3. it is an electro-chemical energy conversion device which converts mechanical energy
into 3-phase AC electrical energy
The synchronous generators are run’s at a particular constant speed that speed is
called as synchronous speed . Hence the generator is called as synchronous
generator.
NS
= 120f/p
Where f = supply frequency
p=poles of the machine
NS= Synchronous speed
DEFINATION
4. WORKING PRINCIPLE
It works on the principle of FARADAY’S LAW..
Whenever a conductor cuts the magnetic field an EMF will be induced in that
conductor.
In alternator the field winding is placed on rotar which required to produce
magnetic flux /magnetic field
The armature conductors/ windings are placed on stator
When promover given to rotar and field winding is excited, a rotating
magnetic field having constant magnitude will be produces RMF
6. CONSTRUCTION OF STATOR…..
Stator: It is hallow cylindrical in shape and it is made up of cold rolled non-
oriented silicon steel. Which is laminated to reduce eddy currents ,it’s inner
surface is slotted.
7. CONSTRUCTION OF ROTAR…..
Based on rotar construction the synchronous generators are classified as 2-
types they are
a) Salient pole type
b)Non-Salient pole type
8. SALIENT POLE TYPE….
The rotar has longer diameter and shorter axial length
Hence the air gap is minimum a long the inter polar q-axis so that the flux
distribution is maximum ,so this type of generators are called as Non-Uniform
flux distribution.
The maximum possible speed is 600-750 rpm
9. NON-SALIENT POLE TYPE….
It is made up of mild steel and outer surface is slotted to accomadate to
house field winding
2/3 rd of surface is slotted for field winding
It has shorter diameter and longer axial length hence the air gap in between
rotar and stator is uniform hence the flux distribution is also uniform.
This type of rotar can be stand for high speed.
