optimum point tracker of the solar cell power supply system
TRANSCRIPT
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Optimum Point Tracker Of The Solar Cell
Power Supply System
Project Report
Submitted to M S Ramaiah Institute of Technology (Autonomous
Institute Affiliated to VTU, Belgaum) in partial fulfillment of the
requirements for the award of
BACHELOR OF ENGINEERING
In
TELECOMMUNICATION ENGINEERING
For the Academic Year 2012-13
Submitted By
ARJUN A R, 1MS09TE004
MANJUNATH T, 1MS09TE021
MANJUNATHA A, 1MS09TE022
Under the guidance of
Internal Guide:
K.R.ShobhaAssociate. Professor
Dept.of Telecommunication Engg,MSRIT, Bangalore 560 054
Head of the department
Dr.K.Natarajan
Professor
Dept.of Telecommunication Engg,
MSRIT, Bangalore 560 054
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Department of Telecommunication Engineering
CERTIFICATE
This is to certify that the Project work entitled Optimum Point
Tracker Of The Solar Cell Power Supply Systemcarried out by
ARJUN A R (1MS09TE004), MANJUNATH T (1MS09TE021),
MANJUNATHA A (1MS09TE022), bonafide students of
M.S.Ramaiah Institute of Technology, Bangalore, in partial fulfillment
for the award of Bachelor of Engineering in Telecommunication
Engineering, of the Visvesvaraya Technological University,
Belgaumduring the year 2012-2013. It is certified that all
corrections/suggestions indicated for Internal Assessment have been
incorporated in the Report. The Seminar Report has been approved as
it satisfies the academic requirements in respect of Seminar work
prescribed for the said Degree.
Internal guide name: Head of the Dept.
K.R.Shobha Dr. K Natarajan
Associate Professor Professor and Head,
Dept. of TC Egg. Dept. of TC Egg,
MSRIT MSRIT
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Declaration
We Arjun A.R, Manjunath T and Manjunatha A students of
Telecommunication Engineering, M.S. Ramaiah Institute of
Technology, Bangalore-560054, hereby declare that the Technical
Seminar entitled Optimum Point Tracker Of The Solar Cell Power
Supply System has been carried out by us in M.S. Ramaiah Institute of
Technology, Bangalore-560054 under the guidance of K.R.Shobha,
Associate Professor, Dept of Telecommunication Egg, MSRIT,
Bangalore.
We declare that the work submitted in this report is our own, except
where acknowledged in the text, and has not been previously submitted
for the partial fulfillment of the degree in Bachelor of Engineering at
the Visvesvaraya Technological University, Belgaum.
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ACKNOWLEDGEMENTS
I would like to express my sincere gratitude to Prof.
K.R.Shobha the internal guide and the contact faculty for her
constant encouragement, continuous feedback and sparing his
valuable time for discussion.
I am grateful to K. Natarajan Prof. and Head, Dept. of
Telecommunication Engineering for his moral support given at
various stages.
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Abstract
The energy extracted from solar photovoltaic (PV) or solar thermal depends on
solar isolation. For the extraction of maximum energy from the sun, the plane
of the solar collector should always be normal to the incident radiation. The
diurnal and seasonal movement of the earth affects the radiation intensityreceived on the solar collector. Sun trackers move the solar collector to follow
the sun trajectories and keep the orientation of the solar collector at an optimal
tilt angle.
Energy efficiency of solar PV or solar thermal can be substantially improved
using solar tracking system. In this work, an automatic solar tracking system
has been designed and developed using LDR sensors and DC motors on a
mechanical structure with gear arrangement. Two-axis solar tracking has been
implemented through microcontroller based sophisticated control logic.
Performance of the proposed system over the important parameters like solar
radiation received on the collector, maximum hourly electrical power,
efficiency gain, short circuit current, open circuit voltage and fill factor has
been evaluated and compared with those for fixed tilt angle solar collector.
