Induction Motor PPT for engineering students

1. Basic Electrical and Electronics
INDUCTION MOTOR

2. INDUCTION MOTOR
 In olden days DC machines are widely used due to its
smooth speed control and production of high starting
torque
 After few decade AC Machines replaced DC machines
due to following reasons
HISTORY

3. INDUCTION MOTOR
 Availability of AC supply ( Generation is AC Supply)
 AC Machines are simple and rugged constructions
 High Efficiency and reasonably good power factor
 High reliability
 Design and maintenance cost is Low
 Simple starting arrangement
Advantages of AC Machines over DC
Machines

4. INDUCTION MOTOR
 it works on the principle of Induction so called
Induction motor
WHAT IS INDUCTION
 There is no electrical connection from main supply to
rotor winding, stator winding is directly connected to
AC source, where as rotor winding receives Energy
from stator by means of INDUCTION
Working Principle of Induction motor

5. INDUCTION MOTOR
 Induction motor consist of two parts
 Stationary part known as STATOR
 Rotating part known as ROTOR
 And these two are separated from each other by
small air-gap (about 0.4 mm to 4 mm)
Construction

6. INDUCTION MOTOR
 iron (or) steel yoke (frame)
 Hollow, cylindrical core made of silicon steel with
laminations
 Slots on the inner periphery of the laminated core
 Insulated conductor ( called stator winding)
 Star connected
 Delta connected
Construction of stator

7. INDUCTION MOTOR
Construction of stator

8. INDUCTION MOTOR
 Hollow, cylindrical core (slotted on outer periphery)
 shaft
 Conductors ( called rotor winding)
Construction of Rotor

9. INDUCTION MOTOR
Depending on the winding connections rotors are of two
types
 Squirrel cage Rotor
 Wound (or) Slip ring rotor
types of Rotor

10. INDUCTION MOTOR
 Laminated cylindrical core
 having parallel slots on its outer periphery
 Conductor or winding
 which is placed in each slot
 End rings
 All these conductors joined at each end
by metal rings called end rings as shown
 Equivalent circuit
Squirrel cage Rotor

11. INDUCTION MOTOR
Squirrel cage Rotor

12. INDUCTION MOTOR
 Laminated cylindrical core
 having a 3-phase star winding
 One side of winding short circuited and
other End connected to 3 slip ring
 Brushes
 Each slip ring is connected to brushes
Slip Ring Rotor

13. INDUCTION MOTOR
Slip Ring Rotor

14. INDUCTION MOTOR
Slip Ring Rotor

15. a
a’
Single N turn coil carrying current i
Spans 180o elec
Resultant flux
Principle of operation

16. Single N turn coil carrying current i
Spans 180o elec
b'
b
Resultant flux
Principle of operation

17. Single N turn coil carrying current i
Spans 180o elec
c'
c
Resultant flux
Principle of operation

18. 3-PHASE SINUSOIDALLY DISTRIBUTED WINDINGS

19. WAVE SPACE
DISTRIBUTIONS

20. INDUCTION MOTOR
 Depending upon the rotor connections induction
motors are two types
 Squirrel cage induction motor
 Slip ring induction motor
Types of INDUCTION
MOTORS

21. INDUCTION MOTOR
 The rotor winding is short circuited at each end
by metal rings called end rings
 The motor which is designed with squirrel cage
rotor called squirrel cage induction motor
SQUIRREL CAGE INDUCTION
MOTOR

22. INDUCTION MOTOR
 One side of the windings are short circuited and
other ends are brought out and connected to slip
rings (mostly star connected)
 The motor which is designed with slip ring rotor
called slip ring induction motor
SLIP RING INDUCTION
MOTOR