An electric current that periodically reverses direction and changes its magnitude continuously with time is known as an Alternating current or AC current and An electric motor that works on an alternating current (AC) is called an AC motor. The AC motor commonly consists of two basic parts that are a rotor and a stator. The rotor is the rotary part of the motor which is attached to the output shaft producing a second rotating magnetic field. the stator is the stationary part of the motor which have coils supplied with AC current to produce a rotating magnetic field. By using permanent magnets, reluctance saliency, or DC or AC electrical windings rotor magnetic field can also be produced.
Working Principle of an AC Motor
The operating principle of an AC Motor depends on magnetism. AC motor contains a coil of wire and two fixed magnets surrounded by a shaft. coil becomes an electromagnet when an AC electric charge is applied to the coil of wire. This electromagnet generates a magnetic field. There is a solid metal axle, a loop of wire, a coil, a squirrel cage made of metal bars, and some other freely rotating metal parts that can conduct electricity inside the stator. For the make of the stator, power is given to the outer coils. The coils are energized in pairs which producing a magnetic field that rotates outside of the motor.
Inside the magnetic field, the rotor is suspended. Due to rotation, the magnetic field is constantly changing because that magnetic field produces an electric current inside the rotor. if the conductor is a wire then the current will flow in a loop. If the conductor is a piece of metal then eddy current will flow in it. the current induced in the conductor will produce its magnetic field. according to the law of electromagnetism, the rotating magnetic field by rotating as well. the motor operates when the shaft and the coil of wires begin to rotate.
The two types of AC motors are induction motors and synchronous motors. An induction motor is a machine that converts the AC electric power into mechanical power by using an electromagnetic induction phenomenon. the synchronous motor is a motor that converts an AC electrical power into mechanical power and which operates only at the synchronous speed. these two types of AC motor have their types also. AC motors are flexible and easy to control. they have Low startup power demands that also protect components on the receiving end. Controllable starting current levels and acceleration.