INFO INSTITUTE OF ENGINEERINGSathy road,Kovilpalayam,Coimbatore-641107

PAPER TITLE

GSM BASED EFFECTIVE REMOTE MONITORING SYSTEM FOR

A SINGLE PHASE SWITCHABLE TRANSFORMER

PREPARED BY

AUTHOR : S.A.SIVAKUMAR Assistant professor Info Institute of engineering

CO-AUTHORS : J.AISWARYA, S.ARAVIND KUMAR S.KALAIVANI, A.KUPPURATHINAM

Final ECE,Info institute of engineering.

ABSTRACT

This project presents design and implementation of a mobile embedded system to monitor and record key operation indicators of a distribution transformer like load currents, transformer oil temperatures. The proposed online monitoring systems integrates a Global Service Mobile (GSM) modem, withstand alone single chip microcontroller and sensor packages. It is installed at the transformer site and the above mentioned parameters are recorded using the built-in 8-channelanalog to digital converter (ADC) of the embedded system. The acquired parameters are processed and recorded in the system memory. If there is any abnormality or an emergency situation the system sends SMS (Short Message Service) messages to designated mobile telephones containing information about the abnormality according to some predefined instructions and policies that are stored on the embedded system EEPROM. This mobile system will help the utilities to optimally utilize transformers and identify problems before any catastrophic failure.

The electrical equipment in the continuous process industries such as sugar, cement, and textile and also in the electricity distribution, the transformers are used. These are operating continuously. Therefore, a reliable monitoring system is necessary to protect the transformers against any major faults. In olden transformers, these facilities are not provided to effectively monitor them throughout the operating period. The concerned authorities attended the faulty transformer, once it is out of service. Hence, an automatic monitoring system is

necessary to protect the transformers from faults.

This project presents the design and development of an automatic real time monitoring system consisting of PIC micro controller, sensors and GSM modem.

INTRODUCTION:

1.1 OBJECTIVE:The main objective of this project

is to design an automatic real time monitoring system in the following steps:

To design the overall system

To design the hardware To develop the embedded

software using embedded-C To test the system

The proposed project “Effective remote monitoring system for a single phase 1 KVA energy efficient switchable transformer” aims in monitoring the transformer from remote place using GSM. To maintain uninterrupted power supply and also to protect the transformer from faults, an automatic monitoring system is needed.

1.2 PRESENT SCENARIO OF TRANSFORMER MONITORING:

At present the manual method of monitoring is adopted that is using analog meters the engineer will manually monitor the operating condition of the transformer.

1.3 NEED OF THE WORK:Transformers are a vital part of the

transmission and distribution system. Monitoring transformers for problems before they occur can prevent faults that are costly to repair and result in a loss of service. Current systems can provide

information about the state of a transformer, but are either offline or very expensive to implement. This report outlines a new approach that is based on using remote monitoring system of the transformer using pic microcontroller with help of GSM technology. Remote condition monitoring of transformers has already been widely known and implemented with various techniques The monitoring is mostly carried out to reveal significant parameters that reflect conditions of transformers, such as voltages, currents, and temperatures. The existence of the Internet provides further flexible remote monitoring in many areas, including power transformers. Thus, many approaches are developed to perform remote monitoring throughout the world by using a network that is connected to the Internet.

1.4 PROPOSED SYSTEM:

The system hardware has four hardware modules as embedded system, GSM modem, mobile users and GSM networks and pc based server.

The embedded module is located at the transformer site. It is utilized to acquire, process, display, transmit and receive the parameters to/from the GSM modem.

The second is the GSM module. It is the link between the embedded system and the public GSM network.

The third is utility module that has a pc based-server located at the utility control

center. The server is attached to GSM modem that receives and transmits SMS from the transformer site via the GSM module.

1.4.1 DEMERITS OF THE EXISTING SYSTEM:

Time consuming.

Expensive

The monitoring system must be

designed for long-time operation.

