∫0 𝑃𝑎𝑐𝑡𝑢𝑎𝑙 (𝑡)𝑑𝑡
(4.1)
The maximum power point tracking (MPPT) is now habitual in gridconnected PV power generation system and it is becoming more popular in
isolated or stand-alone power generation systems as well because of the V-I
characteristics in PV power generation systems is nonlinear, So it is difficult to
supply a constant power to a certain load.
There is confusion with MPPT that many people think that it is a
mechanical device that tracking the sun, it rotates the solar panel or solar cells as
well as tilts it in the direction of sun where the solar irradiance is more.
But the MPPT is an electronic device that extracts maximum possible
power from solar panel. It varies the electrical operating point of the panel by
changing the DC/DC converter duty cycle to matching the load impedance with
PV cells impedance. Mechanical tracking system can be used with MPPT, but
these two systems are completely different from each other.
To understand how the MPPT works, let’s first consider a solar panel. A
solar panel generates power by using the photovoltaic effect then obvious a solar
panel has a P-V characteristic that means for a different operating point of the
solar panel, a different power output can be achieved. Therefore the maximum
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possible power is obtain from the solar panel when it operates at only for one
specific operating point of the P-V characteristic of solar panel. This point in the
P-V characteristic is called the Maximum Power Point (MPP). This MPP changes
when the solar irradiation changes or temperature changes or when the solar
panel is partially shaded [13]. So when these three factor changes, the solar panel
operating point is also changes. To track that constantly changing MPP a device
is needed called Maximum Power Point Tracker (MPPT).
4.2 MPPT Requirements
For implementation of MPPT the following things are required [14, 18].
 Sensors.
 Analog to Digital converter.
 Microcontroller.
 A MPPT algorithm to run the microcontroller.
 PWM output generator.
 A DC-DC Converter.
4.2.1 Sensors
For MPPT many types of sensors are required like current sensor, voltage
sensor, temperature sensor, pyranometer etc. But for this project as already
information is shared in chapter 1 that only two sensors is required i.e. current
sensor and voltage sensor for P and O algorithm implementation.
4.2.1.1 Voltage Sensor
In this project for P and O MPPT implementation solar panel terminal
voltage is required to measure.
We can use Hall Effect base voltage sensor but
for coast effective implementation a very simple voltage sensor based on very
simple concept voltage division theorem is used.
For this kind of voltage sensor two series connected resistors ( 𝑅1 𝑎𝑛𝑑 𝑅2 )
should connect across solar panel terminal and a wire is coming out from
midpoint of these two resistor, that wire is given to the ADC for microcontroller
reading.
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One thing is important 𝑅1 should be greater than 𝑅2
that proportionally
decrease the panel voltage and make it allowable to read by microcontroller.
Suppose solar panel rated voltage is 25 Volt and microcontroller have maximum
allowable voltage is 5 Volt then for 25 Volt voltage sensor have proportionally
down the voltage to 5 Volt by choosing the value of 𝑅2 = 250Ω and 𝑅1 = 1000Ω
that is 𝑅2 = 25 % of 𝑅1 . This combination consumed very less energy (i.e. in few
mW).
4.2.1.2 Current Sensor
For P and O MPPT implementation we need to measure the solar panel output
current for that in this project a Hall Effect based ACS712 current sensor (made
by Allegro Micro Systems) is used.
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Fig. 4.2 ACS712 Current Sensor
Fig. 4.3 Pin Diagram
Features of ACS712 current sensor

It is a fully integrated Hall Effect based linear current sensor.

AC and DC both current sensing capability.

Very cheap and compact size.

5 V supply Voltage.

Sensitivity is 66 to 185 mV/A.

Bandwidth is 50 kHz.
4.2.2 Analog to Digital converter
The Analog to Digital Converter has a task is to measure the input signals
that is in between minimum 0 to maximum 5 V range that represent the solar
panel terminal output current and voltage. Analog to Digital Converter convert
that input signal into binary numbers and send that digital numbers to the
microcontroller. these measurement and conversion perform by ADC should be
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accurate as possible as for that it is better to use a development board kit in which
ADC circuit is already built or use complete development board kit on that both
ADC and microcontroller interface circuit and other important circuit is built
already. One another thing is that two ADC is required to measure two different
quantities i.e. solar panel voltage and current.
