Optimum Point Tracker of the Solar Cell Power Supply System

7/28/2019 Optimum Point Tracker of the Solar Cell Power Supply System

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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.

Documents

Optimum Point Tracker of the Solar Cell Power Supply System