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Table of Contents
Chapter 1: Solar tracker.1.1 Basic concept
1.2 Problem statement
1.3 Literature Survey
Chapter 2: Single axis solar tracker
2.1 Different implementations of solar trackers
2.1.1 Horizontal single axis tracker (HSAT)
2.1.2 Vertical single axis tracker (VSAT)
2.1.3 Tilted single axis tracker (TSAT)
2.1.4 Polar aligned single axis trackers (PASAT)
2.2 Functional block diagram
Chapter 3: Components
3.1 LDR
3.1.1 Photoconductivity
3.1.2 Photo-resistor
3.1.3 LDR circuit
3.1.4 How an LDR works
3.1.5 Using an LDR in the Real world
3.1.6 LDR Characteristics
3.1.7 Applications
3.1.8 LDR summary
3.2 Comparator
3.2.1 Comparator circuit
3.2.1.1 Potentiometer
3.2.1.2 Driver
3.2.1.3 Schmitt Trigger
3.2.2 Speed and power
3.2.3 Hysteresis
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3.2.4 Output type
3.2.5 Internal reference
3.2.6 Continuous versus clocked
3.2.7 Applications
3.3 8-bit Microcontroller
3.3.1 Microcontroller basic architecture
3.3.1.1 Central Processing Unit
3.3.1.2 Memory unit
3.3.1.3 Input / Output ports
3.3.2 Some of Microcontroller Features
3.3.2.1 Supply Voltage
3.3.2.2 The Clock
3.3.2.3 Timers3.3.2.4 Reset Input
3.3.2.5 Interrupts
3.3.2.6 Analog-to-Digital Converter
3.3.2.7 Serial Input-Output
3.3.3 The 8051 microcontroller
3.3.3.1 Architecture
3.3.3.2 Block diagram
3.3.3.3 The Reset
3.3.3.4 The clock source
3.3.3.5 Input /Output Ports (I/O Ports)
3.3.3.6 Special Function Registers (SFRs)
3.3.3.7 Counters and Timers
3.3.3.8 8051 Microcontroller Interrupts
3.3.3.9 Introduction to assembly programming
3.3.4 AT89C52 microcontroller3.3.4.1 Description
3.3.5 8051 circuit board
3.3.5.1 Rectifier
3.3.5.2 Voltage regulator
3.3.5.3 Basic operation
3.3.5.4 Filter
3.3.5.5 Bridge rectifier
3.4 Stepper motor
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3.4.1 Brushless dc motor
3.4.2 Brushless vs. brushed motors
3.4.3 Fundamentals of operation
3.4.4.1 Unipolar motors
3.4.4.2 Bi polar motor
3.4.4 Types of stepper motors
3.4.4.1 Unipolar motors
3.4.4.2 Bipolar motor
3.4.5 Higher-phase count stepper motors
3.4.6 Stepper motor drive circuits
3.4.7 L/R drive circuits
3.4.8 Chopper drive circuits
3.4.9 Phase current waveforms3.4.10 Stepper motor ratings and specifications
3.4.11 Applications
3.4.12 Stepper Motor Merits and Demerits
3.4.13 Normal 4-Step Sequence
3.4.13.1 Step angle
3.4.13.2 Steps per second and rpm relation
3.4.14 the four-step sequence and number of teeth on rotor
3.4.15 Half-Step 8-Step Sequence
3.4.16 Unipolar versus bipolar stepper motor interface
3.4.16 stepper motor interface with microcontroller
3.5 Battery
3.5.1 Rechargable battery
3.5.1.1 Usage and applications
3.5.1.2 Charging and discharging
3.5.2 Principle of operation3.5.3 Categories and types of batteries
3.5.3.1 Primary batteries
3.5.3.2 Secondary batteries
3.5.4 Capacity and discharging
3.5.5 Battery lifetime
3.5.5.1 Primary batteries
3.5.5.2 Secondary batteries
3.6 Solar panel
3.6.1 Photovoltaics
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3.6.2 Solar cell
3.6.2.1 Current developments
3.6.3 Economics
3.6.4 Applications
3.6.4.1 Power stations
3.6.4.2 In buildings
3.6.4.3 In transport
3.6.4.4 Standalone devices
3.6.4.5 Rural electrification
3.6.5 Advantages
3.6.6 Disadvantages
Chapter 4: Project implementation
4.1 Circuit diagram
4.1.1 Comparator circuit
