The document is a presentation by Group-E on transformers. It introduces the group members and their topics. Fatema will discuss step-up and step-down transformers. Fazlay Rabby will cover issues with three-phase transformers. Roudra will discuss transformer types. Mehedi will talk about transformer resistance and magnetic leakage. Alamgir will present the transformer equivalent circuit. Fatema explains that a step-up transformer has more primary turns than secondary turns, increasing voltage, while a step-down transformer reduces voltage with fewer primary turns. Mehedi discusses how transformer windings introduce resistance and magnetic leakage contributes to reactance in the equivalent circuit model.

1. Welcome to our Presentation
Group-E
1.Abu mohammad Fazlay rabby
Id:152-33-2619
2.Fatema tuj zohra
Id:152-33-2610
3.Mehedi hasan
Id:152-33-2625
4.Abdur Rahman
Id:152-33-2692
5.Roudra Gourab
ID:152-33-2693

2. Contents
• Fazlay Rabby ------Problem with 3-phase transformer.
• Roudro---Typs of transformer
• Fatema---Step up and Step down Transformer
• Mehedi ----Transformer with resistance and magnetic leakage
• Alamgir--Equivalent Circuit

3. Three phase transformer
• 3-φ supplies are used for
electrical power generation,
transmission, and distribution,
as well as for all industrial uses

4. Problem with three phase transformer
• Greater cost of standby Units.
• Increased cost and inconvenience of repairs.
• In Single Phase transformer ( three Single Phase Transformer) failure of
one transformer, the other two, Single Phase Transformer still supply the
power, while it is not possible in case of failing a Three Phase
Transformer.
• Each of the 1Ø transformers weight substantially less than the
corresponding 3Ø transformer. This allows a line truck to hang
transformers where a 3Ø transformer might need a crane.

5. Topic-Types of Transformer
Presented by
Gourab Das-152-33-2693

9. Presentation on Step up & step down
transformer
• Fatema tuj johra
• ID-152-33-2610

10. Step-up Transformer
• On a step-up transformer there are more turns on the secondary coil
than the primary coil. The induced voltage across the secondary coil is
greater than the applied voltage across the primary coil or in other
words the voltage has been “stepped-up”.

11. Step up transformer

12. Step down transformer
• A step down transformer has less turns on
the secondary coil that the primary coil. The
induced voltage across the secondary coil
is less the applied voltage across the
primary coil or in other words the voltage is
“stepped-down”.

13. Step down transformer

14. Generally, both primary and secondary windings of
electrical power transformer are made of copper.
Copper is a very good conductor of current but not
a super conductor. Actually, super conductor and
super conductivity both are conceptual, practically
they are not available. So both windings will have
some resistance. This internal resistance of both
primary and secondary windings is collectively
known as resistance of transformer.
Transformer’s Winding resistance

15. Transformer’s Winding resistance in a
exact equivalent circuit

16. Transformer’s magnetic leakage
In a transformer it is observed that, all the
flux linked with primary winding does not get
linked with secondary winding. A small part of
the flux completes its path through air rather
than through the core and this small part of
flux is called as leakage flux or magnetic
leakage in transformers.

17. Transformer’s magnetic leakage in a exact
equivalent circuit

18. Transformer’s impedance
As we said, both primary and secondary windings will have
resistance and leakage reactance. These resistance and
reactance will be in combination, is nothing but impedance
of transformer. If R1 and R2 and X1 and X2 are primary and
secondary resistance and leakage reactance of transformer
respectively, then Z1 & Z2 impedance of primary and
secondary windings are respectively,

19. Presentation
on
Magnetic Leakage in Transformer
Presented by
Md. Abdur Rahman
ID:152-33-2692
Sec:B ; Group:E
Dept. of EEE

20. Index
• Magnetic Leakage
• Transformer With Resistance And Leakage Reactance
• Vector diagram

21. Magnetic Leakage in Transformer
• Magnetic Leakage can be defined as the passage of
magnetic flux outside the path along which it can do
useful work.

22. • In a transformer it is observed
that, all the flux linked with
primary winding does not get
linked with secondary winding.
A small part of the flux
completes its path through air
rather than through the core ,
and this small part of flux is
called as leakage flux of
transformers.

23. Transformer With Resistance And Leakage
Reactance

24. Vector diagram for different kinds of the load
( When Load is Non-Inductive) ( When Load is Inductive) ( When Load is Capacitive)