PPT: Practical Transformer, Transformer Losses & Efficiency, 3 Phase Transformer | Basic Electrical Technology - Electrical Engineering (EE) PDF Download

 Page 1


TRANSFORMER
 INTRODUCTION
 TRANSFORMER EQUATION
 TRANSFORMER RATING
 PRACTICAL TRANSFORMER
 SINGLE PHASE TRANSFORMER
 TRANSFORMER LOSSES
 TRANSFORMER EFFICIENCY
 VOLTAGE REGULATION
 THREE PHASE TRANSFORMER
Page 2


TRANSFORMER
 INTRODUCTION
 TRANSFORMER EQUATION
 TRANSFORMER RATING
 PRACTICAL TRANSFORMER
 SINGLE PHASE TRANSFORMER
 TRANSFORMER LOSSES
 TRANSFORMER EFFICIENCY
 VOLTAGE REGULATION
 THREE PHASE TRANSFORMER
Introduction Introduction
? Atransformer is a static static machines machines.
?? The The word word ‘transformer’ ‘transformer’comes comes form form the the word word ‘transform’ ‘transform’. .
? Transformer is not not an an energy energy conversion conversion device device, but is a device device that that
changes changes AC AC electrical electrical power power at at one one voltage voltage level level into into AC AC electrical electrical
power power at at another another voltage voltage level level through through the the action action of of magnetic magnetic field, field,
without without a a change change in in frequency frequency. .
?? It Itcan can be be either either to to step step- -up up or or step step down down. .
Generation Generation
Station Station
TX1 TX1
Distribution Distribution
ss TX1
TX1
TTransmission ransmission
System System
33/13.5k 33/13.5k
VV
13.5/6.6kV 13.5/6.6kV
6.6kV/415 6.6kV/415
VV
Consumer Consumer
Page 3


TRANSFORMER
 INTRODUCTION
 TRANSFORMER EQUATION
 TRANSFORMER RATING
 PRACTICAL TRANSFORMER
 SINGLE PHASE TRANSFORMER
 TRANSFORMER LOSSES
 TRANSFORMER EFFICIENCY
 VOLTAGE REGULATION
 THREE PHASE TRANSFORMER
Introduction Introduction
? Atransformer is a static static machines machines.
?? The The word word ‘transformer’ ‘transformer’comes comes form form the the word word ‘transform’ ‘transform’. .
? Transformer is not not an an energy energy conversion conversion device device, but is a device device that that
changes changes AC AC electrical electrical power power at at one one voltage voltage level level into into AC AC electrical electrical
power power at at another another voltage voltage level level through through the the action action of of magnetic magnetic field, field,
without without a a change change in in frequency frequency. .
?? It Itcan can be be either either to to step step- -up up or or step step down down. .
Generation Generation
Station Station
TX1 TX1
Distribution Distribution
ss TX1
TX1
TTransmission ransmission
System System
33/13.5k 33/13.5k
VV
13.5/6.6kV 13.5/6.6kV
6.6kV/415 6.6kV/415
VV
Consumer Consumer
MZS
FKEE, UMP
Transformer Equation
? Faraday’s Law states that,
? If the flux passes through a coil of wire, a voltage will be
induced in the turns of wire. This voltage is directly
proportional to the rate of change in the flux with respect
of time.
If we haveNN turns of wire,
dt
t d
Emf V
ind ind
) ( F
- = =
dt
t d
N Emf V
ind ind
) ( F
- = =
Lenz’s Law
Page 4


