1. ELE 2103 Dept . of E & E, MIT Manipal
Transformers
ELE Dept . of E & E, MIT Manipal
Transformers
AC (Single Phase, Three Phase)

2. ELE 2103 Dept of E & E, MIT Manipal
Single phase Transformer
Introduction to Transformers
Classifications
Representation
Principle of Operation
Constructional Features
Emf Equation & Exercise
Ideal Transformer
Practical Transformer
Summary
ELE Dept of E & E, MIT Manipal

3. ELE 2103 Dept of E & E, MIT Manipal
Introduction
Applications
Electric power systems
Power transmission, Distribution Networks
Electronic Circuits
Electric Traction
Special Applications
ELE Dept of E & E, MIT Manipal

4. ELE 2103 Dept of E & E, MIT Manipal
Classifications
No. of Phases
Single Phase, Three Phase
Construction
Core Type, Shell Type
Functional
Step up, Step down
Power level
Power, Distribution Transformers
No. of Windings
One winding, Two winding, Three winding
Special Transformers
Instrument, Isolation, Pulse, Constant Voltage
High Frequency, Phase Changing
ELE Dept of E & E, MIT Manipal

5. N1 = Number of turns on primary N2 = Number of turns on secondary
Representation
Primary Side
Secondary Side
Core V1
Supply side V2
Load side N1
N1 = Number of turns on primary N2
N2 = Number of turns on secondary
Static Device working on principle of electromagnetic induction
Energy transfer from one circuit to another without change in frequency
Electric Circuits linked by common magnetic core
ELE Dept of E & E, MIT Manipal

6. ELE 2103 Dept of E & E, MIT Manipal
Operation I1 I2 Ø V1
LOAD E1 E2 V2
Magnetic Core : Flux path
Flux Linkages : Primary & Secondary
Induced Emf : Primary – Self Induced Emf
& Secondary – Mutually Induced Emf
ELE Dept of E & E, MIT Manipal

7. ELE 2103 Dept of E & E, MIT Manipal
Construction – Core Type
LV winding
Insulation
HV winding
Limbs
Yoke
Laminations
Core
Winding crossover
Primary &
Secondary windings
ELE Dept of E & E, MIT Manipal

8. ELE 2103 Dept of E & E, MIT Manipal
Construction - Shell Type
Yoke
LV winding
Central Limb
Insulation
HV winding
Side Limbs
Laminations
Yoke
Core
Insulation
Secondary
Winding
Terminals
ELE Dept of E & E, MIT Manipal

9. ELE 2103 Dept of E & E, MIT Manipal
emf equation
ELE Dept of E & E, MIT Manipal

10. ELE 2103 Dept of E & E, MIT Manipal
Transformer Ratios
(Transformation Ratio)
N2 < N1 : Step Up type N1 N2 V1 V2
E2 < E1
V2 < V1, I1 < I2 V1 V2
N2 = N1 : 1:1 type
E2 = E1
V2 = V1, I1 = I2
N2 < N1 : Step down type V1 V2
E2 < E1
V2 < V1, I1 < I2
ELE Dept of E & E, MIT Manipal

11. ELE 2103 Dept of E & E, MIT Manipal
Exercise
[1] A 250 kVA, / 415 V, 50 Hz, single phase transformer has 80 turns on the secondary. Determine (a) rated primary and secondary currents (b) primary turns (c) maximum flux (d) emf induced per turn
Ans: (a) A, A
(b) 2120 turns
(c) mWb
(d) Volts / turn
ELE Dept of E & E, MIT Manipal

12. ELE 2103 Dept of E & E, MIT Manipal
Summary
Transformers : Importance, Applications, Classifications
Two winding representation
Principle of Operation
Constructional Features : Core type, Shell type
Emf Equation, Transformation Ratios
Ideal Transformer
Practical Transformer
ELE Dept of E & E, MIT Manipal