4.2.3 Microcontroller
Microcontroller is the main brain of the MPPT that decide the duty cycle
of DC/DC converter
on the basis of measuring digital input of panel terminal
voltage and current. For doing that job we need microcontroller have some
features that it should have more than 1MHz clock frequency, available in DIP
packages, 8 ADCs with 8 bits register length and PWM signal generation is
possible with resolution of 16 bits.
For best of use in this project Arduino complete development board kit is
used [15], it has on chip ADC and PWM generator.
Fig. 4.4 Arduino Development Board
4.2.4 A MPPT algorithm to run the microcontroller
In PV power generation system MPPT performs a very important role that
it extracts maximum possible power from panel by varying the duty cycle of
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DC/DC converter and that duty cycle is controlled by different MPPT techniques
and its algorithms. Some are listed below.
 Open Circuit Voltage.
 Short Circuit Current.
 Constant Voltage.
 Perturb and Observe.
 Incremental Conductance
 Temperature Method.
 Intelligence MPPT Techniques.
1. Fuzzy Logic Based.
2. Artificial Neural Network Based.
These techniques are categorists by its features [16] like Simplicity, Types
of control strategies, Number of Control Variables, Types of Circuitry (digital or
analogical
implementation),
convergence
speed,
Number
of
sensors
required,
Cost effective etc.
In this project very famous Perturb and Observe is chosen by considering
the above features of MPPT techniques specially simplicity, number of sensors
required and cost effective.
Perturb and Observe
The Perturb and Observe (P&O) technique is also known as “Hill
Climbing” method. It is most popular and commonly used [17]. The faction of
basic form of P and O algorithm is as follows. In figure 4.5 a PV panel's output
power curve as a function of voltage (P-V characteristics) is shown in figure 4.5.
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Fig. 4.5 Power vs. Voltage Curve of Panel [Ref Datasheet BP SX 150 S PV module
(1KW/𝑚2 , 25𝑜 𝐶) ]
At a constant irradiance and constant temperature on PV panel assuming
the PV panel is operating at a point which is away from the maximum power
point. In this algorithm first PV panel terminal voltage and current are measured
and corresponding power P(k-1) is calculated after that small increment on
operating voltage or in duty cycle of the dc/dc converter in one direction is
perturbed and hence the corresponding power P(k) is calculated. By comparing
P(k-1) and P(k), ∆P is calculated. If ∆P is positive then the perturbation is
directed in the correct direction and it is moving the operating point nearer to the
MPP. Then further voltage perturbations or i.e. duty cycle perturbations in the
same direction will move the operating point toward the MPP; if ∆P is negative
then perturbation direction should be reversed. In this way the maximum power
point is recognized [18, 19, 20]. The flow chart of P and O is shown in figure 4.6.
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Fig. 4.6 P & O Flow Chart [18, 19]
4.2.5 PWM output generator
We need 16 bits resolution PWM signal output to switching the mosfet of
DC/DC converter. In Arduino development board microcontroller have on-chip
PWM
signal
generator.
So
no
need
to
take
more
care
about
that
for
implementation just we have to write a program for that.
4.2.6 A Dc-Dc Converter
The DC/DC converter is widely used in MPPT circuit for the main
purpose of matching the load impedance with the panel impedance by changing
its operating duty cycle. A DC-DC converter converting a regulated DC output
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voltage from an unregulated DC input voltage [9]. A DC-DC converter is a hart
of MPPT hardware implementation.
MPPT technology uses that DC-DC converter for regulating the solar
input voltage and reach to the peak voltage i.e. MPP and provides impedance
matching from source to load for the maximum power transfer to the load. DCDC converter is already discussed in chapter 3.
4.3 Design of MPPT Circuit on Proteus
In this project Proteus Software is chosen for implementation. Figure 4.7
showing the snapshot of MPPT circuit design on Proteus.
In figure 4.7 solar panel terminal is connected to the Boost converter.
