Why is it that there no rotating magnetic field in a 3 phase transformer but it is there in three-phase induction motor?

In three phase A.C supply the supply voltage wave form are 120 degree electrical, apart and are with same amplitude, and hence currents will produce. A three-phase current in three windings can produce a rotating magnetic field of constant magnitude only if the windings are *spatially* placed 120° apart.

How is the rotating magnetic field produced in a three-phase motor?

The rotating magnetic field is produced by the three-phase current of the stator in the actual three-phase induction motor. It can be replaced by permanent magnets in a permanent magnet synchronous motor. The three-phase windings of the inner stator are spaced 120° electrical degrees apart.

How rotating magnetic field is produced in a three-phase induction motor What is the speed of this field?

When we apply a three-phase supply to a three-phase distributed winding of a rotating machine, a rotating magnetic field is produced which rotates in synchronous speed.

What are the conditions for generation of rotating magnetic field?

When a balanced poly phase current flows in the balanced poly phase winding, a rotating magnetic field is produced. The necessary condition for generation of rotating magnetic field is that “the time angle displacement between the currents and space angle displacement between the winding axes must be equal.”

How a rotating magnetic field is formed in the air gap of a three phase induction motor when the balanced winding of the stator is fed from a balanced supply?

The induction motor rotates due to the rotating magnetic field in induction motor, which is produced by the stator winding in the air gap between the stator and the rotor. The stator has a three phase stationary winding which can be either star connected or delta connected.

What is rotating magnetic field in induction motor?

A rotating magnetic field is the resultant magnetic field produced by a system of coils symmetrically placed and supplied with polyphase currents. Rotating magnetic fields are often utilized for electromechanical applications, such as induction motors, electric generators and induction regulators.

What is necessity of rotating magnetic field in the induction motor?

Description. The rotating magnetic field is the key principle in the operation of induction machines. The induction motor consists of a stator and rotor. The rotor or armature consists of coils wound in slots, which are short circuited and in which the changing flux generated by the field poles induce a current.

Why is a rotating field system used in preference to a stationary field?

Because you would have to draw all the power via slip rings and brush-gear and one could not generate at say 11 kV. That is why a rotating DC field is preferred and why the stator is able to generate at very high voltage levels as the insulation issues are much easier to handle.

Why does the rotor of a 3 phase induction motor rotate?

The rotor is a moving component of an electromagnetic system in the electric motor, electric generator, or alternator. Its rotation is due to the interaction between the windings and magnetic fields which produces a torque around the rotor’s axis.

Why is the rotating magnetic field also called the synchronous speed?

Speed is important to the rotating magnetic field of an AC motor. It is known as “synchronous speed.” This speed is calculated by dividing 120 times the frequency (F) by the number of poles (P). As an example, the synchronous speed for a 2-pole motor operated at 60 Hz is 3,600 RPM.