TRANSFORMER
 INTRODUCTION
 TRANSFORMER EQUATION
 TRANSFORMER RATING
 PRACTICAL TRANSFORMER
 SINGLE PHASE TRANSFORMER
 TRANSFORMER LOSSES
 TRANSFORMER EFFICIENCY
 VOLTAGE REGULATION
 THREE PHASE TRANSFORMER
Introduction Introduction
? Atransformer is a static static machines machines.
?? The The word word ‘transformer’ ‘transformer’comes comes form form the the word word ‘transform’ ‘transform’. .
? Transformer is not not an an energy energy conversion conversion device device, but is a device device that that
changes changes AC AC electrical electrical power power at at one one voltage voltage level level into into AC AC electrical electrical
power power at at another another voltage voltage level level through through the the action action of of magnetic magnetic field, field,
without without a a change change in in frequency frequency. .
?? It Itcan can be be either either to to step step- -up up or or step step down down. .
Generation Generation
Station Station
TX1 TX1
Distribution Distribution
ss TX1
TX1
TTransmission ransmission
System System
33/13.5k 33/13.5k
VV
13.5/6.6kV 13.5/6.6kV
6.6kV/415 6.6kV/415
VV
Consumer Consumer
MZS
FKEE, UMP
Transformer Equation
? Faraday’s Law states that,
? If the flux passes through a coil of wire, a voltage will be
induced in the turns of wire. This voltage is directly
proportional to the rate of change in the flux with respect
of time.
If we haveNN turns of wire,
dt
t d
Emf V
ind ind
) ( F
- = =
dt
t d
N Emf V
ind ind
) ( F
- = =
Lenz’s Law
MZS
FKEE, UMP
Transformer Equation
? For an ac sources,
? Let V(t) = V
m
sin wt
i(t) = i
m
sin wt
Since the flux is a sinusoidal function;
Then:
Therefore:
Thus:
t t
m
w sin ) ( F = F
m m ind ind
fN N Emf V F = F = = p w 2
(max)
t N
dt
t d
N Emf V
m
m
ind ind
w w
w
cos
sin
F - =
F
- = =
m
m m
rms ind
fN
fN N
Emf F =
F
=
F
= 44 . 4
2
2
2
) (
p w
Page 5


TRANSFORMER
 INTRODUCTION
 TRANSFORMER EQUATION
 TRANSFORMER RATING
 PRACTICAL TRANSFORMER
 SINGLE PHASE TRANSFORMER
 TRANSFORMER LOSSES
 TRANSFORMER EFFICIENCY
 VOLTAGE REGULATION
 THREE PHASE TRANSFORMER
Introduction Introduction
? Atransformer is a static static machines machines.
?? The The word word ‘transformer’ ‘transformer’comes comes form form the the word word ‘transform’ ‘transform’. .
? Transformer is not not an an energy energy conversion conversion device device, but is a device device that that
changes changes AC AC electrical electrical power power at at one one voltage voltage level level into into AC AC electrical electrical
power power at at another another voltage voltage level level through through the the action action of of magnetic magnetic field, field,
without without a a change change in in frequency frequency. .
?? It Itcan can be be either either to to step step- -up up or or step step down down. .
Generation Generation
Station Station
TX1 TX1
Distribution Distribution
ss TX1
TX1
TTransmission ransmission
System System
33/13.5k 33/13.5k
VV
13.5/6.6kV 13.5/6.6kV
6.6kV/415 6.6kV/415
VV
Consumer Consumer
MZS
FKEE, UMP
Transformer Equation
? Faraday’s Law states that,
? If the flux passes through a coil of wire, a voltage will be
induced in the turns of wire. This voltage is directly
proportional to the rate of change in the flux with respect
of time.
If we haveNN turns of wire,
dt
t d
Emf V
ind ind
) ( F
- = =
dt
t d
N Emf V
ind ind
) ( F
- = =
Lenz’s Law
MZS
FKEE, UMP
Transformer Equation
? For an ac sources,
? Let V(t) = V
m
sin wt
i(t) = i
m
sin wt
Since the flux is a sinusoidal function;
Then:
Therefore:
Thus:
t t
m
w sin ) ( F = F
m m ind ind
fN N Emf V F = F = = p w 2
(max)
t N
dt
t d
N Emf V
m
m
ind ind
w w
w
cos
sin
F - =
F
- = =
m
m m
rms ind
fN
fN N
Emf F =
F
=
F
= 44 . 4
2
2
2
) (
p w
MZS
FKEE, UMP
Transformer Equation
? For an ideal transformer
? In the equilibrium condition, both the input power will be equaled to the
output power, and this condition is said to ideal condition of a transformer.
? From the ideal transformer circuit, note that,
? Hence, substitute in (i)
m
m
fN E
fN E
F ==
F ==
2 2
1 1
44 . 4
44 . 4
1
2
2
1
2 2 1 1
cos cos
I
I
V
V
I V I V
power output power Input
= \
=
=
q q
………………… (i)
2 2 1 1
V E and V E = =