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Why synchronous machine is called doubly excited machine?


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Answer :

The synchronous machine is called doubly excited machine because in synchronous machine both stator and rotor are excited.

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Answer :

Armature windings of synchronous machines either deliver 3 phase AC or absorb 3 phase AC source,  whereas field windings are energized from DC source. Thus due to presence of AC on armature and DC on field windings, synchronous machines are often referred as doubly excited machines.
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