#IDEAL_PRACTICAL_TRANSFORMER #EQUIVALENT_CIRCUIT OF TRANSFORMER #BASIC ELECTRICAL ENGINEERING #IDEAL TRANSFORMER ON NO LOAD #PRACTICAL TRANSFORMER ON LOAD #ELECTRCL TRANSFORMER #SINGLE PHASE TRANSFORMER Link of all sessions are. DAY 1 (Need/Definition) https://youtu.be/BvaykFJ_NoE DAY 2 (Working principle and Construction) https://youtu.be/06rgxocihaM DAY 3 (EMF equation and Turns Ratio) https://youtu.be/g7e5xBPmv3Y DAY 4 (Classification of Transformer) https://youtu.be/6NP5L4MlvY4 DAY 5 ( Ideal and practical transformer on no load) (Equivalent Transformer) https://youtu.be/6LCLQC1p3lg

1. Prof.Prasant Tiwari
IDEAL & PRACTICAL TRANSFORMER
EQUIVALENT CIRCUIT
ELECTRICAL
TRANSFORMER

2. ELECTRICAL TRANSFORMER
Transformer Syllabus
 Definition/Need of transformer
 Principle of Operation
 Construction
 EMF Equation
 Transformation Ratio
 Classification of Transformer
 Comparison between core & shell type
 Ideal & Practical Transformer
 Equivalent Circuit
 Losses in a Transformer
 Efficiency
Day 1
Day 4
Day 3
Day 2

3. IDEAL TRANSFORMER
Properties of ideal transformer
 Primary and secondary windings has
no resistance.
 All the flux produced by the
primary links the secondary winding
i,e., there is no leakage flux.
 Permeability μr of the core is
infinitely large. In other words, to
establish flux in the core vanishingly
small (or zero) current is required.
 Core loss comprising of eddy current
and hysteresis losses are neglected.
Ideal transformer on No load

4. PRACTICAL TRANSFORMER ON NO LOAD
 When the transformer is operating at no load, the
secondary winding is open-circuited.
 Which means there is no load on the secondary
side of the transformer and, therefore, current in
the secondary will be zero.
 While primary winding carries a small current
I0 called no-load current which is 2 to 10% of the
rated current.
 The no-load current consists of two components:
 Reactive or magnetizing component Im
It is in quadrature with the applied voltage V1. It
produces flux in the core and does not consume any
power).
 Active or power component Iw,
Also know as a working component.It is in phase with
the applied voltage V1.
It supplies the iron losses and a small amount of
primary copper loss.
Iw = working component of I0
Im = Reactive or magnetizing component

5. STEPS TO DRAW THE PHASOR DIAGRAM on NO LOAD
The following steps are given below to draw the phasor
diagram:
1. The function of the magnetizing component is to
produce the magnetizing flux, and thus, it will be in
phase with the flux.
2. Induced emf in the primary and the secondary
winding lags the flux ϕ by 90 degrees.
3. The primary copper loss is neglected, and secondary
current losses are zero as I2 = 0.
4. Therefore, the current I0 lags behind the voltage
vector V1 by an angle ϕ0 called the no-load power
factor angle and is shown in the phasor diagram
above.
5. The applied voltage V1 is drawn equal and opposite
to the induced emf E1 because the difference
between the two, at no load, is negligible.
6. Active component Iw is drawn in phase with the
applied voltage V1.
7. The phasor sum of magnetizing current Im and the
working current Iw gives the no-load current I0.

6. EQUIVALENT CIRCUIT OF TRANSFORMER
 It makes the analysis of transformer very easy at any load
condition.
 The iron losses can be obtained.
 The copper losses at any load can be obtained.
 Per unit parameter can be obtained.
 Efficiency regulation and power factor at any load can be
obtained without actual loading
Need of Equivalent circuit of transformer

7. EQUIVALENT CIRCUIT OF TRANSFORMER
Case 1 - Secondary referred to primary Case 2 – Primary referred to Secondary

8. APPROXIMATE EQUIVALENT DIAGRAM OF TRANSFORMER
Case 1 – Secondary referred to primary
Case 2 – Primary referred to Secondary

9. ELECTRICAL TRANSFORMER
Transformer Syllabus
 Definition/Need of transformer
 Principle of Operation
 Construction
 EMF Equation
 Transformation Ratio
 Classification of Transformer
 Comparison between core & shell type
 Ideal & Practical Transformer
 Equivalent Circuit
 Losses in a Transformer
 Efficiency
Day 1
Day 4
Day 3
Day 2
Day 5