PROTECTION OF X'FORMER

1. IPCOWALA INSTITUTE OF ENGINEERING TECHNOLOGY
(DEP.:- ELECTRICAL & ELECTRONICS ENGINEERING)
Transformer Protection using
Microcontroller and GSM
Technology
PREPARED BY:
KARTIK PATEL

2. 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

3. 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.

4. OVERVIEW OF SEMINAR
• PIC Microcontroller
• Transformers
• Precision rectifier
• Current transformer
• Voltage transformer
• Relay driver circuit with relays
• GSM

5. 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.

6. BLOCK DIAGRAM

7. 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

8. 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.

9. CIRCUIT DIAGRAM

10. 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.

11. PARTS OF CIRCUIT DIAGRAM
• Power supply
• Atmega328/168 microcontroller
• Current measurement
• Voltage measurement
• Relay

12. 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.

13. BLOCK DIAGRAM OF
POWER SUPPLY

14. 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.

15. TRANSFORMERS

16. 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

17. 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

18. BRIDGE RECTIFIER

19. 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.

20. 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.

21. PIN CONFIGURATION

22. VOLTAGE MEASUREMENT

23. 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.

24. CURRENT MEASUREMENT

25. 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

26. RELAYS

27. 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.

28. ADVANTAGES
• It prevents circuitry from damage
• Avoid interruption in power supply
• Remove power black out at pick hours
• Accident prevention
• Transformer safety

29. DISADVANTAGES
• Cost of whole circuitry will increased
• Circuitry become bulky

30. 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

31. 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

32. THANK YOU