Solar panel terminal voltage and current is sensing by sensors, in figure looking
like op-amp circuit is a current sensor representing ACS712.
Fig. 4.7 MPPT Circuit Design on Proteus
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Two ADC converters are showing interfaced with microcontroller and
microcontroller
generates
PWM
signal
to
switching
the
mosfet
of
Boost
converter. Generated PWM signal by microcontroller is shown in oscilloscope is
shown in figure 4.8
4.4 MPPT Hardware Implementation
Photo of MPPT hardware circuit is shown in figure 4.9, in which two
ADC’s, microcontroller and their interfacing connections and PWM generator
circuit is completely replaced by Arduino Development Board Kit and its output
signal i.e. PWM signal is directly given to the gate terminal of mosfet of Boost
converter circuit.
In figure 4.10 panel output voltage and current is showing after MPPT
circuit is connected that means ACS712 current sensor, Arduino development
board kit, and voltage sensor. After that entire MPPT algorithm runs and panel
output voltage is settled to 15.6 Volt which is Vmpp of the panel, so it matches
the impedance from source to load and transfer maximum power.
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Fig. 4.9 MPPT hardware circuit with sensors
Fig. 4.10 Panel O/P Voltage and Current after Connecting MPPT Circuit
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4.5 Summary of Chapter
This chapter describes the necessity of maximum power point tracking
and working of Perturb and Observe method. Proposed design of MPPT
circuit
on
Proteus
using
Perturb
and
Observe
technique
has
been
described. MPPT hardware circuit is implemented with the help of
ACS712
current
sensor
and
Arduino
complete
microcontroller
development board kit, which contains Atmega2560 microcontroller that
generates PWM signal for switching the MOSFET of DC/DC converter.
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Chapter 5
Proposed Battery Charge Controller
5.1
Introduction of Battery Charge Controller
5.2
Proposed Battery Charge controller design on
Proteus using 555 Timer IC
5.3
Hardware
implementation
of
Battery
Charge
Controller
5.4
Difference
between
Battery charge
controller
and Solar Charge Controller.
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5.1 Introduction of Battery Charge Controller
In stand-alone photovoltaic power generation system, to store the
energy produced by the solar PV Array
a
electrical
electrical storage battery is required due
to demand of energy does not always coincide with its generation.
To increase the storage capability of battery more than one battery are can be
used and these batteries can be connected in any combination of series connection or
parallel connection or combination of both series and parallel connections as shown
in figures below.
Fig. 5.1 Series Connection
Fig. 5.2 Parallel Connection
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Fig. 5.3 Parallel-Series Connection
Fig. 5.4 Series- Parallel Connection
In figure 5.1 two 12 Volt batteries are connected in series and built together a
single source of 24 Volt storage element.
In figure 5.2 two batteries (each 12 Volt) are connected in parallel and
formed together a single source of 12 Volt storage elements.
Here voltage rating is
still 12 Volt but current rating of that storage element is increased. In figure 5.3 first
two batteries (each 12 Volt) are connected in parallel and then connect in series with
another set of two batteries (each 12 Volt) which are individually connected in
parallel and formed a single 24 Volt storage element with increasing current ratting.
In figure 5.4 first two sets of batteries (each 12 Volt) are connected first in
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series and after that connect in parallel combination with another same set of two
batteries (each 12 Volt) which are individually connected in series and formed a
single 24 Volt storage element with increasing current ratting.
When multiple batteries are used as a one storage element then it is called Battery
Bank. Normally the battery storage capability is defined by its voltage rating and Ah
(Ampere-Hour) rating. Battery backup time is finding out by following equation.
(5.1)
A storage battery has following primary functions in a PV power generation
system.
 To store electrical energy when it is produced by the PV array and to supply
energy to electrical loads as needed or on demand.
 To supply power to electrical loads at stable voltages and currents, by
suppressing or
smoothing out
transients
that
may occur
in
PV
power
generation system.
 To supply surge or high peak operating currents to electrical loads.
Fig. 5.5 Position of the Battery Charge Controller
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A battery has above characteristics and it performing very important role in solar
photovoltaic power generation system so it is duty and need to protect the battery.