The monitoring system should

provide information for a more

reliable estimation of the

transformer’s remaining lifetime.

It should support the introduction

of condition-based maintenance

and help to avoid unexpected

outages.

1.4.1 MERITS OF THE PROPOSED SYSTEM:

The remote monitoring system for the switchable transformer is however quite unique because it includes measurements of the key operating parameters of the temperature.

Moreover, the system is useful not only in monitoring the parameters of the transformer (such as voltages and currents) but also in controllingthe switching devices and performing switching at appropriate timings

It requires less power and space and it is portable

Maintains uninterrupted power supply.

Protect the transformer from faults.

Automatically monitors the transformer no manual work is needed.

Remote monitoring is possible

SYSTEM ARCHITECTURE:

PIC MICROCONTROLLER

[16F877A]

FEATURES:

• High-performance RISC CPU.

• Only 35 single word instructions

to learn.

• Operating speed: DC - 20 MHz

clock input DC - 200 ns instruction

cycle.

• Up to 8K x 14 words of FLASH

Program Memory, Up to 368 x 8

bytes of Data Memory (RAM) Up

to 256 x 8 bytes of EEPROM data

memory.

• Interrupt capability (up to 14

sources)

• Eight level deep hardware stack

• Direct, indirect and relative

addressing modes.

• Power-on Reset (POR).

• Power-up Timer (PWRT) and

Oscillator Start-up Timer (OST).

• Watchdog Timer (WDT) with its

own on-chip RC oscillator for

reliable operation.

• Programmable code-protection.

• Power saving SLEEP mode.

• Selectable oscillator options.

• In-Circuit Serial Programming

(ICSP) .

• Single 5V In-Circuit Serial

Programming capability.

• In-Circuit Debugging via two

pins.

• Processor read/write access to

program memory.

• Wide operating voltage range:

2.0V to 5.5V.

• High Sink/Source Current: 25

mA.

• Low-power consumption.

3.3.1 MEMORY ORGANIZATION

There are three memory blocks in

each of the PIC16F877A MCUs. The

Program Memory and Data Memory have

separate buses so that concurrent access

can occur and is detailed in this section.

The EEPROM data memory block is

detailed next Section. Additional

information on device memory may be

found in the PIC micro Mid-Range

Reference Manual.

PROGRAM MEMORY

ORGANIZATION

The PIC16F877A devices have a

13-bit program counter capable of

addressing an 8K x 14 program memory

space. The PIC16F877/876 devices have

8K x 14 words of FLASH program

memory, and the PIC16F873/874 devices

have 4K x 14. Accessing a location above

the physically implemented address will

cause a wraparound. The RESET vector is

at 0000h and the interrupt vector is at

0004h.

DATA MEMORY ORGANIZATION:

The data memory is partitioned

into multiple banks which contain the

General Purpose Registers and the Special

Function Registers. Bits RP1

(STATUS<6>) and RP0 (STATUS<5>)

are the bank select bits. Each bank extends

up to 7Fh (128 bytes). The lower locations

of each bank are reserved for the Special

Function Registers

GENERAL PURPOSE REGISTER

The register file can be accessed

either directly or indirectly through the

File Select Register (FSR).

SPECIAL FUNCTION REGISTERS

The Special Function Registers are

registers used by the CPU and peripheral

modules for controlling the desired

operation of the device. These registers are

implemented as static RAM. The Special

Function Registers can be classified into

two sets: core (CPU) and peripheral.

3.4 GSM

GSM (Global System for Mobile

Communications, originally Groupe

Spécial Mobile), is a standard set

developed by the European

Telecommunications Standards Institute

(ETSI) to describe protocols for second

generation (2G) digital cellular networks

used by phones. The GSM standard was

developed as a replacement for first

generation (1G) analog cellular networks,

and originally described a digital, circuit

switched network optimized for full

duplex voice telephony. This was

expanded over time to include data

communications, first by circuit switched

transport, then packet data transport via

GPRS (General Packet Radio Services)

and EDGE (Enhanced Data rates for GSM

Evolution or EGPRS).

