Advantages of stationary armature-rotating field alternator
Alternators are generally high current and high voltage machines. The stationary armature-rotating field construction has many advantages. A few of them include:
1) The current is drawn directly from fixed terminals on the stator without the use of brush contacts.
2) The insulation of stationary armature winding is easier.
3) The number of sliding contacts (slip rings) is reduced. Moreover, the sliding contacts are used for low-voltage DC Source.
4) Armature windings can be constructed more rigidly to prevent deformation due to any mechanical stress.