Transformer Protection using Microcontroller and GSM

Technology

IPCOWALA INSTITUTE OF ENGINEERING TECHNOLOGY(DEP.:- ELECTRICAL & ELECTRONICS ENGINEERING)

PREPARED BY:KARTIK PATEL

CONTENT

• INTRODUCTION

• OVERVIEW OF

SEMINAR

• OBJECTIVES

• BLOCK DIAGRAM

• CIRCUIT DIAGRAM

• POWER SUPPLY

• TRANSFORMER

• RECTIFIER

• BRIDGE RECTIFRER

• MICROCONTROLLER

• VOLTAGE MEASUREMENT

• CURRENT MEASUREMENT

• RELAYS

• ADVANTAGES

• DISADVANTAGES

• FUTURE SCOPE

• REFERENCES

• THANK YOU

INTRODUCTION

• The Project is all about the protecting transformer

under overload condition

• Drop in efficiency and over voltage in transformer

can be prevented with the help of this project.

• Load sharing is possible and the life of the

transformer is increased.

• If short circuit fault is occurs the transformer will get

protected.

OVERVIEW OF SEMINAR

• PIC Microcontroller

• Transformers

• Precision rectifier

• Current transformer

• Voltage transformer

• Relay driver circuit with relays

• GSM

OBJECTIVES

• The main aim of the project is transformer sharing

whenever load is increased for certain value and also

sending this change in information to the respective

authority via SMS by using GSM modem.

• The objective of this project is to protect the

Domestic supply and Power Transformers from over

load power.

BLOCK DIAGRAM

EXPLANATION OF BLOCK

DIAGRAM

• TRANSFORMER

‾ Transformer is used for protecting purpose

• RELAY and RELAY DRIVER

‾ It is electrically operated switch

‾ It disconnect circuit when current flow becomes

greater than desired value.

• CURRENT TRANSFORMER

‾ It is a step down transformer

‾ Divide current according to load

BLOCK DIAGRAM Cont’d

• Precision rectifier

– It converts AC current to DC current.

• Microcontroller

– It compares voltage with reference value.

– It drive a relay circuit as per the reference value

and actual value.

• GSM Modem

– It performs digital cellular communication.

– It gives digital info to respective authority via

SMS.

CIRCUIT DIAGRAM

EXPLANATION OF CIRCUIT

DIAGRAM

• 230v ac supply is step down using CT and PT

• Whole circuit operates on 5v or 12v supply, this

supply provided by using bridge rectifier

• The o/p of CT and PT given measurement circuit.

• Atmega microcontroller compares the o/p with

reference value.

• Reference value are given by using keypad to the

microcontroller.

• Relay are operated by Atmega microcontroller

• LCD displays the value of load.

PARTS OF CIRCUIT DIAGRAM

• Power supply

• Atmega328/168 microcontroller

• Current measurement

• Voltage measurement

• Relay

POWER SUPPLY

• Whole circuitry work on +5v, 12v & -12v DC power

supply of 230v AC is applied to the transformer.

• By using transformer, rectifier, filters, Ic regulators,

etc. we get the desired output.

BLOCK DIAGRAM OF

POWER SUPPLY

DISCRIPTION OF POWER

SUPPLY• Transformer

– 230v AC is step down to 5v and 12v as per

requirement of circuitry.

• Rectifier

– It converts the AC supply into pulsating DC supply.

• Filters

– It removes the ripples from the DC supply which

are coming from the rectifier.

• IC regulator

– IC regulator is providing the fixed DC voltage

which load (i.e. relay and microcontroller) required.

TRANSFORMERS

TRANSFORMER Cont’d

• An electrically isolated but magnetically coupled

device, which transformed electrical power from one

circuit to another circuit without changing frequency

is called TRANSFORMER.

• There are basically two types

‾ Step Down transformer

‾ Step Up transformer

• We are using step down transformer

• CT and PT are step down transformer

RECTIFIER

• It is a circuit which converts AC to DC.

• Output of a rectifier is not pure DC, it is pulsating DC.

• There are basically two types of rectifier

– Half wave rectifier

– Full wave rectifier

-Bridge rectifier

• We are using Bridge rectifier to get desired DC output

voltage of +5v,+12v, and -12v

BRIDGE RECTIFIER

WORKING OF BRIDGE RECTIFIER

• At +ve half cycle there is +ve potential at node A and

–ve potential at node B.

• Due to which D1 and D4 are in forward bias and D2

and D3 are work in reverse bias, we get DC voltage of

+half cycle.

• Similarly at –ve half cycle there is +ve potential at

node B and –ve potential at node A.

• Due to which D2 and D3 are in forward bias and D1

and D4 are work in reverse bias, we get DC voltage of

–ve half cycle.

• Finally we get o/p that is pulsating DC.

ATMEGA MICROCONTROLLER

• The ATmega328 is a low-power CMOS 8-bit

microcontroller based on the AVR enhanced RISC

architecture.

• Atmega are popular for low cost , wide availability,

large user base, free development tools and serial

programming (and reprogramming with flash

memory) capability so we are using this

microcontroller.

PIN CONFIGURATION

VOLTAGE MEASUREMENT

VOLTAGE MEASUREMENT Cont’d

• Potential transformer(PT) is use to monitor the supply

voltage.

• Supply voltage that has to be monitor is step down by

PT.

• The step down voltage is rectified by bridge rectifier.

• Different DC voltage which required by relay and

MC are to be given by using IC regulator .

• The function of voltage measurement is to provide

step down voltage.

CURRENT MEASUREMENT

CURRENT MEASUREMENT Cont’d

• Current transformer(CT) is use to step down current

• The circuit is design to monitor the supply current

• The step down current is converted by voltage with

the help of shunt register

RELAYS

RELAYS Cont’d• It is an electromagnetic device which is use as switch

• It has a magnetic coil which is use to connect or

disconnect the transformer

• It is electrically operated switch

• It disconnect circuit when current flow becomes greater

than desired value

• Both relays are controlled by relay driver

• If the current consumption is above 50% then the lower

relay get switch OFF through the relay driver circuit.

• IF the current consumption is above 80% then the all

relay get switch OFF through the relay driver circuit.

ADVANTAGES

• It prevents circuitry from damage

• Avoid interruption in power supply

• Remove power black out at pick hours

• Accident prevention

• Transformer safety

DISADVANTAGES

• Cost of whole circuitry will increased

• Circuitry become bulky

FUTURE SCOPE• GSM-(global system for mobile communication)

– GSM is globally accepted standard for digital cellular

communication

– Frequency range 900MHZ to 1990MHZ

– PIC microcontroller sends actual load value to the

authority via SMS by using GSM

– In our project we are using only transmitter to

transmit the data

– In our project we are not yet get the required

frequency GSM

REFERENCES

• Electrical technology volume 3rd and 4th by- B. L.

Theraja,1st edition 1959,reprint 2008

• Advance microprocessor and microcontrollers by- A. P.

Godse,3rd edition 2003

• Linear integrated circuits J.S. Katre, 4th edition 2002

• IEEE Transaction on Power Electronics, vol. 19, no. 6,

November 2004 1551by-Mohammad N. Marwali,

Member, IEEE, Jin-Woo Jung, Student Member, IEEE,

and Ali Keyhani, Fellow, IEEE

THANK YOU