Working principIe of induction Motor

In this article we are discuss about working principle of induction motor and their application. we will also discuss about basic function or working of induction motor will also studied about use of induction motor and their application in industries and different load.

As a general rule, conversion of electrical power into mechanical power takes place in the rotating part of an electric motor. In D.Cmotors, the electric power is conducted directly to the armature by brush and commutator .thus in this sense, A D.C motor can be called an conduction motor .However, in A.C motors, the rotor does not receive electric power by conduction but by induction in exactly the same way as the secondary of a 2-winding transformer receives its power from the primary that is why such motor are known as induction motors. In fact, an induction motor can treated as rotating transformer. In which primary winding is stationary but secondary is free to rotate

The Rotor of three phase induction motors rotates without any external supply. When we are given supply to three phase stator winding. A Rotating magnetic field develops in the stator winding and this magnetic field link from Rotor. EMF produce in the Rotor and rotating magnetic field develop in the Rotor. The Rotor Rotate from interaction of stator magnetic field and Rotor magnetic field. It works on transformers principle or mutual induction In which we give supply to primary and take supply from primary  or take mechanical power of rotor . According to Faraday law of electromagnetic induction. this is basic working principle of transformer.

“The Rate of change of flux is directly proportional to induced EMF in the conductor or coil”.

In this Motor EMF direction find by  using Fleming right hand rules

Three phase induction is very useful motor In industries used of 90% induction motor . The Efficiency of induction motor is very high(90%)and power factor are also high( .89 )three phase induction is very useful motor In industries used of  90% induction motor 

1.       Low cost

2.       Absence of commutator

3.       Simple and strong construction

4.       Good operating characteristics

5.       Good power factor

6.       Higher Capacity

7.       Good speed regulation

8.       Proper Size

In three phase induction motor mainly two parts

1.       Stator

2.       Rotor 

Three phase induction motor stator made from silicon steel .Three phase winding fill up in the stator which we given  input A.C supply by external electric source .According to speed of motor decided the no of poles of stator winding.

P= 120F/N_s

From above equation if no. of poles is more than speed of motor is less that means no. of poles is inversely proportionally to speed of motor.

In induction motor two types of Rotor used.

1.       Squirrel cage Rotor

2.       Slip ring Rotor 

In induction Motor, 90% Squirrel cage rotor are used. In Squirrel cage rotor copper bars fill up in the slots of rotor and all copper bars short circuited each other by using of End ring . In this type Rotor does not connect external resistance.

A..       Less maintenance

B.       Does not use of carbon brush

In slip ring rotor three phase winding fill up in the rotor these winding connect star (Y)connection .these three phase winding also connect with three slip ring for input supply .Input supply of motor is given by carbon brush

1.       Improve starting torque by  external resistance

2.       less costly

By this article we can learn about working principle of induction motor and their uses and construction. From above article we will learn about application and construction of induction motor. so it is the working principle of induction motor.
For better understand the working principle of induction motor please watch this video.