thesis final and modified
DESCRIPTION
GSM Based Distribution TransformerTRANSCRIPT
GSM BASED MONITORING OF
DISTRIBUTION TRANSFORMER
MUDASSAR KHALIDYASIR ARAFAT
December 2014
Department of Electrical EngineeringCOMSATS INSTITUTE OF INFORMATION
TECHNOLOGYLAHORE – PAKISTAN
Submission Form for Final-Year
PROJECT REPORT
PROJECT ID 40 NUMBER OF MEMBERS 2
TITLE GSM BASED MONITORING OF DISTRIBUTION TRANSFORMER
SUPERVISOR NAME TRN Fahad Khan AL / EXTERNAL
MEMBER NAME REG. NO. EMAIL ADDRESS
MUDASSAR KHALIDBTE-SP11-039
b
YASIR ARAFATY
BTE-SP11-087 [email protected]
CHECKLIST:
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I/We have enclosed the soft-copy of this document along-with the codes and scripts created by myself/ourselves
YES / NO
My/Our supervisor has attested the attached document YES / NO
I/We confirm to state that this project is free from any type of plagiarism and misuse of copyrighted material
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MEMBERS’ SIGNATURES
Supervisor’s Signature
COMSATS Institute of Information Technology, Lahore Campus Department of Electrical Engineering
This work, entitled “GSM Based Monitoring of Distribution Transformer”
has been approved for the award of
Bachelors in Electrical Engineering
Date
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Head of Department:
Department of Electrical EngineeringCOMSATS INSTITUTE OF INFORMATION
TECHNOLOGYLAHORE – PAKISTAN
Declaration
“No portion of the work referred to in the dissertation has been submitted in support of an
application for another degree or qualification of this or any other university/institute or
other institution of learning”.
MEMBERS’ SIGNATURES
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Acknowledgements
It is usual to thank those individuals who have provided particularly useful assistance, technical or otherwise, during your project.
Your supervisor will obviously be pleased to be acknowledged as he or she will have invested quite a lot of time overseeing your
progress.
In the name of God, the most kind and most merciful
I would like to thank <RELATIVES & FRIENDS> who kept backing me up in all the times,
both financially and morally…
I would also like to thank FAHAD KHAN for his guidance and encouraging me to work hard
and smart. I have found him very helpful while discussing the optimization issues in this
dissertation work. His critical comments on my work have certainly made me think of new
ideas and techniques in the fields of optimization and software simulation.
I am grateful to the God Almighty who provides all the resources of every kind to us, so that we
make their proper use for the benefit of mankind. May He keep providing us with all the
resources, and the guidance to keep helping the humanity.
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Abstract
Transformers have an important role in distribution system. Monitoring of transformer before any faults occur is very necessary and this process prevent us from a big loss. Currently used systems are able to provide information about the state of transformer but either they are offline or very expensive. Transformer is a very expensive device so we have to care about it. This project is about the design and implementation of hardware to monitor the useful parameters like ambient temperature, load currents, over voltage and oil level of distribution transformer. This project aim is to establish low cost solution for monitoring health condition of remotely located distribution transformers using GSM technology. An Embedded module is design to get data from electrical sensing system. The idea of on-line monitoring system is made up of a global service mobile (GSM) Modem, with a PIC microcontroller and different sensors. All this hardware is installed at the distribution site. The above defined parameters are recorded and processed if we find any abnormality then an emergency situation occur and an sms(short message service for mobile) is sent to the mobile engineer to take the notice of this situation.
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Table of Contents1 INTRODUCTION................................................................................................................................1
1.1 OVERVIEW....................................................................................................................................1
1.2 PROJECT SCOPE............................................................................................................................1
1.3 MOTIVATION.................................................................................................................................1
1.4 PROBLEM STATEMENT..................................................................................................................2
2 LITERATURE REVIEW..................................................................................................................3
2.1 MICROCONTROLLER.....................................................................................................................3
2.1.1 Pin Description........................................................................................................................3
2.1.2 Crystal Oscillator....................................................................................................................6
2.1.3 Reset.........................................................................................................................................7
2.2 GLOBAL SYSTEM FOR MOBILE (GSM).........................................................................................7
2.3 GSM MODULE..............................................................................................................................8
2.3.1 SIM900D..................................................................................................................................8
2.3.2 GSM Modem Instructions........................................................................................................9
2.3.3 Serial Communication...........................................................................................................10
2.4 TRANSFORMER............................................................................................................................10
2.4.1 Definition of Transformer......................................................................................................11
2.4.2 Working Principle..................................................................................................................11
2.4.3 Types of Transformer.............................................................................................................12
2.4.4 Faraday's Law of electromagnetic induction........................................................................12
2.5 SENSORS.....................................................................................................................................14
2.5.1 Potential Transformer (PT)...................................................................................................14
2.5.2 Current Transformer (CT).....................................................................................................14
2.5.3 Temperature Sensor (LM35)..................................................................................................15
2.5.3.1 Features.................................................................................................................................16
2.5.3.2 Application.............................................................................................................................16
2.5.3.4 Importance of LM35..............................................................................................................16
2.6 LIQUID CRYSTAL DISPLAY (LCD).............................................................................................16
3 HARDWARE DESCRIPTION........................................................................................................19
3.1 MICROCONTROLLER INTERFACING.............................................................................................19
3.2 TRANSFORMER............................................................................................................................20
3.3 PT SENSOR.................................................................................................................................21
3.4 CT SENSOR.................................................................................................................................21
3.5 TEMPERATURE SENSOR..............................................................................................................22
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3.6 OIL LEVEL MEASURING SENSOR................................................................................................22
3.7 POWER SUPPLY...........................................................................................................................24
3.7.1 Voltage Regulator (7805)......................................................................................................25
3.8 MAX 232...................................................................................................................................25
3.9 RELAY.........................................................................................................................................27
4 FLOW CHART.................................................................................................................................28
REFERENCES..........................................................................................................................................29
APPENDIX A: HDL OR C SOURCE CODE.........................................................................................31
APPENDIX B: HARDWARE SCHEMATICS.......................................................................................32
APPENDIX C: LIST OF COMPONENTS.............................................................................................33
Appendix D: Project Timeline.....................................................................................................................34
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Table of Figures
FIGURE 2-1 AN EXAMPLE OF INSERTING FIGURE INTO YOUR PROJECT ERROR! BOOKMARK NOT DEFINED.
FIGURE 3-1 FUNCTIONAL REQUIREMENTS NUMBERING.......................ERROR! BOOKMARK NOT DEFINED.
FIGURE 4-1 EXAMPLE FIGURE FOR PROTOTYPE APPLICATION.............ERROR! BOOKMARK NOT DEFINED.
FIGURE 4-2 ARCHITECTURE OVERVIEW DIAGRAM...............................ERROR! BOOKMARK NOT DEFINED.
Figure 5-1 Example Figure for User Interface.............................................Error! Bookmark not defined.
