Page 332 - CITS - Electronic Mechanic - TT - 2024

ELECTRONICS MECHANIC - CITS

Stator

It is the outer body of the motor and consists of outer frame, stator core and windings.
The stator is built up of high-grade alloy steel laminations to reduce eddy current losses. It has three main parts,
namely the outer frame, the stator core, and a stator winding.

Working of Single-phase Induction Motor
We know that for the working of any electrical motor whether its AC or DC motor, we require two fluxes as the
interaction of these two fluxes produced the required torque.
When we apply a single phase AC supply to the stator winding of single phase induction motor, the alternating
current starts flowing through the stator or main winding. This alternating current produces an alternating flux
called main flux. This main flux also links with the rotor conductors and hence cut the rotor conductors.
According to the Faraday’s law of electromagnetic induction, emf gets induced in the rotor. As the rotor circuit
is closed one so, the current starts flowing in the rotor. This current is called the rotor current. This rotor current
produces its flux called rotor flux. Since this flux is produced due to the induction principle so, the motor working
on this principle got its name as an induction motor. Now there are two fluxes one is main flux, and another is
called rotor flux. These two fluxes produce the desired torque which is required by the motor to rotate.
Why Single Phase Induction Motor Is Not Self Starting?
The stator of a single phase induction motor is wound with single phase winding. When the stator is fed with a
single phase supply, it produces alternating flux (which alternates along one space axis only). Alternating flux
acting on a squirrel cage rotor can not produce rotation, only revolving flux can. That is why a single phase
induction motor is not self starting.

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CITS : E & H - Electronics Mechanic - Lesson 205 - 222