For that we need a Battery Charge Controller.
The first question come in mind is that what is Battery Charge Controller?
“A battery charge controller is a regulator that regulates the amount of charge
coming from the panel that flows into the battery bank in order to avoid the batteries
overcharging and over discharging by the load”.
The position of the battery charge controller is shown in figure 5.5, which is
connecting between DC/DC converter and battery bank. The reason for why need of
battery charge controller is very clear by its basic functions.
The Battery charge controller has mainly three basic functions:1. To limit the voltage from the solar panel and regulate the voltage so as not to
overcharge the battery.
2. Not to allow the battery to get into deep discharge mode while DC loads are
used.
3. To allow different DC loads to be used and supply appropriate voltage.
5.2 Proposed Battery Charge controller design on Proteus using
555 Timer IC
It is a very new and different technique to control the charging of battery.
This technique can be used any where there battery charge controlling is required
[21]. The Proteus software is used to implement the battery charge controller shown
in fig-5.6 with its connection circuits using 555 Timer IC. Its working is explaining
with its hardware implementation.
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Fig. 5.6 Proteus Design of Battery Charge Controller
Tuning of the Circuit
Tuning of the circuit is required to set the batteries overcharging and over
discharging, for that we have to assume 12V Battery bank is using for its charge
controlling.
Let first decide battery overcharging point that is battery maximum allowable
voltage up to that we can charge it, let considered 14.9 volt for 12 volt battery as
according to the datasheets of many 12 Volt batteries. And discharging point that we
can decide up to what voltage level battery should discharge and after that it should
again start charging for that let assume 11.9 volt here, which is just for keeping the
battery charge near to the 12 Volt.
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For Discharging point: Attach a variable DC power supply to the battery terminals and set the power
supply to 11.9V.
 Measure the voltage at Test Point 1. With adjusting R1 until the voltage at the
test point 1 is as close to 1.667V (14% of 11.9V.) [21]
For Overcharging point: Set your variable DC power supply to 14.9V.
 Measure the voltage at Test Point 2. With adjust R2 until the voltage at the
test point is as close to 3.333V (23% of 14.9V) [21].
5.3 Hardware implementation of Battery Charge Controller
Fig. 5.7 Battery Charge Controller (charging condition)
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Proteus design of Battery Charge Controller is implemented on PCB as shown in
figure 5.7 connecting between boost converter and battery.
In figure 5.7 looking like a small black box, is a 12V normally closed (NC) relay
which the main switch that allows the solar power flow into the battery or into the
dummy load. Relay is NC type so normally it makes contact between solar output
and battery terminals and when relay operates it supply the power to the dummy load
and not allow any power flow to the battery bank. In the operation when green led is
ON showing battery is charging and when red led will on that means relay will have
been operated to switch the supply from battery to dummy load.
555 Timer IC sense the battery voltage, when battery voltage is matched with the
charging and discharging voltage value timer IC produce signal corresponding to its
pre-set voltage value and relay will operate according to that and switching the
circuit. The two variable resistors connected to the 555 timer IC by varying them we
can adjust the voltage level point for battery on that point relay is operative if other
voltage rating battery is uses.
5.4 Difference between Battery charge controller and Solar
Charge Controller
The connection blog diagram of Solar Charge Controller is shown in figure
5.8. The major difference between Solar Charge Controller and Battery
charge controller and are easily understand by comparing both-
In battery charge controller: –
 When battery is fully charge, battery is totally disconnected from converter.
 We can start charging of the battery any time between two fixed point voltage
ranges. (i.e. 11.9v to 14.9v) by switch 1 (connect b/t pin2 & GND).
 We can stop the charging at any time below the lower voltage point of the
battery. (i.e. 11.9v) by switch 2 (connect b/t pin6 & supply).
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Fig. 5.8 connection block diagram of solar charge controller
In solar charge controller: –
 We can’t disconnect the battery from converter because MPPT circuit is
working according to battery voltage. If battery is full charged and we want to
supply any dummy load then we can’t because MPPT will not switch the
converter due to battery is full charge
 We can’t control the charging and discharging action of the battery.