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1 Introduction
In power systems, distribution transformer is an essential electrical equipment which distributes
power to the low-voltage users. Therefore, proper operation of distribution transformer is very
important for efficient power distribution. The life time of DT can be increased by operating it
under rated conditions. The performance of distribution transformer is severely affected if it is
subjected to any abnormalities such as over loading, reduced oil-level etc. The electric power
deficiency and various malpractices followed in Pakistan has lead to frequent power failures
among which distribution transformer over loading is main issue [10] . Although several
monitoring systems are used by electric utility companies, however, they are not efficient.
Therefore, real time monitoring of distribution transformer is a crucial task for reliable
operation of power system [1]. The status of distribution transformer is then transmitted to
control centre for necessary actions.
1.1 Overview
Distribution Transformer is the main equipment in the power system. The main purpose of this
project is real time monitoring of distribution Transformer. Real time monitoring of distribution
transformer is performed by deploying sensors which continuously examine the parameters such
as over voltage, oil-level etc. The monitored data from distribution transformer is processed by
microcontroller module which further transmits this data to the GSM module located at control
centre. On the basis of received of received data, the abnormalities in voltage, current and
temperature overcome by the central control system by performing necessary action against the
abnormality.
1.2 Project Scope
The real time monitoring of the distribution Transformer increase the reliability of power
distribution network and save extra cost needed for changing and replacing distribution
transformer. There are many other methods to monitor transformer but these are inefficient as
they do not provide timely information of distribution transformer.
1.3 Motivation
The traditional electric power system has proved to be incompetent. Therefore, there is a strong
need to upgrade the out dated electric power system with an efficient power network. In this
prospective, sensors and communication infrastructure can enhance the efficiency of traditional
power systems, by deployment of sensors at various stage of power system [1]. Since
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distribution transformer is an expensive part of the power system, effort is required to enhance
the reliability and long life operation of distribution transformer [2]. This project provides a
solution to over loading and over voltage issues frequently countered in distribution transformer
by utilizing temperature and voltage sensors. The acquired data from the sensors is forward to
the central system where decisions are made to overcome abnormality [3][4].
1.4 Problem statement
Distribution transformers are one of the major parts of electric power system. The main problem
that Pakistan is facing now-a days and in past is that how to overcome with the issue of
electricity over loading which causes fatal damage to distribution transformers [10]. GSM based
monitoring of distribution transformers is a cheap and reliable source to overcome with these
problems. It provides real-time monitoring and reliable solution to the inherent in distribution
transformer operation. This gives in-time alert regarding any problem such as temperature
abnormality, over voltage and oil level etc.
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2 Literature Review
This chapter provides a literature review of different modules utilized in this project.
2.1 Microcontroller
A microcontroller (sometimes abbreviated µC, uC or MCU) is a small computer on a single
integrated circuit containing a processor core, memory, and programmable input and
output peripherals [5][6]. There are many families of the microcontroller such as PIC, AVR and
8051 each having different features and specifications. In this project PIC18f452 is used the
microcontroller key features of PIC18f452 are following:
High Performance RISC (Reduced Instruction Set Computer) CPU.
Operating frequency is 40 MHz
Programme memory is 32 Kbyte and its instructions are 16384.
Data memory is 1536 bytes.
Data EEPROM Memory is 256 bytes.
Interrupt Sources are 18.
5 I/O ports A,B,C,D and E in which “A” port has 6 pins, B, C and D have 8 pins and
“E” port has 3 pins.
There are 4 timers.
There are 2 Capture/Compare/PWM Modules.
Serial Communications is MSSP, Addressable and USART.
There are 8 input channels which are 10-bit Analog-to-Digital Module.
Programmable Low Voltage Detection.
Instruction set is of 75 instructions.
40-pin DIP.
2.1.1 Pin Description [13]
PIN18f452 have five ports (A to E) and each port has 3 associated 8-bit registers “A”
register is used to reserve a memory location in RAM[5].
Port A:
Port A is a 6 pin wide bidirectional port and its resources are Timer0, low voltage
detects and ADC [13]. The pin description of this port following:
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Pin-2: The name of this pin is RA0/AN0. Its basic functions are Input/output or
analog input 0.
Pin-3: This pin is called as RA1/AN1. Functionality of it is digital I/O, analog input
1
Pin-4: This pin is known as RA2/AN2, Vref-. Its basic functions are digital I/O,
analog input 2, A/D reference voltage (Low) input.
Pin-5: This pin known as RA3/AN3, Vref+. Functionality of this pin is digital I/O,
analog input 3 A/D reference voltage (high) input [14].
Pin-6: This pin is called as RA4/T0CKI. Basic function of this pin is as digital I/O,
open drain when configured as output and timer0 external clock input.
Pin-7: This pin is known as RA5/AN4/SS/LVDIN. Its functions are digital I/O,
analog input4 [15].
Figure: 2. PIC18F452 [5]
Port B:
It is 8-pin bidirectional port. PORTB can be software programmed for internal weak pull-ups on
all inputs. The resources of this port are Interrupts and Alt CCP2. The pin description of this
port is given below:
Pin-33: This pin is known as RB0/INT0. Functionality of this pin is digital I/O and external
interrupt 0.
4
Pin-34: It is called as RB1/INT1. Its basic function is external interrupt 1.
Pin-35: this pin is known as RB2/INT2. Its functionality is described as digital I/O, external
interrupt 2.
Pin-36: This pin is called as RB3/CCP2. Its functions are digital I/O, capture2 input, Compare2
output and PWM2 output.
Pin-37: This pin is denoted as RB4. Its basic functionality is Digital I/O, interrupt-on-change
pin.
Pin-38: This pin is known as RB5/PGM. Its functions are digital I/O, Interrupt-on-change pin.
Pin-39: This pin is called as RB6/PGC. Its functions are digital I/O, interrupt-on-change pin.
Pin-40: The name of this pin is RB7/PGD. Its functions are digital I/O, Interrupt-on-change pin,
in-circuit debugger and ICSP programming data pin.
Port C:
It is an 8 pin bidirectional port. Its resources are capture compares timers 1-3, SPI, I2 C, and
UART, the pin description of this port is given below:
Pin-15: This pin is known as RC0/T1OSO/T1CKI. Its functions are digital I/O, timer1 oscillator
output and Timer1/Timer3 external clock input.
Pin-16: we can call this pin as RC1/T1OSI/CCP2. Its basic functionality is digital I/O, timer1
oscillator input, capture2 input, compare2 output, and PWM2 output.
Pin-17: This pin is called as RC2/CCP1. its functions are digital I/O, capture1 input/compare1
and output/PWM1 output.
Pin-18: This pin known as RC3/SCK/SCL. Its basic functions are digital I/O, synchronous
serial clock input/output for SPI mode and synchronous serial clock input/output for I2 C mode.
Pin-23: This pin is called as RC4/SDI/SDA. Its functions are digital I/O, SPI Data In and I2 C
Data I/O.
Pin-24: we can call this pin as RC5/SDO. Its basic functions are digital I/O and SPI Data Out.
Pin-25: This pin is denoted as RC6/TX/CK. Its functions are digital I/O, USART asynchronous
transmit and USART synchronous clock [16].
Pin-26: The name of this pin is RC7/RX/DT. Its functions are digital I/O, USART
asynchronous receive and USART synchronous data.
