Losses in alternators are same as DC generator and they are as follows.
a. Copper losses include following losses
Armature copper losses (Ia 2 ra).
Field copper losses (Ife 2 rf).
Losses in brush.
b. Stray losses are as follows Magnetic losses (Iron loss or core loss and pole shoes loss).
Mechanical losses includes bearing friction, slip ring friction and friction due to windage.