4.1.2 Stepper motor interfacing circuit
4.2 Flow chart
4.3 C code
4.31 Working of C code
Chapter 5: Results
5.1 Observation
Chapter 6: Conclusion
Chapter 7: Future scope
References
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List of figures
Fig 2.1 Single axis solar tracker
Fig 2.2 Functional block diagram of solar tracker
Fig 3.1 LDR
Fig 3.2 LDR circuit symbol
Fig 3.3 Darkness activated LDR circuit
Fig 3.4 Light activated LDR circuit
Fig 3.5 Practical LDR circuit
Fig 3.6 LDR Characteristics
Fig 3.7 Comparator circuit
Fig 3.8 Potentiometer
Fig 3.9 Driver circuit
Fig 3.10 Change in input voltage with a Schmitt Trigger
Fig.3.11 Microcontroller central processing unit
Fig.3.12 Memory unit
Fig 3.13 Input / Output ports
Fig.3.14 pin configuration of 8051 Microcontroller
Fig.3.15 Block diagram of 8051 Microcontroller
Fig.3.16 the Reset
Fig.3.17 The clock source
Fig.3.18 Port 0
Fig.3.19 Special Function Registers (SFRs)
Fig.3.20 A Register (Accumulator)
Fig.3.21 B Register
Fig.3.22 R Registers (R0-R7)
Fig.3.23 Program Status Word (PSW) Register
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Fig.3.24 Data Pointer Register (DPTR)
Fig.3.25 Stack Pointer (SP) Register
Fig.3.26 P0, P1, P2, P3 - Input/ Output Registers
Fig.3.27 TH0 & TLO
Fig.3.28 Example
Fig.3.29 TMOD Register
Fig.3.30 Timer Control (TCON) Register
Fig.3.31 IE Register
Fig.3.32 IP Register (Interrupt Priority)
Fig.3.33 Bridge rectifier operation
Fig.3.34 Voltage regulator
Fig.3.35 Stepper motor
Fig.3.36 Animation of a simplified stepper motor (unipolar)
Fig.3.37 Different drive modes showing coil current on a 4-phase unipolar
steppermotor
Fig.3.38 Rotar allignment
Fig.3.39 Common Stepper Motor Types
Fig.3.40 Interfacing Stepper Motor to Microcontroller
Fig.3.41 Interfacing circuit
Fig 3.42 Solar panel
Fig 3.43 Solar cell
Fig 4.1 Stepper motor interfacing circuit
Fig 4.2 Comparator circuit
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Chapter 1
Introduction
Solar tracker
A solar tracker is a device that orients a payload toward the sun. Payloads can be
photovoltaic panels, reflectors, lenses or other optical devices.
In flat-panel photovoltaic (PV) applications, trackers are used to minimize the
angle of incidence between the incoming sunlight and a photovoltaic panel. This
increases the amount of energy produced from a fixed amount of installed power
generating capacity. In standard photovoltaic applications, it is estimated that
trackers are used in at least 85% of commercial installations greater than 1MW
from 2009 to 2012.
In concentrated photovoltaic (CPV) and concentrated solar thermal (CSP)
applications, trackers are used to enable the optical components in the CPV and
CSP systems. The optics in concentrated solar applications accept the direct
component of sunlight light and therefore must be oriented appropriately to collect
energy. Tracking systems are found in all concentrator applications because such
systems do not produce energy unless pointed at the sun.
1.1Basic conceptSunlight has two components, the "direct beam" that carries about 90% of the solar
energy, and the "diffuse sunlight" that carries the remainder - the diffuse portion is
the blue sky on a clear day and increases proportionately on cloudy days. As the
majority of the energy is in the direct beam, maximizing collection requires the sun
to be visible to the panels as long as possible.
