What happens if rotor rotates at synchronous speed?

What happens if rotor rotates at synchronous speed?

If the motor turned at the same RPM as the magnetic field, there would be no relative motion between the rotor and the field. Therefore, no current would be induced into the rotor, and no magnetic field would be created to cause it to turn.

Why it is not possible for a rotor of a synchronous motor to operate at a speed other than synchronous speed?

A synchronous motor with only a field winding carrying a direct current would not be self-starting. At any speed other than synchronous speed, its rotor would experience an oscillating torque of zero average value as the rotating magnetic field repeatedly passes the slower moving rotor.

What is synchronous speed of a rotor?

The synchronous speed is the speed of the revolution of the magnetic field in the stator winding of the motor. Thus, an AC machine in which the rotor moved at a speed and built a constant relationship between the frequency of the voltage in the armature winding and the number of poles is called a Synchronous Machine.

What happens if NS NR?

Nr=Ns which implies that slip will be zero. Torque equation of 3-phase induction motor is give by : so we can clearly see that there is factor of slip in torque equation. So if slip will be zero , torque developed would be zero & hence motor won’t run.

What happens if excitation fails in synchronous generator?

If the excitation of the generator fails, suddenly there will be no more magnetically locking between rotor and rotating magnetic field of stator. But still the governor will supply same mechanical power to the rotor due to this sudden magnetic unlocking; the rotor will be accelerated beyond the synchronous speed.

What is the effect of field failure of salient pole synchronous motor connected with infinite bus?

16. What is the effect of the field failure of salient pole synchronous motor connected with infinite bus? (a) Reduce motor torque and speed.

Why the rotor of induction motor Cannot rotate at synchronous speed what happens when the rotor speed is equal to the synchronous speed?

The first answer can be given as, the torque developed in the rotor is proportional to the Slip. If the rotor run at synchronous speed then there will be no difference between the synchronous speed and rotor speed, so the Slip will be zero, hence no torque will be developed and the rotor will slow down.

Why does synchronous motor run at synchronous speed?

A synchronous motor runs at synchronous speed only because it is meant to run like that . It cannot run on a speed other than synchronous speed. Stator(N) links with Rotor(S).

What is the relationship between rotor speed and voltage?

The above equation (1) shows that the rotor speed N bears a constant relationship with the field poles and the frequency of the generated voltage in the armature winding. A machine that runs at synchronous speed is called a synchronous machine.

What is the synchronous speed of an alternating motor?

The synchronous speed is the speed of the revolution of the magnetic field in the stator winding of the motor. It is the speed at which the electromotive force is produced by the alternating machine. The Synchronous Speed is given by the relation shown below.

What happens if there is no torque in a synchronous motor?

If there’s no torque, I think the motor’s speed will decrease because of air friction. In order to have torque (and keep the motor running at a constant speed), there needs to be a small difference between the synchronous speed and the actual mechanical speed of the motor.

What happens when the speed of the motor is reduced?

When the speed is reduced, magnetic flux lines produced by the stator windings again cut the rotor’s windings, inducing a current and the resulting magnetic field. Torque is again established.