Merits, Demerits and Applications of Three Phase Induction Motor

Merits, Demerits and Applications of Three Phase Induction Motor.

Advantages Of Three Phase Induction Motor

simple and rugged construction
low initial as well as maintenance cost
nearly constant speed
high overload capacity
simple starting arrangement and
high power factor.

Because of low resistance of rotor in comparison to that of slip-ring induction motor, it has low rotor copper loss and, therefore, higher efficiency.

Disadvantages Of Three Phase Induction Motor:

large starting current
very sensitive to fluctuations in supply voltage
low power factor at light loads
speed control very difficult and
very poor starting torque due to its low rotor resistance.

Application Of Three Phase Induction Motor:

These motors are suitable for industrial drives of small power where speed control is not required such as for printing machinery, flour mills and other shaft drives of small power.

The slip-ring induction motors in comparison to squirrel cage motors have low starting current and high starting torque but suffer due to low power factor and low efficiency.

The motors are used for most industrial drives of high power a requiring high starting torque.