The energy contributed by the direct beam drops off with the cosine of the angle
between the incoming light and the panel. In addition, the reflectance (averaged
across all polarizations) is approximately constant for angles of incidence up to
around 50, beyond which reflectance degrades rapidly.
For example trackers that have accuracies of 5 can deliver greater than 99.6% of
the energy delivered by the direct beam plus 100% of the diffuse light. As a result,
high accuracy tracking is not typically used in non-concentrating PV applications.
The sun travels through 360 degrees east to west per day, but from the perspective
of any fixed location the visible portion is 180 degrees during an average 1/2 day
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period (more in spring and summer; less, in fall and winter). Local horizon effects
reduce this somewhat, making the effective motion about 150 degrees. A solar
panel in a fixed orientation between the dawn and sunset extremes will see a
motion of 75 degrees to either side, and thus, according to the table above, will lose
75% of the energy in the morning and evening. Rotating the panels to the east and
west can help recapture those losses. A tracker rotating in the east-west direction is
known as a single-axis tracker.
The sun also moves through 46 degrees north and south during a year. The same set
of panels set at the midpoint between the two local extremes will thus see the sun
move 23 degrees on either side, causing losses of 8.3% A tracker that accounts for
both the daily and seasonal motions is known as a dual-axis tracker. Generally
speaking, the losses due to seasonal angle changes is complicated by changes in the
length of the day, increasing collection in the summer in northern or southern
latitudes. This biases collection toward the summer, so if the panels are tilted closer
to the average summer angles, the total yearly losses are reduced compared to a
system tilted at the spring/fall solstice angle (which is the same as the site's
latitude).
There is considerable argument within the industry whether the small difference in
yearly collection between single and dual-axis trackers makes the addedcomplexity of a two-axis tracker worthwhile. A recent review of actual production
statistics from southern Ontario suggested the difference was about 4% in total,
which was far less than the added costs of the dual-axis systems. This compares
unfavorably with the 24-32% improvement between a fixed-array and single-axis
tracker.
1.2 Problem statementTo generate maximum output power, the plain of the solar panel must always be
perpendicular to the Suns incident rays. In ordinary solar power generation
system, the plane of the solar panel will receive perpendicular Suns rays for only a
fraction of time.Hence the system doesnt make optimum usage of the available
Suns energy. By employing single axis solar tracker technique, the plain of the
panel is rotated to an optimum position so that the panel absorbs maximum amount
of incident Suns energy and hence generating more output power. Hence the
power generation can be increased using single axis solar tracker technique.
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1.3 Literature survey
Paper 1
"Solar Tracker Robot using Microcontroller" by A.B. Afarulrazi, W. M. Utomo,
K.L. Liew and M. Zarafi published in 2011 International Conference on Business,
Engineering and Industrial Applications.
Summary
In the paper entitled," Solar Tracker Robot using Microcontroller" by A.B.
Afarulrazi, W. M. Utomo, K.L. Liew and M. Zarafi published in 2011 International
Conference on Business, Engineering and Industrial Applications describes to
design and develop an automatic Solar Tracker Robot (STR) which is capable to
track maximum light intensity. The efficiency of the solar energy conversion can be
optimized by receiving maximum light on the solar panel. STR is microcontroller
based and built to move the solar panel in one axis, which is from east to west and
vice versa. Servo motor is the actuator used to move the solar panel due to the high
torque and small in size. The STR will automatically adjust the position of the
robot so that it always faces the same direction. This will ensure the solar panel
receiving optimum sunlight if external force is applied to move the STR.
Paper 2
"Design and Construction of an Automatic Solar Tracking System by Md. Tanvir
Arafat Khan, S.M. ShahrearTanzil, RifatRahman, S M ShafiulAlam published in
6th Interna-tional Conference on Electrical and Computer Engineering ICECE
2010, 18-20 December 2010, Dhaka, Bangladesh.
