OVER LOAD PROTECTION OF

TRANSFORMER

A Project Report
Submitted in partial fulfillment of the requirements for the
award of the
B.TECH
IN ELECTRICAL ENGINEERING

Submitted By
ANUPAM SAMANTA (Roll No- 18201622067)
JOYDEEP RANA (Roll No- 18201622062)
RITTIK MONDAL (Roll No- 18201622036)
AKASH BHANDARI (Roll No- 18201622063)
SUNIPA PATRA (Roll No- 18201622007)

Under The Guidance of

Mr. BISWANATH BOXY
Assistant Professor Department of
Electrical Engineering

INSTITUTE OF SCIENCE AND

TECHNOLOGY
CHANDRAKONA TOWN, PASCHIM MEDINIPUR,
WEST BENGAL
SESSION 2024-2025
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CERTIFICATE
This is to certify that this project report entitled “Over Load Protection Of
Transformer” submitted by JOYDEEP RANA (Roll No- 18201622062) to the
Institute of Science and Technology, Chandrakona Town, Paschim Medinipur,
West Bengal (approved by A.I.C.T.E, New Delhi, Govt. of India &affiliated to
MAKAUT, West Bengal) during the year of ………. in partial fulfillment for
the award of the degree of B.TECH in Electrical Engineering is a bona fide
record of project work carried out by us under my supervision. The contents of
this report, in full or in parts, have not been submitted to any other Institution or
University for the award of any degree.

Date: 10.01.2025

Mr. BISWANATH BOXY

Guide
Assistant Professor
Dept. of Electrical Engineering
Institute of Science and Technology
Chandrokona Town, Paschim Medinipur

Mr. SAGNIK MAITI Mr. KARUNAMOY BHATTACHARYA

HOD Principal
Assistant Professor Institute of Science and Technology Chandrokona
Dept. of Electrical Engineering Town, Paschim Medinipur
Institute of Science and Technology
Chandrokona Town, Paschim
Medinipur

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DECLARATION
I, the undersigned, declare that this written submission represents my ideas in
my own words and where others' ideas or words have been included, I have
adequately cited and referenced the original sources. I also declare that I have
adhered to all principles of academic honesty and integrity and have not
misrepresented or fabricated or falsified any idea/data/fact/source in my
submission. I understand that any violation of the above will be cause for
disciplinary action by the Institute and can also evoke penal action from the
sources which have thus not been properly cited or from whom proper
permission has not been taken when needed.

Date : 10.01.2025

………………………………..
ANUPAM SAMANTA (Roll No- 18201622067)

………………………………..
JOYDEEP RANA (Roll No- 18201622062)

………………………………..
RITTIK MONDAL (Roll No- 18201622036)

………………………………..
AKASH BHANDARI (Roll No- 18201622063)

………………………………..
SUNIPA PATRA (Roll N0- 18201622007)

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PROJECT APPROVAL CERTIFICATE

This is to certify that the work embodied in this project entitled “Over Load
Protection Of Transformer” is carried out by JOYDEEP RANA (Roll No-
18201622062), is approved for the B.TECH in Electrical Engineering of Institute of
Science and Technology, approved by A.I.C.T.E, New Delhi, Govt. of India &
affiliated to MAKAUT,WB.

Date:
10.01.2025

Mr. BISWANATH BOXY ……………………………………

Guide
Assistant Professor Examiner
Dept. of Electrical Engineering ………………………………..
Institute of Science and
Technology Mr. Karunamoy
Chandrokona Town, Bhattacharya
Paschim Principal

Mr. SAGNIK MAITI

HOD Mr. KARUNAMOY BHATTACHARYA
Assistant Professor Principal
Dept. of Electrical Engineering, Institute of Science and Technology
Institute of Science and Technology Chandrokona Town, Paschim Medinipur

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ACKNOWLEDGEMENTS

I feel that it is a great privilege and honor to work under the guidance of
Assistant Professor Mr. BISWANATH BOXY, department of Electrical
Engineering for their wholehearted and invaluable guidance throughout my
project. This project would not have taken this shape without their
encouragement and blessing.
I am grateful to the faculty members and staff of Institute of Science and
Technology for their direct and indirect support for helping me in completion of
my project.
I would like to thank my friends and batch mates for their continuous help and
encouragement.
Finally, I want to express my gratitude to almighty for blessing and patience
without it may not be possible.
Date: 10.01.2025

………………………………..
ANUPAM SAMANTA (Roll No- 18201622067)

………………………………..
JOYDEEP RANA (Roll No- 18201622062)

………………………………..
RITTIK MONDAL (Roll No- 18201622036)

………………………………..
AKASH BHANDARI (Roll No- 18201622063)

