An asynchronous motor is a device whose rotor rotates at a speed less than synchronous. N <NS
Synchronous speed is defined as the speed of the magnetic field of a rotating machine, which is again determined by the number of poles and the frequency in the machine.
Asynchronous motors are also called induction motors. Motors are operated on electromagnetic induction, and the rotor does not receive electrical power. ( OR ) A motor that runs on alternating current is called the asynchronous motor.
An Asynchronous motor is commonly used in the world. It is a motor that can be operated without being direct electrically connected to the rotor. This motor basically runs on an induced current inside the rotor from the stator’s rotating magnetic field. In this design of the motor, the movement of the rotor cannot be synchronized through the moving field of the stator. The rotating stator field of this motor can induce a current in the rotor windings. In turn, this current will create a force that pushes the rotor towards the stator.
An asynchronous motor always only runs with a lagging power factor. The motor speed decreases with increasing load.
If the applied voltage changes, it affects the torque of the induction motor. The induction motors do not have an external device connected to excite the rotor, and therefore the rotor speed depends on the variable magnetic induction.
This changing electromagnetic field causes the rotor to rotate at less than the speed of the stator magnetic field. As the rotor speed and stator magnetic field speed vary, these motors are known as an induction motors.
Definition of Asynchronous Motor
An AC asynchronous motor in which the stator is not synchronized with the rotor and can rotate freely at a speed lower than the synchronous speed due to slip. This is because the rotating magnetic field does not interact with the induced rotor field. In this motor, torque is generated when the rotor is out of phase with the stator, and the current induced in the rotor follows Lenz’s law. This is called an asynchronous motor.