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Chapter 6
1Φ Inverter for Proposed system
6.1 Overview on 1Φ Inverter
6.2 Proteus Design of Proposed 1Φ Inverter
6.3 Hardware Implementation of 1Φ Inverter
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6.1 Overview on 1Φ Inverter
In any solar power generation system one of most important section is
converting generated DC power to AC power for running or operating or working
of the AC loads. A device called Inverter that convert DC power to AC power.
In this earth more than 90% electric equipment are driven by AC, we
called it as AC loads that is proved by just watching surround us every electrical
equipment are working by consuming AC power. So for using them we must
required AC power even for small to very small load, AC power is required either
it is grid connected system or isolated system. If we want in isolated system many
loads should be DC load for that we have to specially order to the manufacturing
company that will increase our expenditure then it is better to purchase AC
electric equipment from market that will reduce much more our cost for electric
appliances. So when loads are AC then AC power must required and for that we
have to convert solar DC power to AC power that’s way an inverter is an
important part of solar power generation. It doesn’t depend on what kind of
system it is. By seeing figure 6.1 it will very clear and position of inverter in the
system will also be clear.
Fig. 6.1 Inverter Position and importance
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Types of Inverter:According to the usability the inverter can divide into two categories1) Isolate or stand alone inverter - in this type inverter takes only DC
power from source like battery or solar pane and convert that power into
AC power and supply the AC load.
2) Grid connect inverter – in this type inverter sometimes take energy from
DC power supply and convert it into AC power and supply to the grid and
sometimes it takes energy from grid and charge the battery when DC
source (solar power ) is not available.
In this project a very simple compact in size single phase solar inverter is
designed and implemented. A very simple and compact size is designed due to
this project is mainly focus on design and implement cost effective solar power
generation system to make it easy in behavior to use renewable energy sources.
This design is much lookalike solar micro inverter.
6.2 Proteus Design of Proposed 1Φ Inverter
Figure 6.2 showing the Proteus design of simple solar inverter using 555
Timer IC for generating square wave with time period of 0.02 second that is 50Hz
in frequency to switching the mosfet IRFZ44N [22]. In that circuit two N-channel
mosfet is used for sequentially switching to provide the path for DC current flows
through the transformer. Transformer rating is 230/ 2x12 V; the secondary of the
transformer is two winding 12 volts each. Transformer is must chose according to
load ratings.
555 Timer IC is connected in Astable mode for continuously generating
square wave of frequency 50Hz. The generating frequency can be adjusted by
resistor R2 and capacitor C2. The output of the 555 Timer IC is directly given to
the any one mosfet and other mosfet is given by
phase shift that is logical
inverted with the help of BC549 transistor as shown in figure 6.2.
As the transformer secondary have two winding, middle terminal is
supplied by 12 volt battery that may in the range of 11 volt to 14 volt and other
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two end terminals are connected to the mosfet. This mosfet IRFZ44 can be used
up to 200W loads. The transformer primary AC voltage output wave form across
the 100 ohm load is shown in figure 6.3.
Fig. 6.2 Propose design of Solar Inverter
Fig. 6.3 AC Output Voltage wave form of inverter
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This inverter has non stabilized square wave output voltage of frequency
50 Hz.
That can supply small electrical appliances like fluorescent lamps, radios,
electric shavers, and cell phone charger. The maximum load depends on the
transformer ratings, transistors, and the size of its heat sink [21].
6.3 Hardware Implementation of 1Φ Inverter
Its hardware implementation is down and checked in brad board after that
implemented on PCB by connecting elements as shown in its circuit diagram as
designed in Proteus Software. The hardware implementation diagram is shown in
figure 6.4
Fig. 6.4 Square Wave Single Phase Inverter
One 12 volt battery is supplied to the circuit as well as transformer middle
terminal. The other two end terminal is connected to the two mosfet’s drain
terminal individually and their source terminals are connected to ground or
battery negative terminal. Any one mosfet can be directly connected to the 555
Timer IC output pin number 3 and other one should be connected through BJT as
in here BC548 is used.