Further improvements were made when

the 3GPP developed third generation (3G)

UMTS standards followed by fourth

generation (4G) LTE Advanced standards.

3.5 LCD

A Liquid crystal display is a flat

panel display, electronic visual display,

or video display that uses the light

modulating properties of liquid crystals.

Liquid crystals do not emit light directly.

LCDs are available to display arbitrary

images (as in a general-purpose computer

display) or fixed images which can be

displayed or hidden, such as preset words,

digits, and 7-segment displays as in

a digital clock. They use the same basic

technology, except that arbitrary images

are made up of a large number of

small pixels, while other displays have

larger elements.

PROCESSFLOW:

start of thread

start priority of thread

scan keypad

A Key is

Pressed ?

process based on pressed key

sleep

y

n

TRANSFORMER:

start of subroutine

print requested address to UART

NutTcpSend(Sock,SMB,LSMB); NutTcpSend(sock,TCPT,xreq,lreq);

NutTcpSend(Sock,TCPTEMB,LEMB); NutTcpRecieve(sock,buff,sizeof(buff));

print recieved data to UART

parse Data of parameters&Display

to LCD

return

A transformer is a power

converter  that transfers electrical

energy from one circuit to another

through inductively coupled conductors—

the transformer's coils. A

varying current in the first

or primary winding creates a

varying magnetic flux in the transformer's

core and thus a varying magnetic

field through the secondary winding. This

varying magnetic field induces a

varying electromotive force (EMF), or

"voltage", in the secondary winding. This

effect is called inductive coupling.

If a load is connected to the secondary

winding, current will flow in this winding,

and electrical energy will be transferred

from the primary circuit through the

transformer to the load. In an ideal

transformer, the induced voltage in the

secondary winding (Vs) is in proportion to

the primary voltage (Vp) and is given by

the ratio of the number of turns in the

secondary (Ns) to the number of turns in

the primary (Np) as follows:

By appropriate selection of the ratio of

turns, a transformer thus enables

an alternating current (AC) voltage to be

"stepped up" by making Ns greater than Np,

or "stepped down" by making Ns less

than Np. The windings are coils wound

around a ferromagnetic core, air-core

transformers being a notable exception.

SOFTWARE DESCRIPTION

5.1 HITECH C

HI-TECH C PRO compilers can also be

operated in Lite mode with no memory

restrictions or time limits. It supports all

devices, however OCG optimizations

Are not available. HI-TECH Software has

provided this freeware compiler, HI-TECH

C PRO compilers in Lite mode, as a low-

cost tool for hobbyists and students,

however the license allows its use for

commercial purposes as well. It is ideal as

a teaching tool for an introduction to the C

language and embedded

Programming.

5.2 MPLAB SIMULATOR:

MPLAB SIM is a discrete-event

simulator for the PIC microcontroller

(MCU) families. It is integrated into

MPLAB IDE integrated development

environment. The MPLAB SIM debugging

tool is designed to model operation of

Microchip Technology's PIC

microcontrollers to assist users in

debugging software for these devices

MPLAB IDE is an integrated

development environment that provides

development engineers with the flexibility

to develop and debugs firmware for

various Microchip devices

MPLAB IDE is a Windows-based

Integrated Development Environment for

the Microchip Technology Incorporated

PIC microcontroller (MCU) and dsPIC

digital signal controller (DSC) families.

The MPLAB X IDE is the new graphical, integrated debugging tool set for all of Microchip’s

more than 800 8-bit, 16-bit and 32-bit MCUs and digital signal controllers, and memory devices.