Summary
In the paper entitled," Design and Construction of an Automatic Solar Tracking
System by Md. Tanvir Arafat Khan, S.M. ShahrearTanzil, RifatRahman, S M
ShafiulAlam published in 6th International Conference on Electrical and Computer
Engineering ICECE 2010, 18-20 December 2011, Dhaka, Bangladesh describes a
microcontroller based design methodology of an automatic solar tracker. Light
dependent resistors are used as the sensors of the solar tracker. The designed
tracker has precise control mechanism which will provide three ways of controlling
system. A small prototype of solar tracking system is also constructed to implement
the design methodology presented here. In this paper the design methodology of amicrocontroller based simple and easily programmed automatic solar tracker is
presented. A prototype of automatic solar tracker ensures feasibility of this design
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methodology.
Paper 3
"IMPLEMENTATION OF A PROTOTYPE FOR A TRADITIONAL
SOLAR TRACKING SYSTEM" by Nader Barsoum published in the 2009
Third UKSim European Sympo-sium on Computer Modeling and Simulation.
Summary
In the paper," IMPLEMENTATION OF A PROTOTYPE FOR A
TRADITIONAL SO-LAR TRACKING SYSTEM" by Nader Barsoum
published in the 2009 Third UKSim Euro-pean Symposium on Computer
Modeling and Simulation describes in detail the design and construction of a
prototype for solar tracking system with two degrees of freedom, whichdetects the sunlight using photocells. The control circuit for the solar tracker is
based on a PIC16F84A microcontroller (MCU). This is programmed to detect
the sunlight through the photocells and then actuate the motor to position the
solar panel where it can receive maximum sunlight. This paper is about
moving a solar panel along with the direction of sunlight; it uses a gear motor
to control the position of the solar panel, which obtains its data from a
PIC16F84A microcontroller. The objective is to design and implement an
automated, double-axis solartracking mechanism using embedded system
design in order to optimize the efficiency of overall solar energy output.
Paper 4
"Microcontroller Based Solar Tracking System" by AleksandarStjepanovic,
SladjanaStjepanovic, FeridSoftic, ZlatkoBundalo published in Serbia,Nis,October
7-9, 2009.
Summary
In the paper entiled," Microcontroller Based Solar Tracking System" by
AleksandarStjepanovic, SladjanaStjepanovic, FeridSoftic, ZlatkoBundalo
published in Serbia,Nis,October 7-9, 2009 describes the design and construction
of a microcontroller based solar panel tracking system. Solar tracking allows
more energy to be produce because the solar array is ableto remain aligned to the
sun. The paper begins with presenting background theory in light sensors and
stepper motors as they apply to the project.In the conclusions are given
discussions of design results. The paper begins with presenting background
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theory, light sensors and stepper motors as they apply to the project. The paper
continues with specific design methodologies pertaining to photocells, stepper
motors and drivers, microcontroller selection, voltage regulation, physical
construction, and a software/system operation expla-nation. The paper concludes
with a discussion of design results and future work.
Paper 5
"Microcontroller-Based Two-Axis Solar Tracking System" by LwinLwinOo
and Nang KaythiHlaing published in Second International Conference on
Computer Research and Development.
Summary
In the paper entiled " Microcontroller-Based Two-Axis Solar Tracking
System" by LwinLwinOo and Nang KaythiHlaing published in Second
International Conference on Computer Research and Development describes
to develop and implement a prototype of two-axis solar tracking system based
on a PIC microcontroller. The parabolic reflector or parabolic dish is
constructed around two feed diameter to capture the suns energy.The focus of
the parabolic reflector is theoretically calculated down to an infinitesimally
small point to get extremely high temperature. This two axis auto-tracking
system has also been constructed using PIC 16F84A microcontroller. The
assembly programming language is used to interface the PIC with two-axis
solar tracking system. The temperature at the focus of the parabolic reflector
is measured with temperature probes. This auto-tracking system is controlled
with two 12V, 6W DC gear box motors. The five light sensors (LDR) are used
to track the sun and to start the operation (Day/Night operation). Time Delays
are used for stepping the motor and reaching the original position of the
reflector. The two-axis solar tracking system is constructed with both
hardware and software implemen-tations. The designs of the gear and the
parabolic reflector are carefully considered and precisely calculated.