Port D:
It is 8 pin bi-directional I/O port, or a Parallel Slave Port (PSP) for interfacing to a
microprocessor port. These pins have TTL input buffers when PSP module is enabled, the pin
description of this port are given below:
Pin-19: This pin is called as RD0/PSP0.
Pin-20: This pin is known as RD1/PSP1.
Pin-21: This pin is denotes as RD2/PSP2.
Pin-22: This pin is called as RD3/PSP3.
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Pin-27: This pin is known as RD4/PSP4.
Pin-28: This pin is denotes as RD5/PSP5.
Pin-29: This pin is called as RD6/PSP6.
Pin-30: This pin is known as RD7/PSP7.
The basic functionality of all above defined pins is digital I/O.
Port E:
It is 3 pin bidirectional port. It is also parallel slave port.
Pin-8: This pin is known as RE0/RD/AN5. Its basic functions are digital I/O, read control for
parallel slave port and analog input 5.
Pin-9: This pin is denotes as RE1/WR/AN6. Its functionalities are as digital I/O, write control
for parallel slave port and analog input 6.
Pin-10: This pin is called as RE2/CS/AN7. Functions of this pin are digital I/O, chip select
control for parallel slave port and analog input 7.
Pin-12 & 31: The function of these pins is to provide ground for logic and I/O pins.
Pin-11 & 32: These pins are used to provide supply to logic and I/O pins.
2.1.2 Crystal Oscillator
Crystal oscillators are also called ceramic resonator. They are used to generate desired
frequency by varying the capacitance of the oscillator[5]. By increasing the capacitance stability
will also increase, however, startup time will also increase. In this project, a crystal oscillator of
20 MHz with two capacitors of 33pF used which provide stable operation [15].
Figure: 2.2 [5]
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2.1.3 Reset
External power-on reset circuit is required only if the VDD power-up slope is too slow. The
circuitry for operation of reset is pin1 as shown in figure (2.1). The diode D helps to discharge
the capacitor quickly when VDD power is down, R < 40 kΩ is recommended to make sure that
the voltage drop across R does not violate the device’s electrical specification [6]. Moreover, R1
should be from 100Ω to 1 kΩ will limit any current flowing into MCLR from external capacitor
C, in the event of MCLR/VPP pin breakdown due to electrostatic discharge (ESD) or electrical
overstress (EOS).
Figure: 2. 3 [5]
2.2 Global System for Mobile (GSM)
GSM (Global System for Mobile communications) network is the most deployed mobile
communication network [8]. European Telecommunications Standards Institute (ETSI)
developed this standard for 2G advanced digital cellular systems utilized by mobile phones. It is
an open, advanced digital cellular technology utilized for transmitting mobile voice and data
services [8]. GSM supports voice calls and data transfer speeds up to 9.6 kbps, together with the
transmission of SMS. The important features of GSM are following:
Without any loss in audio quality GSM gives mobility.
Minimum Interference.
Encryption procedures utilized gives high security as a part of the air Interface and also
use of SIM.
SMS (short message services).
Emergency calls
These are different variants of GSM standards which are listed below [7]:
1. GSM 900:
Uplink is from 890 to 915 MHz [8]
Downlink is from 935 to 960 MHz
2. GSM 1800:
Uplink is from 1710 to 1785 MHz7
Downlink is from 1805 to 1880 MHz
3. GSM 1900:
Uplink is from 1850 to 1909 MHz
Downlink is from 1930 to 1989 MHz
For GSM services this project utilized GSM module. The discussion of GSM module is given
below.
2.3 GSM Module
A GSM module is a specific sort of modem which often accepts any SIM card, and runs
spanning a request with a cell phone agent, just like a cell phone. The function of GSM modem
is similar to a cell phone [7]. Different parts of GSM module are hi-lighted in fig (2.4).
Figure: 2. 4 GSM Module
2.3.1 SIM900D
Simultaneous communication (SIMCom) provides an ultra-compact in addition to reliable
wireless module SIM900D [7]. This can be a complete Quad-band GSM/GPRS module in the
SMT variety and built with a really powerful single-chip processor chip integrating
AMR926EJ-S key, allowing someone to benefit through small measurements and cost-effective
solutions. The SIM900D delivers GSM/GPRS 850/900/1800/1900MHz frequencies for voice.
Features of SIM900D are following:
It weighs about 6.2g
It is Controlled via AT commands
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Supplies a voltage range of 3.2 to 4.8V
Consumes low power approximately 1.0mA(sleep mode)
Operation temperature is about -40 °C to +85°C
2.3.2 GSM Modem Instructions
GSM module follow AT Commands, where AT stands for attention commands. AT commands
[17] are classified as the instructions used for controlling a modem. Every command line starts
with "AT" or "at". For example, when AT dial is passed. Many of the commands are used for
managing wired dial-up modems [7]. AT commands are supported by GSM/GPRS modems and
mobile phones.
There are two types of AT commands [17]:
Basic commands: These commands are AT commands that do not start with "+". For
example, D (Dial), A (Answer), H (Hook control) and O (Return to online data state)
are basic commands.
Extended commands: These commands are AT commands that start with "+". All GSM
AT commands are extended commands. For example, +CMGS (Send SMS message),
+CMSS (Send SMS message from storage), +CMGL (List SMS messages) and
+CMGR (Read SMS messages) are extended commands.
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2.3.3 Serial Communication
In this project, serial communication from modem to microcontroller is provided by connecting
Tx and Rx pins to modem Rx and Tx pin respectively [18]. The third pin of modem is
grounded. In this project MAX232 or RS232 is used to communicate and get proper result
between microcontroller and GSM module. Max232 or RS232 both are utilized as logic
converter [7]. If microcontroller works in TTL level and GSM modem works in CMOS level
then logic converter like RS232 is interfaced to get same logic level. However, this project
operates both Microcontroller and GSM modem in TTL logic level.
Figure: 2. 5 Interfacing Microcontroller and GSM modem using MAX232
2.4 Transformer
The history of transformer was commenced in early 1880's. First constant potential transformer
was invented in 1885, in the year 1950, 400KV electrical power transformer was introduced in
high voltage electrical power system [10]. In the early 1970s, unit rating as large as 1100MVA
was produced and 800KV and even higher KV class transformers were manufactured in year of
1980. Transformers have become essential for the AC transmission, distribution, and
utilization of electrical energy.
Figure: 2.5 Transformer
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2.4.1 Definition of TransformerA transformer is an electrical device that transfers energy between two or more circuits
through electromagnetic induction Electrical power transformer is a static device which
transforms electrical energy from one circuit to another without any direct electrical connection
and with the help of mutual induction between two windings. It transforms power from one
circuit to another without changing its frequency but may be in different voltage level [10].
2.4.2 Working Principle
In a transformer, two coils are arranged concentrically so that the magnetic field generated by
the current in one coil induces a voltage in the other. This physical principle can only be applied
in AC systems, as only a time-varying magnetic field is able to induce a voltage [24]. By using
a different number of winding turns in the two coils, a higher or lower voltage can be obtained.