It includes a feature-rich editor, source-level debugger, project manager, software simulator, and

supports Microchip’s popular hardware tools, such as the MPLAB ICD 3 in-circuit debugger,

PIC kit™ 3, and MPLAB PM3 programmer. Based on the open-source Net Beans platform,

MPLAB X runs on Windows® OS, MAC® OS and Linux, supports many third-party tools, and

is compatible with many Net Beans plug-ins

5.2.1 MPLAB IDE FEATURES:

In the MPLAB IDE, you can:

Create source code using the built-in

editor.

Assemble, compile and link source

code using various language tools. An

assembler, linker and librarian come

with MPLAB IDE. C compilers are

available from Microchip and other

third party vendors.

Debug the executable logic by

watching program flow with a

simulator, such as MPLAB SIM, or in

real time with an emulator, such as

MPLAB ICE. Third party emulators

that work with MPLAB IDE are also

available.

Make timing measurements.

View variables in Watch windows.

Program firmware into devices with

programmers such as PICSTART Plus

or PRO MATE II.

Find quick answers to the questions

from the MPLAB IDE on-line Help.

SYSTEM REQUIRES:

The following minimum configuration

is required to run MPLAB IDE (6.20):

PC-compatible Pentium class system

Microsoft Windows 98 SE,

Windows 2000 SP2, Windows NT

4.0 SP6,Windows ME, Windows

XP

64 MB memory (128MB

recommended)

85 MB of hard disk space

Internet Explorer 5.0 or greater

5.2.2 TEST CODE WITH

SIMULATOR:

In order to test the code, we need

some kind of software or hardware that

will execute the PIC micro instructions. A

debug execution tool is a hardware or

software tool that is used to inspect code as

it executes a program (in this case

tutor84.asm). Hardware tools such as

MPLAB ICE or MPLAB ICD 2 can

execute code in real devices, but if we

don't have hardware yet, the MPLAB

simulator can be used to test the code.

The simulator is a software

program that runs on the PC to simulate

the instructions of the PIC micro MCU.

It does not run in "real time," since

the simulator program is dependent upon

the speed of the PC, the complexity of the

code, overhead from the operating system

and how many other tasks are running.

SIMULATION OUTPUT

In the First Phase, The main modules in the projects like LCD interface, ADC routine,

GSM routines. The results are shown in Fig 6.1 to Fig 6.4.

Figure 6.1 process1_GSM detection

Figure 6.2 process2_GSM detection

Figure 6.3 process3_Message Display in LCD

Figure 6.4 process4_ GSM at command

FUTURE ENHANCEMENTS:

The remote monitoring system that

had been developed was very useful in

understanding conditions of the

transformer. It also enables operators to

monitor the parameters away from the

transformer.

The result of the experimentations

showed that the system could handle

remote monitoring control tasks for the 1-

Kva switchable transformer. The system

may contain either embedded Ethernet

units or computers or a combination of

them. The use of embedded Ethernet units

as a client and a server however provides

the most compact system.

The experimental results obtained

in this research only used a limited amount

of oil sample. Future work could utilize

more samples that represent any common

failure to the transformer. By collecting

more samples, it is possible to achieve

more robust and accurate diagnostic

capability.

The diagnostic module designed in

this research still require a USB

Connection to main computer in order to

transfer the data. This limits the portability

and increases the work needed for

installation. An area of future research

could focus on the development of a

hardware and signal-processing module

that would utilize wireless communication.

Finally, there is also a great amount

of work that can be done in the area of

pattern recognition of faults and life

expectancy. Once a large database of data

has been collected from several different

transformers and different types of

faults have been witnessed, it will be

possible to try to classify behaviors and

how they relate to impending failures. In

the long term, the pattern classification

could lead to life expectancy predictions

for the transformer.

REFERENCES

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and P. Verho( 2007), “Studies to

utilize loading guides and ANN for

oil-immersed distribution transformer

condition monitoring,” IEEE Trans.

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207.

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Machado( 2006),

“Programmable electronic

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in-service power transformers,”IEEE

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pp. 625–634.

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