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In this type inverter circuit 555 Timer IC is used as Astable multi-vibrator mode
to generate switching signal for mosfet. Here two variable resistors are used in
555Timer IC Astable mode circuit connection for generating desired frequency
signal by varying them and choosing the accurate value of capacitor.
Fig. 6.5 Output Voltage Wave form of 1φ Inverter
Figure 6.5 showing the voltage wave form output across 150 ohm load of ½ Watt.
This wave form is square due to 555 timers IC switching continuously both
mosfet alternatively to provide the path for grounding for 12 volt DC from
transformer terminals. Due to that another side of transformer voltage direction is
continuously changing and making square wave as shown in the figure 6.5, the
transformer should be step up so that voltage will be high at another side.
That square wave can be make sine wave by using RC filter. But the frequency
may change that we have to take care and design the filter according to that so the
net output wave form of the filter should have50 Hz. By using the RC filter that
square wave form is changed into sine wave as shown in figure 6.6.
Fig. 6.6 Output Voltage Wave form of 1φ Inverter with RC filter
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Chapter 7
Conclusion and Scope for Further Work
7.1 Conclusion
7.2 Scope for Further Work
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7.1 Conclusion
In this project a simple low cost but effective solar PV power generation
system for small and not grid connected load up to 5 KW prototype model is
designed in Proteus software and implemented except solar panel that is not
implemented only achieved its characteristics by designing in Proteus of Vikram
solar Eldora 37W series.
While the designing of MPPT portion especially code writing for its
algorithms
execution
is
very difficult.
MPPT
algorithms
are
straightforward
simple enough, but implementing an operative MPPT controller isn't a simple
task. Many papers written on this subject they merely use the computer
simulations output rather than real hardware outputs, the readers ascertain that
actually lacking of significant data and information. Hall Effect base current
sensors are very efficient, simple in connections and easy in use but it is little bit
expensive in the India only. For MPPT circuit implementations always have to
use complete development board kit for microcontroller otherwise its circuitry
will complex and less efficient.
In all DC-DC converters boost have additional advantage that if suppose
MPPT circuit is fail then mosfet will not switching in that condition also load is
directly connected to the panel and panel still supply the load at less efficiency
other DC-DC converter can’t do that.
In the market various type of battery charge controller is available but in
this thesis proposed battery charge controller has a relay that automatically switch
the power from battery supply to other load when the battery is full charge.
Proteus
software
is
better
choice
than
Matlab
for
electrical
circuit
designing because these days many hybrid component are available in market,
Proteus provide that components with their technical names as well as by its
technical codes like 555 Timer IC and other integrated chips that are not available
in Matlab library and Proteus also provide the facility that we can operate the
switches or sliding device on executing time so that we can see and analyze the
National Institute of Technology Rourkela
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changing waveforms but in Matlab once we run we can’t change anything until
its execution completion.
7.2 Scope for Further Work
Further work in this area may use different MPPT method and modified
algorithms for increasing efficiency in fast changing environmental conditions.
Try to design such model for solar PV system which should compact size and
cheaper and also its maintaining and operating cost should be less so that people
attract to use in behavior and don’t go for conventional sources even for isolated
systems.
Inverter
should
be
design
by
using
SMPS
circuits
if
further
implementation will happen from this project. Over all physical implementation
of the system will remains for the future research
National Institute of Technology Rourkela
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REFERENCES
[1] Zhao Chaohui. “Emerging Technology: Photo-Voltage Generation Status and
Trends”. Journal of Shanghai Dianji University, 2008, 11(1): 104-109.
[2] Peter Wurfel "Basic principles of solar cells and the possible impact of nanostructures" IEEE Cat. No. 03CH37497 3rd World Conference on Phofovoltaic
Energy Conversion May 11-18, 2003 Osab. Japan, Page 2672 - 2675 Vol.
