Transformer

1. RAMAKRISHNA MISSION SHILPAMANDIRA
TOPIC- 3 PHASE TRANSFORMER, CONSTRUCTION AND APPLICATIONS
CHANDAN MAITRA
ELECTRICAL ENGINEERING DEPARTMENT
ROLL NO 19
2ND
YEAR 3RD
SEMESTER

2.  Transformer is a static bilateral electrical device.
 It transfers electrical energy from one circuit to another circuit without changing its
frequency.
 Used to increase or decrease voltage or current.
 It works only AC power supply.
 Transformers rated in KVA.
 Efficiency of a transformer is nearly about 95-99%
 It is electrically separate magnetically coupled.
INTRODUCTION

3. PARTS OF 3 PHASE TRANSFORMER
1.CORE
2.WINDING
3.INSULATION
4.TRANSFORMER TANK
5.TRANSFORMER OIL
6.BUCHHOLZ RELAY
7.CONSERVATOR TANK
8.BREATHER
9.EXPLOSION VENT
10.BUSHING
11.RADIATOR

4. CONSTRUCTION OF A THREE PASE TRANSFORMER
High voltage
bushing

5. WORKING PRINCIPLE OF THREE PHASE TRANSFORMER
• It works on FARADAY’S principle of mutual
induction.
• When AC supply is given to the primary winding
an alternating flux induced in the core.
• EMF is induced in the secondary winding for the
alternating flux .
• Current of transformer follows FLAMING’S right
hand rule.

6. EQUATION OF A TRANSFORMER
1.Induced EMF of a transformer,E=4.44ՓmfN
where,
E=RMS value of the induced emf
Փm = maximum value of flux
f=frequency of the supply
N=number of turns of the coil
2.Efficiency of a transformer(ɳ)=(output power/input power) x 100

7. Transformers for 3 phase circuits can be constructed by in one of the following ways:
1.Three separate single phase transformers are suitably connected for 3 phase operation.
such an arrangement is called a 3 phase bank transformers.
2.A single 3 phase transformer in which the cores and windings for all three phases are
combined in a single structure.
According to core construction 3 phase transformer can be divided into two types:

8. A 3 phase transformer consists of three transformers,either separate or combined on one
core. The primaries and secondaries of any 3 phase transformer can be independently
connected in either a star(Y) or delta( ).
Windings of athree phase transformer can be connected in various configurations as
1.star-star.
2.star-delta.
3.delta-star.
4.delta-delta.
5.open delta.
Three phase transformer winding connections

9. APPLICATIONS

10. MANUFRACTURERS

11. CONCLUSION
• Transformer is a static bilateral device that transfers electrical energy from one circuit to another circuit
without changing it’s frequency.
• Main part of the transformer are core, winding and insulation.
• It works only in AC
• Transformer oil acts as well as coolant and insulator.
• Efficiency of a transformer is nearly 95-99%.
• Three phase transformer is used to transfer large amount of power transfer.
• Used in power stations,industries,substations,railways etc.
• As per connection 3 phase transformers are STAR-STAR,STAR-DELTA,DELTA-STAR,DELTA-DELTA, OPEN DELTA.

12. THANK YOU