………………………………..
SUNIPA PATRA (Roll N0- 18201622007)

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 CIRCUIT DIAGRAM

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 CONTENTS

1. AIM:-

2. OBJECTIVE:-

3. DESCRIPTION OF THE PROJECT:-

4. WORKING FUNCTION OF THE SYSTEM:-

5. FUNCTIONALITY OF THE SYSTEM:-

6. WHO ARE THE TARGET AUDIENCE:-

7. TECHNOLOGY REQUIRE: -

8. COMPONENTS USED:-

9. CIRCUIT DIAGRAM:-

10. ADVANTAGES

11. DISADVANTAGES:-

12. FUTURE SCOPE: -

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 AIM

 The aim of this project is to protect the transformer during overloading. It

will also have sensor to sense the Overload current of transformer and
cut off the extra load. Transformer Safety device are used to
reducing the extra load automatically, and transformer can be
protected.

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 OBJECTIVE

Objective: - The major objectives of this project are: -

 To verify how transformer safety system work.
 Decide the feature require.
 To verify how system cut off the load.
 To verify how timer sensor work.
 To verify how device, protect the transformer from overload.
 To verify how transformer safety operation work.
 To verify how much load is sufficient for transformer and how much
load for cut off.
 To verify how much voltage is requiring to operate the timer sensor.
 To verify how transformer will supply power for operating load.

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 DESCRIPTION OF THE PROJECT

Power travels from the power plant to house through an amazing system
called the power distribution grid. For power to be useful in a home or business, it
comes off the transmission grid and is stepped-down to the distribution grid.
This may happen in several phases. The place where the conversion from
"transmission" to "distribution" occurs is in a power substation. It has
transformers that step transmission voltages (in the tens or hundreds of thousands
of volts range) down to distribution voltages (typically less than 10,000 volts). It
has a "bus" that can split the distribution power off in multiple directions. It
often has circuit breakers and switches so that the substation can be disconnected
from the transmission grid or separate distribution lines can be disconnected from
the substation when necessary. Transformer is the vital component in the
electric power transmission and distribution system. The problem of overloads,
voltage variation and heating effects is very common. It takes lot of time to its
repair and also involves lot of expenditure. This work is all about protecting the
transformer under overload condition. Due to overload the efficiency gets reduced
and the secondary winding gets overheated or it may be burnt. So, by reducing
the extra load, the transformer can be protected. This can be done by transformer
safety sensor timer circuit through. When the load exceeds the reference value, the
transformer safety device automatically cut off the extra load. Therefore,
transformer safety device work efficiently under overload condition and the
damage can be prevented.

For home appliances, commercial and industrial loads, the transmitted voltage
must be steeped down to a distribution level. This may happen in several phases.
In sub- stations the voltage gets stepped down from transmission level (in the
tens or hundreds of thousands of volts range) to the distribution level (typically
less than 10,000 volts). A sensor circuit is designed to log the data from master
transformer and if it is found to be in overload condition, immediately extra
load will be disconnected to transformer and the transformer safe and protected.
Initially when we switched ON the load that load will be running by transformer.
Once load has been increased on transformer above its rated capacity then
safety device will automatically cut off the load.

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 WORKING FUNCTION OF THE
SYSTEM
Here, used Transformer 12V,750mA ,7805 three terminal voltage regulator is used
for voltage regulation. Bridge type full wave rectifier is used to rectify the AC
output of secondary of 230/12V step-down transformer. In this project we are
using the 4 load (L-1, L-2, L-3, L-4), 3 load are connected in parallel through
Transformer. And last load also connected through transformer with the help of
timer sensor circuit, which will connect and disconnect the load by sensing the
current. And we are using the 4 switch (S-1, S-2, S-3, S-4) which will connect in
series with each load and we are using R-1 resistor for protection of 3mm LED
Light load.

Transformer is a stepdown transformer and we called main transformer,

transformer has its own load handling capacity. (750Ma) In case of a normal
operation the transformer takes the load but as the load is beyond the rated
capacity of main transformer, then extra load is disconnected automatically and
protect the transformer.

Load switching network is provided to ON/OFF the load on the transformers

which is connected to load bank. we are using the 4 switch for each load. Over
current (750mA) and voltage(12V) set in the sensor circuit.

As we keep the switch S1 ON Then the load L1 Will be on and 188 mA current
will flow through transformer. And switch S2 ON then load L2 Will be on and 376
mA current will flow through the transformer and we will on the S3 Switch the
load L3 will be on and 564 mA current will flow through the transformer, then we
will on the last load L4 then current will increase the maximum set value of
sensor circuit that time sensor will disconnect the extra load L4 with in 5sec. and
transformer will be safe condition.

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 WHO ARE THE TARGET AUDIENCE?

