Working Principle of Three Phase Induction Motor.
The motor that works
in the process of electromagnetic induction is called an induction motor. We know
that an induction motor consists of 2 main parts.
Namely: stator and
rotor.
The stator is the
stationary part of the motor and the rotor is the moving part. The stator of a
three-phase induction motor has 3 coils, where we supply three-phase AC power.
The coils have an angle of 120 degrees with each other.
When we make an
electrical connection to the stator, current starts flowing in its coil. The AC
current generates a magnetic field in the stator, called the stator flux. Due
to three-phase current 3 magnetic fields will be created
. The value of the
magnetic field generated will remain the same but will change direction again
and again. Which will generate a rotating magnetic field?
According to
Faraday's law of electromagnetic induction, we know that whenever the number of
magnetic field lines of the magnetic flux of a wire coil change, an electromagnetic force is absorbed into that coil.
This is called an induced
electromotive force. If the conductor is connected to a closed circuit, the electric current will start flowing through it. This is called induced electric
current.
The rotor also has a
short circuit coil like a stator. When the stator flux comes in contact with
the rotor coil, an electric current is induced in the rotor according to
Faraday's formula.
The current flow in the rotor for this induced
electromagnetic ball. This is called the rotor current.
That is, the electric
current has its coil located in a magnetic field. Now, according to Lorentz's
ball formula, an electric magnetic force will be induced in its coil or rotor
coil.
This will cause the rotor coil to start rotating. The Squirrel Cage rotor
can be used as a short circuit coil of the rotor coil.
The flux that the
rotor current produces is called the rotor flux. This flux is made in the
induction process so this type of motor is called an induction motor.
But the
rotor flux will lag behind the stator flux. Which will create torque in the
rotor which will force the rotor to rotate in a rotating magnetic field? This
is how an induction motor works.