Various power stages in the case of a d.c generator are shown below
Following are the three gnerator efficiencies
1. Mechanical Efficiency
2. Electrical Efficiency
3.Overall or Commercial Efficiency
It is obvious that overall efficiency is the product of mechanical and electrical efficiencies. For good generators,its value may be as high as 95%.
Condition for Maximum Efficiency
In general generator efficiency = Output / (Output + losses)
The condtion for maximum efficiency of generator is given by
i.e Variable loss = Constant loss.