[3] Matt
Boreland
Foresight
-
and
Darren
Horizon
Bagnall,
“Current
Scanning
and
Report,
future
photovoltaics”,
5th
July
2006.
http://eprints.soton.ac.uk/id/eprint/264403
[4] Tim Bruton, et al, “Towards 20% Efficient Silicon Solar Cells Manufactured
at 60 MWp Per Annum”, Proceedings of the 3rd World Conference on
Photovoltaic Energy Conversion, 2003, Vol.1, pt. 1, pp. 899-902
[5] W. Xiao, W. G. Dunford, and A. Capel, “A novel modeling method for
photovoltaic cells”, in Proc. IEEE 35th Annu. Power Electron. Spec. Conf.
(PESC), 2004, vol. 3, pp. 1950–1956.
[6] P G Nikhil and D Subhakar "An Improved Simulation Model for Photovoltaic
Cell" IEEE 978-1-4244-8165-1/11 2011
[7] J. A. Gow, C. D. Manning “Development of a photovoltaic array model for
use in power electronics simulation studies”, IEE Proceedings on Electric
Power Applications, vol. 146, no. 2, pp. 193-200, March 1999.Datasheet
Vikram Solar ELDORA 40-P
[8] Muhammad H. Rashid "Power Electronics: Circuits, Devices & Applications"
Text Book.
[9] A. Roman, R. Alonso, P. Ibanez, S. Elorduizapatarietxe and D. Goitia,
“Intelligent PV module for grid-connected PV systems,” IEEE Trans. on Ind.
Electron., Vol. 53, No. 4, Aug. 2006.
[10] W. Xiao, N. Ozog and W. G. Dunford, “Topology Study of Photovoltaic
Interface
for
Maximum
Power
Point
Tracking,”
IEEE
Transactions
on
Industrial Electronics, vol. 54, no. 3, June 2007.
National Institute of Technology Rourkela
Page 57
[11] L. Zhang, W. G. Hurley and W. Wolfle, “A New Approach to Achieve
Maximum Power Point Tracking for PV System with a Variable Inductor,”
2nd IEEE International Symposium on Power Electronics for Distributed
Generation Systems, pp. 948-952, 2010.
[12] V. Agarwal H. Patel. Maximum power point tracking scheme for pv systems
operating
under
partially
shaded
conditions.
IEEE
Trans.
Ind.
Electron.,
Algorithm
and
Software
55:1689{1698, 2008.
[13] Thesis
"Maximum
Power
Point
Tracking:
Development" Delft University of Technology Faculty of EEMCS June 27,
2012
[14] Datasheet Arduino Development Board Kit “ http://www.arduino.cc/ ”
[15] Bidyadhar
Comparative
Subudhi,
Study
Senior
on
Member,
Maximum
IEEE,
Power
and
Point
Raseswari
Tracking
Pradhan
"A
Techniques
for
Photovoltaic Power Systems" IEEE Trans. On Sustainable Energy, VOL. 4,
NO. 1, JANUARY 2013
[16] D. Hohm and M. Ropp, “Comparative Study of Maximum Power Point
Tracking algorithms,” Progress in Photovoltaics: Research and Applications,
pp. 47-62, 2002.
[17] Trishan Esram and Patrick L. Chapman "Comparison of Photovoltaic Array
Maximum Power Point Tracking Techniques" IEEE TRANSACTIONS ON
ENERGY CONVERSION, VOL. 22, NO. 2, JUNE 2007
[18] M. E. Ropp D. P. Hohm. Comparative study of maximum power point
tracking algorithms. Prog. Photovolt: Res. Appl., 11:47{62, 2003
[19] Md. Rabiul Islam, Youguang Guo, Jian Guo Zhu, M.G Rabbani, "Simulation
of PV Array Characteristics and Fabrication of Microcontroller Based MPPT",
6th International Conference on Electrical and Computer Engineering ICECE
2010, 18-20 December 2010, Dhaka, Bangladesh.
[20] Karel Castex, Julio Lara, David Wade, and Jing Zou “Integrated Renewable
Power System (IRPS)” Orlando, Florida, 32816-2450.
[21] Inverter circuit available at “http://danyk.cz/menic230_en.html”.
[22] Allegro® ACS712 Fully Integrated, Hall Effect-Based Linear Current Sensor
Datasheet.
National Institute of Technology Rourkela
Page 58
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