The working principle of transformer is based on Faraday's Law of electromagnetic
induction. A varying current in the transformer's primary winding creates a varying magnetic
flux in the core [10]. This varying magnetic field at the secondary induces a varying
electromotive force (emf) or voltage in the secondary winding.
Figure: 2.7 Transformer working principal
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2.4.3 Types of Transformer
There are two types of transformers [10] which are discussed below:
Step-Up Transformer:
Step up transformer has greater number of turns in secondary winding [24].
Therefore, the output voltage is greater than input voltage.
Step Down Transformer:
Step-down transformer basically step down the voltage because it has less numbers
of turns in secondary winding. Consequently output voltage at secondary winding (VS) is
given by:
Np/Ns=Vp/Vs (2.1)
Where:
NP = Number of turns on primary coil
NS = Number of turns on secondary coil
VP = Primary voltage
VS = Secondary voltage
2.4.4 Faraday's Law of electromagnetic induction
Faraday's law of induction is a basic law of electromagnetism. It is the fundamental operating
principle of transformers.
Whenever a conductor is placed in a varying magnetic field an EMF gets induced across the
conductor, and if the conductor is a closed circuit then induced current flows through it
[24].
Magnetic field can be varied by following:
By moving magnet
By moving the coil
By rotating the coil relative to magnetic field
The magnitude of induced emf is equal to the rate of change of flux linkages with the coil. The
flux linkages is the product of number of turns and the flux associated with the coil.
Consider the conductor is moving in magnetic field. The flux at initial (Φ1) and final (Φ2)
position is given by following relation:
Φ1 = NΦ1 (2.2)
Φ2 = NΦ2 (2.3)
Where N is speed of the motor and Φ is flux.
Change in flux (∆Φ) is calculated by:
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∆Φ = N (Φ1 - Φ2) (2.4)
let Φ1 - Φ2 = Φ (2.5)
Therefore, change in the flux linkage = NΦ
and, rate of change in the flux linkage = NΦ/t
so rate of change of flux linkages = N (dΦ/dt)
According to Faraday's law of electromagnetic induction, rate of change of flux linkages is
equal to the induced emf so,
E = N (dΦ/dt) (volts) (2.6)
Faraday's law tells us that a changing magnetic flux will induce an emf in a coil. The induced
emf for a coil with N loops is:
E = -N (dΦ/dt) volts (2.7)
Place two coils next to each other. If the first coil has a current going through it, a magnetic
field will be produced, and a magnetic flux will pass through the second coil [10]. Changing the
current in the first coil changes the flux through the second, inducing an emf in the second coil,
which is known as mutual inductance.
Figure: 2.8
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2.5 Sensors
Sensors are installed on transformer site which reads and measures the physical quantity from
the distribution transformer and then it converts it into the analog signal. Sensor are used for
sensing load current, ambient temperature, winding temperature and oil level. A sensor is a
device which receives and responds to a signal when touched. A multitude of different
measurable variables can be collected for on-line monitoring. However, it is very rarely useful
to use the entire spectrum. Therefore, sensor technology must be adjusted to the specific
requirements of a particular transformer depending on their age and condition. Following
general set-up of sensors for example is proposed for the use at a Distribution transformer
2.5.1 Potential Transformer (PT)
Voltage and potential transformers are utilized to quantify voltage (potential). The secondary
voltage is significantly corresponding to the primary voltage and contrasts from it in phase by
an angle that is roughly zero. Voltage and potential transformers that are intended for checking
single-phase and three-phase line voltages in power metering applications are utilized primarily
as venture down gadgets. They are intended for interfacing line-to-line or line-to-neutral in the
same path as standard voltmeters [24]. The secondary voltage has an altered relationship to the
primary voltage with the goal that a change in potential inside the primary circuit is checked
precisely by meters associated over the secondary terminals [10].
Voltage and potential transformers can be utilized with voltmeters for voltage estimations, or
with current transformers for wattmeter or watt-hour meter estimations. Voltage transformers
and potential transformers are likewise used to work defensive transfers and gadgets, and in
numerous different applications. Since they are utilized basically as a part of an observing limit,
notwithstanding, voltage or potential transformers by and large oblige more prominent
precision. For illustrations, items utilized by open utilities for deciding power use must be exact
since these voltage or potential transformers are utilized for charging clients.
2.5.2 Current Transformer (CT)
The Current Transformer (C.t), is a sort of "instrument transformer" that is intended to create a
substituting current in its secondary winding is corresponding to the current being measured in
its primary [24].
Current transformers decrease high voltage currents and flows to a much lower esteem and give
an advantageous method for securely observing the real electrical current streaming in an AC
14
transmission line utilizing a standard ammeter. The main of operation of a current transformer is
the same as that of a conventional transformer [10].
Not at all like the voltage or Power Transformer took a gander at formerly, the current
transformer comprises of stand out or not very many turns as its primary winding . This primary
winding be of either a solitary level turn, a loop of substantial obligation wire wrapped around
the centre or simply a conveyor or transport bar put through a focal gap as demonstrated.
Because of this kind of game plan, the current transformer is regularly alluded as well as an
"series transformer" as the primary winding, never has more than a not very many turns, is in
arrangement with the current convey conductor [24].
The secondary winding have an expansive number of loop turns wound on an overlaid centre of
low-misfortune attractive material which has an extensive cross-sectional region so that the
attractive flux thickness is low utilizing much littler cross-sectional range wire, contingent on
how much the current must be ventures down. This auxiliary slowing down normally evaluated
at a standard 1 Ampere or 5 Amperes.
There are three fundamental sorts of current transformers: "wound", "toroidal" and "bar".
For most current transformers the primary and secondary currents are communicated as a
proportion, for example, 100/5. This implies that when 100 Amps is streaming in the primary
winding will bring about 5 Amps streaming in the secondary winding. By expanding the
quantity of secondary windings, N2, the primary current can be made much littler than the
current in the primary circuit being measured. As it were, as N2 builds, I2 goes around a relative
sum.
Turns Ratio = n = Np /NS = Is/IP (2.8)
Secondary Current, Is = IP (NP/NS) (2.9)
2.5.3 Temperature Sensor (LM35)
This framework spares vitality by effective power administration of a room which utilizes
certain controlling instruments oversaw by a microcontroller. Temperature readings are taken
from an LM35 sensor and contrasted and the client characterized limit threshold
The LM35 [25] series are precision integrated-circuit temperature sensors, whose output voltage
is linearly proportional for the Celsius (Centigrade) temperature. The LM35 thus comes with an
edge over linear temperature sensors calibrated in Kelvin, since the user is not required to
subtract a substantial constant voltage from its output to have convenient Centigrade scaling. It
draws59 μA by its supply, It has very low self-heating, less as compared to 0.1°C.
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Figure: 2.9 LM35
2.5.4 Features [25]
The features of LM35 are:
Calibrated instantly with ° Celsius (Centigrade).
Rated full −55° to +150°C range.
Created for remote applications.
Low cost due in order to wafer-level trimming.
Performs from 4 to 30volts, 5v or 12v are used mostly.
Less when compared with 59 μA current drain.
Low self-heating, 0.08°C.
