Induction motor is an AC electric motor in which the el […]
Induction motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. Induction motor therefore does not require mechanical commutation, separate-excitation or self-excitation for all or part of the energy transferred from stator to rotor.
Which is the best, a 3-phase induction motor or a 1-phase induction motor?
For performance of motor and for balanced load on 3 phase supply, 3-phase motor is better. If you consider economy of motor as also wiring and switchgear, single phase motor is better.
Single phase motor is simpler and easlier to install, and more readily available.
Three phase motor needs 3 phase switchgear and wiring, and both motor and control gear are costlier.
For smaller HP motors and fractional HP motors, water pump motors, fans motors, domestic electrical appliances like washing machines, refrigerator etc, 1-phase induction motor will be the best.
Where as for higher HP motors above 2 HP either for domestic use or for the industrial use three phase induction motor manufacturers will be the best.
However in industries mixture of both is used, depending upon the objective of application.
Three phase induction motor is better because:
Its size and weight will be smaller for a given horse power.
Its torque will not fluctuate with time (a major advantage with three phase machines as compared to single phase ones)
It will not have a capacitor which sufferes from the problem of ageing.