An Application of 3 phase synchronous motor Construction of 3 phase alternator

1. GROUP-IV
PRESENTATION BY
MATTHIAS GYAMAR
DEBA NIKA
TAJ ATU

2. CONTENTS
•1. An application of 3 phase
synchronous motor
•2. Construction of 3 phase
Alternator

3. APPLICATION OF 3 PHASE SYNCHRONOUS
MOTOR
• Defination
• A 3-phase synchronous motor is a 3-phase synchronous machine which is
operated as a motor i.e. Converts electrical energy input into mechanical
energy output.
• A synchronous motor has a unique feature that is it runs at a constant speed
equal to the synchronous speed at all load provided that the load on the
motor does not exceed the limiting value. If the load on the motor exceeds
the limiting value, then the motor will come to rest and the average torque
developed by the motor becomes zero. Because of this, a synchronous
motor is not inherently self-starting.

4. Synchronous motors are normally used
in applications in which a constant and
precise speed is required. Typical
applications of these low power
motors are positioning machines.

5. TYPES OF 3 PHASE SYNCHRONOUS MOTOR
APPLICATION ARE :-
1. Fan

6. 2. Air blower

7. 3. Paper mills

8. CONSTRUCTION OF 3 PHASE ALTERNATOR
•Definition
An alternator is a type of generator that converts mechanical
energy into electrical energy. The output of the generator can be
either alternating current AC or direct current DC.

9. Unlike DC generator that has rotating
armature winding and a stationary
magnetic field. The alternator is made
of a stationary armature winding and a
rotating magnetic field. The field
windings are placed in the rotor while
the armature windings are placed in
the stator.

10. CONSTRUCTION OF 3 PHASE ALTERNATOR
• An alternator has 3,-phase winding on the stator and
a d.c. Field winding on the rotor.
1. Stator
It is the stationary part of the machine and is built up of
silicon
steel laminations having slots on its inner periphery. A
3-phase
winding is placed in these slots and serves as the
armature

12. 3 PHASE ALTERNATOR STATOR CONSIST OF
• Stator frame/Yoke
• Stator core
• Stator winding
Stator frame/Yoke :-
The stator frame is the outermost part of the alternator. It is made up
of cast iron or cast steel or welded steel plates. It encloses all the parts
of the alternator from entering dust. It also holds the stator core and
winding in proper position and gives mechanical protection to the
entire machine.

13. • Stator core :-
The stator core is the stationary part of the alternator. The
structure of the stator core is similar to the dc armature core
with silicon steel (steel alloy) laminations. The inner periphery of
the laminated stator core consists of slots to accommodate
three-phase armature conductors. The stator winding (armature
winding) is placed in the slots.

14. • Stator Winding or Armature Winding :
• Armature winding is made up of insulated copper or
aluminum conductor placed in stator core slots. These
stationary conductors when cut by the magnetic field
emf get induced in them. Basically, the armature of an
alternator consists of three-phase winding either in
star or delta connection.

15. 2. Rotor
The rotor carries a field winding which is supplied
with direct current through two slip rings by a
separate d.c. Source. This d.c. Source (called exciter)
is generally a small d.c. Shunt or compound generator
mounted on the shaft of the alternator.Rotor
construction is of two types, namely;
1. Salient (or projecting) pole type
2. Non-salient (or cylindrical) pole type