2.5.5 Application
The LM35 can be connected effectively in the same route as other coordinated circuit
temperature sensors. It can be stuck or established to a surface and its temperature will be
around 0.01°Cof the surface temperature
2.5.6 Importance of LM35
We can measure temperature more precisely than using a thermistor. The LM35 creates a higher
yield voltage than thermocouples and may not oblige require that the yield voltage be enhanced
or amplified. A characteristic for the LM35 is that it draws just 60 micro amps from its supply
and has a low self-heating ability [25]. We will need to utilize a voltmeter to sense Vout
16
2.6 Liquid Crystal Display (LCD)
The display utilized is 20x4 LCD (Liquid Crystal Display); which implies 20 characters every
line by 4 lines. The standard is alluded as JHD204A, which suggest to the controller chip which
gets information from an outside source (PIC18F452) and communicates or interact with the
LCD [23].
EN, RS, and RW are control lines.
The EN line is called "Enable." This control line is utilized for telling the LCD that we are
sending information. For sending information to the LCD, the program should verify that the
line is low (0) and afterward set the other two control lines or put information on the data bus.
At the point when alternate lines are prepared totally [23], bring EN high (1) and should hold up
for the base time needed by the LCD datasheet and end by bringing it low (0) once more.
The RS line is "Register Select" line. At the point when RS is low (0), the information is treated
with a charge or extraordinary guideline, (for example, clear screen, position cursor). At the
point when the RS is high (1), the information sent is text data which is shown on the screen.
For instance, to show the letter "B" on the screen you would set RS high (1).
The RW line is "Read/Write" control line. At the point when RW is low (0), the data on the data
bus is written or composed to the LCD [23]. At the point when RW is high (1), the program is
effectively addressing (or reading) the LCD. One instruction only ("Get LCD status") is read
command. All the others are write commands so RW will dependably be low.
Figure: 2.10 LCD [23]
The pin description of LCD is given in table(2.1)
17
Table: 2.1 Pin description of LCD
Pin Number Name Descriptions
1 VCC Ground
2 VSS Power supply (+5)
3 VEE LCD contrast
4 RS Control pin
5 R/W Control pin
6 E Control pin
7 DB0 Not required in 4-bit operation
8 DB1 Not required in 4-bit operation
9 DB2 Not required in 4-bit operation
10 DB3 Not required in 4-bit operation
11 DB4 Data or address pin
12 DB5 Data or address pin
13 DB6 Data or address pin
14 DB7 Data or address pin
15 LED+ LED Backlight Anode (+)
16 LED- LED Backlight Cathode (-)
18
3 Hardware Description
This chapter provides detailed description of different modules of hardware user in in this
project. The hardware component consists of transformer, sensors, GSM module and
microcontroller etc.
3.1 Microcontroller Interfacing
Interfacing [16] of microcontroller with other modules in this project are given in the fig (3.1)
Figure: 3.
19
Pin description of PIC18F452 which utilized in this project is listed below:
Pin-1: Reset pin
Pin-2: Interface PT sensor 1
Pin-3: Interface CT sensor 1
Pin-4: Interface PT sensor 2
Pin-5: Interface CT sensor 2
Pin-7: Interface temperature sensor (LM35) 1
Pin-8: Interface temperature sensor (LM35) 2
Pins-17, 18 and 19: Interfacing oil level of transformer
Pin-21, 22, 23, 24, 28, 29 and 30: interfacing with LCD
Pin-25: Interfacing MAX232
Pin-15: Interfacing GSM module
Pin-33: Interfacing buzzer
Pin-35: Interfacing relay 2
Pin-34: Interfacing relay 1
Pin-11 and 32: +5V supply
Pin-12 and 31: Grounded
Pin-13 and 14: Interfacing crystal oscillator
3.2 Transformer
The transformer used in this project is an isolation transformer [24]. In this project we monitor
the parameters of this transformer because at that level we can’t use 11 KVA transformers. With
this transformer we install some sensors which measure the parameters of this transformer. It is
a 200W or 0.25KVA transformer.
Figure: 3.2 Isolation transformer20
3.3 PT Sensor
In order to measure different parameters of the transformer sensors are deployed with
distribution transformer. PT sensor is installed at the transformer side to measure the voltage of
the transformer. This sensor comprises of a step-down transformer which take 220 AC voltage
and
provides 12V
AC which is further
passed to bridge
for
rectification. The
output of rectifier
which is 12V
DC is then further
minimized using
variable resistance. Moreover, this final output is provided to the microcontroller as shown in
fig (3.3)
Figure: 3.3 hardware design of PT sensor
3.4 CT Sensor
CT sensor is also installed at the transformer side it is responsible to the measure of current of
the transformer and response when the current exceeds from its threshold value. This sensor
21
comprises of a step up transformer, diode (1N4007), variable resistance and a capacitor as
shown in fig (3.4). In CT sensor step-up transformer is connected parallel to the source and load
to measure current. Here is also a scaling factor used which take 1A current and gives 1V DC or
2A and give 2V DC then this output give to the Microcontroller.
Figure: 3.4
3.5 Temperature Sensor
Temperature sensor is used to measure the temperature of the transformer [25]. This sensor
wills response when temperature of the transformer will go beyond the prescribed limit. LM35
sensor is used which has 3-pins and it operate at +5V DC. It convert 10mV to 1 0C. In this
project LM35 is used. The pin description of LM35 is given as:
Pin 1: Input voltage unto 5.5v
Pin 2: Analog voltage out
Pin 3: Ground
Figure: 3.5
3.6 Oil Level Measuring
Sensor
Oil level measuring sensor also
installed at transformer side. It measures the oil level of the transformer because many
transformers are damaged or spoiled due to the oil level decreasing. Therefore, proper operation
22
of distribution transformer
can be established by ensuring
appropriate oil level. It has
three level low, medium and
high. Hardware design [20]
[21] shown in fig (3.6)
Figure: 3.6
The circuit configuration
of oil level sensor
depicted in figure (3.7) ,
F is the common pin,
A is the low pin, B is
the medium pin and C is the high pin for detecting the oil level of the transformer.
23
Figure: 3.7
3.7 Power Supply
Power supply is the circuit from which we get our desired dc voltage to run other circuits. The
voltage we get from the principle line is 230V AC yet alternate parts of our circuit require 5V
DC. Consequently a step-down transformer is utilized to get 12V AC which is later changed
over to 12V DC utilizing a rectifier shown in fig (3.8). The yield of rectifier still contains a few
ripples despite the fact that it is a DC signal because of which it is called as Pulsating DC. To
remove the ripples and get smoothed DC power filter circuits are utilized. Here a capacitor is
utilized. The 12V DC is rated down to 5V utilizing a positive voltage controller chip 7805.
Therefore an altered DC voltage of 5V is acquired. Block diagram of power supply is given
below
Input
230 AC
main
Power
supply
Transformer Rectifier Smoothing Voltage
Regulator
Output
Regulated
5V DC
Transformer: A transformer is an electrical device that exchanges energy between two or more
circuits through electromagnetic induction and it steps down high voltage AC to low voltage
AC.
Rectifier: Electrical device that changes AC to DC.
Smoothing: Smooth’s the DC to get rid of ripples.
