Why the rotor of an induction motor rotates in the same direction as the stator magnetic field?
Since the rotor circuit is closed, currents start flowing in the rotor conductors. Now, rotor conductors are carrying currents and are in the magnetic field. Therefore, mechanical force acts on the rotor, tending to move it in the same direction as the stator field.
Why there is a case that the speed of the stator will not be same as the speed of the rotor in a synchronous motor?
Actual speed of the induction motor will be less than the synchronous speed. The reason for this is if the armature turns exactly at synchronous speed, then the magnetic field of the stator windings no longer cuts the rotor windings. Under this condition, no current would be induced to the rotor windings.
What is the relationship between the speed of rotation of the rotor and the speed of rotation of the magnetic field?
The rotation of the rotor and magnetic field are asynchronous. This difference in speed of rotation between the rotor and magnetic field is known as slip. There is a linear relationship between the slip and the produced torque in the driving range of induction motors.
What is the relative speed between stator field and rotor field?
The relative speed between the rotating field and stator winding is Ns – 0 = Ns. Therefore, the frequency of induced current or voltage in the stator winding is f = Ns P/120—the supply frequency. When the rotor is stationary, s = 1.
Why does the rotor rotates in 3 phase induction motor?
When the three-phase power supply to the stator. This current flows to the stator winding(conductor). Then it produces magnetic flux and it’s rotated to the clockwise direction around the conductor. For this flux rotor received magnetomotive forces and the rotor build up rotating torque.
Why rotor slots are skewed?
The rotor or stator slot of the induction motor skewed through some angle so that the bars lie under alternate harmonic poles of the same polarity or other words, bars must be skewed through two pitches. The main purpose of skewing is to reduce the magnetic logging between the starter and the rotor.