For motor design around the world there are two basic method one is efficiency based design (EBD) & another is Power factor based design (PFBD). In efficiency based design the motor magnetic circuit are so designed to avail maximum efficiency while keeping the power factor reasonable. On the other hand , power factor based design (PFBD) ensures the maximum optimization of power factor keeping the efficiency reasonable.
Difference between – efficiency based design (EBD) & power factor based design (PFBD)
Starting torque : EBD has low rotor resistance thus it has lower starting torque.
Starting current: As we know that starting current depends on the balance between rotor resistance and stator leakage reactance, the starting current will be high for EBD as it has lower resistance.
No load current : For EBD the no load current is higher then PFBD.
WHy EBD is more popular than PFBD :
The efficiency based design is a permanent thing that is designing the motor magnetic circuits. When the motor is in use there is no means to modify it. But on the other hand the power factor could be improved by using power factor correction equipment.