Regulator: A voltage controller is intended to naturally keep up a consistent voltage level.
24
Figure: 3.8
3.7.1 Voltage Regulator (7805)
Voltage regulator, any electrical device that keeps up the voltage of a power source inside
acceptable limits [12]. The voltage regulator is expected to keep voltages inside the
recommended range that can be endured by the electrical equipment utilizing that voltage. Such
a device is widely utilized as a part of motor vehicles of different sorts to match the yield
voltage of the generator to the electrical load and to the charging requirements of the battery.
Voltage controllers likewise are utilized as a part of electronic supplies in which excessive
variations in voltage would be detrimental.
e
Figure: 3.9
3.8 MAX 232
MAX 232 is use for serial communication of microcontroller and PC. Its configuration is given
in the figure (3.10)
25
Figure: 3.10
In this figure (3.11) pin-12 is Rx and pin-11 is Tx both are connected to the pin 26 and 25 of the
microcontroller.
26
Figure: 3.11
3.9 Relay
Relay is an electrical switch that uses an electromagnet to move the change from the OFF to ON
position rather than an individual moving the switch from OFF to ON. It takes a generally little
amount of power to turn on a relay yet the relay can control something that draws significantly
more power.
Figure: 3.12
3.10 Buzzer
A buzzer is an audio signalling device, it may be electromechanical or mechanical. Use
of buzzers include alarm devices and conformation of user input. These buzzers or beeper are
applicable to automobile equipment’s and its pin type terminal construction enables direct
mounting on to printed circuit boards. The circuit of buzzer is shown in the figure given below:
27
Figure: 3.13
Electronic symbol of buzzer is shown by figure given below:
Figure: 3.14
4 Flow Chart
28
µc
Initialize
Read voltages
of transform
Yes
No
Yes
No
Yes
5 Methodology
The methodology for this project is briefly described in the fig (3.15)
29
If
(volts>26
0)
Relay 1 ON
Send SMS
Read current
of transform
If
(amps>6
0)
Buzzer ON
Dial number
Read
temperature
Measure oil
level
Send to PC
Send message
Values
If
(counter>6
0)
Figure: 3.15
6 Results
The results of this project are given in following figures (3.16)
30
Figure: 3.16
Different readings of transformer and temperature are given in the following figure (3.17)
Figure: 3.17
Over voltage of transformer is given in figure (3.18)
31
Figure: 3.18
32
7 Conclusion
The GSM based monitoring of distribution transformer is useful as compared to manual
monitoring. It is also reliable as it is impossible to monitor the oil level and overloading etc.
After receiving message of any abnormality we can take action regarding any failure occurrence
in the transformers. In power distribution network there are several distribution transformer and
connecting each transformer with such system we can easily figure out that which transformer is
giving abnormal readings with the help of messaged received. So, there is no need for checking
all transformers. The time for getting messages may vary because of GSM network traffic but
still it is better than manual monitoring.
7.1 Future work
For receiving and storing transformer parameters information periodically about all the
distribution transformers of a particular utility in a database application a server module can be
included to this system. This database will be a useful source of information on the utility
transformers. Analysis of these stored data helps the utility in monitoring the behavior of their
distribution transformers and identify faults before any fatal failures. Thus, it will be cost saving
as well as improves system reliability.
33
References
[1] Leibfried, T, “Online monitors keep transformers in service”, Computer Applications in
Power, IEEE, Volume:11 Issue: 3 , July 1998 Page(s):36 -42.
[2] Chan, W. L, So, A.T.P. and Lai, L., L.; “Interment Based Transmission Substation
Monitoring”, IEEE Transaction on Power Systems, Vol. 14, No. 1, February 1999,
pp. 293-298.
[3] Akbari, A “ A new method for monitoring of distribution transformers”,
Environment and Electrical Engineering (EEEIC), 2012 11th International
Conference on, 18-25 May 2012, pages 632 – 636
[4] Wei He ; Zhanlong Zhang ; Kang Ju ; Jun Deng, “A Distribution transformer
electromagnetic environment multi-parameter monitoring system”, Automation
Congress, 2008. WAC 2008. World, Sept. 28 2008-Oct. 2 2008, Page(s):1 – 4
[5] http://www.microchip.com/wwwproducts/Devices.aspx?product=PIC18F452
[6] http://www.warburtech.co.uk/products/pic/microcontrollers/
40.pin.pic.microcontrollers/microchip.pic18f452.microcontroller/
[7] Huang Yinghong ; Zhang Kun ; Li Zhuang, “General Application Research on
GSM Module” , Internet Computing & Information Services (ICICIS), 2011
International Conference, 17-18 Sept. 2011, Page(s):525 – 528
[8] Rahnema, M., “Overview of the GSM system and protocol architecture”,
Communications Magazine, IEEE (Volume:31 , Issue: 4 ), Page(s):92 – 100
[9] Thomas, James W, Industry and General Applications, IEEE Transactions on
(Volume:IGA-6 , Issue: 6 ), Page(s):563 – 569
[10] Mack, James E.; Shoemaker, Thomas (2006). "Chapter 15 - Distribution
Transformers". The Lineman's and Cableman's Handbook (11th ed.). New York:
McGraw-Hill. pp. 15–1 to 15–22. ISBN 0-07-146789-0
[11] data sheet for 7805 , http://www.engineersgarage.com/electronic-components/7805-
voltage-regulator-ic