 Functionality of the system:

 Automatic Load Cut off by sensor.

 No manual error fit and forget system.
 Highly sensitive low cost and reliable circuit.
 It prevents the main transformer from damage due to the problems
like overload and overheat.
 Un-interrupted power supply to the consumers is supplied.
 The load voltage and current are effectively monitored.
 Electrical Network Monitoring & Control.
 Electrical Integrated Control.
 integrated Protection and Control

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 WHO ARE THE TARGET AUDIENCE?

 Industrial areas.
 Used in substation
 Shopping malls.
 Process Industrial Power.
 Distribution Station.
 Agricultural Transformer.

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 TECHNOLOGY REQUIRE

 Embedded system.
 Sending technology.
 Automation technology.

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 COMPONENTS USED

S.N COMPONETS RATING QYT

1 Transformer 12 V/ 750mA 1
2 Wood Board A4 1
3 PCB Board 4x4 2
4 PCB Board 2x6 1
5 On/off 2 pin switch One Way 4
6 3 MM Led white color 3 mm 4
7 Resistor 1k Ohm 1
8 2 pin Screw terminal 2 pin 5
9 Diode IN4007 6
10 IC Regulator 6V 1
11 Battery Clip 1
12 Battery 9v 1
13 NPN Transistor BC547 1
14 Capacitor 25v 1000uf 1
15 Resistor 10k 1
16 Relay 5v 2
17 Strip single line I - type Pin Male header 1x7 1
18 Jumper Wire Female to Female 7
19 Jumper Wire male to female 5
20 2 PIN plug 230V 1
21 Double Sided Foam tape Normal size 1

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 TRANSFORMER

A transformer is an electrical device that transfers electrical energy between

two or more circuits through electromagnetic induction. Electromagnetic
induction produces an electromotive force within a conductor which is
exposed to time varying magnetic fields. Transformers are used to increase
or decrease the alternating voltages in electric power applications

The transformer reduces the voltage from mains to 12VAC

(RMS).

 Used Rating: -

 Type: - Step Down.

 Input Voltage: - 230V AC 50HZ.
 Output Voltage: - 12V AC 50HZ.
 Current Rating: - 750mA.

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 RECTIFIRE

A rectifier is an electrical device that converts alternating current, which

periodically reverses direction, to direct current, which flows in only one
direction.

 Used Rating: -
 Type: - Bridge Type
 Input Voltage: - 12 AC 50HZ.
 Output Voltage: - 6V Dc
 Current Rating: - 750mA.

 Used Components: -
 2 Pin Screw Terminal: - 2 Nos.
 1N4007 Diode: - 4 Nos.
 7806 IC Regulator: - 1 Nos.
 2x3 PCB Board : 1 Nos.

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 SENSOR CIRCUIT

Sensor Circuit sense the over load current and load exceeds the reference value,
and automatically cut off the extra load. Therefore, transformer safety device
work efficiently under overload condition and the damage can be prevented.

 Used Rating: -
 Type: - Sensor with timer
 Input Voltage: - 9V DC.
 Cutoff value: - 730mA.

 Used Components: -
 2 Pin Screw Terminal: - 1 Nos.
 1N4007 Diode: - 2 Nos.
 Capacitor 24V 1000 uf : - 1
Nos.
 2x3 PCB Board: -1 Nos.
 BC547 NPN Transistor: - 1Nos.
 1k Resistor: - 1 Nos.
 Male Strip Pin:- 2+2 = 4 Pin

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 LOAD CIRCUIT: -

An electrical load is simply any component of a circuit that consumes

power or energy. Its include light bulbs and appliances all load current
sense th

 Used Rating: -
 Input Voltage: - 6V DC.

 Used Components: -
 2x8 PCB Board: -1
Nos.
 LED: - 4Nos.
 1k Resistor: - 1 Nos.
 Male Strip Pin:- 14
Nos.
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 ADVANTAGES:-

The Transformer safety device has some advantages likes

1. Load protection
2. Increase the reliability.
3. Increase the efficiency
4. Protect the transformer

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 DISADVANTAGES:-

The Transformer safety device has some disadvantages likes

1. Increasing circulating currents
2. Increasing breaker capacity.
3. load capability
4. increased losses

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 APPLICATION:-

1. Transformer safety device use for load protection in substation.

2. Safety for transformer. And overloading condition
Mostly Transformer safety device use current rating increase in
system and load

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 FUTURE SCOPE:-

The future scope of our project is particularly in Substation. In

substations particularly during the peak hours there is a need for the
operation of additional transformer to supply the additional load
requirement. Our project automatically disconnects the load under
critical condition . Thus there is no need to operate extra
transformers under normal loads, particularly during off peak hours.

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