3. INTRODUCTION
A transformer is a static machines.
The word ‘transformer’ comes form the word ‘transform’.
Transformer is a device that changes AC electrical power at one
voltage level into AC electrical power at another voltage level through
the action of magnetic field, without a change in frequency.
It can be either to step-up or step down.
Generation
Station
TX1 TX1
Distribution
s
TX1
TX1
Transmission
System
33/13.5k
V
13.5/6.6kV
6.6kV/415
V
4. HISTORY
The principle of operation
of transformer are
discovered by Michael
faraday in 1831 and joseph
henry in 1832.
Faraday perform the first
experiment on induction
between coils of wire
including winding a pair of
coils around an iron ring
thus creating the first
closed core transformer.
8. WORKING PRINCIPLE
It works on faraday`s law
of electro magnetic
induction.
Faraday law- If the flux
passes through a coil of
wire ,a voltage will be
induced in turns of wire
.This voltage is
proportional to the rate
of change of flux .
9. Practical Transformer (Equivalent Circuit)
V1 = primary supply voltage
V2 = 2nd terminal (load) voltage
E1 = primary winding voltage
E2 = 2nd winding voltage
I1 = primary supply current
I2 = 2nd winding current
I1
’ = primary winding current
Io = no load current
V1 = primary supply voltage
V2 = 2nd terminal (load) voltage
E1 = primary winding voltage
E2 = 2nd winding voltage
I1 = primary supply current
I2 = 2nd winding current
I1
’ = primary winding current
Io = no load current
V1
I1 R1
X1
RC
Ic
Xm
Im
Io
E1 E2
V2
I1
’
N1: N2
R2
X2
Load
I2
11. TYPES
POWER TRANSFORMER
DISTRIBUTION
TRANSFORMER
It is used in transmission
network of higher voltages
for step –up and step-down
application .
These are loaded fully during
24 hr`s a day, so CU and Fe
losses takes place.
It is used for lower voltage
distribution network as a
means to end user
connectivity.
These are not loaded fully at
all time ,so Iron loss takes
place 24 hr`s a day and CU
loss based on load cycle.
13. PROTECTION OF TRANSFORMER
RELAY
A relay is an electrically
operated switch. These are
used to protect electrical
circuits from over loader
faults.
A conservator is an air tight
metal drum placed above the
level of the top of the tank
and connected it by pipe,
partially filled with oil.
16. EFFICIENCY
Efficiency=output power/input power.
All day efficiency= energy output over 24 hours/energy
input over 24 hours.
Voltage regulation=( V fullload-V noload)/V fullload
17. APPLICATION
• It can rise or lower the level of voltage and current in
AC circuit same power.
• It can be used to prevent DC from passing from one
circuit to other.
• It can isolate two circuits electrically .
• It is used in power system, power transmission and
distribution.
• It uses in application like rectification, furnaces,
electronic supplies.