[12] 7805 VOLTAGE REGULATOR IC CIRCUIT, http://www.rakeshmondal.info/IC-
7805-Voltage-Regulator
[13] PICmicro™, Mid-Range MCU Family Reference Manual, (Last Accessed on March
2014), http://ww1.microchip.com/downloads/en/devicedoc/33023a.pdf
[14] PIC Microcontroller Memory Organization Tutorial, (Last Accessed on May, 2014),
http://www.microcontrollerboard.com/pic_memory_organization.html
[15] A PIC Microcontroller Introduction (Last Accessed on May 2014), http://www.best-
microcontroller-projects.com/pic-microcontroller.html
34
[16] PIC 18F452 Product Features, (Last Accessed on June 2014),
https://www.microchip.com/wwwproducts/devices.aspx?dDocName=en010296
[17] GSM AT Commands, (Last Accessed on July 2014),
http://m2msupport.net/m2msupport/sms-at-commands/
[18] Joe Campbell, “C Programmers Guide to Serial Communication” 1st edition, April
1st 1987 by SAMS
[19] Milan Verle, “PIC Microcontrollers”, 1st Edition, 2008 by mikroElektronika, ISBN:
978-86-84417-15-4, http://www.mikroe.com/products/view/11/book-pic-
microcontrollers/
[20] Robert L. Boylestad, Louis Nashelsky, “Electronic Devices and Circuit Theory”, 9th
Edition, 2005 by Prentice Hall, ISBN: 0131189050
[21] Bernard Grob, “Grob Basic Electronics”, 8th Edition, Jan 1997 by McGraw-Hill,
ISBN: 002802253X
[22] PIC Analog to Digital Converter Tutorial, (Last Accessed on August 2014),
http://www.microcontrollerboard.com/analog-to-digital-converter.html
[23] LCD 20x4 datasheet, (Last Accessed on June 2014),
https://www.google.com.pk/#q=lcd+20x4+datasheet
[24] Abulsalam, “Fundamental of electric machines”, edition illustrated, pages 376
[25] Temperature sensor LM35 specification, (Last accessed on July),
http://www.facstaff.bucknell.edu/mastascu/elessonshtml/sensors/TempLM35.html
35
Appendix A: C Source Code
#include <18F452.h> // ic number define
#device adc=10 //adc 10 bit
#use delay (clock=20000000) // 20mhz
#use rs232(baud=9600,STREAM=pc)
#use rs232(baud=9600,stream=gsm)
#include<lcd.c>
void process_volt_1_ac();
void process_amps_1_ac();
void process_temp_1();
void process_volt_2_ac();
void process_amps_2_ac();
void process_temp_2();
void process_send_pc();
void process_oil_level();
int32 adc_value;
int16 ac_volt_1,ac_volt_2;
int16 ac_amps_1,ac_amps_2;
int16 temp_1,temp_2;
int8 volt1_1,volt1_2,volt1_3;
int8 amps1_1,amps1_2,amps1_3;
int8 temp1_1,temp1_2,temp1_3;
int8 volt2_1,volt2_2,volt2_3;
int8 amps2_1,amps2_2,amps2_3;
36
int8 temp2_1,temp2_2,temp2_3;
int1 flag1,flag2,flag3,flag4;
int8 counter1;
#DEFINE buzzer PIN_B0
#DEFINE relay1 PIN_B1
#DEFINE relay2 PIN_B2
#DEFINE led1 PIN_D1
#DEFINE oil_l PIN_C2
#DEFINE oil_m PIN_C3
#DEFINE oil_h PIN_D0
void main(){ // main loop
SETUP_ADC_PORTS(ALL_ANALOG); // adc initialize
setup_adc(ADC_CLOCK_INTERNAL);
output_low(relay1);
output_low(relay2);
output_high(buzzer);
output_high(led1);
delay_ms(1000);
output_low(buzzer);
output_low(led1);
delay_ms(100);
flag1 = TRUE;
flag2 = TRUE;
flag3 = TRUE;
flag4 = TRUE;
37
counter1 = 0;
fprintf(pc,"TRANSFORMER PROJECT\n\r");
delay_ms(100);
lcd_ini(); // lcd initialize
delay_ms(300);
lcd_line1(0);
printf(lcd_data,"LCD_TEST");
fprintf(gsm,"AT\r");
delay_ms(500);
fprintf(gsm,"AT+CMGF=1\r");
delay_ms(500);
fprintf(gsm,"AT+CMGD=1\r");
delay_ms(500);
fprintf(gsm,"AT+CMGS=\"03446656938\"\r");
delay_ms(500);
fprintf(gsm,"System Initialize\r");
delay_ms(500);
output_high(buzzer);
output_high(led1);
delay_ms(1000);
output_low(buzzer);
output_low(led1);
delay_ms(100);
while(true){ // start while loop
38
output_toggle(led1);
process_volt_1_ac();
process_amps_1_ac();
process_temp_1();
process_volt_2_ac();
process_amps_2_ac();
process_temp_2();
process_water_level();
process_send_pc();
counter1++;
if(counter1>60){
counter1 = 0;
fprintf(gsm,"AT+CMGF=1\r");
delay_ms(500);
fprintf(gsm,"AT+CMGD=1\r");
delay_ms(500);
fprintf(gsm,"AT+CMGS=\"03446656938\"\r");
delay_ms(500);
fputc('T',gsm);
fputc('1',gsm);
fputc('_',gsm);
fputc('V',gsm);
fputc('=',gsm);
fputc(volt1_3,gsm);
fputc(volt1_2,gsm);
fputc(volt1_1,gsm);
39
fputc('V',gsm);
fputc('T',gsm);
fputc('2',gsm);
fputc('_',gsm);
fputc('V',gsm);
fputc('=',gsm);
fputc(volt2_3,gsm);
fputc(volt2_2,gsm);
fputc(volt2_1,gsm);
fputc('V',gsm);
fputc('T',gsm);
fputc('1',gsm);
fputc('_',gsm);
fputc('A',gsm);
fputc('=',gsm);
fputc(amps1_3,gsm);
fputc('.',gsm);
fputc(amps1_2,gsm);
fputc(amps1_1,gsm);
fputc('A',gsm);
fputc('T',gsm);
fputc('2',gsm);
fputc('_',gsm);
fputc('A',gsm);
fputc('=',gsm);
fputc(amps2_3,gsm);
fputc('.',gsm);
fputc(amps2_2,gsm);
fputc(amps2_1,gsm);
fputc('A',gsm);
fputc('T',gsm);
fputc('E',gsm);
fputc('M',gsm);
40
fputc('P',gsm);
fputc('1',gsm);
fputc('=',gsm);
fputc(temp1_2,gsm);
fputc(temp1_1,gsm);
fputc('C',gsm);
fputc('T',gsm);
fputc('E',gsm);
fputc('M',gsm);
fputc('P',gsm);
fputc('2',gsm);
fputc('=',gsm);
fputc(temp2_2,gsm);
fputc(temp2_1,gsm);
fputc('C',gsm);
delay_ms(500);
}
} //end while loop
} //end main loop
void process_volt_1_ac()
{
set_adc_channel(0); // adc channel select
adc_value=read_adc();
ac_volt_1 = adc_value;
volt1_3 =0x30+ ac_volt_1/100; //bcd
volt1_2 =0x30+ (ac_volt_1/10) % 10;
volt1_1 =0x30+ (ac_volt_1/1) % 10;
lcd_line1(0);
printf(lcd_data,"T1_V=");
lcd_data(volt1_3);
lcd_data(volt1_2);
41
lcd_data(volt1_1);
lcd_data('V');
if(ac_volt_1>260){
output_high(relay1);
delay_ms(10);
if(flag3){
flag3 = false;
fprintf(gsm,"AT+CMGF=1\r");
delay_ms(500);
fprintf(gsm,"AT+CMGD=1\r");
delay_ms(500);
fprintf(gsm,"AT+CMGS=\"03446656938\"\r");
delay_ms(500);
fprintf(gsm,"Transformer1 Over Volts\r");
