why a three phase induction motor cannot run at synchronous
speed ?

Answers were Sorted based on User's Feedback



why a three phase induction motor cannot run at synchronous speed ?..

Answer / noushad s

the source for the torque in a three phase induction motor
is the slip.and slip energy is caused due to the
difference in speed of the rotation of stator flux wave and
the rotor.where the former rotates in synchronous speed.as
a result emf will be induced in the rotor and which as per
lenzes law will try to oppose the cause of the emf here
which is relative speed .the rotor now tries to catch the
stator flux wave.if it runs in synchronous speed means
there is no relatyive speed and no slip energy and no
torque and hence the motor will stop.

Is This Answer Correct ?    152 Yes 15 No

why a three phase induction motor cannot run at synchronous speed ?..

Answer / rahul ranjan

An induction motor cannot run at synchronous speed. It is
because of emf is induced in rotor in the induction motor
due to relation between stator magnetic field and induced
flux of the rotor. If rotor run at synchronous speed, then
relative speed between rotor and stator field is zero, no
emf will be induced in the rotor and hence motor will be
stop

Is This Answer Correct ?    49 Yes 8 No

why a three phase induction motor cannot run at synchronous speed ?..

Answer / raul

if the 3 phase induction motor runs at synchronous speed,
then there will be no cutting of flux by the rotor
conductors, hence no induced emf in the rotor conductors n
hence no torque would be produced n finally the motor
stalls at synchronous speed.

Is This Answer Correct ?    42 Yes 20 No

why a three phase induction motor cannot run at synchronous speed ?..

Answer / shivam patidar

As if 3 phase induction motor run on synchronous speed then Ns-N=0, it means slip(s)=0.
this means their is no any relative speed b/w rotor and stater. So no torque will be generated in rotor.......

Is This Answer Correct ?    3 Yes 0 No

why a three phase induction motor cannot run at synchronous speed ?..

Answer / deviprasad panda

When relative speed is zero then emf is not induced (emf=0) so current is zero...so lorentz law is not applicable....so frequency is zero ....so torque is zero....then motor is stop .....
Thats why induction motor not achieve synchronous speed

Is This Answer Correct ?    0 Yes 0 No

why a three phase induction motor cannot run at synchronous speed ?..

Answer / sarfraz

An induction motor cannot run at synchronous speed because it is the "slippage" of the rotor relative to the rotaing magnetic field that generates the current in the windings contained within the rotor. This induced (hence the term induction) current sets up the opposing magnetic fields that cause the rotor to rotate.

Is This Answer Correct ?    11 Yes 13 No

why a three phase induction motor cannot run at synchronous speed ?..

Answer / karthick

due to slip between rotor and stator

Is This Answer Correct ?    13 Yes 20 No

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