23-02-2013, 03:09 PM
SYNCRONOUS MACHINES
Principle of Operation
The operation of a synchronous generator is based on Faraday's law of electromagnetic induction, and in an ac synchronous generator the generation of emf's is by relative motion of conductors and magnetic flux.
These machines can be used as either motors or generators but their predominant use is in generation.
Principle of Operation
Its characteristic feature is that the armature rotates through a stationary magnetic field, and the generated AC is brought to the load by means of slip rings and brushes.
The revolving-armature alternator is found only in alternators of small power rating and is not generally used. This is because a rotating armature requires slip rings and brushes to conduct the current from the armature to the load.