delay_ms(500);
}//end flag3
}
else{
flag3 = true;
output_low(relay1);
delay_ms(10);
}
}
42
void process_amps_1_ac()
{
set_adc_channel(1); // adc channel select
adc_value=read_adc();
ac_amps_1 = adc_value;
amps1_3 =0x30+ ac_amps_1/100;
amps1_2 =0x30+ (ac_amps_1/10) % 10;
amps1_1 =0x30+ (ac_amps_1/1) % 10;
lcd_line1(10);
printf(lcd_data,"T1_A=");
lcd_data(amps1_3);
lcd_data('.');
lcd_data(amps1_2);
lcd_data(amps1_1);
lcd_data('A');
if(ac_amps_1>60){
output_high(buzzer);
delay_ms(200);
output_low(buzzer);
printf("temp2 ");
delay_ms(200);
if(flag1){
flag1 = false;
fprintf(gsm,"AT+CMGF=1\r");
delay_ms(500);
fprintf(gsm,"AT+CMGD=1\r");
43
delay_ms(500);
fprintf(gsm,"ATD03446656938;\r");
delay_ms(500);
}//end flag1
}
else{
flag1 = true;
printf("temp3 ");
delay_ms(200);
}
}
void process_volt_2_ac()
{
set_adc_channel(2); // adc channel select
adc_value=read_adc();
ac_volt_2 = adc_value;
volt2_3 =0x30+ ac_volt_2/100;
volt2_2 =0x30+ (ac_volt_2/10) % 10;
volt2_1 =0x30+ (ac_volt_2/1) % 10;
lcd_line2(0);
printf(lcd_data,"T2_V=");
lcd_data(volt2_3);
lcd_data(volt2_2);
lcd_data(volt2_1);
lcd_data('V');
if(ac_volt_2>260){
44
output_high(relay2);
delay_ms(10);
if(flag4){
flag4 = false;
fprintf(gsm,"AT+CMGF=1\r");
delay_ms(500);
fprintf(gsm,"AT+CMGD=1\r");
delay_ms(500);
fprintf(gsm,"AT+CMGS=\"03446656938\"\r");
delay_ms(500);
fprintf(gsm,"Transformer2 Over Volts\r");
delay_ms(500);
}//end flag3
}
else{
flag4 = true;
output_low(relay2);
delay_ms(10);
}
}
void process_amps_2_ac()
{
set_adc_channel(3); // adc channel select
adc_value=read_adc();
45
ac_amps_2 = adc_value;
amps2_3 =0x30+ ac_amps_2/100;
amps2_2 =0x30+ (ac_amps_2/10) % 10;
amps2_1 =0x30+ (ac_amps_2/1) % 10;
lcd_line2(10);
printf(lcd_data,"T2_A=");
lcd_data(amps2_3);
lcd_data('.');
lcd_data(amps2_2);
lcd_data(amps2_1);
lcd_data('A');
if(ac_amps_2>60){
output_high(buzzer);
delay_ms(200);
output_low(buzzer);
printf("temp4 ");
putc('\0');
putc(13);
putc(10);
delay_ms(200);
if(flag2){
flag2 = false;
fprintf(gsm,"AT+CMGF=1\r");
delay_ms(500);
fprintf(gsm,"AT+CMGD=1\r");
delay_ms(500);
fprintf(gsm,"ATD03446656938;\r");
46
delay_ms(500);
}//end flag1
}
else{
flag2 = true;
printf("temp5 ");
delay_ms(200);
}
}
////////////////////////////////////////////////////////////
void process_temp_1()
{
set_adc_channel(4);
adc_value=read_adc();
temp_1 = adc_value;
temp1_3 =0x30+ temp_1/100;
temp1_2 =0x30+ (temp_1/10) % 10;
temp1_1 =0x30+ (temp_1/1) % 10;
lcd_line3(0);
printf(lcd_data,"TEMP1=");
lcd_data(temp1_2);
lcd_data(temp1_1);
lcd_data('C');
}
47
void process_temp_2()
{
set_adc_channel(5);
adc_value=read_adc();
temp_2 = adc_value;
temp2_3 =0x30+ temp_2/100;
temp2_2 =0x30+ (temp_2/10) % 10;
temp2_1 =0x30+ (temp_2/1) % 10;
lcd_line3(10);
printf(lcd_data,"TEMP2=");
lcd_data(temp2_2);
lcd_data(temp2_1);
lcd_data('C');
}
void process_send_pc(){
fputc('C',pc);
fputc('N',pc);
fputc('T',pc);
fputc('1',pc);
fputc(' ',pc);
fputc(volt1_3,pc);
fputc(volt1_2,pc);
fputc(volt1_1,pc);
fputc('V',pc);
fputc('C',pc);
fputc('N',pc);
fputc('T',pc);
fputc('2',pc);
fputc(' ',pc);
fputc(volt2_3,pc);
48
fputc(volt2_2,pc);
fputc(volt2_1,pc);
fputc('V',pc);
fputc('C',pc);
fputc('N',pc);
fputc('T',pc);
fputc('3',pc);
fputc(' ',pc);
fputc(amps1_3,pc);
fputc('.',pc);
fputc(amps1_2,pc);
fputc(amps1_1,pc);
fputc('A',pc);
fputc('C',pc);
fputc('N',pc);
fputc('T',pc);
fputc('4',pc);
fputc(' ',pc);
fputc(amps2_3,pc);
fputc('.',pc);
fputc(amps2_2,pc);
fputc(amps2_1,pc);
fputc('A',pc);
fputc('C',pc);
fputc('N',pc);
fputc('T',pc);
fputc('5',pc);
fputc(' ',pc);
fputc(temp1_2,pc);
fputc(temp1_1,pc);
fputc('C',pc);
fputc('C',pc);
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fputc('N',pc);
fputc('T',pc);
fputc('6',pc);
fputc(' ',pc);
fputc(temp2_2,pc);
fputc(temp2_1,pc);
fputc('C',pc);
delay_ms(100);
}
void process_oil_level(){
if(!input(oil_l) && input(oil_m) && input(oil_h)){
lcd_line4(0);
printf(lcd_data,"OIL_LEVEL= LOW ");
delay_ms(10);
}
else if(!input(oil_l) && !input(oil_m) && input(oil_h)){
lcd_line4(0);
printf(lcd_data,"OIL_LEVEL= MEDIUM");
delay_ms(10);
}
else if(!input(oil_l) && !input(oil_m) && !input(oil_h)){
lcd_line4(0);
printf(lcd_data,"OIL_LEVEL= HIGH ");
delay_ms(10);
}
else{
lcd_line4(0);
printf(lcd_data,"OIL_LEVEL= EMPTY ");
delay_ms(10); } }
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Appendix B: Hardware Schematics
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Appendix C: List of Components
Power supply:
Power supply 230VAC
Transformer 200 W or 0.25 KVA
Voltage regulator IC7805
LED 1.63V to 4.8V
Capacitor Different types
Embedded system:
Microcontroller PIC18F452
Crystal oscillator 20 MHz
LCD 20*4
GSM module:
GSM module SIM900D
Sensors:
Sensors CT, PT, LM35 and oil level sensor
MAX232
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Appendix D: Project Timeline
DATE
PROJECT ID 40TOTAL NUMBER
OF WEEKS IN PLAN
36
TITLE GSM Based Monitoring Of Distribution Transformer
No.STARTING
WEEKDESCRIPTION OF MILESTONE DURATION
1 1 Study of GSM System & Working 3 weeks
2 4 Study of transformer over load and power loss issues 3 weeks
3 7 Study for Database development/Programming 4 weeks
4 11 Familiarity with Complete System & Put it all together 4 weeks
5 15 Project Design 4 weeks
6 19 Hardware Implementation 6 weeks
7 25 Testing and Results Analysis 6 weeks
8 31 Documentation/Thesis Writing 6 weeks
* You can provide Gantt chart instead of filling this form, if you like
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